Under the stressed condition, a complex feedback mechanism for stress is activated to maintain homeostasis of the body and secretes several stress hormones. But these stress hormones impair synthesis and secretion of the reproductive hormones, followed by suppression of ovarian function. Cytochrome P450 1A2 (CYP1A2) plays a major role in metabolizing exogenous substances and endogenous hormones, and its expression is recently identified at not only the liver but also several organs with respect to the pancreas, lung and ovary. Although the expression of CYP1A2 can be also affected by several factors, understanding for the changed pattern of the ovarian CYP1A2 expression upon stress induction is still limited. Therefore, CYP1A2 expression in the ovaries from immobilization stress-induced rats were assessed in the present study. The stress-induced rats in the present study exhibited the physiological changes in terms of increased stress hormone level and decreased body weight gains. Under immunohistological observation, the ovarian CYP1A2 expression in both control and the stressed ovary was localized in the antral to pre-ovulatory follicles. However, its expression level was significantly (p < 0.01) higher in the stress-induced group than control group. In addition, stress-induced group presented more abundant CYP1A2-positive follicles (%) than control group. Since expression of the ovarian CYP1A2 was highly related with follicle atresia, increased expression of CYP1A2 in the stressed ovary might be associated with changes of the ovarian follicular dynamics due to stress induction. We hope that these findings have important implications in the fields of the reproductive biology.

Cytochrome P450 1A2 (CYP1A2) is a member of the cytochrome P450 superfamily enzymes in mammals and plays a major role in metabolizing endogenous hormones in the liver. In recent days, CYP1A2 expression has been found in not only the liver but also other tissues including the pancreas and lung. However, little information is available regarding the expression of CYP1A2 in the ovary, in spite of the facts that the ovarian follicle growth and atresia are tightly associated with controls of endocrine hormonal networks. Therefore, the expression of CYP1A2 in the ovaries of prepubertal and pubertal rats was investigated to assess its expression pattern and puberty-related alteration. It was demonstrated that the expression level of CYP1A2 was significantly (p < 0.01) higher in the pubertal ovaries than prepubertal counterparts. At the ovarian follicle level in both groups, whereas CYP1A2 expression was less detectable in the primordial, primary and secondary follicles, the strongly positive expression of CYP1A2 was localized in the granulosa cell layers in the antral and pre-ovulatory follicles. However, the ratio of CYP1A2-positive ovarian follicle was significantly (p < 0.01) higher in the ovary of pubertal group (73.1 ± 3.1%) than prepubertal one (41.0 ± 10.5%). During the Immunofluorescence, expression of CYP1A2 was mainly localized in Fas-positive follicles, indicating the atretic follicles. In conclusion, these results suggested that CYP1A2 expression was mainly localized at the atretic follicular cells and affected by the onset of puberty. Further study is still necessary but we hypothesize that CYP1A2 expresses in the atretic follicles to metabolize residue of the reproductive hormones. These findings may have important implications for the fields of reproductive biology of animals.

We investigate the effect of the modification of cellulose acetate propionate as an organic vehicle for silver paste on solar cell efficiency. For the modification of cellulose acetate propionate, poly(ethylene glycol) is introduced to the hydroxyl groups of a cellulose acetate propionate backbone via esterification reaction. The chemical structure and composition of poly(ethylene glycol) functionalized cellulose acetate propionate is characterized by Attenuated total reflectance Fourier transform infrared, 1H nuclear magnetic resonance, differential scanning calorimetry and thermogravimetric analysis. Due to the effect of structural change for poly(ethylene glycol) functionalized cellulose acetate propionate on the viscosity of silver paste, the solar cell efficiency increases from 18.524% to 18.652 %. In addition, when ethylene carbonate, which has a structure similar to poly(ethylene glycol), is introduced to cellulose acetate propionate via ring opening polymerization, we find that the efficiency of the solar cell increases from 18.524% to 18.622%.

본 연구는 수분함량에 따른 보리와 호밀 silage의 발효특성을 평가하기 위하여 수행하였다. 보리와 호밀의 수분함량은 수분첨가 또는 예건을 통해 50%, 65% 및 80%로 조절하였다. 보리 silage의 pH와 Lactate: Acetate 비율은 저수분 처리구 (4.54와 6.23), 호밀 silage에서는 중수분 처리구 (4.33과 9.24)가 가장 높았 다. 보리 silage의 propionate 함량은 저수분 처리구가 고수분 처리구에 비해 높았으나, 보리와 호밀 silage의 lactate, 총휘발성지방산 및 acetate 함량은 고수분 처 리구가 저수분 처리구에 비해 높았다. 보리 silage의 total-N 함량은 중수분 처리구가 저수분 처리구에 비해 높게 나타났으며, 호밀 silage는 저수분 처리구가 타 처 리구에 비해 높았다. 보리 silage의 NH3-N 함량과 total-N:NH3-N 비율은 고수분 처리구가 높게 나타났 다. 보리와 호밀 silage의 buffering capacity는 수분 함량이 높을수록 증가하였으나, pH가 높을수록 감소하 였다. 보리와 호밀 silage의 수분 함량은 pH와는 부 (-)의 상관관계를 나타내었으나, 휘발성지방산과 NH3-N 함량 및 total-N중 NH3-N 비율과는 정 (+)의 상관관계를 나타내었다. 이상의 결과에서 보리와 호밀 silage 제조를 위한 적정 수분함량은 70~80%로 확인되 었으며, 사료작물의 수분을 60%까지로 예건하는 것은 silage 품질 저하를 초래할 수 있는 것으로 사료된다.

As global warming is higher by CO2, most of countries have an effort to develop CO2 reducing technology like a CO2 sequestration and a CO2 curing method using cement based materials. In this study, CO2 uptake rate and compressive strength were investigated when CO2 curing method was applied in cement mortar. The CO2 uptake rate was ranged from 10.1% to 11.6% by mass measurement method and from 6.2% to 16.3% by TGA method. This means that mass measurement method by electronic scale is more accurate than TGA method to estimate CO2 uptake rate. The early compressive strength of 1 hour CO2 curing specimens was higher than that of 1 hour atmospheric curing specimens, but lower than that of 5 hours steam curing specimens. 3 days and 7 days compressive strength of specimens by atmospheric curing and steam curing were increased both. But compressive strength of 1 hour CO2 curing specimens was lower than that of other two curing methods.