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.

Phase Transformation Modeling for Hypo Peritectic Steel in Continuous Cooling

Jun‑hyun Jo,Kyung‑woo Yi 대한금속·재료학회 2021 METALS AND MATERIALS International Vol.27 No.7

Phase change of steel during cooling affects the slab qualities in continuous casting. Especially, crack susceptibility of hypoperitectic steel is high because large volume shrinkage occurs by peritectic phase transformation during solidification andcooling. In continuous cooling, phase change is different from the behaviors under the equilibrium condition, such as undercoolingand extend of peritectic reaction, etc. Therefore, we develop a new phase change model considering thermodynamics,empirical equations, and carbon diffusion in each phase to predict phase change behavior during continuous cooling. Inthis model, phase change of hypo peritectic steel comprises 5 stages until all phases become the γ phase. The velocities ofthe δ/γ interface and phase fractions during cooling are calculated according to cooling rate, undercooling of the γ phase,and carbon contents. The results show that if solidification ends by the δ phase during dTp,the γ phase is formed by massivetransformation. On the contrary, if peritectic reaction starts with liquid, the γ phase is formed and grows by diffusionaltransformation. In latter case, massive transformation of remaining δ phase can occur with high undercooling or very fastcooling rates. This analysis shows that there are several different paths depending on carbon contents of hypo peritectic steels.

Numerical Analysis on Crack Generation Behavior of Hypo Peritectic Steel in Continuous Casting Process

Jun‑hyun Jo,Min‑seok Park,Kyung‑woo Yi 대한금속·재료학회 2021 METALS AND MATERIALS International Vol.27 No.11

Hypo peritectic steels exhibit a high possibility of longitudinal crack during continuous casting. Therefore, many researchershave studied the mechanisms of crack generation in hypo peritectic steel. Stress in solidified shell, or volume contractionwith small liquid fractions were suggested as the mechanisms of crack generation. A new model was developed for predictingpossibility of crack generation by calculating strain rates in solid, volume contraction rate during solidification, and theprobability of liquid unfilling in continuous cooling processes. The results show that massive transformation from the δphase to the γ phase, and peritectic transformation during solidification can be the main crack generation mechanisms. Furthermore,a linear relationship exists between the amount of undercooling for peritectic transformation (dTp) and the carboncontent of the boundary for dividing the two crack generation mechanisms. Additionally, the longitudinal crack ratios ofthe field results are analyzed through strain rates in solid and liquid unfilling possibilities. Relative positions in the range ofhypo peritectic steel and effective carbon contents are suggested to analyze the crack ratio of steels with alloying elements. This analysis shows that the results obtained from the new models for crack generation possibility are usable, and dTpcangenerate the behavioral differences in crack generation according to the conditions.

대학생의 여가 인식에 관한 연구 : 경주대학교 재학생을 대상으로 focused on KYONGJU University student

조현호,유영준 경주대학교 2000 論文集 Vol.13 No.-

Korean is exposed to a rapid growth in economy and considerable amount of time for leisure. There is no doubt that the leisure industry is playing a significant role in making our lives enjoyable and therefore leading a quality lift. In a range of research. it has been shown that the essence of leisure functions properly where the degree of leisure satisfaction is high. Thus, this study attempts to identify the cognition of leisure by undergraduate students in Kyongju University and to suggest alternative solutions for then. The research findings and their implications are summarized as follows. Firstly, a large percentage of the students take a serious view of work and leisure. Secondly, the satisfiers of own leisure activity are rather than dissatisfied students, because they regard their leisure activities as reasonableness and soundness. Lastly, students consider leisure as their mental state of comformt and pleasure. The results implies that systematic and in-depth education on the leisure and enrichment of leisure facilities are required in order to become higher students' satisfaction of own leisure activities.

이온화에너지 처리 아이스크림 및 우유의 단회투여 독성시험

이희준,최현종,한선경,구본철,신명수,함준상,조철훈,이완규 충북대학교 동물의학연구소 2006 Journal of Biomedical and Translational Research Vol.7 No.1

본문참조

그레이브스병에서 방사성 요오드 치료에 따른 갑상선 자극 호르몬 수용체 결합억제 면역글로불린(Thyrotropin Binding Inhibitory Immunoglobulin, TBII)의 변화

조영석,권기현,이준철,나소영,이효진,홍우정,이유선,김군순,송민호,김영건,노흥규 충남대학교 의학연구소 2003 충남의대잡지 Vol.30 No.2

Prediction of thrapeutic response to radioiodine in Graves' disease is poorly understood. Although thyrotropin binding inhibitor immunoglobulin(TBII) level is a strong index for relapse after antithyroid drug medication, conflicting results are reported regarding its prognostic significance in Graves' disease treated with RAI. This study is dengned to evaluate possible relationship between post-treatment hypothyroidism and TBII in Graves' disease treated with RAI. Fourty two patient with Graves' disease after radioiodine treatment were studied retrospectively. The subject were divided into hypothyroid group and euthyroid or hyperthyroid group. We evaluated the association of hypothyroidism and TBII with radioiodine treatment dose. The mean age of hypothyroid group was 48±11 years and euthyroid or hyperthyroid group was 47±12 years. There was no difference in two groups. And there was no significant difference in post- treatment TBII between two groups(49.9±28.5%, 29.9±14.3%, p-value >0.05). The treatment-dose had no influence on post-treatment thyroid state. Euthyroid or hyperthyroid group was done with 13.6±6.9mCi and hypothyroid group was 17.0±10.4mCi(p-value > 0.05). TBII had no prognostic significance on long-term hypothyrodism in Graves' disease treated with radioiodine. And, treatment-dose had no influence on post-treatment thyroid state.

악성종양에서 혈청 Intercellular Adhesion Molecule-1의 혈청

조덕연,김현수,박상준,김종숙,최지영,윤환중,김삼용 충남대학교 의과대학 지역사회의학연구소 1995 충남의대잡지 Vol.22 No.1

Intercellular adhesion molecule-1 (ICAM-1) is a glycoprotein serving as ligands for leukocyte intergrin receptors, i.e. LFA-1, MAC-l. It has been suggested that the expression of ICAM-1 and the levels of circulating ICAM-1 were increased in several malignancies. We measured serum ICAM-1 by ELISA in patients with stomach cancer (n=25), acute lymphoblastic leukemia (n=7), non-Hodgkin's lymphoma (n=14), and metastasis of unknown origin (n=5). Serum levels of circulating ICAM-1 in all malignancies were significantly higer than in normal controls. And serum level of ICAM-1 in stomach cancer ptients having metastatic disease was higher than in patients with localized disease (p=0.027). These results suggest that elevated serum ICAM-1 is a rather common feature for malignancies, not unique for certain types of cancer such as malignant melanoma. It remains to be clalified whether marked increase of serum ICAM-1 in metastatic stomach cancers simply reflect tumor burden or this molecule plays a role in progression in stomach cancer.

대학생의 일상생활 속에서 나타난 여가활동에 관한 탐색적 연구 : 경주대학교 재학생을 사례로 하여 a case study on the Students of Gyeongju University

유영준,조현호 경주대학교 창의력개발연구소 2004 創意力開發硏究 Vol.- No.7

The purpose of this research is to provide guiding alternatives of sound leasure activities by breaking with terms for types and behaves of its in university student's daily life. For these me, students who took class on 「Theory of leisure, has been studied concepts of leasure spontaneously as a observer, and then they has been submitted to diary-style life record table which are done activities of one week. By doing practice on diary analysis method on basis of one's life record, which are analyzed student s life and act for one week by emphasis upon leasure time. And also to increase reliance on research results, by presenting in class examples of 10 persons among main interview group, whether are unified with their opinions. The results has been shown that portion of leasure activities has various value at range of 15.7~38.0 percentage on total activities time. Most examples have presented that students have been spent leasure time efficiently, after they have examined with leasure time and made life record by themselves.

단기배양을 통한 말초혈액 CD34 양성세포의 체외증폭

박상준,김철희,배광봉,김현수,김종숙,윤환중,조덕연,김삼용 충남대학교 의과대학 지역사회의학연구소 1997 충남의대잡지 Vol.24 No.1

Background: It is suggested that clinical practice in the areas of bone marrow transplantation and gene therapy might rely on the ex vivo expansion of hematopoietic stem/progenitor cells. However, the condition for ex vivo expansion of hematopoietic progenitor cells is not well established. The authors pursued a series of experiments to define the proper conditions for the expansion of hematopoietic cells in the short-term liquid suspension culture of mobilized peripheral blood CD34+ cells. Methods: 1.0ml cultures were initiated with 9×10^3 PB CD34+ cells, which were isolated from PB mononuclear cells (MNCs) by high-gradient cell sorting, in 12 well plates with the various combinations of hematopoietic growth factors(HGF). The following recombinant human HGFs were used: stem cell factor(SCF) 100ng/ml, granulocyte colony-stimulating factor(G-CSF) 100ng/ml, GM-CSF(granulocyte, macrophage colony-stimulating factor) 100ng/ml, interleukin-1 beta(IL-1B) 1ng/ml, interleukin-3(IL-3) 20ng/ml, interleukin-6 (IL-6) 100ng/ml. At the end of culture, colony-forming cells were evaluated by semisolid clonogenic assay. Results: 1) Using the high-gradient magnetic sorting system, CD34^+ cells were isolated with a yield of 40 3% 2) In 7 day culture of PB CD34^+ cells(9×10^3 cells), nucleated cells expanded mean 10×10^3(range, 9 to 20×10^3) with the addition of SCF alone, 35×10^3(range, 10 to 60×10^3) with SCF plus G-CSF plus GM-CSF, and 130×10^3(range, 40 to 300×10^3) with the combination of SCF, G-CSF, IL-1, IL-3, IL-6, GM-CSF. In 14 day culture, nucleated cells expanded 10×10^3 to 1,860×10^3 with combination of human hematopoietic growth factors. 3) In 10 day culture without medium change of PB CD34^+ cells, CFU-GM numbers expanded 16. 5 fold(range, 7 to 59 fold) with the addition of SCF plus G-CSF plus Il-1 plus IL-3, 31.3 fold(range, 20.5 to 101.1 fold) with the combination of SCF, G-CSF, IL-1, IL-3, GM-CSF. In 14 day culture with or without medium change of PB CD34^+ cells was inferior to 10 day culture for CFU-GM expansion. 4) There was no significant difference for CFU-GM expansion between five growth factors(SCF,G-CSF,IL-1,IL-3,GM-CSF) and six growth factors(five growth factors plus IL-6). Conclusion: The authors could confirm that short-term suspension culture of peripheral blood CD34+ cells could expand hematopoietic progenitor cells. Ten-day culture with medium change of CD34+ cells with the addition of five growth factors, i.e. SCF, G-CSF, IL-1B, IL-3, and GM-CSF, might be the most efficient in this system.

결핵균항원에 대한 폐결핵환자의 임파구 증식반응에 관한 연구

백태현,김준배,박정규,김화중,조은경,최대경 충남대학교부설 생명공학연구소 1992 생물공학연구지 Vol.2 No.-

T lymphocytes are thought to play a central role in cell mediated immune response. To study the T lymphocyte proliferative response to purified 30-kDa antigen from Mycobacterium tuberculosis H37Rv, peripheral blood lymphocytes(PBL) isolated from healthy controls and tuberculosis patients were stimulated with the 30-kDa antigen, crude antigen and PHA. Healthy controls and tuberculosis patients were divided into PPD(+), PPD(-) groups and AFB(-), AFB(+) groups, respectively. PBL proliferation were determined by the ^3H-thymidine incorporation assay and MTT colorimetric assay. PBL proliferation with 30-kDa and crude protein antigens measured by both methods were almost identical(r=0.74, p<0.001). The lymphocyte proliferation to 30-kDa antigen and crude antigen were singnificantly increased in PPD(+) healthy controls and tuberculosis patients when compared to those in PPD(-) controls, but response to PHA was no significant difference. Analysis to T cell subsets of proliferated lymphocytes performed by the indirect immunoalkaline phosphatase techniques were no difference between not only healthy controls and patients groups, but also stimulated antigen or PHA, and especially, at all groups, the percentage of T8 cell was higher than that of T4 cell.