• The Korean Journal of Mycology
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• v.32 no.1
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• pp.31-38
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• 2004

An endophytic bacterial strain EB215 that was isolated from cucumber (Cucumis sativus) roots displayed a potent in vivo antifungal activity against Colletotrichum species. The strain was identified as Burkholderia cepacia based on its physiological and biochemical characteristics, and 16S rDNA gene sequence. Optimal medium and incubation period for the production of antifungal substances by B. cepacia EB215 were nutrient broth (NB) and 3 days, respectively. An antifungal substance was isolated from the NB cultures of B. cepacia EB215 strain by centrifugation, n-hexane partitioning, silica gel column chromatography, preparative TLC, and in vitro bioassay. Its chemical structure was determined to be pyrrolnitrin by mass and NMR spectral analyses. Pyrrolnitrin showed potent disease control efficacy of more than 90% against pepper anthracnose (Colletotrichum coccodes), cucumber anthracnose (Colletotrichum orbiculare), rice blast (Magnaporthe grisea) and rice sheath blight (Corticium sasaki) even at a low concentration of $11.1\;{\mu}g/ml$. In addition, it effectively controlled the development of tomato gray mold (Botrytis cinerea) and wheat leaf rust (Puccinia recondita) at concentrations over $33.3\;{\mu}g/ml$. However, it had no antifungal activity against Phytophthora infestans on tomato plants. Further studies on the development of microbial fungicide using B. cepacia EB215 are in progress.

• Ocean and Polar Research
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• v.36 no.1
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• pp.13-24
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• 2014

We established the first complete ice core processing method and analytical procedures for fundamental proxies, using a 40.2 m long ice core drilled on the Mt. Tsambagarav glacier in the Mongolian Altai mountains in July 2008. The whole core was first divided into two sub ice core sections and the measurements of the visual stratigraphy and electrical conductivity were performed on the surface of these sub core sections. A continuous sequence of samples was then prepared for chemical analyses (stable isotope ratios of oxygen ($^{18}O/^{16}O$) and hydrogen ($^2H/^1H$), soluble ions and trace elements). A total of 29 insoluble dust layers were identified from the measurement of visual stratigraphy. The electrical conductivity measurement (ECM) shows 11 peaks with the current more than 0.8 ${\mu}A$ Comparing the profiles of $SO_4{^{2-}}$ and $Cl^-$ concentrations to correlate with known volcanic eruptions, the first two ECM peaks appear to be linked to the eruptions (January and June 2007) of Kliuchevskoi volcano on the Kamchatka Peninsula of Russia, which supports the reliability of our ECM data. Finally, the composition of stable isotopes (${\delta}^{18}O$ and ${\delta}D$) shows a well-defined seasonal variation, suggesting that various chemical proxies may have been well preserved in the successive ice layers of Tsambagarav ice core. Our ice core processing method and analytical procedures for fundamental proxies are expected to be used for paleoclimate and paleoenvironmental studies from polar and alpine ice cores.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.1
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• pp.217-223
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• 2013

Background: Hepatocellular carcinoma (HCC) is one of the most common cancers worldwide, and the outcomes for patients are still poor. It is important to determine the original type of synchronous multinodular HCC for preoperative assessment and the choice of treatment therapy as well as for the prediction of prognosis after treatment. Aims: To analyze clinicopathologic characteristics and prognoses in patients with multicentric occurrence (MO) and intrahepatic metastasis (IM) of synchronous multinodular hepatocellular carcinoma (HCC). Methods: The study group comprised 42 multinodular HCC patients with a total of 112 nodules. The control group comprised 20 HCC patients with 16 single nodular HCC cases and 4 HCC cases with a portal vein tumor emboli. The mitochondrial DNA (mtDNA) D-loop region was sequenced, and the patients of the study group were categorized as MO or IM based on the sequence variations. Univariate and multivariate analyses were used to determine the important clinicopathologic characteristics in the two groups. Results: In the study group, 20 cases were categorized as MO, and 22 as IM, whereas all 20 cases in the control group were characterized as IM. Several factors significantly differed between the IM and MO patients, including hepatitis B e antigen (HBeAg), cumulative tumor size, tumor nodule location, cirrhosis, portal vein and/or microvascular tumor embolus and the histological grade of the primary nodule. Multivariate analysis further demonstrated that cirrhosis and portal vein and/or microvascular tumor thrombus were independent factors differentiating between IM and MO patients. The tumor-free survival time of the MO subjects was significantly longer than that of the IM subjects ($25.7{\pm}4.8$ months vs. $8.9{\pm}3.1$ months, p=0.017). Similarly, the overall survival time of the MO subjects was longer ($31.6{\pm}5.3$ months vs. $15.4{\pm}3.4$ months, p=0.024). The multivariate analysis further demonstrated that the original type (p=0.035) and Child-Pugh grade (p<0.001) were independent predictors of tumor-free survival time. Cirrhosis (p=0.011), original type (p=0.034) and Child-Pugh grade (p<0.001) were independent predictors of overall survival time. Conclusions: HBeAg, cumulative tumor size, tumor nodule location, cirrhosis, portal vein and/or microvascular tumor embolus and histological grade of the primary nodule are important factors for differentiating IM and MO. MO HCC patients might have a favorable outcome compared with IM patients.

• Clinical and Experimental Reproductive Medicine
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• v.15 no.1
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• pp.40-52
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• 1988

Estradiol-17${\beta}$($E_2$) levels in the blood were estimated according to varying the time and amount of the administration of $Clomid^{(R)}$. $Clomid^{(R)}$ were administered on the 2nd, 3rd and 4th menstrual day corresponding to the recruitment period and on the 5th menstrual day corresponding to the selection period of the ovarian follicles, respectively. And $Clomid^{(R)}$ were administered 50 mg, 100 mg and 150 mg/day, repectively. The effects of the sequential HMG to $E_2$ levels in the blood were also estimated. The results were as following : 1. Blood $E_2$ levels according to the day and amount of administration of $Clomid^{(R)}$ were the highest in the group 3(D $2{\sim}6$, 150 mg/day, with HMG) and the lowest in the group 6(D $5{\sim]9$, 50 mg/day, without HMG). $E_2$ levels showed increasing tendency to 0 day. 2. In the cases of the administration of $Clomid^{(R)}$ during the $2nd{\sim}6th$ menstrual day, $E_2$ levels according to the amount were similar among groups and showed increasing tendency daily. 3. In the cases of administration of $Clomid^{(R)}$ during the $2nd{\sim}6th$ menstrual day, $E_2$ levels according to the sequential HMG independent of the amount of $Clomid^{(R)}$ were higher in the with HMG group than without HMG groups. 4. In the case of the administration of $Clomid^{(R)}$ during the $5th{\sim}9th$ menstrual day, $E_2$ levels according to the amount were the highest in the 100 mg/day group and the lowest in the 50mg/day group. 5. In the cases of administration of $Clomid^{(R)}$ independent of the amount during the 5th${\sim}$9th menstrual day, $E_2$ levels according to the sequential HMG were higher in the with HMG group than without HMG group. 6. $E_2$ levels according to the amount independent of the day of the administration of $Clomid^{(R)}$ were the highest in the 100 mg/day group and 150 mg/day, 50 mg/day group in low sequence. 7. $E_2$ levels according to the sequential HMG independent of the day and amount of the administration of $Clomid^{(R)}$ were higher in the with HMG group than the without HMG group. 8. $E_2$ levels according to the day of the administration of $Clomid^{(R)}$ independent of the amount of $Clomid^{(R)}$ and sequential HMG were the highest in the group D 2${\sim}$6 and the lowest in the group D 5${\sim}$9. According to the above results, there were higher $E_2$ levels in the group with sequential HMG than without HMG. Therefore, the hypothesis, postulated initially by the author, was not verified that sequential HMG would not affect the $E_2$ levels which were related to the process of the selection of the ovarian follicle in the connection with 'FSH window'. Because it may be the stimulation after the selection of later predominant follicle. And the highest level of $E_2$ was estimated in the $Clomid^{(R)}$ 150 mg/day group with sequential HMG on the 2nd${\sim}$6th day, and the higher levels were estimated in the 2nd${\sim}$6th day, 3rd${\sim}$7th day and 4th${\sim}$8th day groups than the 5th${\sim}$9th day group. The lower levels were estimated in the $Clomid^{(R)}$ 50 mg/day group without HMG than 100 mg/day and 150 mg/day on the 5th${\sim}$9th day. Therefore, further study will be needed that combines analyses of the E2 levels in the blood according to the various administration of $Clomid^{(R)}$ with or without sequential HMG and determination of the numbers and size of the ovarian follicles by ultrasonogram.

• Journal of Plant Biotechnology
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• v.42 no.3
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• pp.161-167
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• 2015

Sweetpotato [Ipomoea batatas (L.) Lam] grows well in harsh environmental conditions, and is cultivated as one of the top seven food crops in the world. Recently, sweetpotato is drawing interest from people as a healthy food because it is high in dietary fiber, vitamins, carotenoids and overall nutrition value. However, few studies have been conducted on sweetpotato genome sequencing in spite of its importance. This review is aimed at increasing the efficiency of sweetpotato genome sequencing research as well as establishing a base for gene utilization in order to control useful traits. Recently, animal and plant genome sequencing projects increased significantly. However, sweetpotato genome sequencing has not been performed due to polyploidy and heterogeneity problems in its genome. Meanwhile research on its transcriptome has been conducted actively. Recently, a draft of the diploid sweetpotato genome was reported in 2015 by Japanese researchers. In addition, the Korea-China-Japan Trilateral Research Association of Sweetpotato (TRAS) has conducted research on gene map construction and genome sequencing of the hexaploid sweetpotato Xushu 18 since 2014. The Bill & Melinda Gates Foundation launched the 'sweetpotato genomic sequencing to develop genomic tools for Sub-Sahara Africa breeding program'. The chloroplast genome sequence acquired during sweetpotato genome sequencing is used in evolutionary analyses. In this review, the trend of research in the sweetpotato genome sequencing was analyzed. Research trend analysis like this will provide researchers working toward sweetpotato productivity and nutrient improvement with information on the status of sweetpotato genome research. This will contribute to solving world food, energy and environmental problems.

• Clinical and Experimental Reproductive Medicine
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• v.31 no.2
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• pp.105-110
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• 2004

Objectives: Despite severe oligospermia, males with Y chromosome microdeletion can achieve conception through ICSI (Intracytoplasmic Sperm Injection). However, ICSI may not only result in the transmission of microdeletions but also the expansion of deletion to the offspring. The purpose of this study was to screen vertical transmission, expansion of microdeletions and de novo deletion in male fetuses conceived by ICSI. Materials and Methods: A total of 32 ICSI treated patients with their 33 (a case of twin) male fetuses conceived by ICSI were used to make this study group. Sequence-tagged sites (STSs)-based PCR analyses were performed on genomic DNA isolated from peripheral blood of fathers and from the amniocytes of male fetuses. Ten primer pairs namely, sY134, sY138, MK5, sY152, sY147, sY254, sY255, SPGY1, sY269 and sY158 were used. The samples with deletions were verified at least three times. Results: We detected a frequency of 12.5% (4 of the 32 patients) of microdeletions in ICSI patients. In 4 patients with detected deletions, two patients have proven deletions on single STS marker and their male fetuses have the identical deletion in this region. Another two patients have two and three deletions, but their male fetuses have more than 3 deletions which include deletions to their father's. Meanwhile, seven male fetuses, whose fathers were analyzed to have all 10 STS markers present, have deletions present in at least one or more of the markers. Conclusions: Although the majority of deletions on the Y chromosome are believed to arise de novo, in some cases a deletion has been transmitted from the fertile father to the infertile patient. In other cases the deletion was transmitted through ICSI treatment, it is likely that one sperm cell is injected through the oocyte's cytoplasm and fertilization can be obtained from spermatozoa. Our tests for deletion were determined by PCR and our results show that the ICSI treatment may lead to vertical transmission, expansion and de novo Y chromosome microdeletions in male fetuses. Because the sample group was relatively small, one should be cautious in analyzing these data. However, it is important to counsel infertile couples contemplating ICSI if the male carries Y chromosomal microdeletions.

• Journal of Korean Society of Forest Science
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• v.101 no.3
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• pp.501-508
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• 2012

This study was carried out to compare species diversity of soil bacteria from Baekdudaegan mountain forests (Bonghwa-gun, Mungyeong-si and Sangju-si) in Gyeongsangbuk-do and to analyze the effects of soil environments on diversity and population of soil bacteria. Soil bacteria were isolated from soil samples by streak plate method, and identified by DNA extaction and 16S rDNA sequence analyses. The population of soil bacteria from the soil samples of Bonghwa-gun was the highest with $5.1{\times}10^5cfu/g$, and followed by those from Mungyeong-si and Sangju-si with $1.9{\times}10^5cfu/g$ and $1.1{\times}10^5cfu/g$, respectively. The population of soil bacteria from surface layer soil was the highest, and then gradually decreased according to soil depth. The increase in population of soil bacteria from soil samples of different sites was correlated with the increase of the altitude of soil sampling site, depth of A horizon, liquid phase among three phases of soil, water content and bulk density of soil. Two hundreds and sixty eight bacterial colonies from Bonghwa-gun were classified into 10 species, 8 genera. One hundred and thirty four bacterial colonies from Mungyeong-si were classified into 15 species, 9 genera. Forty four bacterial colonies from Sangju-si were classified into 5 species, 2 genera. The dominant species (occupancy rate) from Bonghwa-gun and Mungyeong-si were Bacillus weihenstephanensis (36% and 40%, respectively), and Sangju-si was Bacillus cereus (39%). The relationships between soil environment and community structure of soil bacteria were analyzed statistically by using ecological indices. The diversity, evenness and dominance indices of soil bacteria were 6.30, 2.04 and 0.59 in Bonghwa-gun, 9.09, 2.94 and 0.51 in Mungyeong-si, and 4.55, 2.34 and 0.71 in Sangju-si, respectively. The diversity and evenness indices were increased by the increase of water content, drainage condition and gravel content of soil, while the dominance index was decreased.

• Economic and Environmental Geology
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• v.12 no.2
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• pp.51-73
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• 1979

The zinc-lead deposits at the Yeonhwa I mine were investigated in terms of ore-forming geologic setting, structural style of ore control, geometry of individual orebodies, zoning, paragenesis and chemical composition of skarn minerals, as well as metal grades and ratios of selected orebodies. The Yeonhwa I mine is characterized by a large swarm of chimney type massive orebodies with thin skarn envelopes, boldly developed through a thick sequence of Pungchon Limestone, the overlying Hwajeol Formation, and the underlying Myobong Slate of Cambrian age. Nearly 20 orebodies of similar shape, but of varying size are arranged in a V-shaped pattern with northwest and northeast trends, clearly indicating an outstanding ore control by a conjugate system of fractures with these trends. Important orebodies are the Wolam 1, 2, 3, and 5 orebodies in the west, and the Namsan 1, 2, 3. and 5 orebodies in the east, among others. The Wolam 1 orebody, which was observed from the -360 level through the -240, -120, and 0 levels to the surface outcrops (totaling a vertical height of about 500m), shows a vertical variation in skarn mineralogy, ranging from pyroxene-garnet zone on the lower levels. through pyroxene (without garnet) zone on the intermediate levels, and finally to rhodochrosite vein on the upper levels and surface. Microprobe analyses of pyroxene and garnet on a total of 14 mineral grains revealed that pyroxenes are manganoan salitic in most samples, with downward increase of Fe and Mn, whereas garnets are highly andraditic, containing fractions of subordinate grossular with downward decrease of Fe. This indicates a reverse relationship of Fe-contents between pyroxene and garnet with depth. Ore minerals are major sphalerite, subordinate galena, and minor chalcopyrite. Sulfide gangue minerals include major pyrrhotite, and minor pyrite and marcasite of later age. Two types of variational trends in metal grades and ratios with depth are present on the plots of assay data from the Wolam orebodies: one is a steady upward increase in Pb, Zn, and Pb:Zn ratios, with a terminal decline at the top of orebody: the other is an irregular or sinusoidal change. The former is characteristic of chimney-type orebodies, whereas the latter is of vein· shaped orebodies. The Pb grades show large variations among orebodies and from level to level, whereas the Zn grades are relatively constand or less variable.

• Economic and Environmental Geology
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• v.43 no.2
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• pp.137-148
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• 2010

The Myoungbong mine located in Boseong-gun, Jellanamdo consists of Au-Ag bearing quartz veins which filled the fissures of Bulguksa granitic rocks of Cretaceous. The tailings obtained from the Myungbong mine were used to investigate the effects of various processes, such as oxidation of primary sulfides and formation(alteration) of secondary and/or tertiary minerals, on arsenic immobilization in tailings. This study was conducted via both mineralogical and chemical methods. Mineralogical methods used included gravity and magnetic separation, ultrasonic cleaning, and instrumental analyses(X-ray diffractometry, energy-dispersive spectroscopy, and electron probe microanalyzer) and aqua regia extraction technique for soils was applied to determine the elemental concentrations in the tailings. Iron (oxy)hydroxides formed as a result of oxidation of tailings were identified as three specific forms. The first form filled in rims and fissures of primary pyrites. The second one precipitated and coated the surfaces of gangue minerals and the final form was altered into yukonites. Initially, large amounts of acid-generating minerals, such as pyrite and arsenopyrite, might make the rapid progress of oxidation reactions, and lots of secondary minerals including iron (oxy)hydroxides and scorodite were formed. The rate of pH decrease in tailings diminished, in addition, as the exposure time of tailings to oxidation environments was prolonged and the acid-generating minerals were depleted. Rather, it is speculated that the pH of tailings increased, as the contribution of pH neutralization reactions by calcite contained in surrounding parental rocks became larger. The stability of secondary minerals, such as scorodite, were deteriorated due to the increase in pH, and finally arsenic might be leached out. Subsequently, calcimn and arsenic ions dissociated from calcites and scorodites were locally concentrated, and yukonite could be grown tertiarily. It is confirmed that this tertiary yukonite which is one of arsenate minerals and contains arsenic in high level plays a crucial role in immobilizing arsenic in tailings. In addition to immobilization of arsenic in yukonites, the results indicate that a huge amount of iron (oxy)hydroxides formed by weathering of pyrite which is one of typical primary minerals in tailings can strongly control arsenic behavior as well. Consequently, this study elucidates that through a sequence of various processes, arsenic which was leached out as a result of weathering of primary minerals, such as arsenopyrite, and/or redissolved from secondary minerals, such as scorodite, might be immobilized by various sorption reactions including adsorption, coprecipiation, and absorption.

• Korean Journal of Microbiology
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• v.40 no.4
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• pp.342-347
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• 2004

A bacterial strain YC4963 with antifungal activity against Colletotrichum orbiculare, a causal organism of cucumber anthracnose was isolated from the rhizosphere soil of Siegesbeckia pubescens Makino in Korea. Based on physiological and biochemical characteristics and 16S ribosomal DNA sequence analysis, the bac­terial strain was identified as Pseudomonas aurantiaca. The bacteria also inhibited mycelial growth of several plant fungal pathogens such as Botrytis cinerea, Fusarium oxysporum and Rhizoctonia solani on PDA and 0.1 TSA media. The antifungal activity was found from the culture filtrate of this isolate and the active compound was quantitatively bound to XAD adsorption resin. The antibiotic compound was purified and identified as phenazine-l-carboxylic acid on the basis of combined spectral and chemical analyses data. This is the first report on the production of phenazine-l-carboxylic acid by Pseudomonas aurantiaca.