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41.
42.
Fullerene pipes 总被引:10,自引:0,他引:10
J Liu AG Rinzler H Dai JH Hafner RK Bradley PJ Boul A Lu T Iverson K Shelimov CB Huffman F Rodriguez-Macias YS Shon TR Lee DT Colbert RE Smalley 《Science (New York, N.Y.)》1998,280(5367):1253-1256
Single-wall fullerene nanotubes were converted from nearly endless, highly tangled ropes into short, open-ended pipes that behave as individual macromolecules. Raw nanotube material was purified in large batches, and the ropes were cut into 100- to 300-nanometer lengths. The resulting pieces formed a stable colloidal suspension in water with the help of surfactants. These suspensions permit a variety of manipulations, such as sorting by length, derivatization, and tethering to gold surfaces. 相似文献
43.
FL BOWEN P FISARA P JUNQUERA DT KEEVERS RH MAHONEY HR SCHMID 《Australian veterinary journal》1999,77(7):454-460
OBJECTIVE: To assess a ready-to-use formulation of dicyclanil to prevent blowfly strike on Merino sheep under Australian conditions. DESIGN: Randomised clinical trials conducted in an environment house and in the field. PROCEDURE: Two environment house trials were used to measure the protection against flystrike provide by a jetting or a ready-to-use 5% spray-on formulation of dicyclanil over 22 and 31 weeks respectively. Oviposition and strikes were recorded weekly for each sheep. In two field trials the occurrence of strike in Merino sheep treated off-shears or in long wool with dicyclanil or with cyromazine was compared for up to 38 weeks after treatment. Efficacy was assessed by calculating the cumulative percentage of sheep struck. RESULTS: Under environment house conditions, sheep jetted with dicyclanil at 1.50, 0.75 and 0.30 g per sheep developed 0, 8 and 9 strikes respectively during the 22 weeks of the trial, whereas there were 358 strikes present in the placebo group. Sheep sprayed with dicyclanil at 2.25, 1.50 and 0.75 g per sheep developed 5, 11 and 29 strikes respectively between weeks 15 and 31 after treatment, whereas there were 185 strikes present in the untreated controls. In field trials the cumulative percentage of sheep struck reached 1% between weeks 12 to 13 after sheep had been treated with cyromazine. Sheep treated with dicyclanil reached the 1% limit at week 21 after treatment. CONCLUSION: Under Australian field conditions, a ready-to-use 5% spray-on formulation of dicyclanil applied off-shears or to long wool protected Merino sheep from blowfly strike for a period of at least 20 weeks. 相似文献
44.
Twenty cats presented with respiratory signs identified as asthma lasting for several months or years. The episodes of acute coughing and dyspnea were severe, requiring frequent glucocorticoid therapy. An allergic diagnosis was proposed in order to identify the putative allergens involved and to try specific therapy. Three cats developed diabetes mellitus secondary to glucocorticoid treatments. Two of them could not be tested and were given inhalant therapy with bronchodilators and glucocorticoids several times during the day and night. Intradermal tests were performed in 18 cats using 42 aeroallergens. Three tests were negative, even after a second test. Inhalant therapy was prescribed for three cats. Fifteen cats showed positive intradermal test reactions to house dust mites, storage mites and less frequently, pollens. When intradermal test results were positive for storage mites or cockroach, elimination of dried food was first recommended. This was sufficient for remission of the respiratory signs in three cats. Specific immunotherapy was prescribed for the other 12 cats. At the initiation of immunotherapy, all cats were treated with inhaled medications. After 6–9 months, immunotherapy was effective in controlling clinical signs of asthma without any other symptomatic treatment in eight cats. Four cats still required inhaled salbutamol and beclometasone two to three times weekly, instead of two to three times daily. This study demonstrates the role of allergenic stimuli in feline asthma and the advantage of specific immunotherapy as a long-term treatment.
Funding: Self-funded. 相似文献
Funding: Self-funded. 相似文献
45.
46.
Ruiz-Trillo I Riutort M Littlewood DT Herniou EA Baguña J 《Science (New York, N.Y.)》1999,283(5409):1919-1923
Because of their simple organization the Acoela have been considered to be either primitive bilaterians or descendants of coelomates through secondary loss of derived features. Sequence data of 18S ribosomal DNA genes from non-fast evolving species of acoels and other metazoans reveal that this group does not belong to the Platyhelminthes but represents the extant members of the earliest divergent Bilateria, an interpretation that is supported by recent studies on the embryonic cleavage pattern and nervous system of acoels. This study has implications for understanding the evolution of major body plans, and for perceptions of the Cambrian evolutionary explosion. 相似文献
47.
Shaw SC Wood JL Freeman J Littlewood JD Hannant D 《American journal of veterinary research》2004,65(7):1014-1020
OBJECTIVE: To estimate the heritability of atopic dermatitis in Golden and Labrador Retrievers. ANIMALS: 429 dogs related to 13 dogs with atopic dermatitis. PROCEDURE: Atopic dermatitis was defined on the basis of the type and frequency of clinical signs recorded in the clinical records, and each dog was classified with atopic dermatitis or probable atopic dermatitis or as nonatopic. By use of data from atopic and nonatopic dogs, regression analyses of parental status on offspring status were performed to estimate heritability. RESULTS: There was no difference in the frequency of atopic dermatitis between sexes or between breeds. There was a marked association between the atopic status of the parent and that of the offspring, particularly for sires. By use of data from 32 litters in which the status of both parents was known and considering only those dogs classified with atopic dermatitis or as nonatopic, the heritability (+/- SE) of atopic dermatitis was estimated to be 0.47 (+/- 0.17). CONCLUSIONS AND CLINICAL RELEVANCE: Atopic dermatitis has a strong genetic component, and breeding of dogs with clinical signs of atopic dermatitis should be discouraged. 相似文献
48.
Nitrogen excretion (total N, NH3 and urea-N) across the gills (ZN) and in the urine (UN) as well as in the feces (FN) was measured for individual rainbow trout (250–550 g) in relation to dietary protein and lipid. Total N excreted across the gills represented over 96% of the combined ZN and UN. The proportion of N excreted as NH3N was much higher across the gills than in the urine. For the four diets of 35 or 49% protein and 10 or 20% lipid fed at 0.5 and 1.0% body weight d?1, total N excretion (ZN + UN) was proportional to N intake raised to the power of 0.383. N excretion was slightly but not significantly reduced by high dietary lipid levels. The proportion of NH3N excreted (ZN + UN) relative to ingested N increased with dietary protein concentration at both meal sizes. Urea-N relative to N intake did not differ with dietary protein or lipid concentration. Fecal-N relative to intake varied inversely with dietary N and was independent of dietary lipid at both meal sizes. Digestibility varied directly with dietary concentration of protein and lipid and inversely with starch. Recovered N (RN) was approximately one-half of N intake for all diets at both meal sizes. 相似文献