토양 미생물인 Streptomyces tubercidicus에서 분리한 GTPcyclohydrolase Ⅰ 저해제

한지만,김시욱,이인화,박열,정혜광,윤성명,유진철 조선대학교 약학연구소 1998 藥學硏究誌 Vol.19 No.1

GTP cyclohydrolase I (EC 3.5.4.16) catalyzes the conversion of GTP to D-erythro-7,8-dihydroneopterin triphosphates and formic acid. and thus performs the first committing step in the biosynthesis of the pteridine moiety of folk acid in microorganisms and of tetrahydrobiopterin in higher animals. GTP cyclohydrolase I isolated from Streptomyces tubercidicus was inhibited by DL-6-methyl-5,6,7,8-tetrahydropterin and xanthopterin, and was not inhibited by tetrahydrofolic acid, pterin, pterin-6-carboxylic acid, biopterin, neopterin, ribofravin. These results suggest that bacterial GTP cyclohydrolase I may be regulated by its metaboilic end product.

급성기 피질하부 뇌경색에서 확산강조 자기공명영상과 관류 자기공명영상의 임상적 유용성

이승한,김병채,최성민,김명규,서정진,조기현 全南大醫大 2001 전남의대학술지 Vol.37 No.3

데이타베이스 시스템을 이용한 웹 자원 관리 엔진의 설계 및 구현

이명석,김진호,김상욱,유한양 강원대학교 정보통신연구소 1999 정보통신논문지 Vol.3 No.-

In this paper, we propose a web resource management engine based on general DBMSs. The web resources management engine manages the meta information describing the characteristics of resourves in a target web site. The engine extracts the meta information from HTML documents in the site and stores it into a predefined database called virtual schema. We use a general-purpose DBMS for maintaining the virtual schema. For design of the virtual schema, we model each element of HTML documents as a DBMS relation, and each attribute of an element as an attribute of its corresponding DBMS relation. We also model the link information among HTML documents as another relation. In order to merge the web and database having the virtual schema, we employ some additional tags in HTML documents, which were originally proposed in the INFORMIX WebDataBlade. Our web resource management engine has the following good features: (1) it supports dynamic changes of the web resources in a site by issuing update queries on the virtual schema, (2) it provides such searches that are based on structural characteristics of HTML documents since the virtual schema keeps the necessary information, (3) it provides the standard SQL interface for users to simply search and update the web resources, and finally, (4) it is portable to any DBMSs by just extending the gateway between the web and database since it only uses the common facilities supported by general-purpose DBMSs.

Thiobacillus sp. IW.에 의한 황화수소 제거

차진명,고한철,이인화 조선대학교 부설 유전생물공학연구소 1994 유전생물공학연구지 Vol.4 No.-

Thiobacillus sp. IW., capable of oxidizing hydrogen sulfide, was isolated from waste coal mine water around Hawsun in Chunnam province. The isolate was motile gram-negative rod shape, formed spore and grew up to be aerobically facultative chemolithotroph by using energy released from the oxidation of reduced inorganic sulfur compounds. It was found that the optimum thiosulfate concentration for growth was 32mM. The G+C content of the DNA was 65.0 mol%. The isolate had 16:1+17cyc, 16:0 as their major non-hydroxylated cellular fatty acids, 3-OH 12:0 as a hydroxylated fatty acid and also contained unidentified C_18 branched fatty acid. The ubiquinone system in the respiratory chain was Q-9. The cell productivity was 6.25mg/1.h and the isolate grew logarithmically up to 18 hour. The maximum specific growth rate of cell was 0.78h^-1 and generation time was 0.9 hour. In order to oxidize hydrogen sulfide in a bubble column reactor, Thiobacillus sp. IW. was immobilized on Polyvinylpyridine(PVP). 1.2l of broth medium containing 7.5g of immobilized PVP was used as a liquid phase and gas was supplied through the sintered glass distributor under hydrogen sulfide concentration controlled air stream. A Michaelis-Menten equation was applied for kinetics modeling and the maximum removal rate(V_m) and saturation constant(K_s) of hydrogen sulfide were 52.4(g-S/kg-dry PVP.d) and 62.88ppm, respectively.

이해를 위한 문장 처리에서 통사 요인과 의미 요인

김영진,조명한 서울대학교 어학연구소 1981 語學硏究 Vol.17 No.1

Studies in sentence comprehension reveal that conflicting views currently exist about the part played by syntax. The autonomy model of syntax processing claims that the operation of syntactic processor is not guided or intervened by an assessment of the plausible semantic relations while the automaticity model views that the crucial properties of sentence to which listeners normally attend are semantic rather than syntactic. The present experiments were carried out to examine the listener's on-line accessibility to the surface structure of sentences, and to find out any possible effects of semantic factors on syntactic processing. The method of click monitoring was adopted and the RT was measured throughout the Experiments I, Ⅱ, Ⅳ and V with the exception of Experiment Ⅲ in which subjects were asked about the semantic relations implied in the stimulus sentence. The on-line measures of RT showed no difference of word-order effects either in the materials of both concrete and abstract sentences (Experiment I and Ⅱ) or between the reversible and nonreversible sentences (Experiment Ⅳ). To be surprisingly enough when compared with the English data, moreover, there was no difference in the syntactic computational difficulty between the subject relatives and the object relatives (Experiment Ⅲ).On the other hand, the sentence containing the left branching relatives (the right branching sentences) were consistently superior to the center-embedded relative sentences, the results being due to the left-to-right syntactic processing. In addition, the word meaning coherence made significantly reduce the monitoring RT in overall levels of syntactic complexity without interaction (Experiment V). The shortened RT without interaction of semantic factor with syntactic structure supports the automaticity claims. However, the fact that difference between the right branching and self-embedded sentences occurred only when there is more than one relative (Experiment Ⅲ) enables one to favor the autonomy model in so far as no additional load is imposed upon the upper-limit of the short-term processing capacity. Accordingly, mental strategies for the Korean language comprehension were proposed, in which the syntactic processing undergoes the left-to right coding procedure and the semantic processing represents the bottom-up procedure.

혈소판 농축 혈장이 임플란트 주변 골형성에 미치는 효과에 대한 연구

백명환,한석환,권종진 大韓顎顔面成形再建外科學會 2003 Maxillofacial Plastic Reconstructive Surgery Vol.25 No.1

Various methods have been used to fill in the defects around the implants. Recently, researchs of developing and purifying various growth factors, and efforts to apply these growth factors in clinical situations have been carried out. Among those tries, platelet-rich plasma(PRP) containing abundant PDGF and TGF-β obtained by the sequestration and concentration of platelets by the gradient density centrifugation became one of the popular and preferred methods becuase of relatively simple procedure and abundant growth factor components. Bone morphogenic protein(BMP), platelet-derived growth factor(PDGF), and transforming growth factor-beta(TGF-β) are growth factors in the PRP that promote the bone formation. To elucidate the effects of PRP on the bone formation in peri-implant bone defects, twenty-seven Steri-Oss implants were inserted in the mandibular premolar areas of 8 adult dogs and artificial bone defects(3×4×4㎜) were prepared at the buccal side of the implants in 1st premolar, at the distal side of the implants in 3rd premolar. The control groups were filled with bovine bone grafts without PRP, and the experimental groups were filled with bovine bone grafts with PRP. Animals were sacrificed at 1, 2, 4, 8, and 12 weeks after the operation and speimens were observed by light and electron microscope. The results were as follows. first, the bone formation was observed at 1st week in the experimental groups, but at 2nd week in the control groups. second, the mature bone was observed at 4th week in the experimental groups. but 8th week in the control groups. the bone growth rate of experimental groups was more rapid than that of control groups. third, at 12th week, bone density ratio was higher in the experimental groups(71.65%) than that of the control groups(48.49%). fourth, Grafted bovine bone were almost completely absorbed at 1st week in experimental groups, but it was still present at 8th week in control groups. From the above results, PRP may accelerate the formation of new bone by promoting absorption of the graft material and increasing the growth rate of bone.

비ST분절상승 급성관동맥 증후군 환자에서 N-terminal Pro B-type Natriuretic Peptide(NT-proBNP)를 이용한 관동맥 협착의 중증도 및 초기 위험도 평가

김기석,한혜숙,황경국,연태진,김동운,조명찬 대한순환기학회 2004 Korean Circulation Journal Vol.34 No.2

상전환 공정 이중구조막의 형상에 있어 침지용 비용매가 미치는 영향

이근우,서범경,임난주,한명진 한국공업화학회 2003 응용화학 Vol.7 No.1

Polusulfone scintillation proximity membranes of a double-layered structure wereprerared with Cerium Activated Yttrium Silicate (CAYS) impregnated in a membranestructure. Using the prepared membranes, the radioactivity of an area contamintedby radionuclids can be monitored without any scintillation cocktail The membranewere fromed through two separate casting and coagulation processes. The transparentand dense support layer was obtained by solidifying a polysulfone-methylene chloridebinary solution through vacuum. CAYS-dispersed polymer solutions were cast over the top of solidified, transparent polymer films and coagulated by immersing into acoagulation bath, containing either water or isopropanol. The prepared membranesconsist of double layers. The bottom laver is a dense. pure polymer film. and thetop works as an active layer to detect a radioactive contamination .The membrane structures are significantly different depending on the nonsolvent type.

Evaluation of Agronomic Characteristics and Resistance to Phytophthora Root Rot in Atractylodes japonica Breeding Lines

Jin Tae Jeong(정진태),Jong Won Han(한종원),Jeong Hoon Lee(이정훈),Tae Jin An(안태진),Yi lee(이이),Myeong Won Oh(오명원),Kyung Ho Ma(마경호),Yeong Ho Yun(윤영호),Kyung Sook Han(한경숙) 한국약용작물학회 2023 한국약용작물학회 학술대회논문집 Vol.2023 No.1

방사능탐지용 CAYS 함침 이중구조 폴리설폰막의 형상 및 특성에 제막공정의 습도가 미치는 영향

Han Myeong Jin,Nam Suk Tae,Lee Kune Woo,Seo Bum Kyoung 한국막학회 2005 멤브레인 Vol.15 No.3

방사능 오염도 측정에 사용하기 위한 이중구조 고분자막이 폴리설폰과 세륨활성화된 이트륨실리케이트(CAYS)를 이용하여 제조되었다. 제조된 막은 순수 고밀도 고분자 지지층과 이에 제막된 고분자 용액의 상전환 공정에 의해 고형화된 CAYS 함침 활성층의 이중구조로 구성된다. 제막공정에서 대기방치 공정이 생략되었을 때 CAYS를 포함하는 활성층은 전형적인 비대칭 구조를 지니며, CAYS 입자들이 고분자 구조 사이에 박혀있는 형상을 지닌다. 제막공정에서 대기에 방치하는 시간이 증가할수록 막의 형상은 스폰지 구조를 띠며 CAYS는 고분자 구조로부터 분리되어 막 내부에 셀 같은 공간에 밀집되어 존재함을 보였다. 한편, 두 충 사의 계면형상은 고분자 고형화 과정에서의 상전환 속도와 밀접한 관련되었으며, 대기방치 시간의 증가에 따라 계면의 구분이 뚜렷하게 나타나지 않았다. 방사능 탐지 특성에서 스폰지 구조를 지니는 막의 고분자 구조는 방사성핵종이 통과할 수 없는 밀집된 형상을 지니면서 탐지효율의 감소를 초래하는 것으로 나타났다. Double-layered polymer films to assay the radioactive contamination were formulated using polysulfone (PSF) and cerium activated yttrium silicate (CAYS), consisting of a dense support layer and a CAYS-holding top layer prepared via the diffusion-induced phase inversion. As the vapor exposure process was omitted, the CAYS-holding layer showed a typical asymmetric structure, with CAYS being transfixed into the polymer network spread with large macropores. With the increase in vapor exposure time before immersion, morphology of the films transformed from asymmetric to sponge-like structures, with CAYS being localized in cellular structure. The border structure between the two layers reflects the phase inversion behavior of a cast solution during the coagulation. In the radioactive detection, the polymer phase in a film holding a sponge-like structure is so dense that the radionuclides, deposited on the film, could not filter through the phase, consequently resulting in the loss in the detection efficiency of the film.