• 한국미생물·생명공학회지
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• 제19권5호
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• pp.456-463
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• 1991

Bif. longum KCTC 3215에 의한 Beta-galactosidase의 최적생성조건은 탄소원으로 lactose 1.0, 초기 pH 7.0, 배양온도 $37^{\circ}C$ 및 배양시간 17시간 후였다. 이 효소는 protamine sulfate, ammonium sulfate, DEAE-Sephadex A-50 ion exchange chromatography 및 Sephadex G-150 gel filtration 등 4단계 정제과정을 거쳐 9.25배 정제되었다.

• 폴리머
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• 제38권6호
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• pp.787-790
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• 2014

본 연구에서는 실란 커플링제의 함량에 따른 에폭시 복합재료의 열안정성 및 접착특성을 고찰하기 위하여, 일반적으로 널리 사용되는 diglycidyl ether of bisphenol F(DGEBF)계 에폭시수지에 실란 커플링제로는 3-glycidoxypropyl trimethoxysilane(GPTMS)를 변량 배합하여 에폭시 시편을 제조하였다. TGA 데이터를 통해 고분자 분해온도(polymer decomposition temperature, PDT), 최대 중량 감소 시의 온도(temperature of miximum rate of weight loss, $T_{max}$), 적분 열분해 진행 온도(integral procedural decomposition temperature, IPDT), 그리고 분해 활성화 에너지($E_a$)를 구하였다. 또한 접착특성은 철판 사이에 제조한 에폭시 복합재료를 도포하여 접착력 시편을 제작하고, 상온에서 UTM(universal testing machine)을 사용하여 접착력을 측정하였다. 그 결과, DGEBF계 에폭시의 경우 실란커플링제 도입에 따라 미처리 에폭시 복합재료에 비해 접착력이 향상되었고, 일정 함량 도입 후에는 접착력이 오히려 감소하는 경향을 보였다.

• 한국작물학회지
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• 제49권2호
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• pp.73-81
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• 2004

Effects of ambient and elevated $\textrm{CO}_2$ and high temperature, and their interactions with zero and applied nitrogen supply (NN-no nitrogen and AN-applied nitrogen) were studied on soybean (Glycine max L.) in 2001. In this experiment, elevated $\textrm{CO}_2$ (650 $\mu\textrm{mol}.\textrm{mol}^{-1}$) and temperature (+$5^{\circ}$) increased total dry mass at final harvest by 125% and 119% and seed weight per plant by 57% and 105% for NN and AN plants, respectively. Although the influence of temperature and temperature x $\textrm{CO}_2$ were not significant, the influences of $\textrm{CO}_2$ concentration and temperature x $\textrm{CO}_2$ concentration were significant on total dry weight and seed weight, respectively. In particular, seed weight per plant was increased, while weight per one hundred seed weight was decreased with elevated $\textrm{CO}_2$ and temperature. The N supply increased biomass and seed weight per soybean plants. The results of this study suggest that the long-term adaptation of soybean growth at an elevated $\textrm{CO}_2$ concentration and high temperature might potentially result in a increase in dry matter production and yield.

• Biomolecules & Therapeutics
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• 제6권3호
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• pp.289-295
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• 1998

The bioequivalence of two nilvadipine products was evaluated in 16 normal male volunteers (age 22-32 yr, body weight 57-80 kg) following sidle oral dose. Test product was Overca $l_{R}$ tablet (Choong-Wae Pharm. Corp., Korea) and reference product was Nivadi $l_{R}$ tablet (Hyundai Pharm. Corp., Korea). Both products contain 4 mg of nilvadipine. One tablet of the test or the reference product was administered to the volunteers, respectively, by randomized two period cross-over study (2$\times$2 Latin square method). The determination of nilvadipine was accomplished using a validated capillary column GC with electron-capture detection. As a result of the assay validation, the quantiflcation of nilvadipine in human plasma by this technique was possible down to 0.5 ng/ml using 1 ml of plasma. Absolute overall recovery from five replicate analyses of nilvadipine-spiked sample were 88.4$\pm$ 10.24% (mean$\pm$ 5.D.) for human plasma of 10 ng/ml. The coefficients of variation (C.V.) were less than 20% and the actual concentration of nilvadipine measured by GC ranged from 80 to 99% in all plasma. Average drug concentrations at each sampling time and pharmacokinetic parameters calculated were not significantly different between two products (p>0.05); the area under the curve from time zero to 8 hr (AUCo-$_{8 hr}$) (22.8$\pm$5.90 vs 22.2$\pm$6.10 ng . hr/ml), maximum plasma concentration ( $C_{max}$) (10.0$\pm$2.85 vs 9.3$\pm$3.28 ng/ml) and time to reach maximum plasma concentration ( $T_{max}$) (1.2$\pm$0.31 vs 1.3 $\pm$0.47 hr). The differences of mean AU $Co_{8hr}$ $C_{max}$, and $T_{max}$ between the two products (2.25, 7.65, and 10.30%, respectively) were less than 20%. The power (1-$\beta$) and treaeent difference (7) for AU $Co_{8hr}$, and $C_{max}$ were more than 0.8 and less than 0.2, respectively. Although the power for Tmax was under 0.8, Tm\ulcorner of the two products was not significantly different from each other (p>0. 05). These results suggest that the bioavailability of Overeat tablet is not significantly different from that of Nivadil tablet. Therefore, two products are bioequivalent based on the current results.sults.lts.lts.lts.

• The Korean Journal of Pain
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• 제12권1호
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• pp.36-42
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• 1999

Background: The current maximal recommended doses of lidocaine are 7 mg/kg with $5\;{\mu}g/ml$ of epinephrine. But in clinical practice, sometimes more doses of lidocaine are required to produce adequate regional anesthesia. Method: Twenty-two healthy women patients were divided into two groups and pretreated with valium 5 mg p.o., morphine 5 mg i.m., and midazolam 2 mg i.v. before operation. Of these, 7 mg/kg of 2% lidocaine with $5\;{\mu}g/ml$ of epinephrine were given to 11 patients epidurally. Initial 3 ml of epinephrine mixed lidocaine was given as a test dose and remaining doses were given 5 ml/30 sec with 3 min intervals. Radial arterial blood were drawn at 5, 10, 15, 20, 30, 45, 60, 90, 120 min to measure plasma lidocaine concentrations. After confirming all of the peak plasma concentrations of 7 mg/kg lidocaine were absolutely under $5\;{\mu}g/ml$, the other 11 patients were given 10 mg/kg of 2% lidocaine with $5\;{\mu}g/ml$ of epinephrine epidurally and blood samplings were taken according to the same method of 7 mg/kg group. The peak plasma concentration ($C_{max}$), time to reach to $C_{max}$ ($T_{max}$), time to reach to $T_4$, maximal sensory block level, systemic toxicity, and vital sign changes were investigated. Result: $C_{max}$ was significantly higher in 10 mg/kg group ($5.1{\pm}1.3\;{\mu}g/ml$) than 7 mg/kg group($3.3{\pm}0.5\;{\mu}g/ml$), but $T_{max}$ ($10.5{\pm}2.7$ min vs $10.9{\pm}3.1$ min) was not different. Time to reach $T_4$ was significantly shorter in 10 mg/kg group ($9.5{\pm}2.7$ min) than 7 mg/kg group ($12.7{\pm}3.2$ min) but maximal sensory block level ($T_{3.7{\pm}0.7}$ vs $T_{2.7{\pm}1.0}$) was not different. In four patients of 10 mg/kg group, peak plasma concentrations exceeded $5\;{\mu}g/ml$, but no systemic toxicities appeared. No significant vital sign changes were observed. Conclusion: The current maximal recommended doses of lidocaine, merely based on body weight are not always appropriate. Further studies are needed to determine more precise guideline of maximal doses that include various pharmacokinetic components.

• BMB Reports
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• 제28권5호
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• pp.375-381
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• 1995

Two forms of glucoamylase (GI and GII) from starch-grown Lipomyces kononenkoae CBS 5608 mutant were purified to apparent homogeneity by means of ultrafiltration, Sephacryl S-200 gel filtration and DEAE Sephadex A-50 chromatography. The apparent molecular weight was calculated as ca. 150 kDa for GI and ca. 128 kDa for GII, respectively. Both enzymes were glycoproteins with isoelectric points of 5.6 (GI) and 5.4 (GII). They had a pH optimun of 4.5 and were stable from pH 5 to 8. The temperature optimum for both enzymes was $60^{\circ}C$, but they were rapidly inactivated above $70^{\circ}C$. The $K_m$ values toward starch were estimated to be 6.57 mg per ml for GI and 4.52 mg per ml for GII, and the $V_{max}$ values were 16.28 ${\mu}M$ per mg for GI and 32.25 ${\mu}M$ per mg for GII, respectively. The $K_m$ and $V_{max}$ values of GII for ${\alpha}-$ or ${\beta}-cyclodextrin$ were estimated to be 0.15 mg per ml and 2.0 mg per ml, respectively ($K_m$) and 1.02 ${\mu}M$ per mg or 1.02 ${\mu}M$ per mg, respectively ($V_{max}$). Neither enzyme exhibited pullulanase activity but they released only glucose from starch or cyclodextrin. Amino acid analysis indicated that both glucoamylases were enriched in proline and acid amino acids. Glucoamylase GII strongly cross-reacted with a monoclonal antibody raised against GI enzymes, and the two enzymes shared very similar amino acid composition. Western blot analysis indicated that L. kononenkoae CBS 5608 mutant produced two forms of glucoamylase on starch, and that synthesis of them was subject to glucose repression.

• 한국작물학회지
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• 제41권4호
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• pp.456-464
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• 1996

밀의 영양체 저장탄수화물인 fructan의 대사에 관련된 fructan exohydrolase(FEH) 효소의 특성을 구명하기 위해 FEH를 밀의 줄기와 엽초에서 정제, 실험한 결과를 요약하면 다음과 같다. 1. FEH의 분자량은 63.7kD이었으며, pH 5.5와 3$0^{\circ}C$에서 최고의 활성을 보였다. 2. FEH의 $K_{m}$ 과 $V_{max}$는 fructan의 크기에 따라 각각 10~37mM, 5g~179mM로 변이를 보였으며, tetrasaccharide가 본 실험에서 사용된 기질 중에서 가장 낮은 $K_{m}$ 과 $V_{max}$를 보였다. 3. 밀의 FEH는 $eta$(2 $\longrightarrow$1)로 연결된 fructan에 대하여 기질 특이성을 보였으며 $\beta$(2 $\longrightarrow$6) fructan과 sucrose는 분해할 수 없었다.

• 화약ㆍ발파
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• 제17권1호
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• pp.27-55
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• 1999

The excavation works for deep foundation in urban areas have recently increased complaints of blasting vibration and settlement of ground level. Foundation must be excavated approximately up to 24-28m depths from the surface. The roads and subway line pass through the excavation area. The Dae-chung station is also located at the nearest distance 5-35m from the working site. To protect subway station and adjacient some structures from blasting and settlement, the level of ground vibration, displacements and stress were monitored and analyzed. The results can be summarized as follows ; 1. An empirical particle velocity equation were obtained by test blasts at Nassan Missi 860 Office tel construction site. $V{\;}={\;}K(D/\sqrt{W})^{-n}$, where the values for n and k are estimated tobe 0.371 and 1.551. From this ground vibration equation, the max. charge weight per delay time against distance from blasting point is calculated. Detailed blasting method is also presented. 2. To measure the horizontal displacement in directions perpendicular to the borehole axis, 6 inclinometers installed around working sites. The displacement at the begining was comparatively high because the installation of struts was delayed, but after its installation the values showed a stable trend. Among them, the displacement by 3 inclinometers installed on a temporary parking area showed comparatively high values, for example, the displacement measured at hole No. IC-l recoded the max. 47.04mm for 6 months and at hole No. IC-2 recorded the max. 57.33mm for 7 months. So, all of these data was estimated below a safe standard value 103mm. 3. Seven strain gauge meter was installed of measure the magnitude and change of stress acted on structs. The measured value of maximum stress was $-465{\;}kgf/\textrm{cm}^2,{\;}-338.4{\;}kgf/\textrm{cm}^2,{\;}302.3{\;}kgf/\textrm{cm}^2$ respectively. In compareto the allowable stress level of steel, they are estimated to be safe.

• 한국환경농학회지
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• 제30권2호
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• pp.196-201
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• 2011

BACKGROUND: Bioavailability enhancement by solubilization of lipophilic drugs in nano-emulsion has been reported and it may be useful in pharmaceutical and nutraceutical products. This study was performed to compare in vivo bioavailability of nano-emulsion formulation with that of the general product as control. METHODS AND RESULTS: The pharmacokinetics assessment of Vitamin A, D and E complex of nanoemulsion formulation (LaVita), in comparison to the general product, was performed in the male rat plasma by a single oral dose at 20 mL/kg body weight (n=3/group). For nano-emulsion formulation (LaVita), $C_{max}$ of vitamin A and E in plasma were much higher and the area under the curve (AUC) of vitamin A, D and E were 14-63% higher, and the half-life of vitamin E was 2-fold longer than the general product. According to statistical analysis, each $C_{max}$ of vitamin A, D & E was significantly higher (p<0.01, 0.05 and 0.01, respectively) than that of general product. Half-life of vitamin A was significantly higher (p<0.01) and AUC of vitamin A and D were also significantly higher than the general product. CONCLUSION(s): Considering significant increment of $C_{max}$ and AUC, LaVita made of nano-emulsion could be more effective the absorption rate and extent for bioavailability of vitamin A, D & E than those of general product.

• 폴리머
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• 제30권5호
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• pp.437-444
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• 2006

Hydroxypropyl methylcellulose phthalate (HPMCP)에 isophorone diisocyanate (IPDI)와 2-hydroxyethyl methacrylate (HEMA)를 순차적으로 반응하여 우레탄 그룹을 형성하고 HPMCP에 비닐 그룹을 도입하여 반응형(reactive) HPMCP를 합성하였다. 제조된 반응형의 HPMCP와 반응전의 순수한 HPMCP의 분자량, 산가, 임계 미셀 농도(CMC) 등을 측정하였으며, 스티렌의 유화 중합에 고분자 유화제로서 도입하였다. HPMCP의 함량을 단량체인 스티렌 대비로 6, 9, 12, 18, 24 wt%로 도입하여 HPMCP 혼성 폴리스티렌 나노입자를 제조하고, 최대 중합 속도($R_{p,max}$), 입자당 평균라디칼 개수(n), 입자 크기 분포 등을 분석하였다. 또한 제조된 HPMCP 혼성 폴리스티렌 나노입자의 모폴로지를 TEM으로 분석하여 core-shell 구조임을 확인하였으며, TGA를 이용하여 열적안정성의 변화를 분석하였다. 반응형 HPMCP는 순수 HPMCP와는 달리 HEMA의 비닐 그룹으로 인해 높은 중합속도와 작은 입자 크기, 높은 표 값을 나타내었으며, 높은 젤 함량을 나타내었다.