김치에서 분리한 Lactobacillus sp. JC-7과 Lactobacillus acidophilus 88간의 Electrofusion 최적조건 설정

조영배,최현정,백형석,전홍기 부산대학교 유전공학연구소 1997 분자생물학 연구보 Vol.13 No.-

김치 발효 숙성기간을 연장하고 신선도를 오랫동안 유지 할 수 있는 김치발효 starter의 개발을 목적으로 최적숙성기에 있는 김치로부터 bacteriocin생성능이 없는 유산균을 분리하여 동정하였으며, bacteriocin생성능이 우수한 L.acidophilus 88을 융합시키기 위해 electrofusion에 대한 최적 조건을 검토하였다. 분리균주는 Lactobacillus속으로 동정되어 Lactobacillus sp. JC-7이라 명명하였다. Electrofusion에 의해 생성된 융합주를 식별하기 위해 streptomycin(2.5㎎/ml)에 내성을 나타내는 Lactobacillus sp. JC-7변이주와 kanamycin(600㎍/ml)에 내성을 나타내는 L.acidophilus 88변이주를 분리하였다. Electrofusion을 100V/㎝, 120msec(72ohms,1670 capacitance) 에서 수행했을 때 융합효율이 가장 양호하였으며 전기장의 세기와 시간이 중가할수록 융합 효율이 현저히 감소하였다. 2가 양이온은 농도가 중가할수록 대체적으로 융합효율을 감소시키는 경향을 나타내었으나 1mM MGCl_2에서는 대조군에 비해 융합효율이 약간 증가하였다. PEG매개에 의한 융합법의 융합효율을 비교한 결과, 융합효율은 chemical fusion<electrofusion<electrofusion+20% PEG순을 나타내었다. Evaluation of Optimum Conditions for the Electrofusion between Lactobacillus sp. JC-7 Isolated from Kimchi and Lactobacillus acidophilus 88. Young-Bae Jo, Hyun-Jung Choi, Hyung-Suk Baik and Hong-Ki Jun*. Department of Microbiology, Pusan National University, Pusan 609-735,Korea-A lactic acid bacterium was isolated from kimchi. The isolated strain was identified as the genus Lactobacillus thrugh its morphological characteristics and named as Lactobacillus sp. JC-7. The optimum conditions for the electrofusion between streptomycin(2.5㎎/ml)resistant mutant of Lactobacillus acidophilus 88 and kanamycin(600㎍/ml) resistant mutant Lactobacillus sp. JC-7 were evaluated. The highest number of fusants were obtained at a capacitance value of 120msec(1670㎌), a field strength of 100V/㎝,and a pulse controller setting of 72Ω. The potimum pH of elecroporation buffer was 7.5 and the concentration of divalent cation was 1mM MG^2+. Electrofusants were efficiently obtained by addition 20% polyethylene glycol to electroporation buffer. The yield of fusion was better than that of using polyethylene glycol mediated chemical induction.

하청 근로자들의 건강수준 평가

최홍열,고상백,장세진,차봉석,임형준,이상윤,김재용,강동묵,조수헌 大韓産業醫學會 2001 대한직업환경의학회지 Vol.13 No.1

목 적 : 하청노동을 이용한 노동 유연화 전략은 근로자들의 고용을 불안정시키고, 근로자들의 삶에 부정적 영향을 미치고 있다. 따라서 이 연구는 하청업체 근로자들의 고용현황을 조사하고, 기존의 업체중심의 건강평가의 문제점을 지적하고자 하였다. 또한 하청업체 근로자들의 건강평가의 현재적 의미와 사회적 배제의 특성을 알아보고자 하였다. 방 법 : 모기업과 하청업체 근로자들의 건강수준을 비교하기 위하여, 정기건강진단(일반, 특수)과 채용건강진단 자료를 이용하고자 하였다. 건강진단에서 누락된 비정규직을 포괄하기 위하여 SF-36을 이용하여 건강설문조사를 시행하였다.결 과 : 조선업 하청업체 근로자들의 고용기간은 짧고, 빈번한 노동이동 현상을 보였다. 3년간 건강진단 수검 현황을 통해 살펴볼 때, 1998년 수검자중 2000년까지 연속해서 검진 받은 수검자는 40.3%였다. 건강진단 결과 유소견자 규모를 통해 모기업과 하청업체간의 건강수준을 비교해 보았다. 모기업은 일반질병 요관찰자와 질병자를 포함한 유소견자가 1,011명으로 약 10 %의 유소견율을 보이고 있고, 질병자의 경우 596명으로 유병률이 5 %를 상회하고 있다. 반면 하청업체의 경우 1,967명의 수검자중 유소견자가 115명으로 6 %의 유소견율을 보이고있고, 질병자는 82명으로 4 %의 유병률을 보이고있다 채용건강진단을 받은 수검자는 6,260명 이었으며, 이 중 유소견자 수는 2,373명으로 전체 수검자의 37.9 %를 차지하였다. 건강설문지의 경우는 전체 건강수준의 총합은 하청보다 원청 근로자가 높았고 통계적으로 유의하였다. 결 론' 정기건강검진 결과는 하청근로자들이 고용형태에 따라 검진을 받지 못한 경우가 많아, 건강 근로자 효과로 표현될 가능성이 있다. 따라서 채용건강진단 결과는 다른 측면에서 하청업체 근로자들의 건강수준의 현실적 반영이라고 할 수 있다. 향후 하청업체 근로자들의 건강문제를 감시하고 개선하려면 기존의 업체 중심의 접근으로는 하청 근로자의 건강문제를 제대로 다룰 수 없고, 업종과 지역을 동시에 고려하여 접근할 필요가 있다. 또한 단기 고용 근로자 및 비정규직 근로자를 사회보장의 확충과 모기업의 연대책임 강화 및 기업복지 차원에서 포괄하는 방안이 모색되어야 하겠다. Objectives : The strategy for the labor flexibility through subcontracted labor have brought a negative effect on the lives of the workers, such as the increase of the unstable employment. This study was conducted to analyze the relationship between the employment of subcontracted firms and the health status of them, and to find out some problems which have been caused in the process of health evaluation and the characteristics of social exclusion. Methods : We reviewed the periodical health examination and preemployment health examination in order to compare health status of the subcontracted workers with those of the parent firm workers. The SF-36 questionnaire was administered to assess the self-perceived health status. Results : The result shows that compared to the working duration of the parent firm workers, those of the subcontracted workers were shorter, and the job transfer rate was higher. In the periodical health examination, the prevalence of occupational and general disease was higher in the parent firm(10%) than in the subcontracted firms(6%). Preemployment health examination plays an important role in worker's health manage- ment. Among 6,260 workers who received preemployment health examination, the prevalence of disease was 37.9%. Mean scores of health status measured by SF-36 were lower in the subcontracted firm than in the parent firm. Conclusions : Due to social exclusion of the subcontracted workers from the periodical health examination, there is a possibility that the periodical health examination have the healthy worker effect. These results suggests that the preemployment health examination could be a more appropriate indicator which is able to assess the health status of the subcontracted workers than the periodical health examination.

자외선 경화형 불포화 폴리에스테르 수지의 합성과정이 저장안정성에 미치는 영향

洪錫杓,崔相久 全北大學校 1992 論文集 Vol.34 No.-

Storage stability of UV curable unsaturated polyester was studied in accordance with synthesis process and inhilitor charging. When resin was synthesized at 160∼170℃, storage stability was mainly influencd by reaction time. THQ showed best storage stability among inhibitors. Appropriate charge of THQ was 150ppm in initial of first reaction, 350ppm in initial of second reaction and 350ppm in SM thinning.

이온빔 스퍼터링과 열처리에 의해 SiOx/SiO_(2) 다층구조에 형성한 Si 나노결정의 광루미네센스 특성 연구

홍승휘,최석호 경희대학교 자연과학종합연구원 2003 자연과학논문집 Vol.9 No.1

The effects of stoichiometry(x) and substrate temperature(T_(s)) on SiOx/S_(1)O_(2) multilayers(MLs) have been systematically investigated during their growth by reactive ion beam sputter deposition, The photoluminescence(PL) spectra of the post-annealed samples are strongly correlated with the formation of S_(1) nanocrystals in the MLs, which is confirmed by high resolution transmission electron microscopy. These results suggest that T_(s) and x play an important role for the visible PL attributed to the quantum confinement effect of S_(1) nanocrystals.

보강섬유의 배향이 고분자 복합재료의 물성에 미치는 효과

崔相久,李和雨,洪錫杓 全北大學校 1993 論文集 Vol.35 No.-

The tensile and flexural strength of unsaturated polyester laminated with 20% glass-fiber(volume %) were tested. Those were compared with its abtained from Holister's equation. The strengths of laminated polyester were mainly depended on the properties of interface between fiber and resin than the strengths of material itself. For crossplied laminates, correct strength coincided with Holister's were not abtained, but could be explained by Holister's theory. The fractural strength of orientation angle 0∼5˚ was influenced by shear resistance besides the strength of glass fiber.

벽시계틀 소재로 사용되는 목재와 플라스틱의 접착력 향상에 관한 연구

洪錫杓,崔相久,金鍾石 全北大學校 1991 論文集 Vol.33 No.-

Wood and plastic were used as elemental materials of the frame of clock. In this research, it was studied to improve adhesive strength between this materials by new adhesion process. Vinyl or acryl emulsion(H-403, H-422, Y-840, Y-850) was used as the adhesive. The adhesive properties was tested experimantally on various partial process including sanding, cleaning of sanded surface and pressing of bonded areas. The results obtained in this experiments were follows : 1) Y-850 represented most excellent adhesive properties. 2) The maximum of adhesive strength could be obtained by sanding with sand paper #600, pressing of 0.3∼0.5kg/㎠, and cleaning with acetone. In that case, increase of 20% in adhesive strength was showed than obtained by traditional process.

카본블랙의 종류 및 배합제의 혼합방법에 따른 NR/HNBR 블렌드의 특성

洪錫勻,庾吉祥,金鍾石,崔相久 全北大學校 1992 論文集 Vol.34 No.-

It was studied how physical properties, heat resistance, oil resistance, ozone resistance of NR(natural rubber)/HNBR(hydrogenated acrylonitrile butadiene rubber) blends influenced by different mixing methods and various carbon black types. Of the various mixing methods, masterbatch mixing method was better than others in considering the overall stabilities of the compounds. The most important parameter which influenced on heat, oil and ozone resistance was rubber material than sorts of carbon black. The resistance for heat, oil and ozone of NR compounds were improved by blending HNBR and these effects were revealed clearly at elevated temperatures.

에폭시 수지를 혼합한 아스팔트 방식재의 특성

홍석표,최상구,강석근,이화우 全北大學校 1995 論文集 Vol.39 No.-

Epoxy resins were mixed with asphalt solution in the range of 0 - 60phr for the total components. The blending properties, curing properties, and surface properties for mixtures were investigated experimentally. Compatability of epoxy resins with asphalt were relatively good over mixture temperature 50℃. Interpenetrated polymer networks(IPNs) were partially formed between epoxy resins and asphalt. Increase of hardness was depended on the crosslinking density of epoxy resins and oxidation of asphalt. Defects of coated surface including crater, pinhole, and crack could be improved by adding epoxy resins 20 phr.

부재료 첨가에 따른 갓김치의 항산화성

최영숙,황정희,김재이,전영수,최홍식 부산대학교 김치연구소 2000 김치의 과학과 기술 Vol.6 No.-

Antioxidative activities (AA) of mustard leaf kimchi (MLK) by the addition of optional ingredients among selected minor materials were studied. In order to determine AA of MLK with different spices, the model systems of ground cooked beef with green onion, garlic, and red pepper powder were prepared and stored for 4 weeks at 4℃. AA of red pepper added group was stronger than those of others. AA of red MLK was relatively higher than that of (green) MLK. For the enhancement of AA of MLK, another model systems were prepared with the selected antioxidative optional ingredients, which were bonnet bellflower root, leek, burdock, sea tangle, sea mustard, seastaghorn at the level of 2% or 4%. The extracts of water, 75% methanol and hexane of MLK, bonnet bellflower root added MLK, and seastaghorn added MLK had a considerable AA with the inhibition of peroxide formation during the autioxidation of linoleic acid mixtures in aqueous model systems at 37℃. Therefore, AA was more effective in MLK containing specific optional ingredients than that of MLK alone significantly.

CTBN고무 분산 에폭시 복합재의 기계적물성 및 파단면에 관한 연구

洪錫杓,崔相久 全北大學校 1989 論文集 Vol.31 No.-

We examined the mechanical properties (flexural and impact) and fracture surface of CTBN(carboxyl terminated butadiene acrylonitrile) rubber dispersed epoxy composites which are cured with MTHPA(methyl tetrahydro phthalic anhydride) or DICY(dicyandiamide). Rubber dispersed epoxy composites are prepared to blend epoxy mixture with CTBN rubber or CTBN rubber modified epoxy. It contains 0-25% CTBN rubber of liquid compoment. The results obtained in this experiment are as follows ; 1. The flexural stength is better in using the CTBN rubber than CTBN rubber modified epoxy. 2. In excess of 25% CTBN rubber, the cured epoxy composites are closed to rubber rather than epoxy in properties. It is very flexible. 3. In respect of the flexural stength and flexural modulus, CTBN x13 rubber is superior to CTBN x8 rubber. In excess of 5% CTBN rubber, The mechanical properties of both decrease sharply. 4. In respect of the impact stength, flexural stength and rubber dispersion, MTHPA is superior to DICY.