• 미생물학회지
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• 제5권1호
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• pp.15-19
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• 1967

Chlorella ellipsoidea cells were cultured in an iron, copper, zinc, manganese, molybdenum or boron-free medium. Physiological activities such as growth rate, reproduction, endogenous and glucose respiration, photosynthetic activity and biosythesis of chlorophyll of the micro-element definition cells were measured. It generally, growth rate, respiratory and photosynthetic activities, and biosynthesis of chlorophyll of the micro-element deficient cells decreased more or less, compared with those of the normal cells. The growth of the algal cells in an iron-free medium were retarded severely with the chlorosis, and the photosynthetic activity of the cells decreased remarkably even though the low content of chlorophyll in the cells owing to the iron-deficiency is considered. Therefore, it is deduced that iron takes part in the photosynthetic process itself, possibly by its participation in the photo phosphorylation coupled with electron transport. Respiratory activity of boron-deficient cells showed the most severe decrease whereas those of the molybdenum-deficient cells showed very slight decrease in spite of severe growth retardation.

• 한국자원식물학회지
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• 제27권3호
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• pp.229-235
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• 2014

Flax (Linum usitatissimum L.) has been used for the edible oil in Korea. The evaluate the effect of plant growth retardants on flaxseed yield, oil content, and gibberellin level, chloromequat chloride (CMC), paclobutrazol (PBZ), and prohexadione-Ca (PHC) were used as plant growth retardants in this study. These plant growth retardants were foliar-sprayed to flax plant at 55 days after seeding. The concentrations of each plant growth retardant were as followed: CMC 250, 500, 1000 ppm, PBZ 40, 80, 160 ppm and PHC 500, 1000, 2000 ppm. PHC treatment to forming bolls was more stimulated than CMC and PBZ. The highest ripened seed rate was observed in PHC treatment at 2000ppm. The high see yields were obtained in PHC treatment following PBZ and CMC, in turn. Seed yield that significantly increased in PBZ and PHC was found to be increased 12.4 ~ 23.9% as compared to the control. The PHC showed higher flaxseed production and oil yield than that of CMC and PBZ. The results obtained in the present study suggest that higher concentration of plant growth retardant (PHC) increased flaxseed yield and oil content. The optimal concentration of PHC treatment was observed in 2000 ppm. It concludes that the foliar application of PHC 2000 ppm may be useful for the increasing oil and higher seed production in flax plants.

• BMB Reports
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• 제40권5호
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• pp.708-714
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• 2007

The two-component signal transduction, which typically consists of a histidine kinase and a response regulator, is used by bacterial cells to sense changes in their environment. Previously, the SphS-SphR histidine kinase and response regulator pair of phosphate sensing signal transduction has been identified in Synechocystis sp. PCC 6803. In addition, some response regulators in bacteria have been shown to be cross regulated by low molecular weight phosphorylated compounds in the absence of the cognate histidine kinase. The ability of an endogenous acetyl phosphate to phosphorylate the response regulator, SphR in the absence of the cognate histidine kinase, SphS was therefore tested in Synechocystis sp. PCC 6803. The mutant lacking functional SphS and acetate kinase showed no detectable alkaline phosphatase activity under phosphate-limiting growth conditions. The results suggested that the endogenous acetyl phosphate accumulated inside the mutants could not activate the SphR via phosphorylation. On the other hand, exogenous acetyl phosphate could allow the mutant lacking functional acetate kinase and phosphotransacetylase to grow under phosphate-limiting conditions suggesting the role of acetyl phosphate as an energy source. Reverse transcription PCR demonstrated that the transcripts of acetate kinase and phospho-transacetylase genes in Synechocystis sp. PCC 6803 is up-regulated in response to phosphate limitation suggesting the importance of these two enzymes for energy metabolism in Synechocystis cells

• 한국자원식물학회지
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• 제26권6호
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• pp.695-700
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• 2013

Flax (Linum usitatissimum L.) has been used for the only edible oil in Korea. We carried out the field experiment in order to investigate the possibly combined effects of mepiquat chloride (MC) and trinexapac-ethyl (TE) on oil composition, lignan content, seed yield and endogenous gibberellins content of flax cultivar. Plant growth retardants mepiquat chloride (300 and 600 ppm) and trinexapac-ethyl (100, 200 and 300 ppm) were foliar-sprayed to flax plant at 50days after seeding. The plant height was decreased in the combination of mepiquat chloride 600 ppm with trinexapac-ethyl 100, 200 and 300 ppm. Mepiquat chloride treatment combined with trinexapac-ethyl observed the highest response on seed yield, followed by mepiquat chloride 300 ppm with trinexapac-ethyl 100 ppm, mepiquat chloride 300 ppm with trinexapac-ethyl 200 ppm and mepiquat chloride 300 ppm with trinexapac-ethyl 300 ppm. Lignan content was increased in all of the combination treatments. It concludes that the combination of mepiquat chloride 300 ppm with trinexapac-ethyl 300 ppm will be useful to increasing oil and lignan content in flax plants.

• Environmental Sciences Bulletin of The Korean Environmental Sciences Society
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• 제4권1호
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• pp.51-57
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• 2000

Changes in the proline accumulation of ten-day-old seedlings of Vigna angularis in response to NaCl treatment were monitored. The proline content increased gradually both with an increase in the exposure time to salt stress and in a concentration-dependent manner. The increased proline accumulation was stronger in the shoots than in the roots. The salt stress by itself resulted in a significant inhibition of the chlorophyll content. Pre-treatment with proline before salinization lasting 48 h did not significantly affect the endogenous proline level in the roots, in contrast, a considerable increase of proline was observed in the shoots. The application of exogenous proline to the seedlings increased the endogenous proline content and improved the root and shoot growth under saline conditions. Detached leaves also exhibited an increased proline level in response to the applied NaCl, however, at a lower magnitude than in the intact seedlings. The proline alleviated the inhibitory effect of the NaCl in a concentration-dependent manner, thereby suggesting that salinity is a strong inducer of proline accumulation. In addition, abscisic acid eliminated the inhibitory effect of the salt salinity, thereby indicating a protective role on salinity stress and a regulatory role in proline synthesis. Accordingly, it would appear that proline may be involved in salt tolerance.

• Journal of Plant Biology
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• 제38권2호
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• pp.143-151
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• 1995

Addition of plant growth hormones [0.01 mg/L NAA and 0.2mg/L benzyladenine (BA)] to a woody plant medium stimulated the adventitious bud formation of poplar explants during culture. Endogenous IAA content increased rapidly at the initial culture stage and then decreased, being followed by rapid increment again at the late culture. But the content of trans-zeatin riboside (t-ZR) increased continuously during the culture. Cytoplasmic soluble proteins were analyzed by one- and two-dimensional SDS-PAGE. Increased amount of 40 kD band was detected by one-dimensional electrophoresis using Coomassie Blue staining during the culture and two distinctive proteins whose mol wt is 40,000 were detected by two-dimensional electrophoresis using autoradiography and these proteins were synthesized continuously prior to the adventitious bud formation. When the midvein segments were transferred to the actinomycin D-containing medium, the spots of adventitious bud-related proteins(ABRPs) did not disappeared but weakened in intensity. So, it is concluded that genes coding for the ABRPs are regulated to some degree at the transcriptional level. Also, they were not observed in BA-free medium, suggesting that these proteins be regulated by cytokinin, which made then possible to form the adventitious bud.

• 한국식품영양학회지
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• 제21권4호
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• pp.430-435
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• 2008

The main cause of diabetic neuropathy, one of the most debilitating complications, is the chronic hyperglycemia, the increase sorbitol or the decrease of nerve growth factor(NGF). NGF, a protein, plays a major role in the development and maintenance of peripheral nervous system. Systemic administration of NGF prevents manifestations of neuropathy in rodent models of diabetic neuropathy. In the previous investigation, we report the hypoglycemia effect of Dioscorea rhizoma extract(DRE) in diabetic mice. The present study shows protective effect of DRE on diabetic neuropathy by induction of NGF protein. We investigated the NGF level in salivary gland and sciatic nerve of normal mouse and the effect of DRE on sciatic nerve conductivity and thermal hyperalgesia test in Type 2 db/db mouse. DRE increased endogenous NGF level in salivary gland and sciatic nerve of mouse. And sensory nerve conductivity velocity(SNCV), motor nerve conductivity velocity(MNCV) and thermal hyperalgesia increased in DRE treatment mice compared with control group. On the basis of our results, we conclude that DRE increase induction of endogenous NGF level and have protective effect on diabetic neuropathy by induction of NGF. Therefore, we propose that long-term use of DRE might help prevention of diabetes-associated complication; diabetic neuropathy.

• 자원ㆍ환경경제연구
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• 제18권3호
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• pp.523-544
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• 2009

본 연구는 목적은 내생적 환경정책모형(endogenous environmental policy)에 기초하여 외국인직접투자(foreign direct investment), 경제성장, 환경규제의 상호관계를 실증적으로 분석하는 것이다. 외국인자본비율의 1% 증가는 0.044%(고정효과), 0.047%(확률효과)의 경제성장효과를 유발하였으며, 노동자 1인당 생산량의 1% 증가는 2.038%(고정효과), 1.890%(확률효과)의 환경규제강화를 유도하는 것으로 계측되었다. 그러나 생산 과정에 있어 강력한 환경규제가 기술혁신의 유인으로 작용한다는 포터의 가설(Porter's theory)을 지지할 만한 실증결과는 보여주지 못하였다. 또한 2개의 대기오염물질 (NOx, $CO_2$)을 기준으로 규모효과(0.0119, 0.0172)가 기술효과(-0.0048, -0.0007)보다 크게 추정되었다. 이는 국제사회의 꾸준한 노력에도 불구하고 더욱 적극적인 환경보호를 위해 각국의 공공지출액을 증액시킬 필요성이 있음을 의미한다.

• 한국콘텐츠학회논문지
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• 제12권10호
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• pp.430-438
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• 2012

본 연구에서는 코스닥 증권시장에 상장된 벤처기업을 대상으로 내생적 성장 연구개발비가 기업가치에 미치는 영향을 분석하였다. 연구방법은 실증연구방법을 택하였으며, 다중회귀분석을 이용하여 코스닥에 상장된 벤처기업을 대상으로 검증을 실시하였다. 분석결과 벤처기업의 내생적 성장 연구개발비가 기업규모에 양(+)의 유의한 영향을 미치고 있는 것으로 나타났다. 반면 유형자산과 광고선전비 및 교육훈련비 등은 음(-)의 유의한 영향을 미치는 것으로 나타났다. 벤처기업의 기업규모가 기업가치에 양(+)의 유의한 영향을 보인 것은 기술개발을 중점적으로 추진하는 벤처기업의 특성상 내생적 성장 무형자산이 기업가치에 유의적인 영향을 미치고 있는 것으로 해석된다. 결론적으로 코스닥 등록 벤처기업의 내생적 성장 연구개발비와 기업가치 간에는 양(+)의 상관관계를 갖고 있는 것으로 검증되었고, 벤처기업은 개발비 등 무형자산에 대한 투자가 집중되는 기업의 특성으로 인하여 벤처기업의 기업규모(총자산)가 기업가치에 양(+)의 유의한 영향을 미치는 것으로 분석되었다.

• Clinical and Experimental Reproductive Medicine
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• 제20권1호
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• pp.37-43
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• 1993

In 27 patients with the past history of poor response to the gonadotropin superovulation induction due to poor follicular growth or permature surge of endogenous luteinizing hormone, the effectiveness of pituitary supperssion with the gonadotropin releasing hormone agonist(GnRH-a) in in vitro fertilization(IVF) program was evaluated in 43 cycles using a combination regimen of D-Trp-6 LHRH(Decapeptyl, Ferring)and FSH/hMG from June, 1989 to August, 1990 at Korea University Hospital IVF Clinic. At midluteal phase of menstrual cycle, Decapeptyl-CR was administered by long-term protocol to minimize initial agonistic effect of endogenous gonadotropins. After the confirmation of pituitary suppression, about 2-3 weeks after GNRH-a administration, ovarian follicle growth was stimulated with FSH/hMG and followed by transvaginal ultrasonic measurement of follicle size and by monitoring of serm E2 and LH if necessary. When compared with the control group stimulated with gonadotropin regimen only, the cancellation rate and occurrence rate of premature LH surge during gonadotropin treatment were significantly lower in study group(11.6% and 2.4%, respectively). There is no significant differences in the mean number of aspirated oocytes, fertilization/cleavage rate, embryo transfer(ET) rate, and mean number of embryos transferred between the two groups. The pregnancy rate per treatment cycle, 16.3%, and per ET cycle, 23.3%, were significantly higher in the study group compared with those of control group. These data suggest that GnRH-a therapy is effective for previous poor responder In gonadotropin superovulation induction for IVF.