In this experimental study, the characteristic of damages on GFRP rebar exposed to high temperature only and immerged in alkaline solution after the exposure to high temperature was analyzed through microscopic image analysis. The found microcrack and pores in resin matrix were quantitatively compared if there was effect of pre-exposure to high temperature. The damages, such as microcrack and pores in resin matrix, by alkali exposure were mainly found in rebar surface. On the other hand, the pores caused by high temperatures were extensively found in a section and had greater width than those caused by the alkali exposure. In results of the quantitative comparison, the accumulated length and widths of microcrack and pores in resin matrix in pre-exposed GFRP rebar to high temperature were respectively 1.5 and 1.4 times of those in the GFRP rebar only immerged in alkali solution. Therefore, the deterioration of resin matrix by the alkali exposure could be accelerated due to the pre-exposure to high temperature.

There are many evidences that carotenoids may act as antioxidants and protect humans from serious disorders such as skin degeneration and aging, cardiovascular disease, certain types of cancer, and age-related diseases of the eye. Carrots (Daucus carota L.) are consumed as an important dietary source of b-carotene, a-carotene and lutein. Astaxanthin, a keto-carotenoid has been used to raise red color of fish body and to improve immune activity in fish-breeding industry. In this study, transgenic carrot plants were generated to overproduce carotenoids including astaxanthin, a non-natural ketocarotenoid in this plant, using an efficient storage root-expression system. Among the nineteen transgenic carrot plants, transformed by a storage root-specific (ibMads) or a storage root (ibAGP1) or the constitutive CaMV35S promoters with three genes involved in carotenoid synthesis [Psy (Phytoen synthase), Crtl (Lycopen-β-cyclase), CrtO (β-carotene ketolase)], transgenic plants with ibAGP1 promoter, an amyloplast targeting sequence (TP1) and a single CrtO gene gave high content of keto-carotenoids and b-carotene. For fish body coloration, carotenoid extract or astaxanthin significantly made the body color of red seabreams more reddish than those of normal diet-fish in the 3 weeks feeding. In addition, the serum lysozyme activity in carotene-treated fish was significantly higher than that in normal diet-fed fish (P<0.05) in the 6 weeks feeding. In these cases, neither carotenoid extract- nor astaxanthin-contained diet did influence on growth rate and food utilization in red seabreams. These results suggested that carotenoid extract prepared in the present study may be useful in the body coloration and the enhancement of nonspecific immune response of red seabreams. Meanwhile, b-carotene (50 mM) up-regulated peroxisome proliferator-activated receptor a expression (PPAR-a) by about two fold in CV-1 cells, while the carotenoid extracts and astaxanthin failed to affect on the expression. Carotenoid extracts (250 mg/ml) from wild type carrot or transgenic carrots showed moderate DPPH scavenging activity.

Carrots (Daucus carota L.) are consumed as an important dietary source of provitamin A including β-carotene, α-carotene and lutein. An HPLC method was applied to determine the content of the carotenoid composition in carrot cutivars cultivated in Korea. HPLC analyses were carried out with five carrot cultivars (Socheon-5-chon, Hongsim-5-chon, Myeongju-5-chon, Seonhongbom-5-chon and Betarich) sown at April, 2007 and six cultivars (Yeoreum-5-chon, Hanyeoreum-5-chon, Sinheukjeon-5-chon, Bibariheukjeon, Manina and Betarich) sown at August of the same year. In general, the former varieties are not used for the sowing at summer because of their bolting (growth of floral axis). The former and the latter carrots were harvested after 110 and 96 days from seeding, respectively, and the carotenoids were extracted with acetone after freeze-drying. The amount of α-carotene (117.7∼205.3 μg/g・DW) was similar to that of β-carotene (113.1∼189.6 μg/g・ DW) for the carrot cultivars sown at spring, while the content (46.2∼71.1 μg/g・DW) was about a half of β-carotene content (92.5∼140.2 μg/g・DW) for the latter cultivars. In addition, the average content of lutein (25.2 μg/g・DW) in the former cultivars was eight times higher than that in the latter cultivars (3.1 μg/g・DW). Among the spring cultivation types, Socheon-5-chon and Myeongju-5-chon showed higher amount of α-carotene and β-carotene, while the higher amount was determined in Yeoreum-5-chon and Sinheukjeon-5-chon among the autumn cultivation types. Validation of the HPLC-DAD method showed good linearity (r2 > 0.997) of the three compounds analyzed in a wide concentration range (0.025∼20 μg/ml). The R.S.D. values for intra-day and inter-day precision were less than 19.2% and the mean recovery of each compound was 85.4∼104.7%.