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51.
Synthesis of macroporous minerals with highly ordered three-dimensional arrays of spheroidal voids 总被引:2,自引:0,他引:2
Titania, zirconia, and alumina samples with periodic three-dimensional arrays of macropores were synthesized from the corresponding metal alkoxides, using latex spheres as templates. In a fast, single-step reaction, the monomeric alkoxide precursors permeate the array of bulk polystyrene spheres and condense in air at room temperature. Close packed, open-pore structures with 320- to 360-nanometer voids are obtained after calcination of the organic component at 575 degreesC. The examples presented demonstrate the compositional diversity possible with this technique. The resulting highly structured ceramics could have applications in areas ranging from quantum electronics to photocatalysis to battery materials. 相似文献
52.
N Holland J M Sala H C Menezes M T Lafuente 《Journal of agricultural and food chemistry》1999,47(7):2513-2518
Fruits of cv. Fortune mandarin were periodically harvested throughout the ripening period to evaluate changes in carbohydrate content and metabolism in flavedo tissue and to determine the potential role of carbohydrates in the tolerance of citrus fruit to chilling injury (CI). Sucrose showed little change in the flavedo during the season, but fructose and glucose increased, in nearly equal amounts, throughout the fall and winter, reaching a maximum in January. Starch levels were less abundant than soluble carbohydrates and rose continuously until March. Sucrose phosphate synthase (SPS; EC 4.1.14) activity decreased from December throughout ripening. Changes in sucrose synthase (SS; EC 2.4.1.13) and acid and alkaline invertase (Inv; EC 3.2.1.26) activities correlated with changes in the reducing sugars, but acid invertase was less active than the other sucrose-metabolizing enzymes. Carbohydrate changes in the flavedo of Fortune mandarins with fruit maturity appear not to be related to the chilling tolerance of fruits during cold storage. 相似文献
53.
W A Rees J D Harkins M Lu R E Holland A F Lehner T Tobin T M Chambers 《American journal of veterinary research》1999,60(7):888-894
OBJECTIVE: To determine pharmacokinetics of single and multiple doses of rimantadine hydrochloride in horses and to evaluate prophylactic efficacy of rimantadine in influenza virus-infected horses. ANIMALS: 5 clinically normal horses and 8 horses seronegative to influenza A. PROCEDURE: Horses were given rimantadine (7 mg/kg of body weight, i.v., once; 15 mg/kg, p.o., once; 30 mg/kg, p.o., once; and 30 mg/kg, p.o., q 12 h for 4 days) to determine disposition kinetics. Efficacy in induced infections was determined in horses seronegative to influenza virus A2. Rimantadine was administered (30 mg/kg, p.o., q 12 h for 7 days) beginning 12 hours before challenge-exposure to the virus. RESULTS: Estimated mean peak plasma concentration of rimantadine after i.v. administration was 2.0 micrograms/ml, volume of distribution (mean +/- SD) at steady-state (Vdss) was 7.1 +/- 1.7 L/kg, plasma clearance after i.v. administration was 51 +/- 7 ml/min/kg, and beta-phase half-life was 2.0 +/- 0.4 hours. Oral administration of 15 mg of rimantadine/kg yielded peak plasma concentrations of < 50 ng/ml after 3 hours; a single oral administration of 30 mg/kg yielded mean peak plasma concentrations of 500 ng/ml with mean bioavailability (F) of 25%, beta-phase half-life of 2.2 +/- 0.3 hours, and clearance of 340 +/- 255 ml/min/kg. Multiple doses of rimantadine provided steady-state concentrations in plasma with peak and trough concentrations (mean +/- SEM) of 811 +/- 97 and 161 +/- 12 ng/ml, respectively. Rimantadine used prophylactically for induced influenza virus A2 infection was associated with significant decreases in rectal temperature and lung sounds. CONCLUSIONS AND CLINICAL RELEVANCE: Oral administration of rimantadine to horses can safely ameliorate clinical signs of influenza virus infection. 相似文献
54.
55.
R. Kröger M. T. Moore C. M. Cooper M. M. Holland 《Water, air, and soil pollution》2009,201(1-4):209-218
Flooded post-harvest rice paddies were examined as systems for reducing diazinon (organophosphate insecticide) concentrations in stormwater runoff. Two paddies were cultivated in Oryza sativa L. and amended with a 3-h simulated stormwater diazinon runoff event. Initial diazinon adsorption peaked at 347 and 571 μg kg?1 (3% mass load reduction) for mean above-ground plant tissue concentrations in each pond, respectively. Subsequent senescence of above-ground tissue showed significant decreases in tissue mass (r 2?=?0.985) and adsorbed diazinon mass (90?±?4% and 82?±?1%) within 1 month of amendment. There were no corollary increases in water column diazinon concentrations. Furthermore, control O. sativa tissue placed within the treatment ponds had below-detectable levels of diazinon throughout the decomposition phase, suggesting a lack of within pond transference of dissipated diazinon. This study shows the relative effectiveness of diazinon adsorption by post-harvest rice plants and a potential mitigation strategy of senescence and pesticide degradation for contaminated tailwater. 相似文献
56.
A Spatio-Temporal Downscaler for Output From Numerical Models 总被引:2,自引:0,他引:2
Veronica J. Berrocal Alan E. Gelfand David M. Holland 《Journal of Agricultural, Biological & Environmental Statistics》2010,15(2):176-197
Often, in environmental data collection, data arise from two sources: numerical models and monitoring networks. The first
source provides predictions at the level of grid cells, while the second source gives measurements at points. The first is
characterized by full spatial coverage of the region of interest, high temporal resolution, no missing data but consequential
calibration concerns. The second tends to be sparsely collected in space with coarser temporal resolution, often with missing
data but, where recorded, provides, essentially, the true value. Accommodating the spatial misalignment between the two types
of data is of fundamental importance for both improved predictions of exposure as well as for evaluation and calibration of
the numerical model. In this article we propose a simple, fully model-based strategy to downscale the output from numerical
models to point level. The static spatial model, specified within a Bayesian framework, regresses the observed data on the
numerical model output using spatially-varying coefficients which are specified through a correlated spatial Gaussian process. 相似文献
57.
58.
Susan O. Mitchell Emily J. Baxter Celia Holland Hamish D. Rodger 《Aquaculture International》2012,20(5):813-825
Gill health and disease in farmed Atlantic salmon (Salmo salar) were studied at a marine site on the west coast of Ireland. Fish were sampled on a regular basis during the summer and autumn of 2009. A novel histopathological scoring system was devised to give a semi-quantitative measure of gill pathology. The index criteria for gill histopathology were lamellar hyperplasia, lamellar fusion, circular anomalies (necrosis or sloughing) and lamellar oedema, a score from 0 to 3 being assigned for each parameter. Ancillary criteria, such as hypertrophy, haemorrhage and the presence of specific pathogens, were assigned a score of 0 or 1. Environmental monitoring undertaken included zooplankton and phytoplankton sampling, as well as temperature and oxygen recordings for the site. Epitheliocystis was frequently observed at low levels but was not associated with any significant gill pathology. Clinically significant gill pathology was observed on one occasion during the sampling period, coinciding with the occurrence of Pelagia noctiluca, Muggiaea atlantica and Solmaris corona. Throughout the longitudinal study, the scoring system provided an accurate and effective means of assessing gill health, demonstrating the ability of this practical tool to be used in future studies of gill health and disease. 相似文献
59.
60.
Test environment evaluation has become an increasingly important issue in plant breeding. In the context of indirect selection, a test environment can be characterized by two parameters: the heritability in the test environment and its genetic correlation with the target environment. In the context of GGE biplot analysis, a test environment is similarly characterized by two parameters: its discrimination power and its similarity with other environments. This paper investigates the relationships between GGE biplots based on different data scaling methods and the theory of indirect selection, and introduces a heritability-adjusted (HA) GGE biplot. We demonstrate that the vector length of an environment in the HA-GGE biplot approximates the square root heritability (\( \sqrt H \)) within the environment and that the cosine of the angle between the vectors of two environments approximates the genetic correlation (r) between them. Moreover, projections of vectors of test environments onto that of a target environment approximate values of \( r\sqrt H \), which are proportional to the predicted genetic gain expected in the target environment from indirect selection in the test environments at a constant selection intensity. Thus, the HA-GGE biplot graphically displays the relative utility of environments in terms of selection response. Therefore, the HA-GGE biplot is the preferred GGE biplot for test environment evaluation. It is also the appropriate GGE biplot for genotype evaluation because it weights information from the different environments proportional to their within-environment square root heritability. Approximation of the HA-GGE biplot by other types of GGE biplots was discussed. 相似文献