• Title/Summary/Keyword: Stepwise reaction

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Kinetic Study of Macrocyclic Ligand-Metal Ion Complexes (거대고리 리간드와 금속이온과의 착물에 관한 반응속도론적 연구)

  • Moon-Hwan Cho;Jin-Ho Kim;Hyu-Bum Park;Si-Joon Kim
    • Journal of the Korean Chemical Society
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    • v.33 no.4
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    • pp.366-370
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    • 1989
  • A new macrocyclic ligand 1,15,18-triaza-3,4;12,13-dibenzo-5,8,11-cycloeicosane (NdienOdien$H_4$ = $N_3O_3$) has been synthesized and identified by element analysis, NMR and IR spectrophotometry. Stepwise protonation constants of ligand are determined by potentiometry in 95% methanol solution(I = 0.1 mol $dm^{-3}$, $Me_4$NCl). log $K_1$;log $K_2$;log $K_3$ = 9.1;8.1;3.6.The kinetics of the acid-promoted dissociation reactions of complex cations of nickel(II) and copper(III) with NdienOdien and NdienOen macrocyclic ligands having, respectively, 17 and 20 ring members, have been studied spectrophotometrically in HCl$O_4$ NaCl$O_4$ aqueous solutions. From the temperature effect on kinetic constant ($k_{obs}$), the parameters of activation(${\Delta}H^{\neq}$, ${\Delta}S^{\neq}$) of dissociation reaction for $ML^{2+}$ with $H^+$ ion have been determined. We have proposed the possible mechanism of the reaction from the data obtained.

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Synthesis and Curing Behavior of Crystalline Biphenyl Epoxy Resin (결정성 바이페닐 에폭시 합성 및 경화 거동 연구)

  • Choi, Bong-Goo;Choi, Ho-Kyoung;Choi, Jae-Hyun;Choi, Joong-So
    • Korean Chemical Engineering Research
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    • v.58 no.1
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    • pp.44-51
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    • 2020
  • The basic catalyst 1-benzyl-3-methyl-imidazolium hexafluoroantimonate (BMH) was synthesized and analyzed by FT-IR and 1H-NMR. A crystalized biphenyl-based epoxy was synthesized by using tetramethyl biphenol (TMBP) and epichlorohdrine. In order to consider the curing tendency of the synthesized BMH, the mass ratio was changed to 0.5, 1.0, 2.0 wt.% under heated conditions and the curing tendency was analyzed by differential scanning calorimeter (DSC). As a result, the BMH catalyst showed a fast curing result in the stepwise heating pr℃ess of the biphenol-A epoxy and the cationic polymer. From these results, the BMH catalyst showed excellent thermal stability as a potential heat curing catalyst. In addition, we considered the application possibility of epoxy molding compound (EMC) which required a skeleton structure and a high heat resistance because the synthesized biphenyl epoxy had a characteristic of rapidly lowering viscosity at a constant temperature and a rigid skeleton structure of biphenol. As a result, it was confirmed that the TMBP-based epoxy developed in this study was composed of a crystalline structure, and a curing reaction was observed with a Novolac resin at a high temperature. In the presence of a catalyst, a curing reaction was observed around 150 ℃ and thus TMBP-based epoxy was successfully applied as a raw material of EMC.

A Neurobehavioral Performance Assessment in Lacunar Infarction Case-control Study (열공성 뇌경색 환자-대조군에서 신경행동검사의 수행 평가)

  • Kim, Ham-Gyum;Park, Sue-Kyung;Lee, Kun-Sei;Kim, Hyeoug-Su;Kim, Wha-Sun;Chang, Soung-Hoon
    • Journal of Preventive Medicine and Public Health
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    • v.36 no.3
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    • pp.255-262
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    • 2003
  • Objectives : We carried out tests for neurobehavior by using WHO-NCTB (neurobehavioral core test battery) and Perdue pegboard score test to identify differences between lacunar infarction cases and controls. Methods : Among the subjects who underwent MRI between February 2001 and March 2002 in a university hospital located in Seoul and who were diagnosed only as lacunar infarction without any intracranial disease, 46 patients were selected as cases (male: 21, female: 25). Controls were selected who had no cerebrovascular disease on MRI by matching age (5 years), gender, and education (2 years) in a ratio of 1:1 , Among WHO-NCTB, the following 5 tests and Perdue pegboard score test were used to categorize the study subjects: digit and symbol matching, simple reaction time, Benton visual retention, digit span, and Pursuit aiming test, Results : Among the above 6 tests of neurobehavior, lacunar infarction cases showed lower score than controls except for the simple reaction time test. As the controlling variables of multivariate analysis in the stepwise regression analysis, the followings were selected due to their significant association: age, education, BMI, gender, drinking, exercise, add systolic blood pressure. From multivariate regression analysis, there was significant difference (p<0.05) between lacunar infarction cases and controls in digit and symbol matching, Benton visual retention, digit span, pursuit aiming, and Perdue pegboard score test, but not in the score of simple reaction time test. Conclusions : We suggest that the above 5 tests for neurobehavior, with the exception of the simple reaction time test, might be used as the basis for recommendation of further treatment and other neurological tests by the earlier defection for neurological abnormality in lacunar infarction.

A Study on the Working Environment Recognition and the Caracter Disposition of Nurse Aides (간호조무사의 근무환경인식과 성격성향에 관한 연구)

  • Lee Sun Yi
    • Journal of Korean Public Health Nursing
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    • v.4 no.1
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    • pp.57-74
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    • 1990
  • As the whole world took on the tendency to be highly industrialized, it became necessary for each field of occupation to require professional man power. Especially, since the World War n, the participation of woman power in economic activities has been continually increasing. In our country also, because of the rapid economic growth, change in the way of thinking of women as well as their participation in economic activities are increasing. Thus, woman power is being utilized in various occupational fields from simple physical labor to those that require high-professional skill. Also, continued economic development policies, by setting the establishment of welfare society as the ideology to be fulfilled, brought expansion of medical facilities in the field of public health and increase in man power in that field. As for the nursing specialists, more than 6000 have been being produced per year and as of the end of 1988, the total number of nursing specialists, reached 123, 115. Therefore, this study is done to recognize the professional knowledge and ability of nursing specialists, who take up $40\%$ of the total public-health related man power in our country, through evaluating their working environment and their disposition of character. This study, which was done from September 18th to September 30th 1989, took on the method of using formed questionnaires that had been amended and supplemented during two preparatory investigations, 322 of such questionnaires were used as an analytical material. In the formation of questionnaires, 12 questions were related to the working environment, and 26 in fortotal were related to the disposition of character, 5 for wise-disposition, 11 for activedisposition and 10 for open-disposition. The measuring method, which used 5-point-standard, allowed 5 points for affirmative recognition of the working environment, also 5 points for showing wise, active and open disposition of character and only point in opposite cases. Collected materials were analyzed, through an electronic calculation, into the average value, the standard deflection percentage, pearson corelative number and stepwise multiple regression. Summarizing the results from this study is as follows: 1. It was shown that the nursing specialists with the average of 3.07 have affirmative recognition of their working environment. The questions which drew most affirmative reaction were those concerning finance-management system such as hand, the questions that received negative reaction were those concerning communication method with the average of 2.49. Such reaction seems to have resulted from the cramming regulation by the superior authorities. Concerning the recognition of working environment in relation to employment conditions, more affirmative recognition is shown with the average of 3.14. at hospitals where injection job is not performed. The nursing specialists working at regular hospitals show more affirmative recognition than those at general hospitals, the averages being respectiely 3.16 and 3.03. 2. As for the disposition of character of the nursing specialists, active-disposition was highest with the average of 3.38, next was wise-disposition with 3.20 and the lowest was open-diposition with 2.98. Variable-wise disposition of character shows that wise-disposition and academic background are beneficially correlated by 0.12. Ative-disposition and open-disposition show correlation to the office term by respectively 0.16 and 0.21. In other words. better academic background leads to higher wise-disposition and more - experience results in higher active and open disposition. Also, the class that performs the injection job, in relation to the working environment, might cause change in the self-conceit that identify those in that class with the nurses; however, as far as professional judgment and action, in dealing with nursing job, being wise, active and open is concerned, not much effect is made. 3. The relation between the recognition of the working environment and the disposition of character is that more afirmative recognition- a nursing specialist has about her working environment, the higher the active-disposition becomes by 0.13. The degrees of the relation between recongnition of environment and wise and open dispositions show respectively 0.06 and -0.06 and -0.06. That is to say that when having more affirmative recognition of the working environment, a nursing specialist shows wise but closed disposition of character. This, howerver, didn't mean much statistically. When observing the results mentioned above, it is conspicuous that the nursing specialists, working as substitutes for the nurse at medical institutions of various sizes, get the feeling of being somewhat equal to the nurses and to some extent, fulfill their desire to accomplish their ego; however, as far as professional ability expansion if concerned. they lack wise and open dispositions. Therefore, considiering upon the results of this study, in medical institutions where the work of nursing specialists is regaded equal to that of the nurses, as a medical member who deals with human lives, it is desirable to make the nursing specialists work under the supervision of the nurses and to offer them continuous education to strengthen and improve their natural dispositions.

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A Study OR Investigation of the Factors having Affect on Junior Highschool Boys관 Practice of Health Care (중학교 남학생들의 건강관리 실천과 이에 영향을 미치는 요인 조사 연구)

  • 기경숙
    • Journal of Korean Academy of Nursing
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    • v.15 no.1
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    • pp.59-75
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    • 1985
  • Accepting the health as the fundamental human right, the nation and society came to admit the duty to give it to all the people. Korean government is expanding the Primary Health Care as one of the policies for developing the people's health by the lead of community. Like this current situation the School Health Service which is the center of community Health Service schould be active to keep, promote and maintain the health of students and teachers. This investigation was attempted to help to establish the basis of the Health Education Program which would perform the health education efficiently and bring the reforming of student's health control, by measuring the degree of junior high school student's practice concerning health care and con-firming the relationship of knowledge, concern and level of health. The subjects for this study were made up 296 boys at the third grade in a school, located in Seoul. The tool for this study was questionaire. Data were collected for five days, September 22∼26, 1983. The investigators explained the students how to answer the questions of the survey questionaire and then collected the survey cards immediately. The data were analyzed by means of percentages, Pearson Correlation Coefficient and Stepwise Multiple Regression. The results of this study are as follows. 1. The subjects' reaction to the practice concerning Health Care; According to the average proportion of practice concerning health care, subjects' practice in the aspect of Infectious Disease Care is the highest 82.4% and they showed their practice in the aspect of the accident prevention by 77.5% and in the aspect of mental health by 74.8%. Their practice in the aspect of personal hygiene and daily lifehabit is the lowest 71.2%. 2. Health Knowledge; The whole mark distribution of health knowledge is ranged from the lowest 4 point to the highest, 30 point, therefore point range is 26.0. The Average point is 16.58. 11.2% of students solved more than two thirds of personal knowledge levels. 81.4% of students did more than one third of them. 7.415 of students did less than one third of them. 3. Health Concern; The Students of the average 3.99 point respond positively to the question about the health concern, ‘They think health is more important than money’, this is the highest rate. The students of the average 2.78 respond“when they are sick, they enter the appointed hospital where they own choose”, while it is the lowest. 4. Subjects' response to the health level are at follow: Very healthy 26.0%, healthy 47.0%, less healthy 10.5%, 34.9% of them have ever been sick within two weeks, the number of symptoms they reported amount to 114 and the number of cases poi one person is 0.35. 5. The hypotheses test about the practice concerning health care and the factor which effect on it. 1) The main first hypothesis:“The more knowledge of health the subjects have, the better they practice health care.”was accepted. (r=0.1582, p <0.05) 2) The minor first hypothesis:“The more interest in health subjects have, the better they practice”was accepted. (r=0.4354, p <0.001) 3) The minor second hypothesis;“The healthier subjects are, the better they practice health care”was accepted. (r=0.1069, p<0.05) As other test, partical correlation test is performed in other refine whether health knowledge, a fact influencing the students practice concerning health care, is associated with the practice after controlling the third variables. First, after controlling health concern, the correlation of health knowledge and practice concerning health care was kept. (r=0.1347, p <0.005) Second, after controlling health level, the correlation of health knowledge and practice concerning health care was kept. (r=0.1526, p <0.005) And finally, after controlling economic state, the correlation of health knowledge and practice concern-ing health care was kept. (r=0.1413, p <0.05) Additionally Stepwise Multiple Regression between practice concerning health care and variables. 1.6591 of compliance was explained with the know-ledge (F=5.584, p <0.05), 20.0% of compliance was explained with the health concern added to knowledge. (F=63,213, p <0.005) As the above, health knowledge obviously have effects on the practice about the health care. But, contrary to researcher's expectation, health concern has more affects than health knowledge. Therefore, we must grope the plan to enhance health concern through the regular curriculum and systematic health education for students. Besides, we must study further on, to find the factors which have affect on the practice concerning health care.

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Reduction and Equilibrium of Vanadium-Diethylenetriamine Pentaacetates at Mercury Electrode in Aqueous Solution (수용액중의 수은전극에서 바나듐-디에틸렌트리아민 펜타아세트산염의 환원 및 평형연구)

  • Ki-Suk Jung;Se Chul Sohn;Young Kyung Ha;Tae Yoon Eom;Sock Sung Yun
    • Journal of the Korean Chemical Society
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    • v.33 no.1
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    • pp.55-64
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    • 1989
  • Reduction and equilibrium of vanadium-DTPA (DTPA = diethylenetriaminepentaacetic acid, $H_5A$) complexes at mercury electrodes are studied in 0.5M $NaClO_4$ aqueous solution at 3.2 < pH < 10.5 and 25$^{\circ}$C. At 3.2 < pH < 5.9, the reduction reaction is $V{\cdot}A^{2-}+H^-+e^-=V{\cdot}HA^{2-}$, while at 5.9 < pH < 10.5 it is $V{\cdot}A^{2-}+H^-+e^-=V{\cdot}A^{3-}$. The stability constants of $V{\cdot}HA^{2-}$ and $V{\cdot}A^{3-}$ are found to be $6.46{\times}10^{9}$ and $3.09{\times}10^{14}$, respectively. V(IV)-DTPA undergoes stepwise complexation as $VO^{2+}+H_2A^{3-}=VO{\cdot}HA^{2+}H^{+}$ and $VO{\cdot}HA^{2-}=VO{\cdot}A^{3+}+H$, where acidity constant of $VO{\cdot}HA^{2-}$- is pKa = 7.15. Stability constants of $VO{\cdot}HA^{2-}$ and $VO{\cdot}A^{3-}$ are found to be $1.41{\times}10^{14}$ and $3.80{\times}10^{17}$, respectively. It is detected that $VO^{2+}-DATA$ is reduced irreversibly to $VO^{2-}$ with the transfer coefficient of $\alpha$ = 0.43. At more cathodic overpotential, the reduction is stepwise as V(IV)${\to}$V(III)${\to}$V(II). The first one corresponds to $VO{\cdot}HA^{2-}+e^{-}{\to}VO{\cdot}HA{3+}$ at 3.2 < pH < 7.2 and $VO{\cdot}A^{3-}+e^{-}{\to}VO{\cdot}A^{4-}$ at 7.2 < pH < 10.5. The second is identical to that of V(III). Diffusion coefficients of $VO{\cdot}HA^{2-}$ and $VO{\cdot}A^{3-}$ are found to be $(9.0{\pm}0.3){\times}10^{-6}cm^2/s$ and $(5.9{\pm}0.4){\times}10^{-6}cm^2/ses$, respectively.

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Comparison of Family Support and Mental Health Between the Rural and Urban Elderly (농촌과 도시지역 노인의 가족지지와 정신건강에 관한 비교)

  • Min, Kyung-Hwa;Kim, Sang-Soon
    • Journal of agricultural medicine and community health
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    • v.20 no.2
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    • pp.175-185
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    • 1995
  • This study is to compare family support and mental health between the rural and the urban elderly. In order to do that I collected the data through questioning 238 people in 3 urban areas in Busan and 201 people in 9 rural areas near Daegu. The degree of their family support is 36.70 on the average in the rural area and 40.77 in the urban area. The degree of family support of urban elderly is a little higher. According to general characters between the differences of family support in both areas, in the rural area there are differences in sex, age, whether they have a spouse or not, education level, financial state, number of children, number of co living, status of co living, subjective health status, amount of pocket money and how much they are participating in leisure activity. In the urban area there are differences in sex, whether they have a spouse or not, religion, financial state, number of co living, status of co living, subjective health status, amount of pocket money, how much they are participating in leisure activity and house pattern. In the stepwise multiple regression analysis the main variables that affect degree of family support in the rural area are age, whether they have a spouse or not and financial state which account for 33% of the total variance and in the urban area are subjective health status, financial state, whether they have a spouse or not and number of co-living which account for 35%. Health status is better in the urban area(average 36.87) than in the rural area(57.42). In each item the people whose mark was more than 75%(low) have Depression 8.4%, Somatization 8.0% in the urban area and Somatization 8.5%, Depression 8.5%, Anxiety 4.0%, Phobic anxiety 4.0%, Obsessive compulsive reaction 2.5%, Hostility 2.0%, Paranoid ideation 2.0%, Psychoticism 1.5% and Interpersonal sensitivity 1.5% in the rural area. In the mental health condition, on the basis of 4 points in both areas, the average is Somatization(rural : 1.69, urban : 1.51), Depression (rural : 1.64, urban : 1.37) and Obsessive compulsive reaction(rural : 1.33, urban : 0.99). According to the differences between mental health conditions by general characters, in the rural area the differences are presented in sex, age, whether they have a spouse or not, religion, education level, financial state, number of children, status of co living, subjective health status, amount of pocket money and how much they are participating in leisure activity, in the urban area the differences are presented in sex, whether they have a spouse or not, religion, financial state, number of co living, status of co living, subjective health status, house pattern, amount of pocket money and how much they are participating in leisure activity. In the stepwise multiple regression analysis the main variables that affect mental health condition in the rural are family support degree subjective health status, religion sex, age and financial state which account for 43% of the total and in the urban area are family support degree, subjective health status and financial state which account for 51%. In the matter of family support degree and mental health condition the rural area was -0.4555, of urban area was -0.6446. The rural area that has a high percentage in family support degree and mental health condition Depression was -0.5036, Psychoticism was -0.4265 in the urban area Psychoticism was -0.6452, Depression was -0.5955. Family support has a great influence on mental health of old people and family support and mental health condition can be different according to living area. So in their problems nursing intervention through family and nursing strategies according to living area should be established.

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Job Stress Level and It's Related Factors in Firefighters (소방공무원의 직무스트레스 수준과 관련 요인)

  • Choi, Mi-Suk;Ji, Dong-Ha;Kim, Jin-Woo
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.13 no.10
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    • pp.4917-4926
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    • 2012
  • This study was designed to assess the factor of influence to occupational stress who work in the field of firefighters and questionnaire was uesd to analyse the stress scores and find the primary factors influence to occupational stress. The number of respondents were 408 who received the refresher training and period of investigation was august 2011 through october 2011. A structured questionnaire was employed to evaluate the participants' socio-demographics, job-related factors, health-related behaviors, occupational stress, reaction factor (fatigue, job satisfaction) and buffer factor (social support). Occupational stress and fatigue were assessed using the Korean Occupational Stress Scale-Short Form (KOSS-SF) and the Multidimensional Fatigue Scale (MFS), respectively. The analysis showed that we found a strong correlation between fatigue, job satisfaction and occupational stress. Occupational stress was associated with an increased risk of fatigue and decreased the job satisfaction. In the multiple regression analysis(stepwise), main factor that influence to occupational stress were job satisfaction, gender, age, processing number for a day, exercise. In logistic regression analyses, a higher occupational stress was associated with higher odds of fatigue(High) and the odds was down by 15.0% after adjustment for job satisfaction, gender, age, processing number for a day, exercise. Thus, a job satisfaction promote program for the reduction of occupational stress and the promotion of firefighters's health is strongly recommended.

Studies on the Chemical Resistance of Phytopathogenic Bacteria II. Selective Effect of Chemical Resistance on the Rice Bacterial Leaf Blight Pathogen, Xanthomonas oryzae (Uyeda et Ishiyama) Dowson, to Agrepto (식물병원성 세균의 약제저항성에 관한 연구 II. 벼흰빛잎마름병균의 Agrepto에 대한 저항성의 선발효과)

  • Cho W. C.;Shim J. W.
    • Korean journal of applied entomology
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    • v.16 no.4 s.33
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    • pp.229-234
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    • 1977
  • The experiments were carried out to investigate the selection effects on the drug resistance to Agrepto in Xanthomonas oryzae, the causal bacteria of rice bacterial leaf blight. The results obtained were as follows. 1, The Agrepto was stable at the heat treatment of $105^{\circ}C$ for 20 minutes, when the drug was added in the media. 2. The local isolates of the bacteria, 75-6 and 75-9, showed the different resistante reaction, when they were selected by the Agrepto contained media which concentrations of 10r9/m1 and 100ug/ml. 3. The individuals shelving high degree of resistance, which can grow on the media contained 10,000ug/m1 of Agrepto, could selected by the concentrations as low as 10ug/ml and 100ug/m1, in one generation. 4. The highly resistant isolates which selected by 3-stepwise selections such as 100ug/ml, 3,000ug/ml and 10,000/ml plots, showed nearly normal growth at the media contained 100ug/ml of Agrepto 5. When the isolate 75-9 was selected at the 100ug/m1 of concentration, showed various degrees of resistance, indicating that the isolate may be composed of resistance groups that lower than 500ug/ml, between 500-1,000ug/ml and 1,000-3,000ug/ml, to the Agrept.

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Simultaneous Purification of Enterotoxin A and C by Fast Protein Liquid Chromatography (FPLC에 의한 Staphylococcal Enterotoxin A와 C의 동시분리)

  • Lee, Jung-Hee;Kim, Jong-Bae;Shin, Heuyn-Kil
    • Korean Journal of Food Science and Technology
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    • v.20 no.6
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    • pp.856-861
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    • 1988
  • A new method developed for simultaneous purification of enterotoxin A and C from Staphylococcus aureus strain L 350/1 consisted of chromatography on carboxymethyl (CM)-cellulose using a buffer of variable pH, gel filtration on Ultro gel, and fast protein liquid chromatography(FPLC) using a buffer of variable pH. The enterotoxin A and C were purified by three steps: batchwise adsorption from culture supernatant on Amberlite CG-50; chromatography on CM-cellulose using a buffer of constant pH and molarity; and gel filtration on Sephadex G-75. The purified enterotoxin appeared homogeneous by gel diffusion and polyacrylamide gel electrophoresis. Upon treatment with CM-cellulose using a elution of variable pH, enterotoxin A and C were so close that they were not separated completely. After elution from gels, the enterotoxins appeared as a single peak at the same position. Gel filtration gave a reaction of complete identity to enterotoxin A and C in Ouchterlony immunodiffusion. In FPLC using a CM-cellulose, enterotoxin A and C were simultaneously separated at pH 8.6 and 6.8. When each fraction was performed to gel immunodiffusion, at peak of enterotoxin A and C were not detected each other. In a method of elution by pH-gradient was to be more efficient as a simultaneous separation method in terms of speed, yields and simplicity. The purified toxin A and C were identical to type A and C reference enterotoxin on both disc electrophoresis and Ouchterlony gel diffusion.

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