http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Streptomyces 속 균주 HA-40이 생산하는 내열성 α-Amylase의 효소학적 성질
신운섭,이동희,이현우,권태종,정호권 建國大學校 附設 産業技術硏究所 1988 논문집 Vol.13 No.-
토양으로부터 분리한 Streptomyces 속 균주 HA-40이 생산하는 내열성 α-amylase의 효소학적 성질을 조사한 결과는 다음과 같다. 효소의 작용 최적 온도는 65℃였으며 activation energy 는 16.9Kcal/mole이었고 60℃에서는 안정하였으나 70℃에서는 30분 처리로 약 50%, 1시간 처리로 약 75%가 실활하였다. 그러나 ??를 0.1mM농도로 첨가한 경우엔 70℃ 에서 1시간 처리하여도 잔존활성도가 55%이상으로 열변성에 대한 ??의 보호효과가 있었다. 본 효소는 pH7에서 활성이 가장 강하였으며 안정성도 가장 높았다. 그리고 금속이온 중에서 ??의 첨가로 효소활성이 증대되었으며 ??, ??, ??등에 의해서 활성이 저해되었다. 각종 효소저해제는 대부분 영향을 미치지 못하였으나 EDTA가 반응액 중에 공존하면 효소활성이 강하게 저해되었다 본 효소는 maltotriose이하의 당류에 대해서는 분해력이 없었으며 amylose에 대한 환원당 생성력을 100으로 하였을때 soluble starch 108, amylopectin 94, glycogen 87, dextrin 48, potato starch 25, corn starch 18로 생전분에 대한 분해력은 soluble starch에 비해서 1/4∼1/5 정도밖에 되지 않았다. 그리고 soluble starch에 대한 Km 치는 1.9㎎/㎖였다. The properties of a thermostale α-amylase produced from Streptomyces sp. strain HA-40, isolated from soil, were investigated. The optimal temperature of the enzyme was 65℃ and the enzyme was stable below 60℃. However, at 70℃ about 75% of the activity was lost after 1hr treatment, but by the addition of ?? in the concentration of 0.1mM only 45% of the activity was lost. The enzyme was most active and stable at around pH 7. The activity of the enzyme was increased by the addition of ??, but depressed by ??, ??, and EDTA. The enzyme could be hydrolyze soluble starch, amylose, amylopectin and glycogen well, and could also digest dextrin and raw starch. The Km value for soluble starch was 1.9㎎/㎖.
흰쥐에서의 Puromycin Aminonucleoside-유발 단백뇨에 대한 선택적 Thromboxane A₂수용체길항제, KT2-962의 효과
서대규,신인철,고현철,하경란,강주섭 한양대학교 의과대학 1994 한양의대 학술지 Vol.14 No.1
The administration of puromycin aminonucleoside(PAN) to rats caused to nephrotic syndrome which characterized ascites, proteinurisa, hypoalbuminemia, and hyperlipidemia similar to those observed in human minimal change disease. Recently, several studies indicate that renal endogenous thromboxane(Tx) A₂may have an important role in pathophysiology of various renal disease. In this sutdy, we hafve examined the protective effct of a selective TxA₂receptor antagonist, KT2-962(KT2) on PAN-induced proteinuria in rats. Thus, male Wistar rats were given either daily subsutaneous injection of PAN, 20mg/kg, for 10 consecutive days from 3 days before to 7 days with PAN treatment. Urine was collectd, and body weight was measured in interval of 2 days during 2 weeks and urinary N-acetyl-β-Dglucosaminidase(NAG) activity as an index of renal tubular cell damage and urine protein were measured. In addition to measuring BUN, serum creatinine and creatinine clearance were measured to assess the degree of renal functional damage in 14th day. The results(Means SE) otained can be summarized as follows: 1)Body weight(gm) was progressively increased and gained about 46.4gm and 39.2gm on 2 weeks of treatment in the control and KT2 groups respectively. In constrast, there was weight loss about 27.4gm in the PAN group. But, it was increased about 23.2 gm in KT2+PAN grou and means that KT2 has significantly(p<0.05) suppressed weight loss by PAN. 2)Urine flow (ml/24 hours) was slightly increased in both control and KT2 groups during 2 weeks. But, it was significantly(p<0.05) increased after 7th groups during 2 weeks. But, it was significantly(p<0.05) increased after 7th day. But, concurrent administration of KT2 significantly(P<0.05) suppressed PAN-induced polyuria in KT2+PAN group. 3)Urinary protein(mg/24 hours0 was slightly increased in both control and KT2 groups. But, it was progressively increased and reached at the maximal level, 3.2 folds of initial level to 11th day and thereafter slightly reduced proteinuria to 14th day in the PAN group. In contrast, KT2 cotreatment with PAN was significantly(P<0.05) suppressed PAN-induced proteinuria in the KT2+PAN group. 4)Urinary NAG activity was markedly increased and reached to maximal level, 122.03 18.53 U/mg of urine creatinine, 12.7 folds of initial by day 9 and thenafter progressively decreased to 5.4 folds of initial level by day 14 in the PAN group. But, when KT2 was administered with PAN, it was significantly depressed its increment to day 13. But, it was reached to maximal level, 99.05 42.55, 12.7 folds of inital level much than PAN group. This result indicated that KT2 had a partial preventive effect on PAn-induced renal tubular cell damage. 5)The BUN and serum creatinine level(mg/dl) were significantly(p<0.05) increased from initial level, 18.48 1.28 and 0.50 0.03 to 118.42 41.34 and 1.66 0.27 respectively, and creatinine clearance(ml/min) was significantly(P<0.05) decreased from initial level, 0.44 0.02 to 0.28 0.07 by day 14 by PAN treatment. But, when PAN was given together with KT2, the increment of BUN and serum creatinine except for creatinine clearance were significantly(P<0.05) inhibited in the KT2+PAN group. Based on all these results obtained in this study, it is concluded that the coadministration of KT2-962 with PAN can be ingibited protein excretion in urine and suggested that endogenous TxA₂would take part in PAN-induced proteinuria in rats.
부모멘트를 받는 합성보의 전단합성 거동에 대한 유한요소해석
신현섭(Shin, Hyun-Seop) 한국산학기술학회 2013 한국산학기술학회논문지 Vol.14 No.8
부모멘트를 받는 합성보 슬래브에서 인장균열 발생과 균열의 진행에 따른 슬래브의 강성저하가 전단연결부 의 합성거동에 미치는 영향을 실험적으로 분석하기는 매우 어렵다. 본 논문에서는 부모멘트를 받는 합성보에서 콘크 리트 슬래브 및 강재 보, 스터드를 포함한 전단연결부 등의 형상과 물성을 최대한 실제와 유사하게 모델링하는 기법 을 이용함으로써, 부재 간 합성작용을 해석할 수 있는 3차원 유한요소모델을 개발하였다. 개발된 3차원 유한요소모델 을 이용하여 부모멘트 구간에 설치되는 합성보의 전체 휨거동 및 기존의 1차원 또는 2차원 모델로는 해석이 어려운 전단합성작용을 분석할 수 있었다. 해석결과에 따르면 부모멘트를 받는 합성보에서의 전단연결부 거동은 철근콘크리 트 슬래브의 철근비 및 인장 균열거동에 지배를 받게 됨을 알 수 있었다. 전단연결부의 하중-슬립 관계를 검토해 본 결과, 전단연결부의 슬립강성은 슬래브의 초기균열 및 철근의 항복이 발생한 시점을 기준으로 변화됨을 알 수 있었 다. 또한, 구간별로 합성율이 100% 미만으로 설계되는 부분합성 설계가 합성설계의 효율성 측면에서 더 유리할 수 있다는 기존의 실험적 연구결과를 간접적으로 확인할 수 있었다. In the composite beam subjected to the hogging moment it is very difficult to evaluate the influence of the reduction of slab stiffness due to cracks and their development on the horizontal shear behavior of shear connection. In this study, a 3D FE model is developed by which one can analyze the composite action in the composite beam subjected to the hogging moment. In this FE model, each structural member and shear connection are modeled as similar as possible to details of the composite beam. Bending behaviour, and composite action which could not be analyzed using the existing 1D or 2D FE model are investigated by the 3D model. Analysis results show that the reinforcement ratio and crack behaviour of the slab are main factors which exert a strong influence on the composite action. According to the analysis results about load-slip behavior, initial crack of slab and yielding of rebars have a influence on the slip stiffness of shear connection. The existing experimental results, that the design of partial interaction can be more efficient in designing of shear connection of the composite beams, are indirectly verified by the FE analysis.