• 대한약리학회지
• /
• 제29권1호
• /
• pp.57-63
• /
• 1993

심장에 작용하는 약물의 기전연구에 있어서 약물의 작용이 심근수축에 필요한 대사 기질과의 관계를 검토하고자, 심근 수축력 유지에 필요한 에너지원인 각종 대사기질의 정상쥐 적출 심방 수축력 유지능력과 굶긴 쥐 적출 심방의 수축력 유지 능력을 비교 관찰한 바 다음과 같은 실험결과를 얻었다. 1. 굶긴 쥐의 체중은 정상쥐에 비해 기아 (starvation) 시작 2일에서 약 15%의 체중감소를 나타냈다. 2. 정상 쥐의 적출 심방은 기질제거 용액에서 30분에 약 40%의 현저한 수축력의 감소를 보였다. 그러나 2일간 굶긴 쥐의 적출 심장은 기질제거액에서 30분에 약 13%의 수축력의 감소를 보여 정상 쥐에서의 수축력 저하보다 현저히 낮은 감소율을 나타냈다. 3. 기질제거 용액에서 glucose, pyruvate 및 acetate가 적출 심장의 수축력을 회복시키는 능력은 굶긴 쥐에서보다 정상쥐에서 현저히 높게 나타났다 4. 이상의 data들은 기질제거 용액에서 굻긴 쥐 적출 심장은 정상 쥐 적출 심장에 비해 현저히 적게 외인성 기질을 쓰고 있음을 시사하고 있다. 이상의 연구 결과로 미루어 보아 기아가 흰쥐의 현저한 체중감소를 초래하나, 심근의 수축성에 대해서는 유해하지 않은 것 같이 보여지며, 오히려 기아 기간 중 흰쥐의 적출 심장의 수축 기능에 필요한 내인성 대사 기질의 축적을 증가시킨다는 사실을 시사하고 있다.

• Transactions on Electrical and Electronic Materials
• /
• 제14권3호
• /
• pp.116-120
• /
• 2013

This paper proposes a novel RF MEMS dc-contact switch with stiff membrane on a quartz substrate. The uniqueness of this work lies in the utilization of a seesaw mechanism to restore the movable part to its rest position. The switching action is done by using separate pull-down and pull-up electrodes, and hence operation of the switch does not rely on the elastic recovery force of the membrane. One of the main problems faced by electrostatically actuated MEMS switches is the high operational voltages, which results from bending of the membrane, due to internal stress gradient. This is resolved by using a stiff and thick membrane. This membrane consists of flexible meanders, for easy movement between the two states. The device operates with an actuation voltage of 6.43 V, an insertion loss of -0.047 dB and isolation of -51.82 dB at 2 GHz.

• Journal of the Korean Data and Information Science Society
• /
• 제19권4호
• /
• pp.1091-1100
• /
• 2008

The purpose of this study is to find out how energy substrate's utilizations in the maximal exercise-cardiorespiratory function and the energy metabolic variation- have the effect on before and after the supplements of coenzyme Q10(100mg per day for 8 weeks) based on the male students(CoQ10=8, placebo=8) of high school. The results of this study are as follows: Maximal oxygen uptake and maximal oxygen per weight are found to have the significant increase respectively in supplement group. Glucose is found to have the significant decrease after the supplement of CoQ10. And then FFA is found to have the significant increase. In the above results, the supplements of CoQ10 and cardiorespiratory function in the maximal exercise are found to have the improvement. CoQ10 in the anaerobic exercise spares the energy's utilization of Glucose and then is found to have the increase of the utilization of FFA. CoQ10 in the aerobic exercise is reported to have the increase of the utilization of FFA and then CoQ10 in the maximal exercise is also recognized to have the increase of the utilization of FFA, or energy substrates.

• 한국생물공학회:학술대회논문집
• /
• 한국생물공학회 2002년도 생물공학의 동향 (X)
• /
• pp.351-354
• /
• 2002

부산광역시 수영 하수처리장의 소화조에서 농축조로 보내지는 혐기성 슬러지를 탈기된 증류수와 1:1로 희석하여 11.900 mg/L로 만든 후 혐기성 고정 생물막 반응기에 15일간 생물막을 부착시킨 후, 부유 슬러시를 제거하고 각 반응기에 각각 8.00 mgTOC/L, 9.76 mgTOC/L, 및 18.97mgTOC/L의 기질 농도를 유입하여 HRT 0.496일로 각 반응기에 연속적으로 주입하여 실험하였다. 기질 전달 현상과 관련하여 각 반응기에 대한 실험 결과는, 저농도로 기질이 유입된 반응기 l과 2에서는 생물막 두께 및 기질 제거율, 기질 소비 속도 상수($k_v$), 유효 확산 계수($D_{eff}$) 가 비슷하였으나, 고농도로 기질이 유입된 반응기 3에는 자농도로 기질이 유입된 반응기 1과 2 보다 높은 값을 나타내었다. 이는 본 실험에 사용된 혐기성 미생물이 고농도의 기질을 유입하였을 때, 더욱 원활하게 성장함에 따라 높은 기질 소비를 나타내었다.

• Structural Engineering and Mechanics
• /
• 제73권6호
• /
• pp.685-698
• /
• 2020

The dynamic stability of a functionally graded polymer microbeam reinforced by graphene oxides subjected to a periodic axial force is investigated. The microbeam is assumed to rest on an elastic substrate and is subjected to various immovable boundary restraints. The weight fraction of graphene oxides nanofillers is graded across the beam thickness. The effective Young's modulus of the functionally graded graphene oxides reinforced composite (FG-GORC) was determined using modified Halpin-Tsai model, with the mixture rule used to evaluate the effective Poisson's ratio and the mass density. An improved third order shear deformation theory (TSDT) is used in conjunction with the Chebyshev polynomial-based Ritz method to derive the Mathieu-Hill equations for dynamic stability of the FG-GORC microbeam, in which the scale effect is taken into account based on modified couple stress theory. Then, the Mathieu-Hill equation was solved using Bolotin's method to predict the principle unstable regions of the FG-GORC microbeams. The numerical results show the effects of the small scale, the graphene oxides nanofillers as well as the elastic substrate on the dynamic stability behaviors of the FG-GORC microbeams.

• Journal of Microbiology and Biotechnology
• /
• 제24권12호
• /
• pp.1622-1628
• /
• 2014

DagA, a ${\beta}$-agarase, was produced by cultivating a recombinant Streptomyces lividans in a glucose medium or a mixed-sugar medium simulating microalgae hydrolysate. The optimum composition of the glucose medium was identified as 25 g/l glucose, 10 g/l yeast extract, and $5g/l\;MgCl_2{\cdot}6H_2O$. With this, a DagA activity of 7.26 U/ml could be obtained. When a mixed-sugar medium containing 25 g/l of sugars was used, a DagA activity of 4.81 U/ml was obtained with very low substrate utilization efficiency owing to the catabolic repression of glucose against the other sugars. When glucose and galactose were removed from the medium, an unexpectedly high DagA activity of about 8.7 U/ml was obtained, even though a smaller amount of sugars was used. It is recommended for better substrate utilization and process economics that glucose and galactose be eliminated from the medium, by being consumed by some other useful applications, before the production of DagA.

• 한국물환경학회지
• /
• 제26권1호
• /
• pp.140-147
• /
• 2010

In existing design method for aeration tank water temperature was considered as governing variable for applying safety factor. This study tried a few new approach of aeration tank design using SOUR at various temperature conditions. Specific substrate utilization rate (U) and specific oxygen uptake rate (SOUR) both were analyzed at various temperature and SRT. The laboratory scale reactor was operated on various temperature ($10^{\circ}C$, $20^{\circ}C$, $25^{\circ}C$) and SRT (5day, 10day, 20day, 30day). In this study, SOUR tended to increase with the temperature increased. On the other hand, SOUR tended to decrease when SRT increased from 5 days to 30 days. Empirical equations were obtained SOUR=a/SRT+b and $SOUR=(a/m){\cdot}U+(b-a(n/m))$ from the relationship between SRT, U and SOUR. Empirical equations shows the possibility as a new design method for the aeration basin.

• Journal of Microbiology
• /
• 제34권2호
• /
• pp.105-116
• /
• 1996

Of actinomycetes isolated from volcanic compost soils, 115 representative strains which showed distinctive morphologicla features were numerically classified, compared with reference strains of Streptomyces. One hundred and twenty unit characters were tested and the average probability of error was 4.27%. The cluster analysis resulted in two groups: group A included strains of actinomycetes except streptomycetes. Group A was divided into 2 major clusters (over 5 strains), 10-diaminopimelic acid. Group B was divided into 5 clusters, of which 4 clusters contained mesodiminopimelic acid and 1 cluster LL-diaminopimelic acid. The major clusters of group A showed higher abilities of substrate utilization and degradation, and higher resistance to inhibitors, whereas the minor and single member clusters of group A showed relatively higher antimicrobial activities. On the other hand, all clusters of group B showed relatively lower abilities of substrate utilization and degradation and lower resistance to inhibitors.

• 운동영양학회지
• /
• 제15권4호
• /
• pp.183-189
• /
• 2011

Caffeine and capsaicin increase resting energy metabolism. However, most measurements have been conducted in short-term studies. Therefore, we investigated the effects of caffeine and capsaicin on energy expenditure and energy substrate utilization in resting rats for 6 h. The caffeine (Experiment 1) experiment included four male rats aged 5 weeks and measured the effects of oral administration of caffeine (10 or 50 mg/kg) on respiratory gas, energy expenditure, and energy substrate oxidation for 6 h. Experiment 2 included four male rats aged 6 weeks to measure the effects of capsaicin (10 mg/kg) using the same method as in Experiment 1. The results of Experiment 1 indicated that O₂ uptake and carbohydrate oxidation after caffeine administration for 2 h was higher in the 10 mg trial than that in the 50 mg or placebo trials (P < 0.05). However fat oxidation was not significantly different. In contrast, capsaicin (Experiment 2) observed no differences between the placebo and the capsaicin trials. In conclusion, caffeine initially increased the resting energy consumption for 2 h, and this energy expenditure was due to carbohydrate oxidation. Capsaicin did not change oxygen uptake, respiratory exchange ratio, fat oxidation, or carbohydrate oxidation.

• 대한토목학회논문집
• /
• 제1권1호
• /
• pp.43-51
• /
• 1981

미생물(微生物)의 부착식(附着式) 성장(成長)을 이용(利用)한 폐수처리(廢水處理)의 이해(理解)를 돕기 위해 미생물막모형(微生物膜模型)을 정립(定立)하고 이의 simulation을 통하여 처리효율(處理効率)과 각종(各種) parameter 사이의 관계(關係)를 살펴보았다. 미생물막모형(微生物膜模型)은 기질(基質)의 침투정도(浸透程度)에 따라 두꺼운 막(膜)과 얇은 막(膜)으로 구분(區分)하고 각(各) 경우(境遇)에 대하여 미생물막내부(微生物膜內部)에서의 기질농도(基質濃度)와 flux를 산정(算定)할 수 있게 구성(構成)되어 있다. 모형(模型)의 정립과정(定立過程)에서 얻어진 무차원상수(無次元常數)인 ${\phi}_1$, ${\phi}_2$, 그리고 $\bar{S}_b$에 의해 기질농도(基質濃度)와 flux가 결정(決定)될 수 있음을 알았으며, ${\phi}_1$의 증가(增加)나 ${\phi}_2$의 감소(減少)에 의해 처리효율(處理効率)이 증가(增加)함을 알 수 있다. 또한 높은 처리효율(處理効率)을 유지(維持)하는 system은 모두 두꺼운 막(膜)에 속하는 것을 알 수 있다. 미생물막표면(微生物膜表面) 근처에서의 유속(流速)을 증가(增加)시킴으로써 두께가 일정(一定)한 막(膜)에 있어서 처리효율(處理効率)을 증가(增加)시킬 수 있다. 하지만 유속(流速)의 증가(增加)로 인해 sloughing이 많아져서 막(膜)의 두께가 감소(減少)하여 새로운 정상상태(定常狀態)로 바뀌게 된다. 현재(現在)까지 유속(流速)과 미생물막(微生物膜)두께사이의 관계(關係)가 정량적(定量的)으로 규명(糾明)되지 못하고 있으므로 새로운 정상상태(定常狀態)에서의 효율(効率)은 명백히 규정지을 수 없다.