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        검색결과 290

        201.
        2012.12 KCI 등재 서비스 종료(열람 제한)
        Manganese () is a trace element that is essential for normal physiology, and is predominantly obtained from food. Several lines of evidence, however, demonstrated that overexposure to exerts serious neurotoxicity, immunotoxicity and developmental toxicity, particularly in male. The present study aimed to evaluate the effect of 0, 1.0, 3.3, and 10 mg/kg/day doses of on the reproductive organs in the immature female rats. Rats (PND 22; S.D. strain) were exposed to () dissolved in drinking water for 2 weeks. The animals were sacrificed on PND 35, then the tissues were immediately removed and weighed. Histological studies were performed using the uteri tissue samples. Serum LH and FSH levels were measured with the specific ELISA kits. Body weights of the experimental group animals were not significantly different from those of control group animals. However, ovarian tissue weights in 1 mg and 3.3 mg dose groups were significantly lower than those of control animals (p<0.05 and p<0.01, respectively). Uterine tissue weights of 3.3 mg dose groups were significantly lower than those of control animals (p<0.01), while the 1 mg dose and 10 mg dose failed to induce any change in uterine weight. Similarly, only 3.3 mg dose could induce the significant decrease in the oviduct weight compared to the control group (p<0.05). Non-reproductive tissues such as adrenal and kidney failed to respond to all doses of exposure. The uterine histology revealed that the exposure could affect the myometrial cell proliferation particularly in 3.3 mg dose and 10mg dose group. Serum FSH levels were significantly decreased in 1mg dose and 10 mg groups (p<0.05 and p<0.01, respectively). In contrast, treatment with 1 mg dose induced a significant increment of serum LH level (p<0.05). The present study demonstrated that exposure is capable of inducing abnormal development of reproductive tissues, at least to some extent, and altered gonadotropin secretions in immature female rats. Combined with the well-defined actions of this metal on GnRH and prolactin secretion, one can suggest the might be a potential environmental mediator which is involved in the female pubertal process.
        202.
        2012.09 서비스 종료(열람 제한)
        We examined the morphometric characteristics and fluctuating asymmetry of diploid and triploid marine medaka, Oryzias dancena. We used morphometric parameters the truss and classical dimensions. Significant differences in all the classical and truss dimensions of the diploid and triploid fish. All the dimensions of the triploid fish were greater than those of the diploid fish. The triploid marine medaka shows sexual dimorphism in these characters, and the sexual dimorphism of the triploid marine medaka is similar to that of the diploid marine medaka. Thus, the growth of triploid marine medaka is faster than that of the diploid fish, and it displays clear sexual dimorphism, with male fish having longer dorsal and anal fins than female fish. we examined fluctuating asymmetry of eye diameter, maxilla length, operculum length, number of pectoral fin ray and number of pelvic fin ray. In all experimental groups, Eye diameter and maxilla length showed no significant difference between left side and right side (P>0.05). Trends of operculum length in triploid male group and pectoral fin ray's number in diploid male group showed similar trend with trends of operculum length in triploid female group and pectoral fin ray’s number in diploid female group. However, trends of operculum length in diploid male group and pectoral fin ray's number in triploid male group showed opposite trend with trends of operculum length in diploid female group and pectoral fin ray’s number in triploid female group. Trend of pelvic fin ray's number in all groups showed similar trend with trend of pectoral fin ray’s number in all groups.
        204.
        2012.07 서비스 종료(열람 제한)
        During the last decade, considerable progress has been made to understand the molecular mechanisms of M. grisea infection in rice plants and 10 rice blast R genes have been identified and characterized via map-based cloning methods. In case of rice germplasm, the genetic backgrounds of each germplasm accessions are not uniform and the evaluation for pathogenicity is difficult. To solve these problems, we applied the single resistance gene markers to rice germplasm accessions. A molecular survey was conducted to identify the presence of major blast resistance (R) gene in 363 accessions of Korea landrace rice germplasm. The results revealed that the resistance gene Pik-p (100%), Pib (98%), Pi-d(t)2 (98%) and Piz (76%) were widely observed in tested rice germplasm, but Pita-2, Pik and Pi39 gene were identified in less than 10 accessions. Most of landrace contain the four or five different resistant genes, but these results was not consist of field nursery screening. 13 accessions were shown the blast resistance in field nursery screening and Pik-p, Pib, Pi-d(t)2 and Piz genes were observed in these accessions. The evaluation results of blast resistance genes in rice germplasm will help in breeding of multi disease resistant varieties.
        211.
        2011.08 KCI 등재 서비스 종료(열람 제한)
        We investigated the effects of temperature changes on the oxygen consumption rhythm in Japanese eels, Anguilla japonica, using an automatic intermittent flow respirometer (AIFR). The endogenous rhythm of the oxygen consumption rate (OCR) in the eels (n = 18; 44-74 cm, 145-690 g), freshly collected by bag net from estuaries, was nearly synchronous with the tidal pattern of the estuarine collection site. The magnitude of mean OCR (mOCR) of eels showed variable range of 82.2 - 116.5 ml O2 kg-1 ww h-1 under constant conditions. In case of increasing temperature from 25 to 38℃, the OCR of eels exhibited a gradually increasing trend with a rhythmic pattern until 36℃. Above 36℃, the rhythms of the OCR dampened and the OCR decreased rapidly at around 36 - 37℃. The OCR of the eels exhibited the maximum value at 38℃, and then it sharply decreased. The results suggested that the critical thermal maximum (CTM) regarding the endogenous rhythms of the eels was at around 36 - 37℃ when water temperature increased at 0.5℃/14 h following the acclimation at 25℃. In case of decreasing temperature (0.5℃/14 h) from 25 to 0℃, the OCR of the eels displayed a abrupt decrease up to 23℃, and between at 23 and 20℃, there was an agitation which showed a slight increase in the OCR with a duration of 1-2 days. Below 9℃, the OCR rhythm of the eels showed a constant state regardless of temperature decreasing. These results suggest that the Japanese eel has an upper incipient lethal temperature at 36℃, with a lower thermal limit at 9℃. The biochemical aspects of the eels influenced by water temperature need to be further studied.
        212.
        2010.09 서비스 종료(열람 제한)
        Obesity is often associated with an impairment of the hypothalamic-pituitary-gonadal axis and also unites with reproductive defects and reduced fertility. The leptin-deficient ob/ob mouse is characterized by a morbid obesity and infertility. In the present study, we examined when ob/ob mouse lost their fertility activity according to aged dependent were investigated. The major organ systems in the body, the ovaries of females are the first to exhibit impaired function with advancing age. Here, ob/ob and ob lean various (4, 6, 9, 12 and 24 wks) aged mice were used. Histology (H & E staining) of ovary, vaginal smear and Reverse transcription polymerase chain reaction (RT-PCR) analysis were carried out. Hematoxylin/eosinstained sections show normal histology in ob lean type mice characterized by the presence of multiple primary and secondary follicles and well developed corpora lutea (CL). Ovaries from ob/ob mice, showed 4 and 6 wks mice similar to ob lean type but according to aged dependent ob/ob mice few primary and secondary follicles was seen. Many large empty follicles were present and no proper developed CL, especially 24 wks mice. Vaginal smear showed abnormal estrous cycle in ob/ob mice. Ovaries of ob/ob mice, mRNA results showed that ovulated gene TIMP1, Pgsh2 and Lhcgr expression levels are decreased according to aged dependent compared to ob lean type mice. These data suggest that aged dependent specifically when 24 wks of ob/ob mice lost their reproductive function.
        219.
        2010.04 KCI 등재 서비스 종료(열람 제한)
        Protein related parameters of pan bread and white salted noodles prepared from 26 Korean wheat cultivars and 6 commercial and imported wheat flours were evaluated to elucidate the relationship between rheological properties and end-use characteristics and to determine the effects of Glu-1 and Glu-3 alleles on those characteristics in Korean wheat cultivars. SDS-sedimentation volume based on protein weight was positively correlated with mixograph parameters and maximum height of dough and also positively correlated with bread loaf volume, crumb firmness and springiness of cooked noodles. Within Glu-1 loci, 1 or 2* subunit and 5 + 10 subunits showed longer mixingtime, higher maximum height of dough, and larger loaf volume than null allele, 2.2 + 12, and 2 + 12 subunits. Cultivars with 13 + 16 subunits at Glu-B1 locus showed higher protein content and optimum water absorption of mixograph than cultivars with 7 + 8 subunits. At Glu-3 loci, Glu-A3d showed longer mixing time than Glu-A3e, and Glu-B3d and Glu-B3h had stronger mixing properties than Glu-B3i. Glu-B3h had higher loaf volume and hardness of cooked noodles than Glu-B3d. Glu-D3a had lower protein content than Glu-D3c, and Glu-D3b showed stronger mixing properties than Glu-D3a. Glu-D3c showed lower hardness of cooked noodles than others.
        220.
        2010.04 KCI 등재 서비스 종료(열람 제한)
        End-use properties of 26 Korean wheat cultivars(KWC) were evaluated to assess consumer satisfaction with 6 imported wheat and 5 commercial wheat flours. In end-use quality testing of cooked noodles, Absorption of noodle dough sheet of ASW(Australian standard white) was similar to Anbaek, Eunpa, Gobun, Hanbaek, Jeokjoong, Jonong, Namhae, and Sukang. In lightness of prepared noodle dough sheet, Lightness value(L*) of KWC was lower than those of commercial flour for making white salted noodle(Com1), commercial flour for making for yellow alkaline noodle(Com2), and commercial flour for multi-purpose(Com4). Lightness value(L*) showed significantly negative correlations with particle size of flour, ash, damaged starch, and protein content. Hardness of cooked noodles positively correlated with protein content. In end-use quality of bread, Bread volume of commercial flour for making bread(Com3) was similar to Alchan, Jokyung, Keumkang, and Namhae but firmness was low. Bread volume showed better relationships with higher SDS-sedimentation volume, longer mixing time of mixograph, higher height of dough during development. Diameter of cookie showed significantly negative correlations with particle size of flour, damaged starch, and protein content. Also, Top gain score became higher as the increase diameter of cookie. In end-use quality testing of cooked cookie, Cookie diameter of Com5 was similar to that of Dahong, Geuru, Olgeuru, Tapdong, and Uri but top grain was low.