• Microbiology and Biotechnology Letters
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• v.17 no.4
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• pp.334-342
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• 1989

The Bacillus stearothermophilus cdd gene encoding cytidine deaminase (cytidine/2'-deoxycytidine aminohydrolase; EC 3.5.4.5) was isolated through shot gun cloning by oomplementation of an E. coli cdd mutation. Primarily 3.0 kbp of the exogenote was cloned into the Pstl site of pBR322 (pJSC101). By subsequent deletion and subcloning from the insert of pJSC101 with cdd$^+$ and tetracycline resistancy, about 1.35 kbp of the EcoRI$_1$/PstI$_2$ fragment containing the cdd gene was isolated as pJSC201. The minicell experiment revealed a molecular mass of 33,000 dalton for polypeptide from the cloned DNA fragment complementing the cdd gene. From the lacZ fusion of 550 bp fragment of the EcoRI$_1$/AuaI as a putative promoter region, the transcription direction of the cdd gene on pJSC201 is from EcoRI towards the PstI sites, When the cdd gene was expressed in B. subtilis ED4O (cdd$^-$, pyr$^-$) by transformation with the E. coli-B. subtilis shuttle vector, the gene expression occured more efficiently than in E. coli and the gene appears to be stably maintained in B. subtitis as well as in E. coli.

• Proceedings of the Korean Society for Applied Microbiology Conference
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• 1978.10a
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• pp.204.2-205
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• 1978

발효유 원료유중에 항생물질이 함유되어있을 경우 이것이 발효유 제조에 미치는 영향을 검토하였다. 발효유의 원가유 살균과정, 배양기간, 보존기간중에 있어서 항생물질의 변화를 검토하기 위하여 Bacillus stearothermophilus var. calidolactis C 953을 사용한 cylinder plate법으로 penicillin의 역가를 측정하였다. 저온 장시간 $살균(60^{\circ}C,$ 30분) 조건에서는 조금도 불활성화되지 않았으나, 온도를 높이고, 시간을 길게함에 따라 점점 불활화률이 높아져 $고압멸균조건(121^{\circ}C,$ 15분)에서는 약 90% 이상이 불활화되었다. 또 현재 우리나라에서 발효유제조에 사용되고 있는 Lactobacillus casei, Hy3와 Lactoba-cillus bulgaricus Hy4A, Hy4B를 사용하여 $37^{\circ}C에서$ 배양할 경우 배양기간 중에 있어서 penicillin은 2일내에 95% 이상 불활화되었다. 그리고 $보존기간(5^{\circ}C)$ 중에는 phosphate buffer(pH 6.0)와 10% skim milk의 경우에 10일까지도 거의 불활화가 되지 않았으나, 발효유내에서는 5일만에 85% 이상이 불활화된다는 결과를 얻었다. 이와같은 발효유 배양기간과 보존기간 중의 penicillin 불활화의 원인을 규명하기 위하여 각종 유기산의 영향을 조사한 결과(조건 pH.3.30~3.45, 보존온도 $37^{\circ}C),$ 염산과 유산의 경우 24시간, 구연산의 경우 48시간, 초산의 경우 72시간내에 실험에 사용한 penicillin 농도의 99.99%가 불활화되었다. 이러한 결과로 볼 때 유산발효에서 penicillin이 불활화되는 주원인은 발효에 의하여 생성된 유기산에 의한 것으로 추정된다.방식이군이 중지방식이군과 고지방식이군에 비해 혈장내 LCAT 활성이 유의하게9p<0.001) 증가하였다. 3) 간의 콜레스테롤합성 능력은 정어리유군이 다른지방군보다(p<0.001), 무지방식이군이 식이지방첨가군보다(p<0.001), 동물성지방군의 식물성유지군보다 유의하게(p<0.001) 증가하였으나, 식이 지방의 수준에 의한 차이는 나타나지 않았다. 수용성 식이섬유소가 생리져 기능이 거의 비슷하고 무독성이 관찰됨으로써 신갈나무로부터 제조된 수용성 식이섬유소의 제조 방법이 우수하다고 볼 수 있다.있었다.세에 해당되는 중년 여성의 에너지, 단백질, 철분 섭취량을 권장량과 비교하여 보면, 각각 74.8$\pm$12.6%, 94.6$\pm$26.4% 및 64.5$\pm$14.1%로 당뇨군 (각각 112.8$\pm$28.5%, 157.8$\pm$68.2%, 92.8$\pm$21.7%)에 비해 유의하게 낮았고 정상군과는 유의한 차이를 보이지 않았다.상고나성이 있었다. 혈중 호모시스테인 농도는 질병의 위험요인으로서 뿐 아니라 대사적으로 밀접하게 연관된 비타민 영양상태의 biomarker로서도 그 영향력이 크다고 할 수 있다. 따라서 성별에 다른 다양한 연령집단에서 건강한 일반인과 심혈관계 질환자 등을 대상으로 호모시스테인과 비타민 영양상태에 대한 연구가 체계적으로 이루어 져야 할 것이다.태를 보다 효율적으로 증진시킬 수 있는 대안이 마련되어져야 한다고 사료된다.$\ulcorner$순응$\lrcorner$의 범위를 벗어나지 않는다. 그렇기 때문에도 $\ulcorner$순응$\lrcorner$과 $\ulcorner$표현$\lrcorner$의 성격과 형태를 외형상으로 더욱이 공간상에서는

• Clean Technology
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• v.24 no.3
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• pp.239-248
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• 2018

In this study, pervaporation experiments of water, ethanol and IPA (Isopropyl alcohol) single components and water/ethanol, water/IPA mixtures were carried out using zeolite 4A membranes developed by Fine Tech Co. Ltd. Those membranes were fabricated by hydrothermal synthesis (growth in hydrothermal condition) after uniformly dispersing the zeolite seeds on the tubular alumina supports. They have a pore size of about $4{\AA}$ by ion exchange of $Na^+$ to the LTA structure with Si/Al ratio of 1.0, and shows strong hydrophilic property. Physical characteristics of prepared membranes were evaluated by using SEM (surface morphology), porosimetry (macro- or meso- pore analysis), BET (micropore analysis), and load tester (compressive strength). Pervaporation experiments with various temperature and concentration conditions confirmed that the zeolite 4A membrane can selectively separate water from ethanol and IPA. Water/ethanol separation factor was over 3,000 and water/IPA separation factor was over 1,500 (50 : 50 wt%, initial feed concentration). Pervaporation behaviors of single components and binary mixtures were predicted using ACM (activity coefficient model), GMS (generalized Maxwell Stefan) model and DGM (Dusty Gas Model). The adsorption and diffusion coefficients of the zeolite top layer were obtained by parameter estimation using GA (Genetic Algorithm, stochastic optimization method). All the calculations were carried out using MATLAB 2018a version.

• Journal of the Korean Ceramic Society
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• v.36 no.4
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• pp.343-353
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• 1999

Microwave(2.45 GHz) was used as energy source in hydrothermal reaction to fabricate ultrafine BaTiO3 powder. Using microwave of 700 W, crytal BaTiO3 began to fom after 5 min in microwave-autoclave sys-tem. The crystallinity was not noticeably increased with increasing longer reaction time than 10 min. On the other hand in microwave-reflux system crytal BaTiO3 began to form after 15min and the crystallinity was not noticeably increased with increasing longer reaction time than 1hr,. In either case particle size dis-tribution was considerably uniform due to the effect of homogeneous heating by microwave. In addition mi-crowave heating gave an extremely small degree of particle agglomeration compared to electric heating. Av-erage sizes of as-synthesized powders were 30-60nm. Ba/Ti ratio in sol played an important role in det-ermining the particle size. It seems that excess barium forms different phases such as Ba(OH)2 which makes thin layer on the surface of BaTiO3 powder. This thin layer would inhibit the agglomeration of Ba-TiO3 powders and keep the small grain size. In microwave-autoclave system tetragonal-BaTiO3 was formed directly by the reaction of only 15 min. In the case of microwave-reflux system tetragonal-BaTiO3 was formed by driyng over 25$0^{\circ}C$.

• Proceedings of the KAIS Fall Conference
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• 2003.06a
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• pp.320-321
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• 2003

최근 천연물을 중심으로 한 학문이 발전하면서 천연물이 가지는 생리활성 물질에 대한 관심이 중대되고 있다. 또한 인공합성품의 일부가 안정성의 문제가 제기되면서 천연물의 이용분야는 더욱 확대되고 있다. 급속한 경제발전과 생활수준의 향상으로 식생활을 포함한 생활방식의 다양화로 인하여 과거 감염 위주의 질병이 감소하고 선진국형의 만성퇴행성 질환이 증가하는 추세이다. 혈소판은 혈전증(thrombosis)과 지혈증(haemstasis)에서 중요한 역할을 담당하고 있는 인자로서 현관 내 병적 이상으로 인한 과도한 혈전의 생성은 뇌 -심혈관계 질환의 중요한 유발인자로 작용하므로 뇌ㆍ심혈관계 질환이나 항고지혈증을 연구하는데 유용하게 이용되고 있다. 본 연구에서는 토끼 혈액에서 분리한 세정 혈소판 부유액을 이용하여 작약 MeOH 추출물에서 분리한 천연생리활성물질들을 대상으로 혈소판 응집억제활성에 대하여 연구하였다. 작약 MeOH 추출물의 혈소판 응집억제활성 측정에서 강한 혈소판 응집억제활성 작용을 보였다. 따라서 작약 MeOH 추출물을 크로마토그라피법을 이용하여 분리하였고, NMR을 이용한 분광학적 방법으로 지금까지의 분리한 자료와 비교ㆍ분석하였다. Monoterpene glycoside 계열의 성분들인 15개의 compound와 다수의 fraction들을 HPLC를 이용하여 분리하였으며, collagen으로 유도된 혈소판 응집억제활성측정 방법에서 뛰어난 응집억제활성을 보였다. 표준물질을 이용한 HPLC 분석과 ¹H-NMR 관련 자료의 검색을 통하여 최종적으로 compound 1b가 benzoyloxy-paeoniflorin(2.6％). compound 1d가 paeond(1.3％), compound 2c가 albiflorin(3.2％), compound 2e가 paeoniflorin(33.6％)임을 확인할 수 있었다. Compound 3a의 분석결과 benzoyloxypaeoniflorin과 구조적 유사성은 있으나 동일한 구조식으로 확인할 수 없었다. 그러나 collagen에서 응집억제활성이 90％ 이상으로 뛰어난 활성을 나타내므로 benzoyloxypaeoniflorin과 유사한 구조에서 benzoyl group이 다른 작용기로 치환되었거나 R₁ group이 다른 작용기로 치환된 형태로 추측하였다. Benzoyloxypaeoniflorin은 collagen＞thrombin＞U46616＞A.A(arachidonic acid)＞PAF의 순으로 활성을 보였다. 이는 paeoniflorin의 glycoside 5-carbon위치에 위치한 OH기 대신에 benzoyl기로 치환된 benzoyl 기가 혈소판 억제 산물로 작용한 것으로 추측했다. Paeoniflorin.은 U46619＞thrombin＞collagen＞A.A＞PAF순으로 억제를 보였다. Paeoniflorin이 collagen보다 thrombin에서 강한 억제를 보이는 것으로 Ca/sup 2＋/ chelate를 형성함으로 인해 calciu 대사를 저해하는 것으로 추축했다. Compound 3a는 U46619＞collagen＞A.A＞thrombin＞PAF순으로 억제율을 보이므로 이 화합물은 paeoniflorin의 benzoyl기에 OH기가 다른 치환기로 바뀌거나 paeoniflorin의 glycoside 5-carbon 위치의 OH기 대신에 다른 작용기로 치환된 것으로 추정하였다. 이러한 결과로 작약의 주성분인 paeoniflorin과 유사한 구조를 가진 다른 monoterpene glycoside 계열의 화합물들과 비교 분석하고 구조를 화인하고 이들 성분이 어떻게 혈소판 응집억제활성에 작용하는지를 연구하였다.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.40 no.1
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• pp.51-66
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• 2022

SST (Sea Surface Temperature) is based on the atmosphere-ocean interaction, one of the most important mechanisms for the Earth system. Because it is a crucial oceanic and meteorological factor for understanding climate change, gap-free grid data at a specific spatial and temporal resolution is beneficial in SST studies. This paper examined the production of daily SST grid maps from 137 stations in 2020 through the ordinary kriging with variogram optimization and their accuracy assessment. The variogram optimization was achieved by WLS (Weighted Least Squares) method, and the blind tests for the interpolation accuracy assessment were conducted by an objective and spatially unbiased sampling scheme. The four-round blind tests showed a pretty high accuracy: a root mean square error between 0.995 and 1.035℃ and a correlation coefficient between 0.981 and 0.982. In terms of season, the accuracy in summer was a bit lower, presumably because of the abrupt change in SST affected by the typhoon. The accuracy was better in the far seas than in the near seas. West Sea showed better accuracy than East or South Sea. It is because the semi-enclosed sea in the near seas can have different physical characteristics. The seasonal and regional factors should be considered for accuracy improvement in future work, and the improved SST can be a member of the SST ensemble around South Korea.

• Journal of Animal Environmental Science
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• v.13 no.1
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• pp.13-20
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• 2007

Sawdust biofiltration is an emerging bio-technology for control of ammonia emissions including compost odors from composting of biological wastes. Although sawdust is widely used as a medium for bulking agent in composting system and for microbial attachment in biofiltration systems, the performance of agitated bed composting and sawdust biofiltration are not well established. A pilot-scale composting of hog manure amended with sawdust and sawdust biofiltration systems for practical operation were investigated using aerated and agitated rectangular reactor with compost turner and sawdust biofilter operated under controlled conditions, each with a working capacity of approximately $40m^3\;and\;4.5m^3$ respectively. These were used to investigate the effect of compost temperature, seed germination rate and the C/N ratio of the compost on ammonia emissions, compost maturity and sawdust biofiltration performance. Temperature profiles showed that the material in three runs had been reached to temperature of 55 to $65^{\circ}C$ and above. The ammonia concentration in the exhaust gas of the sawdust biofilter media was below the maximum average value as 45 ppm. Seed germination rate levels of final compost was maintained from 70 to 93% and EC values of the finished compost varied between 2.8 and 4.8 ds/m, providing adequate conditions for plant growth.

• Food Science of Animal Resources
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• v.28 no.3
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• pp.276-282
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• 2008

It is estimated that over 80% of deer antlers produced in the world are consumed in Korea. However, mislabeling or fraudulent replacement of costly antlers with cheaper ones is one of the most common problems in the domestic antler market. Therefore, there is a great need for the development of technology to identify species of antlers. This study was carried out to develop an accurate and reliable method for the identification and authentication of species or subspecies of antlers using DNA sequence analysis and comparison of mitochondrial cytochrome band D-loop region genes among antlers of five deer species, Cervus elaphus sibericus, Cervus elaphus canadensis, Cervus nippon, Cervus elaphus bactrianus and Rangifer tarandus. A variable region of cytochrome band D-loop genes was amplified using PCR with specifically designed primers and sequenced directly. The cytochrome band D-loop region genes showed different DNA sequences between the species of antlers and thus it is possible to differentiate between species on the basis of sequence variation. To distinguish between reindeer (Rangifer tarandus) antlers and other deer antlers, PCR amplicons of the cytochrome b gene were digested with the restriction enzymes NlaIV and TaqI, respectively, which generates a species-specific DNA profile of the reindeer. In addition, samples of 32 sliced antlers labeled Cervus elaphus sibericus from commercial markets were collected randomly and the mt DNA D-loop region of these antler samples was sequenced. Among the antler samples investigated, only 62.5% were from Cervus elaphus sibericus, and others were from Cervus elaphus bactrianus (25.0%), elk (Cervus elaphus canadensis) and reindeer (Rangifer tarandus). Our results suggest that DNA sequencing of mt DNA and PCR-RFLP methods using NlaIV and TaqI enzymes are useful for the identification and discrimination of deer antler species by routine analysis.

• Journal of Food Hygiene and Safety
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• v.20 no.4
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• pp.277-283
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• 2005

A plasticizer is a substance which is added to a material to improve its processability, flexibility and stratchability. Phthalates and adipates are the most frequently used plasticizers of poly(vinyl chloride) (PVC). However, they can migtate into food from PVC food packaging, and some of them are especially suspected as endocrine disruptors. In this study, Simultaneous analysis of 13 phthalates and 9 adipates were carried out by dual-column gas chromatography system equipped wi two FID detectors for rapid confirmation and quantification. The Proposed method was validated with > 0.993 of linearity in the ranges of 10-500 mg/l, < $3.5\%$ RSD of reproducability in 10 inter-days sample preparations, and > $98.1\%$ of recoveries for all the plasticizers. DEHA was detected in all the 3 PVC wraps at levels of 176.9-198.5mg/g. Among the 51 samples of PVC gaskets, the targeted plasticizers were detected in 41 samples. Of these plasticizer detected samples,40 contained DIDP at the levels of 157.3-374.7 mg/g and one contained DMP at the levels of 165.6 mg/g. Also, some plasticizers were detected in other packaging materials such as PET, PP, PE, Pulp. But it might be attributed to contamination in manufacturing.

• Clinical and Experimental Pediatrics
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• v.48 no.11
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• pp.1219-1224
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• 2005

Purpose : The prevalence of obesity in children and adolescents has been rising rapidly in Korea because of changes of diet and lifestyle. As with adults, obesity in children and adolescents can cause diabetes mellitus, hyperlipidemia, cardiovascular diseases and renal diseases. The aim of the present study is to examine the relation of obesity, glomerular filtration rate(GFR) and serum cystatin C concentration in children and adolescents. Methods : Data of 115 children and adolescents aged between 6 years and 20 years without clinical evidence of renal diseases were included in the study. From May 2004 to December 2004, blood samples were collected from children and adolescents who were seen at the Department of Pediatrics at Chungang University Yongsan Hospital. Obesity degrees and body mass indices(BMI) were measured, and GFRs were estimated from Schwartz's formula. Serum cystatin C was measured by particle enhanced nephelometric immunoassay using Behring Nephelometer II. Results : GFRs were significantly different between the obese group(BMI >95 percentile, $145.79{\pm}23.10mL/min$) and the non-obese group(BMI <95 percentile, $134.61{\pm}26.19mL/min$) divided by BMI (P=0.031). GFRs were not significantly different between the obese group(obesity degree >120 percent, $144.29{\pm}23.08mL/min$) and the non-obese group(obesity degree <120 percent, $134.54{\pm}26.57mL/min$) divided by obesity degree(P=0.051), but were significantly different between severe obese group (obesity degree >150 percent, $155.55{\pm}20.40mL/min$) and the non-obese group(P=0.004). GFRs were correlated positively with BMI($r^2=0.037$, P=0.039), but were not correlated significantly with obesity degree($r^2=0.030$, P=0.066). Serum cystatin C concentrations were not significantly different between the obese group and the non-obese group, divided by BMI as well as by obesity degree(P>0.05). Conclusion : Obesity may lead to an alteration of renal hemodynamics such as hyperfiltration, appropriate control and management for obesity is necessary.