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排序方式: 共有177条查询结果,搜索用时 15 毫秒
1.
K G Braund H S Steinberg A Shores J E Steiss J R Mehta M Toivio-Kinnucan K A Amling 《Journal of the American Veterinary Medical Association》1989,194(12):1735-1740
Six dogs with laryngeal paralysis had clinical, electrophysiologic, and pathologic evidence of a more generalized polyneuropathy. Three of the dogs were young Dalmatians, one was a young Bouvier des Flandres, and two were older, large-breed dogs. The results of this study suggest that laryngeal paralysis in dogs may frequently be one clinical sign of an underlying, more generalized polyneuropathy. Two forms of this generalized polyneuropathy may exist: an early form, as seen in young dogs with congenital or hereditary disease, and a delayed-onset form that is usually found in older dogs with so-called idiopathic laryngeal paralysis, some of which may have hypothyroidism. 相似文献
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Sharat Chandra Mehta 《Tropical animal health and production》2014,46(8):1397-1406
The genetic and demographic bottleneck analysis of Indian camel breeds was carried out utilizing 40 microsatellite markers. Allelic polymorphism was observed at 20 loci in the Indian dromedary breeds. A total of 66 alleles were scored. The average number of alleles, expected heterozygosity and polymorphic information content were, respectively, 3.25?±?0.27, 0.56?±?0.04 and 0.49?±?0.04 in Bikaneri; 3.25?±?0.25, 0.53?±?0.03 and 0.46?±?0.03 in Jaisalmeri; 3.0?±?0.21, 0.53?±?0.04 and 0.45?±?0.03 in Kachchhi and 3.1?±?0.19, 0.51?±?0.03 and 0.44?±?0.03 in Mewari breed. Higher genetic variation was observed in most numerous Bikaneri breed. Genetic distances were least between the breed pair Bikaneri and Jaisalmeri which was closely placed with the Kachchhi breed. The Mewari camels had relatively higher genetic distance from the other three Indian dromedary breeds. The bottleneck analysis revealed the presence of genetic bottleneck in all four breeds of Indian dromedary. However, the qualitative graphical method resulted in normal L-shaped distribution of allele frequencies in Jaisalmeri breeds and shifted mode in Bikaneri, Kachchhi and Mewari breeds. The demographic bottleneck analysis revealed minimum reduction (?9.65 %) in the population of camels in Jaisalmeri breeding tract as compared to that of Bikaneri (?14.18 %), Kachchhi (?27.78 %) and Mewari (?32 %) breeding tracts. Conclusively, the genetic bottleneck analysis could explain the demographic bottleneck in the Indian dromedary populations. Therefore, appropriate conservation and improvement efforts are needed in all four dromedary breeds with immediate attention on Mewari and Kachchhi breeds. The present study is the first report in demonstrating the genetic basis of demographic bottleneck in the Indian dromedary populations. 相似文献
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A full ophthalmic examination was performed on 40 Siberian husky dogs using direct and indirect ophthalmoscopy, gonloscopy and nasolacrimal cannulation. Eight (20%) of the dogs were found to have distichia, 10 (25%) had excessive medial caruncular hairs, 8 (20%) had absence, displacement, or narrowing of the nasolacrimal puncta, 2 (5%) had bilateral corneal crystalline opacities, and 2 (5%) had unilateral areas of lateral corneal lipidosis. Fifty percent of the dogs had some abnormality of the iridocorneal (drainage) angle. However, in only one of these was the deformity severe enough to require glaucoma prophylaxis. An association between blue iris colour and malformation of the iridocorneal angle was noted. 相似文献
6.
Exchange behaviour of potassium versus magnesium was studied on surface soil samples of 3 Ustochrepts from a semiarid tropical region in relation to different levels of cattle farmyard manure (FYM, 0, 2.5, 5 and 10%). Magnesium saturated soil samples were equilibrated with KCl + MgCl2 solutions having a range of equivalent ion fraction of K from 0 to 1 in the equilibrium solutions. The experimental results were analysed and interpreted, using different exchange selectivity quotients and thermodynamic parameters. Application of FYM caused a small but consistent increase in the K-preference over Mg as depicted from the normalized exchange isotherms. Standard free energy of K-Mg exchange were strongly negative (ΔGo-6.97 to ?9.47 kJ eq?1 by Gaines and Thomas approach; ΔG'o ?10.85 to ?14.15 kJ M?1 by Babcock and Duckart approach), suggesting a strong thermodynamic preference for K over Mg in these soils. For comparable treatments, ΔGo were about ?0.84 to ?1.25 kJ eq?1 more negative for K-Mg, compared to K-Ca system reported earlier. ΔGo for 10% FYM treatments became more negative over the controls by 2.34, 1.40 and 0.53 kJ eq?1 for Hissar, Panipat and Pehowa soils, respectively. All the selectivity quotients scrutinized in this investigation, viz., Gapon (KG), Vanselow (Kv) and thermodynamic (KN) were strongly K-saturation dependent; the dependence becoming more pronounced with the addition of FYM. 相似文献
7.
Flavonoid constituents of Chorizanthe diffusa with potential cancer chemopreventive activity 总被引:11,自引:0,他引:11
Chung HS Chang LC Lee SK Shamon LA van Breemen RB Mehta RG Farnsworth NR Pezzuto JM Kinghorn AD 《Journal of agricultural and food chemistry》1999,47(1):36-41
An ethyl acetate-soluble extract of Chorizanthe diffusa was found to exhibit significant antioxidant activity, as judged by scavenging stable 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radicals and inhibition of 12-O-tetradecanoylphorbol 13-acetate (TPA)-induced free radical formation with cultured HL-60 cells. Bioassay-directed fractionation of this extract using the DPPH antioxidant assay as a monitor led to the isolation of five structurally related flavonoids (1-5), including the novel compound 5,8,3',4',5'-pentahydroxy-3, 7-dimethoxyflavone (1). Isolates 1-5 demonstrated varying degrees of antioxidant or antimutagenic activity. Two of the compounds, 5,7,3', 4'-tetrahydroxy-3-methoxyflavone (2) and quercetin (4), were subsequently found to inhibit carcinogen-induced preneoplastic lesions in a mouse mammary organ culture model. Inhibitory activity of this type is known to correlate with cancer chemopreventive effects in full-term models of tumorigenesis. 相似文献
8.
Honeys from different floral sources as inhibitors of enzymatic browning in fruit and vegetable homogenates 总被引:2,自引:0,他引:2
Chen L Mehta A Berenbaum M Zangerl AR Engeseth NJ 《Journal of agricultural and food chemistry》2000,48(10):4997-5000
Honeys from different floral sources were evaluated for their antioxidant content and for their ability to inhibit enzymatic browning in fruits and vegetables. Antioxidant contents of honeys vary widely from different floral sources, as do their abilities to protect against enzymatic browning. Polyphenol oxidase (PPO) activity was reduced over a range of approximately 2-45% in fruit and vegetable homogenates, corresponding to a reduction in browning index by 2.5-12 units. Soy honey was particularly effective when compared to clover honey, which had a similar antioxidant content. When compared to commercial inhibitors of browning, honeys were less effective; however, in combination they added to the effectiveness of metabisulfite and ascorbic acid. Honey has great potential to be used as a natural source of antioxidants to reduce the negative effects of PPO browning in fruit and vegetable processing. 相似文献
9.
RP Andres T Bein M Dorogi S Feng JI Henderson CP Kubiak W Mahoney RG Osifchin R Reifenberger 《Science (New York, N.Y.)》1996,272(5266):1323-1325
Double-ended aryl dithiols [alpha,alpha'-xylyldithiol (XYL) and 4,4'-biphenyldithiol] formed self-assembled monolayers (SAMs) on gold(111) substrates and were used to tether nanometer-sized gold clusters deposited from a cluster beam. An ultrahigh-vacuum scanning tunneling microscope was used to image these nanostructures and to measure their current-voltage characteristics as a function of the separation between the probe tip and the metal cluster. At room temperature, when the tip was positioned over a cluster bonded to the XYL SAM, the current-voltage data showed "Coulomb staircase" behavior. These data are in good agreement with semiclassical predictions for correlated single-electron tunneling and permit estimation of the electrical resistance of a single XYL molecule (approximately18 ± 12 megohms). 相似文献
10.
In plants exposed to high metal concentrations, mechanisms to counteract the oxidative burst are crucial for its survival. To investigate the temporal sequence of physiological reactions of peanut seedlings (Arachis hypogaea L.) to cadmium exposure, seeds were cultured in increasing concentrations of CdCl2, ranging from 50 to 300 μM. Germination frequency was scored, and the distributions of Cd in root, stem, and leaves were determined after 2 and 4 weeks of culture. Lipid peroxidation and activities of antioxidative enzymes including catalase (CAT; EC 1.11.1.6) and guaiacol peroxidase (GPX; EC 1.11.1.7) were estimated in these three parts of the plant. Germination of seedlings was not affected, but the growth of seedlings was severely suppressed with increasing concentrations of CdCl2 and incubation period. Pattern of Cd distribution in the three organs varied with concentration and period of exposure to Cd. Increased lipid peroxidation was detected in all parts of the developing seedlings with increasing metal accumulation. Catalase and guaiacol peroxidase activity varied in the three parts of the seedlings with concentration of Cd and incubation period. Guaiacol peroxidase activity appears to be more active in scavenging the reactive oxygen species in developing peanut seedlings. The results of the present experiment demonstrate the advantages of a tissue‐culture model system in studying the complex network of interactions of various factors in stress tolerance. 相似文献