Production and Characterization of Enzymes Involved in Chitin Catabolic Cascade from a Bacterial Strain Isolated from Soil

( Ji Hyun Lee ),( Jeong In Lee ),( So Yeon Park ),( Yoo Kyeong Jang ),( You Bin Lim ),( Hye Yoon Lee ),( Young Min Jung ),( Hae Chang Lee ),( Jong Hwa Lee ),( Shaheen Amna ),( Jae Kweon Park ) 한국키틴키토산학회 2019 한국키틴키토산학회지 Vol.24 No.1

The present study was aimed to isolate the bacteria producing chitinolytic enzymes including chitin deacetylase (CDA) from soil origin. About 24 bacteria were screened for their chitinolytic enzymes producing ability on the basis of colloidal chitin. Amongst one of the most potent isolates designated to JI-02 was further selected as the most prominent chitinolytic and CDAlike enzyme (CDA-X) producer based on the ability of deacetylation of an artificial substrate pNP-acetamilide. The maximum production of CDA-X in crude enzyme from JI-02 was observed in the presence of 1% colloidal chitin at 37°C and pH 6.4 after 120 h of incubation. Potent enzyme activity of CDA-X was determined toward pNP-acetamilide, demonstrating that optimal pH, temperature and ionic strength of the CDA-X were assessed to be 7.0, 52°C and 125 mM, respectively. Unexpectedly, Nacetylglucosamine (GlcNAc) was not fully converted by the action of CDA-X to glucosamine (GlcN) under the established conditions. Further study on enzyme activity toward chitin-oligosaccharides consisting of multi-N-acetylglucosamine (GlcNAc)n, n=2-5 may be necessary to elucidate the mode of action which requires the minimum size of (GlcNAc)n. However, our data suggest that CDA-X can convert chitin to chitosan with the maximum yield of approximately 0.08g/L during the fermentation of the strain in the presence of chitin. Furthermore, we found that crude enzyme showed the significant chitosanolytic activity. Taken together, our data suggest that the strain JI-02 may be a potential candidate as a particular strain for better understating of chitin catabolic pathway.

토양환경지도 자료를 이용한 콩밭 토양의 화학성 비교

박지숙,이민진,정재원,김미혜,이서연,지윤미,한준호,김유학,공명석,한광현,노희명 忠北大學校 農業科學硏究所 2015 農業科學硏究 Vol.31 No.2

It is important to interpret the soil chemical properties in order to effectively manage the farmland. This study was conducted to investigate the soil chemical properties of upland soybean field according to the soil series at 32 upland fields located in the parts of Gangwon-do. Soil sampling sites were selected by using the National Statistics DB and KSIS DB that is a soil environment information system provided by the Rural Development Administration. Soil samples were collected from 0~15 cm of top soil before seeding or transplanting, air-dried, passed through a 2 mm sieve, and analyzed for soil pH, EC, organic matter, available phosphorus (P2O5), exchangeable potassium, exchangeable calcium and exchangeable magnesium. The average chemical properties have exceeded the each nutrient optimum range level of RDA, except the organic matter in experimental soil 2015. And despite application of conventional fertilization, each soil series nutrient contents were change respectively. The results of this study suggest that conventional fertilization should be applied based on the analysis about the amount of accumulated nutrient contents in the soil.

이문화 상호작용으로서 게스트-호스트 관계에 관한 연구

유지윤 한국문화관광학회 2001 문화관광연구 Vol.3 No.2

The favorable type of tourism has moved into alternative tourism from mass tourism. Tourists nowadays seek for closer interactions with people in host society more and more and prefer to have individualized and meaningful experience. The purpose of this study is to gain richer insight into host-guest interactions in international tourism in terms of intercultural and social contact. It is also to manifest development process of host-guest relations and the factors which affect the relational development. The research process includes review of the theories in intercultural interactions and social contact, and ethnographic interviews of 6 informants based on naturalistic inquiry paradigm. As a result of the study development process of the host-guest interactions is produced and 5 main factors which affect the relations are identified.

소형 브러시레스 모우터의 광범위 속도제어에 관한 연구

유지윤 國立 昌原大學校 産業技術硏究所 1989 産技硏論文集 Vol.3 No.-

The main subject of this paper is to examine the relationship among the torque, the speed and the temperature rising subjected to the light weight and small size condition. For this purpose, we examine mainly the temperature characteristics of the motor by both experiments and simulations. The investigations are carried out in the case of both the sinewave excitation and the squrewave excitation, for the control voltage scheme and control current respectibly. The examinations of the temperature characteristics in the control voltage scheme shows that the sinewave excitation is profitable in the low speed rigion, while the squrewave excitation in the high speed revolution. On the other hand, in the control current scheme, the sinewave excitation is most profitable, causing lower temperature rising owing to no harmonic components. This facts coincidents with the theoritical result deduced form the variational method. Finally, this paper describes the transient characteristics of the motor, which is obtained by means of simulation, for various excitation condition.

석면함유 슬레이트 지붕 물받이 퇴적물 중 석면 섬유 함유율

임지현,한솔민,김현석,신유민,박시은,허정윤,김민영,장봉기 순천향대학교 기초과학연구소 2022 순천향자연과학연구 논문집 Vol.28 No.1,2

This study attempted to determine the degree of asbestos release from the aging slate roof by comparing the asbestos content in the slate roof rain gutter with a colored steel plate (tin plate) over the slate roof. Four slate roof houses located in Haengmok-ri, Asan-si, Chungcheongnam-do, and one house constructed with a colored steel plate on the slate roof were selected to collect the sediment of the roof rain gutter. The asbestos fiber content was calculated by a point counting method using a polarization microscope after pretreatment with conversion treatment and hydrochloric acid treatment. The average asbestos content of the four slate roof rain gutter were 1.89%. However, asbestos was not detected in the Slate covering roof rain gutter, which were constructed on the slate roof. Asbestos fiber content was the highest at 2.89% in the slate roof rain gutter installed in 1976, followed by 2.44% in 1953. From the above results, it is necessary to minimize secondary damage as asbestos fibers released from slate roof houses to the surrounding atmosphere or leaked from slate roofs as rainwater may cause soil pollution and seriously affect residents' health. Although covering with colored steel plates (tin plates) has been shown to prevent the leakage of asbestos fibers to some extent, it is believed that a policy alternative to remove the slate roof as soon as possible is needed to solve the fundamental problem.

수완진동 증후군에서 신경장해의 조기진단을 위한 객관화된 방법

윤재국,이헌,최나리,김석환,박형욱,이지호,유철인 大韓産業醫學會 2009 대한직업환경의학회지 Vol.21 No.2

목적: 통각과 진동감각 역치검사 및 수부와 수지의 악력, 그리고 수지의 운동기능검사(태평) 등과 근로자들이 호소했던 증상에 대한 HAVS의 스톡홀름 워크샵 분류와의 관련성을 통해 좀 더 객관화된 신경학적 조기검사 방법을 찾고 타당성을 검증하고자 하였다. 방법: 2000년 1월부터 2007년 12월까지 수부진동에 폭로되고 수부의 불편함을 호소하여 진동 장해에 대한 검사를 시행한 497명의 근로자를 대상으로 하였다. 일차적으로 문진을 통해 직업력에 대해 알아보고 과거력을 조사했다. 대상자들의 스톡홀름 워크샵 분류에 따른 소견을 확인하고 수부의 말초 순환기능 검사(손톱압박, 수지피부 온도), 신경기능 검사(통각과 진동각 역치), 운동기능 검사(악력, 태평) 등을 시행하였다. 다른 질환의 감별을 위한 몇 가지 이학적 검사를 실시하고 스톡홀름 워크샵 분류에 따른 검사 결과들을 분석하였다. 결과: 사용 도구는 그라인더 단독 사용이 265명 (67.3%)으로 가장 많았으며 평균 노출 연수는 14.8년이었다. 통각과 진동감각에서 스톡홀름 워크샵 분류 단계에 따른 역치가 증가하는 경향을 보였으나 통각은 양측 모두 통계적인 유의성이 없었고, 진동감각은 125와 250 Hz에서 양측 모두 유의했다(p=0.006-0.038). 수부와 수지의 악력은 단계가 올라갈수록 감소하는 경향을 보였지만 수부와 수지 모두 우측에서만 통계적으로 유의했다 (p=0.041, p<0.01, p=0.034). 태평 첫수는 단계가 올라 가면서 전반적으로 태핑 첫수가 감소하였으며 좌측에서만 통계적으로 유의했다(p=0.002-0.019). 결론: 본 연구는 수부 진동 노출자들의 수부 불편함에 대한 신경계통을 초기에 정량적으로 객관화하여 진단할 수 있는 단일 방법은 아직 없으며 일상생활의 불편함과 스톡홀름 워크샵 분류 등을 통한 주관적인 증상에 더하여 수지 통각과 진동감각 역치검사, 수부와 수지 악력검사, 운동기능검사(태핑) 등을 통합하면 초기에 객관적으로 진단하는 것이 가능할 것으로 판단된다. Objectives: In order to determine find out the best methods for a more objective detection of neurologic abnormality in early hand ann vibration syndrome(HAVS), early with analyzing the validity of each of the detection methods was analyzed. We evaluated the relationships between the sensorineural stage of Stockholm-revised vibration syndrome classification and the results of several tests. Methods: 497 workers were investigated for symptom, exposure duration, the types of tools used, and medical history from January 2000 to December 2007. Pain sense threshold, vibrotactile threshold, hand grasp force, finger grasp force, and a finger tapping frequency test were performed by the workers. Results: The grinder(67.3%) was the most commonly used tool and the mean exposure duration was 14.8 years. Although the pain sense and vibrotactile threshold level tended to increase according to sensorineural stage of the Stockholm classification, there was statistically significant difference in the vibrotactile threshold of 125, 250 Hz (P=0.006~0.038) but not in the pain sense threshold. Hand and finger grasp force tended to decrease according to the sensorineural stage of Stockholm classification and there was statistically significant difference(P=0.041, <0.001, 0.034) only on the right hand side. The tapping frequency also generally decreased according to the sensorineural stage of the Stockholm classification and there was statistically significant difference (P=0.002~0.019) only on the left hand side. Conclusions: Although there is no single standardized method that can objectively diagnose the Sensorineural component of early HAVS early, the combination of subjective symptoms, the sensorineural stage of Stockholm classification, the pain and vibrotactile threshold test, the hand and finger grasp force, and the finger agility (tapping) test can objectively detect sensorineural component of HAVS early.

환기용 팬의 유동특성에 관한 연구

유근종,윤지훈 國立 昌原大學校 産業技術硏究所 1999 産技硏論文集 Vol.13 No.-

Analysis of ventilation fan flow has been carried out using CFX CFD code. The ventilation fan is applied widely to enhance air flow in open space. Selection of the ventilation fan is an important factor to design air ventilation facility to control air quality. Therefore, the accurate flow analysis is required in process of proper ventilation fan selection. Detailed analysis of fan flow in open space has been performed for 4 different commercially available ventilation fan. Computed air velocities show typical jet flow characteristics. The fan flow expands up to 10m in both of lengthwise and spanwise direction. The analysis also shows that turbulent flow enhances mixing of air in the space. From the analysis, flow analysis using CFD method is found to be an effective tool to select a proper ventilation fan. However, further detailed analysis which includes mass transfer for prediction pollutant behavior is required to complete air quality analysis.

와동형태의 설계에 따라 치아에 발생되는 응력의 변화에 관한 연구 : 인레이의 경우

오세윤,김웅철,김지환,유진호 高麗大學校 倂設 保健大學 保健科學硏究所 1995 保建科學硏究論集 Vol.4 No.1

Because of the anatomical form of posterior teeth, the amount of tooth reduction near the marginal ridge area in the typical, widely used intracoronal cavity will be inevitably maximal, while occlusal forces on the restoration in this area will be relatively minimal In an attempt to dicrease the amount of tooth reduction at the marginal ridge area, a modified cavity for inlay with a uniform depth of 15mm, just as in amalgam filling was designed in this study. To analize the stress development in the teeth in that cavity design, 2㎏/㎟ distributive forces were applied on the inlay restoratives and obtained results were compared with that in the typical cavity design which had a flat pulpal wall with a depth of 1.5m at the central fossa area. Analysis was done with two dimensional finite technique. The obtained results were as follows : 1. The patterns of stress distribution and displacement showed no apparent differences. 2. The stress values and the amount of displacement developed, both in inlay cast gold and in the teeth, in the cavity with a uniform depth were less than that in the cavity with a flat pulpal wall. 3. Greatest maximum principle values were concentrated around the interface between the base of inlay body and the teeth.

Systemic Lupus Erythematosus를 동반한 Multiple sclerosis

이지현,이기주,윤성호,부귀범,손현화,박유환,정춘해,김진호,정원영 조선대학교 부설 의학연구소 1998 The Medical Journal of Chosun University Vol.23 No.2

Multiple sclerosis and lupus erythematosus are chronic, potentially disabling diseases of unknown cause. It is a rare occasion that the finding of both diseases occurs in one patient. Because both diseases may affect the central nervous system, it may be difficult at times to differentiate symptoms of lupus erythematosus from those of multiple sclerosis. As far as we know, there was no case report of SLE in multilple sclerosis in Korea. We report a case of multiple sclerosis accompanied by SLE.

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.