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481.
Knowing the thermodynamic stability of transition metal oxide nanoparticles is important for understanding and controlling their role in a variety of industrial and environmental systems. Using calorimetric data on surface energies for cobalt, iron, manganese, and nickel oxide systems, we show that surface energy strongly influences their redox equilibria and phase stability. Spinels (M(3)O(4)) commonly have lower surface energies than metals (M), rocksalt oxides (MO), and trivalent oxides (M(2)O(3)) of the same metal; thus, the contraction of the stability field of the divalent oxide and expansion of the spinel field appear to be general phenomena. Using tabulated thermodynamic data for bulk phases to calculate redox phase equilibria at the nanoscale can lead to errors of several orders of magnitude in oxygen fugacity and of 100 to 200 kelvin in temperature. 相似文献
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Scott NE Haskins SC Aldrich J Rezende M Gallagher RM Henderson MM 《American journal of veterinary research》2005,66(7):1273-1277
OBJECTIVE: To compare direct measurements of canine oxyhemoglobin (HbO2) saturation and blood oxygen content (ContO2) in healthy dogs with analyzer-calculated values derived by use of a human HbO2 relationship and with hand-calculated values derived by use of a canine HbO2 relationship. ANIMALS: 17 healthy dogs. PROCEDURE: 3-mL samples of heparinized arterial and jugular venous blood were collected from each dog. The pH, Pco2, Po2, hemoglobin, HbO2, carboxyhemoglobin, methemoglobin, and ContO2 were measured; HbO2 and ContO2 were calculated automatically by analyzers and also hand-calculated. Blood gas analyzer-calculated and hand-calculated HbO2 values were compared with co-oximeter-measured HbO2 values. Analyzer-calculated and hand-calculated ContO2 values were compared with oxygen content analyzer-measured values. RESULTS: Hand-calculated HbO2 values for arterial and jugular venous samples were slightly but significantly lower than those calculated by a blood gas analyzer or obtained from a co-oximeter. Hand-calculated and analyzer-calculated arterial and venous ContO2 were similar to measured values. CONCLUSIONS AND CLINICAL RELEVANCE: Although certain HbO2 and ContO2 values generated by use of the different methods were significantly different, these differences are unlikely to be clinically important in healthy dogs. 相似文献
487.
Côté E Manning AM Emerson D Laste NJ Malakoff RL Harpster NK 《Journal of the American Veterinary Medical Association》2004,225(3):384-388
OBJECTIVE: To assess the frequency of heart murmurs in overtly healthy cats. DESIGN: Prospective study. SAMPLE POPULATION: 103 healthy domestic cats. PROCEDURE: Background information and physical characteristics were assessed in cats that were candidates for blood donation during an 8-month period. For cats with heart murmurs, additional information collected included murmur timing, grade, point of maximal intensity, and presence of additional heart sounds. RESULTS: Heart murmurs were detected in 22 of the 103 (21%) cats. Echocardiography was performed in 7 of those 22 cats. The echocardiogram was considered normal in 1 cat; in the other 6 cats, diagnoses included hypertrophic cardiomyopathy (interventricular septal hypertrophic form [IVSH]; n = 4), left ventricular concentric hypertrophy with valvular disease (1), and equivocal IVSH (1). Thirteen cats had more than 1 examination during the study; 3 of them developed heart murmurs. There were no significant differences in age, sex, breed, coat color, eye color, or heart rate between cats with and without murmurs. Among the 103 cats, there were 6 pairs of siblings from 6 multiple-cat households and 16 cats from 7 multiple-cat households in which the cats were not related; the proportion of cats with murmurs was higher in the related cats (5/12) than in the unrelated cats (3/16), but the difference was not significant. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicated that heart murmurs are detectable in a large proportion of overtly healthy cats and that many murmurs appear to be caused by structural heart disease that is in a clinically latent state. 相似文献
488.
Power of a Labrador Retriever-Greyhound pedigree for linkage analysis of hip dysplasia and osteoarthritis 总被引:2,自引:0,他引:2
Todhunter RJ Casella G Bliss SP Lust G Williams AJ Hamilton S Dykes NL Yeager AE Gilbert RO Burton-Wurster NI Mellersh CC Acland GM 《American journal of veterinary research》2003,64(4):418-424
OBJECTIVE: To estimate the number of dogs required to find linkage to heritable traits of hip dysplasia in dogs from an experimental pedigree. ANIMALS: 147 Labrador Retrievers, Greyhounds, and their crossbreed offspring. PROCEDURE: Labrador Retrievers with hip dysplasia were crossed with unaffected Greyhounds. Age at detection of femoral capital ossification, distraction index (DI), hip joint dorsolateral subluxation (DLS) score, and hip joint osteoarthritis (OA) were recorded. Power to find linkage of a single marker to a quantitative trait locus (QTL) controlling 100% of the variation in a dysplastic trait in the backcross dogs was determined. RESULTS: For the DI at the observed effect size, recombination fraction of 0.05, and heterozygosity of 0.75, 35 dogs in the backcross of the F1 to the Greyhound generation would yield linkage at a power of 0.8. For the DLS score, 35 dogs in the backcross to the Labrador Retriever generation would be required for linkage at the same power. For OSS, 45 dogs in the backcross to the founding Labrador Retrievers would yield linkage at the same power. Fewer dogs were projected to be necessary to find linkage to hip OA. Testing for linkage to the DLS at 4 loci simultaneously, each controlling 25% of the phenotypic variation, yielded an overall power of 0.7 CONCLUSIONS AND CLINICAL SIGNIFICANCE: Based on this conservative single-marker estimate, this pedigree has the requisite power to find microsatellites linked to susceptibility loci for hip dysplasia and hip OA by breeding a reasonable number of backcross dogs. 相似文献
489.
Bliss S Todhunter RJ Quaas R Casella G Wu R Lust G Williams AJ Hamilton S Dykes NL Yeager A Gilbert RO Burton-Wurster NI Acland GM 《American journal of veterinary research》2002,63(7):1029-1035
OBJECTIVE: To determine the genetic influence on expression of traits associated with canine hip dysplasia. ANIMALS: 193 dogs from an experimental canine pedigree. PROCEDURE: An experimental canine pedigree was developed for linkage analysis of hip dysplasia by mating dysplastic Labrador Retrievers with nondysplastic Greyhounds. A statistical model was designed to test the effects of Labrador Retriever and Greyhound alleles on age at detection of femoral capital epiphyseal ossification, 8-month distraction index, and 8-month dorsolateral subluxation score. RESULTS: The additive effect was significant for age at detection of femoral capital epiphyseal ossification. Restricted maximum likelihood estimates (+/-SD) for this trait were 6.4+/-1.95, 10.2+/-2.0, 10.8+/-3.1, 11.4+/-2.1, and 13.6+/-4.6 days of age for Greyhounds, Greyhound backcross dogs, F1 dogs, Labrador Retriever backcross dogs, and Labrador Retrievers, respectively. The additive effect was also significant for the distraction index. Estimates for this trait were 0.21+/-0.07, 0.29+/-0.15, 0.44+/-0.12, 0.52+/-0.18, and 0.6+/-0.17 for the same groups, respectively. For the dorsolateral subluxation score, additive and dominance effects were significant. Estimates for this trait were 73.5+/-4.1, 71.3+/-6.5, 69.1+/-6.0, 50.6+/-12.9, and 48.4+/-7.7%, respectively, for the same groups. CONCLUSIONS: In this canine pedigree, traits associated with canine hip dysplasia are heritable. Phenotypic differences exist among founder dogs of each breed and their crosses. This pedigree should be useful for identification of quantitative trait loci underlying the dysplastic phenotype. 相似文献
490.
McGuire NC Schulman R Ridgway MD Bollero G 《Journal of the American Animal Hospital Association》2002,38(6):541-544
Dogs with diabetes mellitus may develop occult urinary tract infections. In this study, diabetic dogs with negative and positive bacterial urine cultures were compared. Records from 51 dogs with diabetes mellitus were reviewed at the University of Illinois. No difference was identified between the groups in urine specific gravity, pH, glucose, ketones, protein, red blood cells, white blood cells, or epithelial cells. Dogs with occult urinary tract infection did have an increased incidence of bacteriuria, but this was not a consistent finding. Therefore, the urine on all diabetic dogs should be cultured to accurately identify the presence or absence of bacterial urinary tract infections. 相似文献