• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2001년도 추계학술발표대회
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• pp.367-369
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• 2001

Recombinant lipase gene (pYEGA ${\alpha}$ -lip) originated from Bacillus stearothermophillus Ll was overexpressed in Saccharomyces cerevisiae. The lipase gene expression level was compared by controlling a constant specifjc growth rates( ${\mu}$ = 0.03, 0.05, 0.07 and $0.1h^{-1}$. Cell g개wth was successfully controlled at the desired rates by feeding rate of glucose and the formation of by-product or accumulation of the glucose was not observed. Above the growth rate of $0.1h^{-1}$. the desired growth rate could not be achieved caused accumulation of by-products(ethanol). The lipase production increased as the specific growth rate decreased. The specific production rate at the lowest specific growth rater(${\mu}$ =0.03) was above 2- folds than the others.

• The Korean Journal of Ecology
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• 제27권5호
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• pp.301-306
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• 2004

The sensitivity to Cd of three ectomycorrhizal fungi, Paxillus involutus, Suillus bovinus and Rhizopogon subcaerulescens, was assessed and compared in terms of radial growth and dry mass production, using both agar and liquid culture. The radial growth of S. bovinus and R. subcaerulescens was significantly reduced at the lowest concentration (0.1mg Cd/L). The 50% effective concentration (EC$_{50}$) values calculated from radial growth rates of the ectomycorrhizal fungi showed that the sensitivity of the fungi to Cd was greatest in S. bovinus and lowest in R. subcaerulescens. Cadmium addition also significantly decreased dry mass production of the ectomycorrhizal fungi. The sensitivity of the fungi to Cd in terms of dry mass production, was greatest in S. bovinus and lowest in P. involutus. Higher growth rates of P. involutus and melanisation of R. subcaerulescens appeared to contribute to reduced Cd toxicity.

• 한국기계가공학회지
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• 제18권4호
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• pp.87-92
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• 2019

In this paper, a closed hydroponics device was designed and fabricated to grow and harvest plants in a small space for safe consumption, which enables horticultural activities that are difficult to perform due to space constraints from urbanization. This device also aimed to minimize the air pollution of crops. To obtain data for the optimal growth conditions for crops in this intelligent plant-growing system, sensors were used to measure and control the growth conditions. To investigate the optimal growth conditions, blue lettuce and crown daisy were selected as representative crops. The growth rates were comparatively analyzed through four experiments for each plant. This hydroponics device was used to collect data on growth rates that are altered depending on cultivation conditions, which can then be used to study methods to control the growth rate of crops.

• Asian Pacific Journal of Cancer Prevention
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• 제16권9호
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• pp.4115-4121
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• 2015

Background: Colorectal cancer is the second most common cause of cancer death with half a million deaths per year. Incidence and mortality rates have demonstrated notable changes in Asian and African countries during the last few decades. In this study, we first aimed to determine the trend of colorectal cancer mortality rate in each Institute for Health Metrics and Evaluation (IHME) region, and then re-classify them to find more homogenous classes. Materials and Methods: Our study population consisted of 52 countries of Asia and North Africa in six IHME pre-defined regions for both genders and age-standardized groups from 1990 to 2010.We first applied simple growth models for pre-defined IHME regions to estimate the intercepts and slopes of mortality rate trends. Then, we clustered the 52 described countries using the latent growth mixture modeling approach for classifying them based on their colorectal mortality rates over time. Results: Statistical analysis revealed that males and people in high income Asia pacific and East Asia countries were at greater risk of death from colon and rectum cancer. In addition, South Asia region had the lowest rates of mortality due to this cancer. Simple growth modeling showed that majority of IHME regions had decreasing trend in mortality rate of colorectal cancer. However, re-classification these countries based on their mortality trend using the latent growth mixture model resulted in more homogeneous classes according to colorectal mortality trend. Conclusions: In general, our statistical analyses showed that most Asian and North African countries had upward trend in their colorectal cancer mortality. We therefore urge the health policy makers in these countries to evaluate the causes of growing mortality and study the interventional programs of successful countries in managing the consequences of this cancer.

• Animal cells and systems
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• 제14권4호
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• pp.315-322
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• 2010

We studied and compared the age structure, body size, and growth rates of field populations of two Korean salamander species (Hynobius yangi and Hynobius quelpaertensis) to elucidate important aspects of basic population dynamics of these two endemic Hynobius species. In both populations, females were sexually mature at three years of age, while H. yangi and H. quelpaertensis males matured at two and three years of age, respectively. Both males and females of H. yangi and H. quelpaertensis attained a maximum age of 11 years and 10 years, respectively. In both species, the snout-vent length (SVL) and body weight (BW) of the females were greater than those of the males. The SVL, BW, and asymptotic SVL of both male and female H. yangi were smaller than those of H. quelpaertensis. The adult growth rates after sexual maturation of male and female H. yangi were lower than those of H. quelpaertensis, possibly resulting in the smaller body size of the former, although overall growth coefficients were not significantly different between the two species. We also compared the age structure and growth rates of three Korean and three Japanese species of Hynobius.

• ALGAE
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• 제37권1호
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• pp.49-62
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• 2022

Water temperature affects plankton survival and growth. The dinoflagellate Shimiella gracilenta survives using the plastids of ingested prey, indicating kleptoplastidy. However, studies on the effects of water temperature on kleptoplastidic dinoflagellates are lacking. We explored the growth and ingestion rates of S. gracilenta as a function of water temperature. Furthermore, using data on its spatiotemporal distribution in Korean coastal waters during 2015-2018, we predicted its distribution under elevated temperature conditions of +2, +4, and +6℃. Growth rates of S. gracilenta with and without Teleaulax amphioxeia prey as well as ingestion rates were significantly affected by water temperature. Growth rates of S. gracilenta with and without prey were positive or zero at 5-25℃ but were negative at ≥30℃. The maximum growth rate of S. gracilenta with T. amphioxeia was 0.85 d^-1, achieved at 25℃, and 0.21 d^-1 at 20℃ without prey. The ingestion rate of S. gracilenta on T. amphioxeia at 25℃ (0.05 ng C predator^-1 d^-1) was greater than that at 20℃ (0.04 ng C predator^-1 d^-1). Thus, feeding may shift the optimal temperature for the maximum growth rate of S. gracilenta from 20 to 25℃. In spring and winter, the distributions of S. gracilenta under elevated temperature conditions were predicted not to differ from those during 2015-2018. However, S. gracilenta was predicted not to survive at some additional stations under elevated temperature conditions of +2, +4, and +6℃ in summer or under elevated temperature conditions of +6℃ in autumn. Therefore, global warming may affect the distribution of S. gracilenta.

• 한국가축번식학회지
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• 제21권2호
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• pp.177-183
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• 1997

The present study examined the effects of epidermal growth factor(EGF) and transforming growth factor-$\alpha$(TGF-$\alpha$) on in vitro maturation of porcine follicular oocytes. Basic medium used TCM-HEPES, and oocytes cultured for 42 hours in vitro. The results obtained are as follows; 1. The nuclear maturation rates of EGF-treated groups(10ng/ml, 75.9% ; 30ng/ml, 69.2% ; 50ng/ml, 67.2% ; 100ng/ml, 71.0%) on the porcine oocytes cultured in medium without pFF in vitro were significantly(P<0.01) higher than those of non-treated group(57.1%). When the oocytes were cultured in media with 10%(v/v) pFF, the nuclear maturation rates of 30ng EGF/ml(77.1%) treated group were significantly(P<0.01) higher than those of non-(59.2%) and EGF-treated groups(10ng/ml, 65.4% ; 50ng/ml, 65.5% ; 100ng/ml, 70.4%). 2. The nuclear maturation rates of 30ng TGF-$\alpha$/ml treated group(71.9%) in media without pFF in vitro were significatnly(P<0.01) higher than those of non-(57.1%) and TGF-$\alpha$ treated groups(10ng/ml, 60.4% ; 50ng/ml, 65.4% ; 100ng/ml, 60.0%). When the oocytes were cultured in media with 10%(v/v) pFF, the nuclear maturation rates of 30 and 50ng TGF-$\alpha$/ml(77.4% and 79.6%) treated groups(10ng/ml, 64.2% ; 100ng/ml, 61.6%). 3. On the effect of EGF(30ng/ml) and/or TGF-$\alpha$(30ng/ml) treated groups in medium without pFF in vitro, the nuclear maturation rates indicated 57.3, 60.4, 75.9 and 79.7% in media with no EGF & TFG-$\alpha$, TGF-$\alpha$ only, EGF only nad EGF＋TGF-$\alpha$ treated groups, respectively. The nuclear maturation rates in medium with EGF only or EGF＋TGF-$\alpha$ were significantly(P<0.01) higher than those non- and TGF-$\alpha$ treated groups. When the oocytes were cultured in media with 10%(v/v) pFF, the nuclear maturation ratesof EGF＋TGF-$\alpha$ treated group(75.9%) were significantly(P<0.01) higher than those of non-(59.2%), TGF-$\alpha$ only (64.2%) and EGF only(69.4%) treated groups.

• 식물조직배양학회지
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• 제27권3호
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• pp.155-161
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• 2000

야생 흰 제비꽃 (viola patrinii DC.)의 callus로부터 분열 활성이 높고 균일한 세포주의 생산성 향상을 위한 현탁배양 방법이 세포의 생장에 미치는 영향에 관하여 조사한 결과는 다음과 같다. Compact callus의 세포생장을 위해서 배지의 종류를 MS, B5, R2, White배지로 나누어서 실험한 결과 MS배지와 R2 배지의 callus 생육이 양호하였으며, White배지를 사용시에는 횐 callus에 붉은 색소 (시코닌계 색소)가 생산되었다. 무기염의 농도에서는 생체중은 MS 기본배지에서 건물중은 1/2 NH$_4$NO$_3$, 1/2 KNO$_3$가 가장 좋았다. 배지중의 NH$_{4}$$^{+}$ 와 HO$_{3}$$^{-}$ 농도비를 100:0, 75:25, 50:50, 25:75, 0:100로 한 결과 25:75의 비에서 생육이 가장 양호하였으며, NH$_{4}$$^{+}$ 의 농도가 낮아질수록 세포에 붉은 색소가 생성되는 경향을 보였다. Casein Hydrolysate (CH)의 농도가 세포의 생장에 미치는 영향은 5 g/L 첨가시 생체중, 건물중 모두 높았다. 조직학적 관찰에 있어서는 2~4주간 된 callus는 대부분의 세포의 크기가 작고 세포질이 농후한 상태로 비교적 균일한 세포로 구성되어 있고 액포화가 거의 이루어지지 않은 상태로 세포의 분열이 왕성하게 이루어지고 있음을 관찰할 수 있었고, 6주간 배양된 callus는 신장되고 액포화된 세포들이 많이 관찰되었다.

• 상하수도학회지
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• 제10권3호
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• pp.55-63
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• 1996

Nitrification reaction consists of two reactions: nitritification which oxidizes ammonia nitrogen to nitrite nitrogen and nitratification which oxidizes nitrite nitrogen to nitrate nitrogen. Each reaction is carried out by Nitrosomonas and Nitrobacter, respectively. The effective maximum growth rates for both bacteria have to be determined to design aeration tank whenever the aeration tanks have to nitrify ammonia nitrogen in influent. And these values are very important to use mathematical models such as IAWPRC model to simulate nitrification in activated sludge. There are several methods to determine these valves, however, the Fed-Batch experiments can determine these values within 72 hours. In this study, the mathematical equations and experimental procedures for Fed-Batch test are presented. Also, the experimental data and reported values are compared. The estimated mean values of maximum specific growth rates for Nitrosomonas and Nitrobacter are $0.5010day^{-1}$ and $0.6704day^{-1}$, respectively.

• Ocean and Polar Research
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• 제25권1호
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• pp.1-7
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• 2003

The purpose of this study was to determine changes in the growth rates and the degree of shell bioerosion exhibited by endolithic organisms of the Japanese scallop family, Patinopecten (Mizuhopecten) yessoensis, on the coast of Furugelm Island (Peter the Great Bay, northwest of East Sea = Sea of Japan) over the last three decades. The areas studied are affected by lumen (Tumangang) River run-off, which is enriched by organic matter and polluting agents. It was found that the linear growth rates of the Japanese scallops living along the coasts of Furugelm Island have decreased over the last three decades. The degree of bioerosion of scallop shells has significantly increased for the same period. These phenomena may be explained by a gradual increase in bottom sediment silting, organic enrichment and pollution of the areas being studied. It was found that the degree of scallop shell bioerosion increased with the scallop's age. At present, In each age group, the shells of the scallops sampled from the muddy sand showed greater erosion than the shells of individuals collected from the sandy substrate.