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Control of a- and c-plane Preferential Orientations of p-type CuCrO2 Thin Films

  • Kim, Se-Yun;Seong, Sang-Yun;Jo, Gwang-Min;Hong, Hyo-Gi;Kim, Jeong-Ju;Lee, Jun-Hyeong;Heo, Yeong-U
    • Proceedings of the Korean Vacuum Society Conference
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    • 2011.02a
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    • pp.119-120
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    • 2011
  • Kawazoe는 1997년 p-type TOS를 만들기 위해서는 3가지가 충족되어야 한다고 언급한바 있다. 첫 번째, 가시광영역에서 투명하기 위해서 cation의 d10s0이 가득 차야 한다. 가득 차지 않은 d10 shell은 광 흡수가 가능하여 투과도를 떨어뜨린다. N-type을 예로 들어 ZnO, TiO, In2O3가 각각 Zn2+, Ti4+, In3+가 되어 d shell을 가득 차게 만드는 것을 볼 수 있다. 두 번째, cation d10s0 shell은 산소의 2p shell과 overlap 되어야 한다. 이 valence band는 홀 전도를 더욱 좋게 한다. 예를 들어 Cu1+(3d), Ag1+(4d)가 해당한다. 세 번째로, 양이온과 산소간의 공유결합을 강하게 하기 위해서 결정학적 구조는 매우 중요하다. Delafossite 구조는 산소가 pseudo-tetrahedral 구조로서 공유결합에 유리하다. 이러한 환경은 O2- (2p6)을 형성하고 홀의 이동도를 증가시킨다. 예를 들어 Cu2O의 경우 앞의 2가지를 만족시키지만 광학적 특성에서 좋지 않다. 그 이유가 3번째 언급한 결정학적인 요인에 있다. 결정 계의 환경은 Cu2O를 따라가면서 3차원적인 연결을 2차원적으로 변형된 delafossite 구조에서는 quantum well이 형성되어 band gap이 커진다. 본 연구에서는 전기적 이방성을 가지고 있는 delafossite CuCrO2 상에서 우선배향을 일으키는 인자 중 기판을 변화시켜 실험을 진행하였다. 결과적으로 기판변화를 통해 우선배향조절이 가능하였으며 CuCrO2 박막을 시켰으며, 결정방향에 따른 전기적 물성의 이방성에 관한 연구는 계속 진행 중에 있다. c-plane sapphire 기판위에는 [00l]로 성장하는 반면, c-plane STO 기판 위에는 [015] 방향으로 성장하는 것을 확인하였다. 이러한 원인은 기판과 증착되는 박막간의 mismatch를 최소화 하여 strain을 줄이고, 계면에서의 Broken boning 수를 줄여 계면에너지를 낮추는 방법이기 때문일 것으로 예상된다. C-plane sapphire 기판위에 증착될 경우 증착온도가 증가함에 따라 c-축으로의 성장이 온전해지며 이에 따라 캐리어농도의 감소와 모빌리티의 증가가 급격하게 변하는 것을 확인할 수 있다. 반면 c-plane STO 기판에서는 증착온도에 따른 박막의 배향변화가 없으며 전기적 물성 변화 또한 비교적 작은 것을 간접적으로 확인하였다.

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A SCANNING ELECTRON MICROSCOPIC STUDY ON THE MARGINAL ADAPTIBILITY IN APPLYING THE CAVITY VARNISH AND DENTIN BONDING AGENT IN AMALGAM RESTORATIONS (아말감 수복시(修復時) Cavity varnish와 Bonding agent 도포(塗布)에 따른 접합성(接合性)에 관(關)한 주사전자현미경적(走査電子顯微鏡的) 연구(硏究))

  • Kim, Seok-Hoon;Cho, Young-Gon
    • Restorative Dentistry and Endodontics
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    • v.15 no.1
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    • pp.107-119
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    • 1990
  • The purpose of this study was to evaluate the marginal adaptability of the amalgam restorations in applying the cavity varnish (Copalite$^{(R)}$) and dentin bonding agent (Scotchbond 2$^{(R)}$) under the scanning electron microscope. For this study, eighteen sound extracted human molars were selected. Class I cavities in 12 teeth and class V cavities in 6 teeth were prepared using an air turbine with No. 701 tungsten carbide bur and finished using a low speed handpiece with No. 557 fissure bur. The prepared specimens were then divided into three groups including 4 class I cavities and 2 class V cavities in each group and restored as follows ; Group I. All the prepared cavities were restored with amalgam only (Control). Group II. Two layers of Copalite$^{(R)}$ cavity varnish were applied to the cavities with a gentle stream of air after each application and cavities were restored with amalgam. Group III. The enamel cavity margins were etched with 37% phosphoric acid gel for 60 sec., rinsed for 30 sec. and dried. One layer of visible lightcured Scotchbond Dental Adhesive$^{(R)}$ was applied and immediately cured for 20 seconds with visible light-cure unit and cavities were restored with amalgam. All the specimens were cut at the neck of the teeth and the occlusal halves of specimens were sectioned buccolingually in the longitudinal axis centering the amalgam restorations, using the disk. The cut specimens were ground with sandpapers (400, 600, 800, 1000 grit), and cleaned for 5 minutes in the ultrasonic cleaner (Brason Co. U.S.A.). In the cut surfaces, the amalgam - tooth interfaces were examined under the scanning electron microscope (JSM, 35C type, JEOL). The obtained results were as follows ; 1. The amalgam-tooth interfaces were reduced more significantly in the Copalite$^{(R)}$ and Scotchbond 2$^{(R)}$ application group than in the control group. 2. In the class I cavities, the Scotchbond 2$^{(R)}$ application group showed the findings similar to the Copalite$^{(R)}$ application group in the cavity floor, and the marginal adaptability was better in the side wall than in the cavity floor. 3. In the class I cavities, the Scotchbond 2$^{(R)}$ application group showed better marginal adaptability in the occlusal margin than in the gingival margin. 4. The marginal adaptability was in the order of the Scothbond 2$^{(R)}$ application group, the Copalite$^{(R)}$ application group and the control group.

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A Survey of the Effect of Nursing Students on Community Health Knowledge (간호학생 실습이 지역주민의 보건지식 및 태도에 미치는 영향 -연세대학교 간호대학 보건간호학 실습을 중심으로-)

  • 조원정;김의숙;이정숙
    • Journal of Korean Academy of Nursing
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    • v.3 no.2
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    • pp.111-119
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    • 1973
  • The purpose of this study was to determine whether or not the delivery of health services effects the health knowledge of the recipients of that service. 10 was hypothesized that the practical application of theory, though health services rendered by public health nursing students during their field experiences. would have a positive relationship with the quantity and quality of health knowledge of the female population of a given community. In April 1970, ninety five women(between an age 15-49) from Koyang-Gun were interviewed regarding their knowledge and attitudes in four areas of health: maternal health, child health. family planning and tuberculosis prevention. After 11 years(Nov. l971), during which time the women received home visits by student nurses, the women were again interviewed using the original questionnaire. Additionally, they were asked where they had received information about each question. During the 1$\frac{1}{2}$ year period the visits were made by a total of 112 students. They visited the community twice a week. The result were as follows: Maternal health There was marked improvement in the knowledge of specific aspects of maternal health such as the proper instruments needed for cutting the cord and nutritional precaution of pregnancy (p<0.05). In each case 42.0 percent of more of this knowledge was attributed to information gained from the nursing students. However even after the nursing students'visits, the knowledge of other general areas of maternal remained poor. Child health There were increases in the knowledge of the respondents for the time to supplement breast feeding and for time to wean infants (p<0.05). In each case 35.0 percent or more of this information was attributed to the student. The increase in knowledge regarding types of immunization was more often attributed to the clinic nurse than to the nursing students. Knowledge of the necessity of booster immunization was poor both before and after the visits by the nursing students. Family planing There were significant increases in correct information regarding the time of I.U.D. insertion (P<0.05) and method of taking the oral pill (P<0.05). More than 42.0 percent of the increase was attributed to the nursing students'visits. However there was a slight decrease in correct information about concept of family planning. Tuberculosis There was a general lack of improvement in all areas concerned with tuberculosis. Two thirds of the respondents felt tuberculosis was hereditary and did not know what B.C.G. was. From this study, it could be concluded that in specific area the health knowledge of the female population studied was positively effected by the visits of the nursing students. The study also, suggests, however, that there was a marked unevenness in the overall increase in health knowledge. This raises serious questions which require further research. Suggested areas for further research are (1) Adequacy of the course content preparing nurses for the field experience. (2) A public health nursing manual for student reference. (3) Where and when specific aspects of health can be taught most effectively.

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A study on the intraoral factor related to oral malodor (구취발생에 관여하는 구강내부요인에 관한 연구)

  • Jung, Mi-Ae;Lee, Eun-Sook
    • Journal of Korean society of Dental Hygiene
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    • v.8 no.1
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    • pp.119-131
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    • 2008
  • This study was peformed in order to find out the relationship between the causing factors and the production of each gas 01 oral malodor, to contribute the oral malodor control at dental clinic as well as to establish the effective application of malodor control project for public oral health program 127 patients from 20 to 40 years old who had been visited for preventive dental cares were participated for the study. Such items as caries status, periodontal status, salivary flow, viscosity, pH. Snyder test, plaque deposit and tongue plaque were checked through the oral examination in order to find out the contributing factors Hydrogen sulfide, Methyl mercaptan, Di-methyl sulfide and Ammonia gas components were checked with Oral-Chroma and Attain, the oral malodor check units. Not only the corelation coefficiencies but also the multi-way variance analysis were calculated between each causing factor and each component of oral malodor gases to estimate the contributing factors of the oral malodor. 1. There was no relationship between the caries status and each component pf the oral malodor such as sulfur compound or Ammonia, both in laboratory test and VAS test (pF0.05). It revealed negative relationship between Hydrogen sulfide and FT(rM-0.1904. pE0.05) as well as the VAS and FT (rM-0.210. pE0.05). S0, it was estimated that the less oral malador was recognized when caries state changed to filled state in Hydrogen sulfide laboratory test or VAS test 2. High relationship was showed between salivary flow and Hydrogen sulfide (rM-0.183, pM0.039), Methyl mercaptan(rM-0.234, p-0.008). Dimethyl sulfide(rM-0.234, pM0.008) and Ammonia(-0.361. pM0.001) gas(pE0.05). 3. There was a high relationship between M-PHP(Modified-Patient Hygiene Performance Index) and tong plaque all kinds of sulfide(rM0.249. pM0.005). Ammonia gas component(rM0.232, pM0.009). 4. It was found that considerable relationship was appeared between the periodontal status and Ammonia gas (rM0.274, pM0.002), so, it should be needed to control Ammonia. Such dental Cares as the prevention or early treatment of periodontal disease and the accelerating the salivary flow as well as reducing the amounts and activities of filament or spiral typed oral micro-organism were recommended for adults, not only for dental care program at the dental clinics but also for public health programs, in order to promote the oral health and quality of file for individual and community peoples.

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The Relation between the Return Rate and the Volatility of Oil Market and Natural Gas Market : Focusing on the Market of US and EU (석유시장과 천연가스시장의 수익률 및 변동성 간의 관계 : 미국과 유럽 시장을 중심으로)

  • Kim, Young-Duk;Lee, Dong-Woo
    • International Area Studies Review
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    • v.14 no.1
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    • pp.99-119
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    • 2010
  • This study explores the natural gas market and the oil market in the U.S. and the European oil market. It focuses on two kinds of analyses; one is to confirm whether there is the predictive power between spot and futures within homogeneous commodity market(or inter-heterogeneous commodity market) through Granger-causality test in terms of the return rate and the volatility. The other is to examine the spot price stabilizing effect of futures price through regression analysis. When it comes to the predictive power of inter-commodity market, there was a conflicting aspect between the return rate of spot and futures. Overall, however, its statistical significance was low. With respect to the volatility, we found that the natural gas market has little influence on the oil market unlike the predictive power of oil market on natural gas market. Concerning the return rate of the predictive power within homogeneous commodity market, we found that the return rate of spot has the predictive power on futures only in the European market. In addition, we identified that there is feedback between spot and futures in the all commodity markets regarding volatility. As a result of the spot price stabilizing effect analysis of futures price, futures volatility increased the spot volatility.

A Study on the Sasang Constitutional Distribution Among the People in the United States of America (북미지역주민(北美地域住民)의 사상체질(四象體質) 분포(分布)에 관(關)한 연구(硏究))

  • Koh, Byung-hee;Kim, Seon-ho;Park, Byung-gwan;Lavelle, Jonathan D;Tecun, Marianne;Anthony Jr., Ross;Hobbs, Ron;Zolli, Frank;Chin, Kyung-hee
    • Journal of Sasang Constitutional Medicine
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    • v.11 no.2
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    • pp.119-150
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    • 1999
  • In spite of recent remarkable recent development in both western and oriental medical sciences, there is still only a shallow understanding of individual differences for various prognoses of incurable diseases and immunopathy diseases. Nevertheless, the care, cure and prevention methods of Sasang Constitutional Medicine are broadly used as an effective treatment of incurable diseases like immunopathy diseases and stress-related diseases and diseases due to aging. In this sense, the establishment of classification norms is urgent and essential for the worldwide application of Sasang Constitutional Medicine(SCM). This study began with the confirmation process of whether Sasang Constitutional types exist in Americans. To accomodate for cultural differences, the distinguishing tool was readjusted so that Sasang Constitutional Types in Americans could be determined. Hence, the selected tool is the new QSCCII+, which is a newly revised English version of the QSCCII. QSCCII was made and standardized by Dept. of SCM in Kyung Hee Medical Center and Dr. Kim7). The evaluation methods of the old version were improved in the new QSCCII+ through necessary statistical manipulation. The original QSCCII was officially authorized by the Korean Society of Sasang Constitutional Medicine as the only computerized version of Sasang diagnostics. This study is the first attempt to design a new diagnostic tool for the classification of Sasang Constitutional types in North Americans with the revision of QSCCII. The subjects of this study were selected from the cooperative people among the students and staffs of the University of Bridgeport and the patients who visited the Clinic in the Health Science Center. This study takes for about 1 year from 1998. 8 to 1999. 8 The conclusions of the study can be summarized as follows: 1. Sasang constitutional types also exist in Americans. It can also naturally be inferred that Sasang Constitutional types exist in all human beings, for there are many different human races in America. 2. There are more So-Yang In's than any other types in American white people. This result confirms the hypothesis that there also exist Sasang Constitutional types in westerners. 3. The result of repetitive tests suggests that the new QSCCII+ is an effective diagnostic tool for westerners when we consider the constant diagnostic results of the QSCCII+. 4. Sasang Constitutional types exit in the sample group regardless of racial difference. 5. The question items that were not often checked by Americans need to be modified into more understandable expressions. 6. The standardization of diagnosis for Americans should be established by use of the QSCCII+ 7. It can be guessed that there are many Tae-yang In's among the 71 persons who could not be clearly classified by the QSCCII+. Due to the scarcity of Tae-yang-In in general, it is important to improve upon the discernability of the QSCC II+. 8. The results of the Sasang Constitutional distribution in North Americans are as follows: The percentage of So-yang In distribution in the sample group is 36.25%(87persons), that of Tae-eum In is 13.75%(33persons), and that of So-eum In is 20.41%(49persons).

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Clinical Efficacy of Clomiphene Citrate and Letrozole Combined with Gonadotropins for Superovulation in Patients with Clomiphene-Induced Thin Endometrium (클로미펜에 얇은 자궁내막을 보이는 환자에서 성선자극호르몬 병합 과배란유도시 클로미펜과 레트로졸의 임상적 효용성)

  • Lee, Eun-Joo;Park, Hyun-Jong;Yang, Hyo-In;Lee, Kyung-Eun;Seo, Seok-Kyo;Kim, Hye-Yeon;Cho, Si-Hyun;Choi, Young-Sik;Lee, Byung-Seok;Park, Ki-Hyun;Cho, Dong-Jae
    • Clinical and Experimental Reproductive Medicine
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    • v.36 no.2
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    • pp.111-119
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    • 2009
  • Objective: The aim of this study was to compare the clinical efficacy of clomiphene citrate (CC) and letrozole combined with gonadotropins for controlled ovarian stimulation (COS) in patients with CC-induced thin endometrium Methods: Fifty-one intrauterine insemination cycles performed in patients who previously had a thin endometrium (<8 mm) to ovulation induction using CC were included in this study. A CC 100 mg/day (CC+gonadotropin group, n=26) or letrozole 2.5 or 5 mg/day (letrozole+gonadotropin group, n=25) was administered on day 3~7 of the menstrual cycle, combined with gonadotropins at dose 75~150 IU every other day starting on day 5~7. We compared total dose of gonadotropin used, endometrial thickness, endometrial pattern, number of follicles ${\geq}14\;mm$ on hCG day, pregnancy rate and multiple pregnancy rate between the two groups, which were statistically analyzed using Mann-Whitney U test or Fisher's exact test, where appropriate. Results: There were no significant differences in clinical characteristics such as age, duration of infertility, number of previous IUI cycles, basal serum hormone levels and cause of infertility between the two groups. In both groups, the endometrium was significantly thicker than that of previous ovulation induction cycles using CC. No significant differences were found in the total dose of gonadotropin used, day of hCG administration, the rate of triple endometrium and pregnancy rate. The number of follicles ${\geq}14\;mm$ was significantly lower ($3.7{\pm}1.7$ vs. $2.8{\pm}1.7$, p=0.03) and the endometrium on hCG day was significantly thicker ($7.7{\pm}1.5$ vs. $9.1{\pm}1.7$, p=0.001) in letrozole+gonadotropin group compared to CC+gonadotropin group. Conclusion: The clomiphene citrate and letrozole combined with gonadotropins appear to avoid the undesirable effects on the endometrium frequently seen with CC for ovulation induction. However, in terms of adequate endometrial development or optimal follicular growth, letrozole may be more beneficial than CC for gonadotropin-combined COS in patients with CC-induced thin endometrium. Further prospective randomized controlled studies in a larger scale will be necessary to confirm our findings.

Effects of Concentrated Pig Slurry Using Membrane Filter on the Growth and Yield of Tomato in Nutriculture (막분리 돈분뇨 농축액비를 이용한 양액재배가 토마토의 생육과 수량에 미치는 영향)

  • Ryoo, Jong-Won;Seo, Woon-Kab
    • Journal of Animal Environmental Science
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    • v.14 no.2
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    • pp.119-128
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    • 2008
  • This experiment was conducted to investigate the effects of concentrated pig slurry using membrane filter on growth of tomato in nutriculture. Pig slurry was filtered by ultra filtration and concentrated by reverse osmosis process. Filtration of pig slurry was necessary to prevent the hose clogging in nutriculture. The concentrated pig slurry (CS) and nutrient solution (NS) were mixed by six different mixing ratios of 0:100, 20:80, 40:60, 60:40%, 80: 20 and 100%:0% based on nitrogen content. The chemical nutrient solution was the solution of National Horticulture Research Station for the growth of tomato. The concentration of nutrient solution was adjusted a range of $1.6{\sim}2.0mS/cm$ in EC. The plant height of tomato treated with CS 20+NS 80% was similar with NS 100% control plot. Plant height was highest in the plot of CS 20+NS 80%. The treatment of 100% concentrated pig slurry was lowest in the gowth characteristics of tomato. Number of cluster was very lower in 100% concentrated pig slurry compared with plot of chemical nutrient solution. In the beginning of growth stage, SPAD reading value was reduced in plot treated with CS 100%, but CS 20+NS 80% plot was higher compared to 100% concentrated pig slurry. SPAD value of tomato leaves was decreased as the amount of CS was increased. The SPAD value also in treatment of concentrated pig slurry was lower in the middle growth stage compared to control plot. The dry weight of stem and leaf were 107.4, 104.2g in plot of NS 100% and CS 20%+NS 80%, respectively. The fruit number and weight were decreased at high application plots of concentrated pig slurry, The fruit setting of tomato showed lowest in the plot treated with 100% concentrated pig slurry, and the growth of tomato severely decreased after application of 100% CS treatment. In conclusion, the growth characteristics such as plant height and fruit weight of tomato were not significantly different between the plots treated with mixture of 20% CS +80%NS and 100% nutrient solution treatment. In conclusion, the mixture solution of 20% of concentrated pig slurry and 80% of nutrient solution could be used as a nutrition solution of tomato nuticulture.

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Comparative Molecular Phylogenetic Relationships in Different Strains of Pleurotus spp. (느타리속 버섯 계통의 분자생물학적 유연관계의 비교연구)

  • Cho, Hae-Jin;Lee, Jae-Seong;Yoon, Ki-Nam;Alam, Nuhu;Lee, Kyung-Lim;Shim, Mi-Ja;Lee, Min-Woong;Cheong, Jong-Chun;Shin, Pyung-Gyun;Yoo, Young-Bok;Lee, U-Youn;Lee, Tae-Soo
    • The Korean Journal of Mycology
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    • v.38 no.2
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    • pp.112-119
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    • 2010
  • Pleurotus spp. have been used for edible and medicinal purposes in Asian countries for a long time. The fruiting bodies of the Pleurotus ostreatus, Pleurotus citrinopileatus and Pleurotus salmoneostramineus contained many physiologically beneficial substances for human health. Therefore, it is necessary to study the genetic diversity of Pleurotus mushroom cultivars commercially cultivated in Korea. Eleven strains of Pleurotus spp. were collected from different geographical regions in South-East Asia and ITS regions of rDNA and RAPD of genomic DNA were analyzed. The size of the ITS1 and ITS2 regions of rDNA from the different strains varied from 167 to 254 bp and 156 to 213 bp, respectively. The sequence of ITS1 was more variable than that of ITS2, and the 5.8S sequences were identical. A phylogenetic tree based on the ITS region sequences indicated that selected strains could be classified into 4 clusters. Eleven Pleurotus species were also analyzed by RAPD with 20 arbitrary primers. Ten of these primers were efficiently amplified the genomic DNA. The number of amplified bands varied with the primers and strains, with polymorphic fragments in the range from 0.1 to 2.0kb. The results revealed that genetic diversity of selected strains of P. ostreatus, P. citrinopileatus and P. salmoneostramineus is low.

Detection of Auxotrophic Mutants form Valsa ceratosperma, the Causal Fungus of Apple Canker (사과나무 부란병균(腐爛病菌) Valsa ceratosperma에서의 Auxotrophic Mutants의 검출(檢出))

  • Hong, Yeon Gyu;Uhm, Jae Youl
    • Current Research on Agriculture and Life Sciences
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    • v.5
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    • pp.119-126
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    • 1987
  • This study was conducted to elucidate the most appropriate method to obtain auxotrophic mutants from Valsa ceratosperma, the causal fungus of apple canker, which may be used as a gene marker in detecting the transfer of the factors of avirulent strains to virulent strains. Among the 3 kinds of synthetic media tested, each have two formula for minimal and complete, the medium which has been used in study of Endothia parasitica (E. P medium) was turned out to be most appropriate for the growth of V. ceratosperma. A medium for single colony formation from pycnidiospore of this fungus was developed by adding 0.5% L - sorbose to the E. P minimal medium. The period of incubation in dark for preventing the photoreactivation after U. V irradiation was estimated as about 60hrs at which most of the spores become binucleate. Largest number of putative auxotrophs were obtained at about 50second of irradiation to the spores smeared on the medium for single colony formation, at which the survival rate of spores was 5 to 6 percent. With these method developed in this experiment, 161 isolates of putative auxotrophs were detected among which the nutrient requirement for 10 isolates were determined. Five out of 10 mutants were still virulent to apple tree and all but one could not sporulate.

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