Search results

1

The retinal fascin gene 2 (FSCN2) ? partial structural analysis and polymorphism detection in dogs with progressive retinal atrophy (PRA)

100%

Horak P., Knoll A., Dvorak J.

Journal of Applied Genetics

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2006

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vol. 47

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issue 4

361-364

EN

The retinal fascin 2 gene (FSCN2) underwent a molecular analysis, a search for polymorphisms and an evaluation as a candidate gene for retinopathies in dogs. Specific fragments of the gene encompassing partial exon 1 and intron 1, and exons 2?5 with respective introns were sequenced and these data were deposited in the GenBank database. Three distinct polymorphic sites detectable with PCR-RFLP were found ? AM050719: g.237G > A, AM050719: g.525A > G, and AM050720: g.1071A > G. No positive associations between these polymorphisms and the PRA-clinical status were observed in the investigated population consisting of Poodles, American Cocker Spaniels, and English Cocker Spaniels. In spite of that, the FSCN2 gene remains an excellent candidate gene for retinopathies in dogs and the results can contribute to further research in this field.

2

Microstructure Mechanisms Governing the Creep Life of Ultrafine-Grained Cu-0.2 wt%Zr Alloy

88%

Kral P., Svoboda M., Dvorak J., Kvapilova M., Sklenicka V.

Acta Physica Polonica A

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2012

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vol. 122

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issue 3

457-460

EN

Equal-channel angular pressing was conducted at room temperature and extrusion was performed up to 12 passes using route where the billets were rotated by 90° in the same sense between consecutive passes. Tensile creep tests were performed at 473, 573 and 673 K at different constant applied stresses. It was observed that the original coarse grain size of unprocessed alloy was reduced to 0.3 μm after 8 equal-channel angular pressing passes and the grain growth during creep was restricted by precipitates with the mean diameter ≈ 4.0 nm. No significant effect on creep resistance was found after one equal-channel angular pressing pass at 473 and 573 K. However, the longest time to fracture was exhibited by alloy after 2 equal-channel angular pressing passes at 573 and 673 K but with further increasing number of equal-channel angular pressing passes a decrease in the time to fracture was observed. Nevertheless, the beneficial effect of equal-channel angular pressing on creep resistance was still documented after 8 passes for temperatures of 473 and 573 K. By contrast, creep tests performed at 673 K showed that the time to fracture of ultrafine-grained material is shorter as compared with that for as-received state. The 3D laser measurement of surface showed that the creep fracture process is accelerated by formation of vertical surface step relief and cavitation at the intersection of the shear bands during creep.

3

Influence of Long-term Annealing and Hot Bending on Creep of P92 Pipe

76%

Kral P., Dvorak J., Kvapilova M., Kucharova K., Sklenicka V., Svobodova M., Cmakal J.

Acta Physica Polonica A

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2015

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vol. 128

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issue 4

543-547

EN

This work is focused on the creep behaviour of the thick-walled hot bended P92 pipe, with an outer diameter of 350 mm and wall thickness of 39 mm, in its different parts, namely in straight parts and bends. Selected creep specimens machined from axial section of pipe were thermally aged at 650°C to simulate microstructure degradation typical for long-term service conditions. Subsequent tensile creep tests at constant load were performed at 600°C under 140 MPa and creep behaviour of various structure states was compared. Microstructure was investigated by scanning electron microscopy equipped with electron backscatter diffraction. It was found that ageing at 650°C for 10⁴ h caused the significant reduction of creep resistance down to about 10% of initial state and an additional slight reduction of creep resistance after longer ageing for 2×10⁴ h. Further, creep behaviour was significantly influenced by specimen position in the extrados and intrados parts of bends. Microstructure investigation revealed that long-term annealing has negligible effect on high-angle grain boundary spacing and misorientation. By contrast, creep deformation of long-term annealed specimens led to significant decreasing in high-angle grain boundary spacing and caused a change in the misorientation distribution of boundaries.

4

Associations of the IGF2 gene with growth and meat efficiency in Large White pigs

76%

Kolarikova O., Putnova L., Urban T., Adamek J., Knoll A., Dvorak J.

Journal of Applied Genetics

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2003

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vol. 44

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issue 4

509-513

EN

The insulin-like growth factor 2 gene (IGF2) has been described in several studies as a candidate gene for meat efficiency in pigs. IGF2 is a member of the growth factors family and has an effect on development of muscle tissue. The effect of IGF2 gene polymorphism on meat efficiency was analysed in a population of 121 Large White pigs. A PCR-based test and RFLP methods were used for detection of genotypes. Allele A, lacking the restriction site, was characterised by the presence of a 0.9-kb fragment. In allele B, the amplimer was cut into a 0.8-kb fragment and some barely detectable fragments. The statistical analysis was carried out according to the General Linear Model procedure. The genotype frequencies observed were: 1.65%, 33.88%, 64.46% for AA, AB and BB genotypes, respectively. There was a significant difference (P 0.05) between the AB and BB genotypes in live weight before the test. A significant association between AB and BB genotypes and body weight before the test was found. No significant difference in other traits of growth and meat efficiency was observed (P > 0.05).

5

Creep Behavior of a Zirconium Alloy Processed by Equal-Channel Angular Pressing

64%

Sklenicka V., Dvorak J., Kral P., Svoboda M., Kvapilova M., Kopylov V., Nikulin S., Dobatkin S.

Acta Physica Polonica A

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2012

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vol. 122

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issue 3

485-489

EN

A Zr-2.5 wt%Nb alloy was processed by equal-channel angular pressing and then tested under creep conditions at 623 K using a tensile stress within the range from 120 to 300 MPa. The results show conventional power-law creep with a stress exponent of n > 3 which is consistent with an intragranular dislocation process involving the glide and climb of dislocations. It is demonstrated that diffusion creep is not important in these tests. For comparison purposes, the experiments were conducted using both the unprocessed alloy and after processing by equal-channel angular pressing. It was found that under same testing conditions the measured minimum creep rates in the pressed alloy with ultrafine grain sizes were faster than in the same alloy in a coarse-grained unprocessed condition.

6

Association od the DdeI growth hormone gene polymorphism with some performance traits in Polish Large White and Czech Large White ? Polish Large White pigs

52%

Putnova l., Krenkova K. L., Krenkova L., Vrtkova V. I., Vrtkova I., Dvorak D. J., Dvorak J., Pietruszka P. A., Pietruszka A., Czarnecki C. R., Czarnecki R.

Journal of Applied Genetics

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2001

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vol. 42

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issue 3

317-324

EN

. The genotypes of growth hormone gene polymorphisms (GH-DdeI, GH-MspI, GH-HaeII, GH-ApaI, GH-CfoI) were determined in 78 pigs [Czech Large White sires (CLWsire line) ? Polish Large White (PLW) sows, Polish Large White sires ? Polish Large White sows], by the PCR-RFLP method. Preliminary studies found only GH DdeI polymorphism to be associated with performance traits. The associations of this polymorphism with growth and carcass traits were investigated. The linear model included the effects of candidate genes, genetic groups, sex and linear covariables of age at slaughter and body weight at weaning. The DdeI polymorphism of the GH gene showed associations with carcass length (P 0.05), average daily gain from birth to weaning (P 0.05) and average daily gain from weaning to slaughter (P 0.05). The association of GH genotypes with feed conversion was near significance. Sex influenced average daily gain from birth to weaning. The genetic groups (Czech or Polish sires) improved fat thickness at sacrum point 3, average daily gain from birth to weaning, lean meat content, weight of chop, weight of shoulder, weight of neck and average daily gain from weaning to slaughter. The regression on age at slaughter and on body weight at weaning influenced the majority of production traits.

Refine search results

The retinal fascin gene 2 (FSCN2) ? partial structural analysis and polymorphism detection in dogs with progressive retinal atrophy (PRA)

Microstructure Mechanisms Governing the Creep Life of Ultrafine-Grained Cu-0.2 wt%Zr Alloy

Influence of Long-term Annealing and Hot Bending on Creep of P92 Pipe

Associations of the IGF2 gene with growth and meat efficiency in Large White pigs

Creep Behavior of a Zirconium Alloy Processed by Equal-Channel Angular Pressing

Association od the DdeI growth hormone gene polymorphism with some performance traits in Polish Large White and Czech Large White ? Polish Large White pigs