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김 추출물이 갱년기 유도 흰쥐의 Collagen 가교형성에 미치는 영향
한희선(Hee-Sun Han),배송자(Song-Ja Bae),김미향(Mihyang Kim) 한국식품영양과학회 2004 한국식품영양과학회지 Vol.33 No.2
난소 절제시술 및 폐경으로 인한 여성 호르몬인 estrogen의 감소는 지속되는 골 손실 가속화 등으로 인한 골 질환의 문제점을 가지고 있다. 그러므로 본 연구에서 흰쥐의 난소를 절제하여 인위적인 폐경을 유도하여 골 손실의 정도를 결합 조직 중의 collagen 함량 및 collagen 성숙가교인 pyridinoline 함량을 측정하여 그 효과를 검토하였다. 난소 절제 후 결합조직 중의 collagen 함량은 연골과 피부에서 난소를 절제하지 않은 Sham군에 비하여 낮았으며, 김 추출물 투여군에서 유의적이지는 않으나 높은 경향을 나타내었다. 골 중 collagen 성숙가교인 pyridinoline 함량은 난소절제에 의해 감소하였으나 골에서는 김 추출물 투여에 의해 난소를 절제하지 않은 Sham군과 비슷한 수준으로 증가하였고, 연골에서는 김 추출물 투여에 의해 Sham군과 비슷한 수준으로 감소하는 경향을 나타내어 pyridinoline 생성에 유익한 효과를 나타내었다. 김 추출물이 collagen 합성 및 성숙가교인 pyridinoline 생성을 회복시킨 본 실험의 결과로 보아 폐경기 여성에게 김 추출물의 섭취는 폐경으로 인한 골 손실을 감소시켜 줄 것으로 사료되어지며, 이러한 작용을 나타낸 김의 성분 및 그 기전에 대해서는 앞으로 더 많은 연구가 필요할 것으로 생각된다. The purpose of this study was to investigate the effects of Porphyra tenera (PT) extracts on formation of collagen cross-link in ovariectomized rats. From day 3 until 42 after the ovariectomy, Sprague-Dawley female rats were randomly assigned to the following groups: sham-operated rats (Sham), ovariectomized control rats (OVX-control), ovariectomized rats supplemented with PT at 50 ㎎/㎏ bw/day (OVX-PT50), 200 ㎎/㎏ bw/day (OVX-PT200). The PT ethanol extracts were orally administrated 1 mL per day. Body weight gain, food intake and food efficiency ratio were significantly different among the groups. The change of collagen content was studied in lung, bone, cartilage and skin of ovariectomized rats. The effects of PT extracts on the amount of collagen were examined by measuring the hydroxyproline, which is a specific amino acid existing in collagen. Pyridinoline is pyridinium cross-link formed in the mature form of collagen from lysine and hydroxylysine residues. Pyridinoline content was analyzed by HPLC. Pyridinoline content in bone collagen was decreased by ovariectomy but supplementation with the PT extracts was similarly increased to Sham. These results suggest that the PT supplementation could decrease bone loss in postmenopausal women.
혼합 액체 연료인 항공유의 점화지연시간 측정에 관한 연구
한희선(Hee Sun Han),왕위엔강(YuanGang Wang),김철진(Chul Jin Kim),손채훈(Chae Hoon Sohn) 한국연소학회 2017 한국연소학회지 Vol.22 No.3
Jet aviation fuel is one of liquid fuel which are used in aircraft engines. Korean domestic jet fuel, called Jet A-1, is tested for measurement of ignition delay time by using a shock tube manufactured recently. The temperature varies from 680 to 1250 K and the pressure and equivalence ratio of Jet A-1/air are fixed 20 atm and 1.0, respectively, for this experiment. The ignition delay time data of Jet A-1 are compared with those of Jet A, which has similar properties to Jet A-1. The behavior of negative-temperature-coefficient (NTC) is observed in the temperature range 750-900 K. In addition, ignition delay time of iso-octane is measured, which is one of the surrogate components for jet aviation fuel. The experimental data are compared and validated with the previous results from the literatures. A surrogate fuel for the present Jet A-1 consists of 45.2% n-dodecane, 32.1% iso-octane, and 22.7% 1,3,5-trimethylbenzene. The predicted ignition delay time for the surrogate agrees well with the measured one for Jet A-1.
충격파관을 이용한 메탄/산소 혼합기의 점화지연시간 측정
한희선(Hee Sun Han),왕위엔강(YuanGang Wang),김철진(Chul Jin Kim),손채훈(Chae Hoon Sohn) 한국연소학회 2017 한국연소학회지 Vol.22 No.1
Ignition delay time of methane/oxygen mixture is measured experimentally with the shock tube in order to obtain the data for high pressure conditions where gas turbines and internal combustion engines are operating. The shock tube experiment is validated first over the temperature range of 1400-2000 K at 10 bar and with the various equivalence ratios of 0.5, 1 and 2. The measured ignition delays are compared with the data from the literatures. And then, experiments are conducted for non-explored conditions, i.e., at 40 bar and with the equivalence ratio of 1.5. The present experimental data show a good agreement with the available ones from the literatures and reasonable dependence on pressure and equivalence ratio. In addition, the effects of the temperature and equivalence ratio on ignition delay time are analyzed.