• Title/Summary/Keyword: Yu Hee Choon

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Characterization of LexA-mediated Transcriptional Enhancement of Bidirectional Hydrogenase in Synechocystis sp. PCC 6803 upon Exposure to Gamma Rays

  • Kim, Jin-Hong;Lee, Min Hee;Kim, Ji Hong;Moon, Yu Ran;Cho, Eun Ju;Kim, Ji Eun;Lee, Choon-Hwan;Chung, Byung Yeoup
    • Rapid Communication in Photoscience
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    • v.1 no.1
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    • pp.21-24
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    • 2012
  • Influence of gamma rays on the cyanobacterium Synechocystis sp. PCC 6803 cells was investigated in terms of a bidirectional hydrogenase, which is encoded by hoxEFUYH genes and responsible for biohydrogen production. Irradiated cells revealed a substantial change in stoichiometry of photosystems at one day after gamma irradiation at different doses. However, as evaluated by the maximal rate of photosynthetic oxygen evolution, maximal photochemical efficiency of photosystem II, and chlorophyll content, net photosynthesis or photosynthetic capacity was not significantly different between the control and irradiated cells. Instead, transcription of hoxE, hoxH, or lexA, which encodes a subunit of bidirectional hydrogenase or the only transcriptional activator, LexA, for hox genes, was commonly enhanced in the irradiated cells. This transcriptional enhancement was more conspicuously observed immediately after gamma irradiation. In contrast, hydrogenase activities were found to somewhat lower in the irradiated cells. Therefore, we propose that transcription of hox genes should be enhanced by gamma irradiation in a LexA-mediated and possibly photosynthesis-independent manner and that this enhancement might not induce a subsequent increase in hydrogenase activities, probably due to the presence of post-transcriptional and/or post-translational regulatory mechanisms.

Effect of Magnetized Water on Cryopreservation in Bovine Spermatozoa (자기활성수가 소 정액 동결에 미치는 영향)

  • Seo, Gi-Beom;Lee, Yong-Seung;Lee, Kyung-Jin;Yu, Han-Jun;Cheong, Hee-Tae;Yang, Boo-Keun;Lee, Seung-Hwan;Lee, Jin-Woo;Park, Choon-Keun
    • Reproductive and Developmental Biology
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    • v.35 no.3
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    • pp.363-367
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    • 2011
  • The purpose of this study was to improve of frozen-thawed sperm using magnetized water in Korean native cattle. Before cryopreservation, without egg-yolk Triladyl$^{(R)}$ solution was flowed though magnet [0, 2000, 4000 and 6000 Gauss(G)] for S min. The freezing of dilluted semen added with Triladyl containing 20% egg-yolk. Analysis of frozen-thawed sperm was estimated viability with SYBR14/PI double stain, membrane intact with hypoosmotic swelling test (HOST), acrosome reaction with FITC-PNA, mitochondria membrane function with Rhodamin 123 by flow- cytometry. Sperm viability was significantly higher in 4000G group than other groups (p<0.05). However, the Hypoosmotic Swelling Test(HOST) was significantly higher in fresh, 4000 and 6000G than 0 and 2000G (p<0.05). In addition, mitochondria membrane damage and acrosome damage were significantly lower in 6000G group than other groups (p<0.05). in conclusion we suggest that magnetized water could be improve ability of sperm on cryopreservation in Korean native cattle.

Isolation, Identification, and Characterization of Pichia guilliermondii K123-1 and Candida fermentati SI, Producing Isoflavone β-Glycosidase to Hydrolyze Isoflavone Glycoside Efficiently, from the Korean Traditional Soybean Paste

  • Kim, Won-Chan;So, Jai-Hyun;Kim, Sang-In;Shin, Jae-Ho;Song, Kyung-Sik;Yu, Choon-Bal;Kho, Yung-Hee;Rhee, In-Koo
    • Journal of Applied Biological Chemistry
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    • v.52 no.4
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    • pp.163-169
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    • 2009
  • A total of 155 microbial strains were isolated from the Korean traditional soybean paste based on their morphological features on the growth of agar plate. Among the isolated strains, a total of 28 strains were capable of hydrolyzing isoflavone glycoside to isoflavone aglycone efficiently in the soybean paste. Finally, two strains, K123-1 and SI, were selected because of their resistance to 15% NaCl and ability to convert isoflavone glycoside to isoflavone aglycone efficiently during the fermentation of soybean paste. The isolated strains K123-1 and SI were identified to be Pichia guilliermondii and Candida fermentati, respectively, using the partial 26S rDNA sequence analysis and phylogenic analysis. Pichia guilliermondii K123-1 and Candida fermentati SI converted daidzin to daidzein up to 96% and 95%, respectively, and genistin to genistein up to 92% when soybean pastes were fermented at $30^{\circ}C$ for 20 days with a single isolated strain. Pichia guilliermondii K123-1 and Candida fermentati SI were able to grow in the presence of 15% NaCl on both liquid medium and agar plate. We think that Pichia guilliermondii K123-1 and Candida fermentati SI might be one of good candidates for making functional soybean paste because they are isolated from the Korean traditional soybean paste and have a good ability to convert isoflavone glycosides to isoflavone aglycones and a high salt tolerance.

Factors Affecting Bone Mineral Density by Dietary Pattern Group for Some Korean College Women (일부 우리나라 여대생의 식사 패턴군에 따른 골밀도에 영향을 미치는 요인 분석)

  • Song, Yoon-Ju;Paik, Hee-Young;Yu, Choon-Hie
    • Journal of Nutrition and Health
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    • v.39 no.5
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    • pp.460-466
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    • 2006
  • To investigate the effects of dietary patterns on bone mineral density and its biochemical markers among Korean healthy college women for 2 years, 34 female college students were recruited through convenience sampling. Bone mineral density was measured using Dual Energy X-ray Absorptiometry (DEXA) twice at baseline and two years later. Osteocalcin and parathyroid hormone were measured in fasting serum and N-teleopeptides of type collagen (NTx) in urine. Dietary intake was assessed by 24-hour recall method 8 times with average 4-month interval. Dietary patterns with percent energy of each food group using cluster analysis were classified into two groups. The first cluster (n = 16) was characterized with high consumption of bread, snack, fast foods, beverage and considerable of rice so it was determined as 'Modified dietary pattern group'. The second cluster was characterized with high consumption of rice and kimchi so determined as 'Traditional dietary pattern group'. There were no significant difference of age, menarcheal age, body mass index but percent of body fat by pattern groups. The traditional group showed higher value of bone mineral density among lumber spine and all femur sites at baseline and 2 years later but it was not significant after adjusted for percent of body fat. Serum osteocalcin and urine NTx was higher among the traditional group at baseline than the modified group. There were similar proportions of carbohydrate:fat:protein between groups but significantly higher intake of protein, iron, vitamin A among the traditional group. In conclusion, there were two distinctive dietary patterns among Korean college women. There was difference of bone mineral density and its biochemical markers between two patterns. Further research would be necessary to explore the relationship between dietary patterns and health risks for larger-sized and various populations.

A Role of Unsaturated Fatty Acid in Animal Reproductive Cells and Biology

  • Hwangbo, Yong;Kim, Hwa-Young;Lee, Yu-Rim;Lee, Seung Tae;Lee, EunSong;Cheong, Hee-Tae;Yang, Boo-Keun;Park, Choon-Keun
    • Reproductive and Developmental Biology
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    • v.40 no.2
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    • pp.15-22
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    • 2016
  • As a one of unsaturated fatty acid, polyunsaturated fatty acids (PUFAs) have multiple actions: as precursor of prostaglandins (PGs), steroid hormone synthesis and energy production in animal reproduction. PUFAs, which include omega-3 (n-3) and omega-6 (n-6), are derived from the diet and changed by diet, species, breed and season. The plasma membrane of spermatozoa in mammals contain various PUFAs. These composition of PUFAs regulate the membrane fluidity and cause lipid peroxidation via generation of reactive oxygen species (ROS). Induced lipid peroxidation by ROS decreased viability and motility of spermatozoa, and it is reduced by addition of antioxidant and low concentration of PUFAs. Because oocytes of animal have a high lipid components, process of oocyte maturation and embryo development are influenced by PUFAs. In in vitro study, oocyte maturation, embryo development, intracellular cAMP and MAPK activity were increased by treatment of n-3 ${\alpha}$-linolenic acid (ALA) during maturation, whereas n-6 linoleic acid (LA) negatively influenced. Also, inhibition of fatty acid metabolism in oocyte influenced blastocyst formation of cattle. PGs are synthesized from PUFAs and various PUFAs influence PGs via regulation of PG-endoperoxide synthase (PTGS). Steroid hormone synthesis from cholesterol is regulated by expression of steroid acute regulator (StAR) protein and mRNA. Exogenous n-3 and n-6 PUFAs altered sex hormone in animal through stimulate or inhibit StAR activity. Because PUFAs altered PG and steroid hormone synthesis, follicular development was influenced by PUFAs. This effect of unsaturated fatty acid could provide information for improvement of reproductive ability in animals.

Treatment outcome in patients with vulvar cancer: comparison of concurrent radiotherapy to postoperative radiotherapy

  • Lee, Ja-Young;Kim, Sung-Hwan;Kim, Gi-Won;Yu, Mi-Na;Park, Dong-Choon;Yoon, Joo-Hee;Yoon, Sei-Chul
    • Radiation Oncology Journal
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    • v.30 no.1
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    • pp.20-26
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    • 2012
  • Purpose: To evaluate outcome and morbidity in patients with vulvar cancer treated with radiotherapy, concurrent chemoradiotherapy or postoperative radiotherapy. Materials and Methods: The records of 24 patients treated with radiotherapy for vulvar cancer between July 1993 and September 2009 were retrospectively reviewed. All patients received once daily 1.8-4 Gy fractions external beam radiotherapy to median 51.2 Gy (range, 19.8 to 81.6 Gy) on pelvis and inguinal nodes. Seven patients were treated with primary concurrent chemoradiotherapy, one patient was treated with primary radiotherapy alone, four patients received palliative radiotherapy, and twelve patients were treated with postoperative radiotherapy. Results: Twenty patients were eligible for response evaluation. Response rate was 55% (11/20). The 5-year disease free survival was 42.2% and 5-year overall survival was 46.2%, respectively. Fifty percent (12/24) experienced with acute skin complications of grade III or more during radiotherapy. Late complications were found in 8 patients. 50% (6/12) of patients treated with lymph node dissection experienced severe late complications. One patient died of sepsis from lymphedema. However, only 16.6% (2/12) of patients treated with primary radiotherapy developed late complications. Conclusion: Outcome of patients with vulvar cancer treated with radiotherapy showed relatively good local control and low recurrence. Severe late toxicities remained higher in patients treated with both node dissection and radiotherapy.

The effect of green tea on ultraviolet B-induced sunburn cell production in the skin of hairless mouse (자외선 B 조사 hairless 마우스에서 일광화상세포 발생 억제에 대한 녹차의 효과)

  • Kim, Sung-ho;Kim, Se-ra;Lee, Hae-june;Lee, Jin-hee;Kim, Yu-jin;Kim, Jong-choon;Jang, Jong-sik;Jo, Sung-kee
    • Korean Journal of Veterinary Research
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    • v.45 no.1
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    • pp.1-6
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    • 2005
  • In this study we assessed the influences of ultraviolet (UV) light B radiation on epidermal cells by apoptotic sunburn cell (SBC) and the effect of green tea treatment on the inhibition of SBC formation in SKH1-hr mouse. The extent of changes following $200mJ/cm^2$ (0.5 mW/sec) was studied at 0, 3, 6, 12, 18, 24, 30 or 36 hours after exposure. SBCs were recognized by 3 hours after irradiation. There was tendency to increase from 3 hours to 24 hours and decrease from then to 36 hours after irradiation. The mice that received 0, 25, 50, 100, 200, 400 or $800mJ/cm^2$ of UVB were examined 24 hours after irradiation. The SBCs were induced as the radiation dose increases from 0 to $200mJ/cm^2$. A further increase of radiation dose has little further effect. The frequency of UVB ($200mJ/cm^2$)-induced SBC formation was reduced by intraperitoneal injection of green tea extract (p<0.01).

Photosynthesis rates, growth, and ginsenoside contents of 2-yr-old Panax ginseng grown at different light transmission rates in a greenhouse

  • Jang, In-Bae;Lee, Dae-Young;Yu, Jin;Park, Hong-Woo;Mo, Hwang-Sung;Park, Kee-Choon;Hyun, Dong-Yun;Lee, Eung-Ho;Kim, Kee-Hong;Oh, Chang-Sik
    • Journal of Ginseng Research
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    • v.39 no.4
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    • pp.345-353
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    • 2015
  • Background: Ginseng is a semishade perennial plant cultivated in sloping, sun-shaded areas in Korea. Recently, owing to air-environmental stress and various fungal diseases, greenhouse cultivation has been suggested as an alternative. However, the optimal light transmission rate (LTR) in the greenhouse has not been established. Methods: The effect of LTR on photosynthesis rate, growth, and ginsenoside content of ginseng was examined by growing ginseng at the greenhouse under 6%, 9%, 13%, and 17% of LTR. Results: The light-saturated net photosynthesis rate ($A_{sat}$) and stomatal conductance ($g_{s}$) of ginseng increased until the LTR reached 17% in the early stage of growth, whereas they dropped sharply owing to excessive leaf chlorosis at 17% LTR during the hottest summer period in August. Overall, 6-17% of LTR had no effect on the aerial part of plant length or diameter, whereas 17% and 13% of LRT induced the largest leaf area and the highest root weight, respectively. The total ginsenoside content of the ginseng leaves increased as the LTR increased, and the overall content of protopanaxatriol line ginsenosides was higher than that of protopanaxadiol line ginsenosides. The ginsenoside content of the ginseng roots also increased as the LTR increased, and the total ginsenoside content of ginseng grown at 17% LTR increased by 49.7% and 68.3% more than the ginseng grown at 6% LTR in August and final harvest, respectively. Conclusion: These results indicate that 13-17% of LTR should be recommended for greenhouse cultivation of ginseng.

A Study on the History of Modern Library in Korea -With Special Reference to the Formation of Modern Library Thought in the Late Yi Dynasty- (근대 한국 도서관사 연구 -개화기에 있어서 근대도서관사상의 형성과정을 중심으로-)

  • Lee Choon Hee
    • Journal of the Korean Society for Library and Information Science
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    • v.16
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    • pp.71-110
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    • 1989
  • The purpose of this study is to investigate the influential factors creating the modern library thought in the latter part of Yi Dynasty. After Korea was forced to make a treaty opening up the country in 1876, Western civilization was introduced and reforms were carried out eventually. Various influential factors could be taken into consideration as follows. (1) The envoys to Japan after 1876 (2) Tourists party to Japan organized by Gentlemen in 1982 (3) The persons who studied abroad (4) Establishment of modern schools and development of publications: on the new learning. (5) News media and others Above all, the persons who studied abroad, such as Yu Gil Jun, Yun Chi Ho, etc., in early stage has contributed most to the extension of public recognition for modern library in Korea. Therefore it can be said that the formation of modern library thought in Korea was based on the theory of the Western library as was the Japan in the period of Meiji Restoration. Patriotic intelectualls in these days believed that reform of the educational system and the diffusion of knowledge was very much meeded in order to preserve an independent Korea and to build up national strength, and then nation-wide campaign for enlightenment was earried on. For that reason the movement of the national library establishment in 1906 also should be regarded from the same point of view, that is, as a part of the enlightenment campaign. Therefore it should not go unheeded that strong patriotism was always streamed under the ground of the library campaign as well as the new learning and new education campaign. Unfortunately every plan of Korean library movement had broken down and missed the chance for having experience of self-development because of the Japanese invasion.

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Effects of α-Linolenic Acid in Frozen-thawed Boar Spermatozoa (돼지 정자의 동결보존 시 α-Linolenic Acid의 효과)

  • Lee, Won-Hee;Hwangbo, Yong;Lee, Sang-Hee;Yang, Jin-Woo;Kim, Hwa-Young;Lee, Yu-Rim;Park, Ji-Eun;Cheong, Hee-Tae;Yang, Boo-Keun;Park, Choon-Keun
    • Reproductive and Developmental Biology
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    • v.40 no.3
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    • pp.27-31
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    • 2016
  • The aim of this study was to evaluate effect of ${\alpha}$-linolenic acid (ALA) on viability, acrosome reaction and mitochondrial intact in frozen-thawed boar sperm. The boar semen was collected by gloved-hand method and cryopreserved in 20% egg yolk freezing extender containing ALA (0, 3, 5, and 10 ng/mL) with 0.05% ethanol. The frozen-boar spermatozoa were thawed at $37.5^{\circ}C$ for 45 sec in water-bath. The spermatozoa samples were evaluated the plasma membrane integrity, acrosome reaction, and mitochondrial integrity using flow cytometry. In results, population of live sperm with intact plasma membrane was significantly higher in control and 3 ng/mL ALA treatment group than ethanol group (p<0.05). In contract, dying sperms were higher in ethanol group than 3 ng/mL ALA treatment (p<0.05). Acrosomal membrane damage in all sperm population was reduced in 3 ng/mL ALA groups compared with ethanol treatment (p<0.05). However, acrosome damage in live sperm population was no significant difference among the all treatment groups. Mitochondrial integrity was not influenced by ALA treatments in both of live and all sperm population. In conclusion, this results show that supplement of ALA during the cryopreservation process could reduce the membrane damages including plasma and acrosomal membrane, whereas ALA did not influence to mitochondria in boar spermatozoa. Therefore, these results suggest that ALA can protect against the membrane damage derived cryo-stress, and cryopreservation efficiency of boar semen would be improved by use of ALA.