• 한국약용작물학회지
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• 제17권3호
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• pp.192-197
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• 2009

Camptotheca acuminata, a native of South China is a well known natural source of monoterpene-indole alkaloid camptothecin(CPT), one of the most promising anti-tumoural compounds. This study was conducted to optimize plant growth regulators and culture conditions on plantlets regeneration through organogenesis from callus of Camptotheca acuminta. Callus were induced from various explants of in vitro germinated plantlets of C. acuminta using WPM medium containing 0.2 ㎎/L 2,4-D. Hypocotyl segments were exhibited higher embryogenic callus than the other explants. Shoot buds formation from embryogenic callus was affected by plant growth regulators, pre-treated dark condition and liquid culture. Organogenesis was optimal in WPM liquid medium containing 0.5 ㎎/L BA. The dark pre-treatment for 2 weeks before the solid culture was effective for organogenesis. The regenerated shoots were rooted in WPM medium with 0.2 ㎎/L NAA and successfully acclimated in green-house conditions.

• Nuclear Engineering and Technology
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• 제52권5호
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• pp.878-888
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• 2020

This paper presents the validation of UNIST in-house Monte Carlo code MCS used for the high-fidelity simulation of commercial pressurized water reactors (PWRs). Its focus is on the accurate, spatially detailed neutronic analyses of startup physics tests for the initial core of the Watts Bar Nuclear 1 reactor, which is a vital step in evaluating core phenomena in an operating nuclear power reactor. The MCS solutions for the Consortium for Advanced Simulation of Light Water Reactors (CASL) Virtual Environment for Reactor Applications (VERA) core physics benchmark progression problems 1 to 5 were verified with KENO-VI and Serpent 2 solutions for geometries ranging from a single-pin cell to a full core. MCS was also validated by comparing with results of reactor zero-power physics tests in a full-core simulation. MCS exhibits an excellent consistency against the measured data with a bias of ±3 pcm at the initial criticality whole-core problem. Furthermore, MCS solutions for rod worth are consistent with measured data, and reasonable agreement is obtained for the isothermal temperature coefficient and soluble boron worth. This favorable comparison with measured parameters exhibited by MCS continues to broaden its validation basis. These results provide confidence in MCS's capability in high-fidelity calculations for practical PWR cores.

• 한국자원식물학회지
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• 제21권3호
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• pp.210-215
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• 2008

Gene-expression analysis is increasingly important in biological research, with real-time reverse PCR (RTPCR) becoming the method of choice for high-throughput and accurate expression profiling of selected genes. However, this technique requires important preliminary work for standardizing and optimizing the many parameters involved in the analysis. Plant stress studies are more and more based on gene expression. The analysis of gene expression requires sensitive and reproducible measurements for specific mRNA sequence. Several genes are regulated in response to abitoic stresses, such as salinity, and their gene products function in stress response and tolerance. The design of the primers and TaqMan probes for real-time PCR assays were carried out using the Primer $Express^{TM}$ software 3.0. The PCR efficiency was estimated through the linear regression of the dilution curve. To understand the expression pattern of various genes under salt stressed condition, we have developed a unique public resource of 9 stress-related genes in poplar. In this study, real-time RT-PCR was used to quantify the transcript level of 10 genes (9 stress-related genes and 1 house keeping gene) that could play a role in adaptation of Populus davidiana. Real-time RT-PCR analyses exhibited different expression ratios of related genes. The data obtained showed that determination of mRNA levels could constitute a new approach to study the stress response of P. davidiana after adaptation during growth in salinity condition.

• 멤브레인
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• 제31권4호
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• pp.282-292
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• 2021

본 연구에서는 Dead-end와 Crossflow 시스템을 사용하여 유기용매 나노여과(Organic Solvent Nanofiltration, OSN) 상용분리막의 성능을 분석하였다. 가교된 polyimide 소재 기반의 Duramem (DM) OSN 분리막의 성능을 ethanol, dimethylformamide (DMF), acetone, acetonitrile 용매에서의 성능을 분석하였다. 네 종류의 분획분자량 성능을 갖는 DM 분리막의 성능을 평가하였을 때 dead-end보다 Crossflow에서 조금 더 정확하고 신뢰성 높은 결과를 얻을 수 있었으며, 동일한 분리막이더라도 용매의 특성에 따라 투과도와 선택도 차이가 크게 난다는 것을 확인할 수 있었다. 이는 압밀화현상으로 인한 초기 안정화 기간의 차이 때문인 것으로 판단되며 분리막마다 안정화기간이 다르므로 신뢰성 높은 결과를 얻기 위해선 Crossflow 시스템을 활용하는 것이 더 적합한 것으로 보인다.

• Journal of Forest and Environmental Science
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• 제26권3호
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• pp.171-179
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• 2010

Effect of chromium (Cr) stress on antioxidant enzyme activities and malondialdehyde (MDA) content were investigated in leaves and roots of mangrove (italic (L.) Druce) seedlings. Cr toxicity effects were also assessed on young seedlings. The seedlings were grown in green house condition for three months in nutrient solution with 0, 0.5, 1, 1.5, 2, 2.5, and 3 mg $L^{-1}$ $CrCl_3$. This study showed that Cr led to the change of antioxidant enzymes such as superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) and activities at different concentrations. The activity of antioxidant enzymes in leaves of K. candel seedlings indicates that enzymes engaged in antioxidant defense in certain level especially in low concentration of Cr treatments. The activities of SOD and POD were activated by Cr in the root level, while CAT activity was inhibited. CAT activity decreased in response to high concentrations of Cr. In the present study indicated that SOD in root was active in scavenging the superoxide produced by Cr. Both in roots and leaves, an increase in malondialdehyde (MDA) content was observed with increase in metal concentration and exposure periods. Our finding indicated that the high concentration of excessive Cr supply may interfere with several metabolic processes of seedlings, causing toxicity to plants as exhibited by chlorosis, necrosis, photosynthetic impairing and finally, plant death.

• 한국직업건강간호학회지
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• 제7권2호
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• pp.177-185
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• 1998

The purposes of this study were to investigate the effects of farming in greenhouses with respect to subjective fatigue symptoms among farmers and the degree of symptoms. The study compared 176 green-house farmers with 216 open field farmers using a subjective fatigue symptoms rating scale developed by the Industrial Research Institute of Fatigue, Japanese Association for industrial Hygiene. 1. With respect to complaint rates of the subjective fatigue symptoms, the results indicated that greenhouse farmers have, in order of severity, high degrees of low back pain, difficulty in collecting thoughts, and apt to forget. 2. With respect to cumulative scores of fatigue symptoms, the results indicated that both groups of farmers exhibited a lack of attentiveness and a high degree of dullness and sleepiness(category I), body projection of fatigue(category II), and difficulty in concentration(category III). 3. With respect to general characteristics, it was found that the degrees of subjective fatigue symptoms were found to be higher among females, people with lower educational levels, and the elderly, regardless of the group. 4. With respect to work related factors, farmers with more years of experiences were found to have higher degrees of subjective fatigue symptoms, except for open field farmers with less than nine years experience. Both groups of farmers were found to have high degrees of subjective fatigue symptoms when working less than eight hours a day and less than six months a year. 5. With respect to health habits, for people who get less than eight hours of sleep per day exhibited higher fatigue scores than people who get more than eight hours. People who do not smoke and drink also exhibited higher fatigue scores than people who smoke and drink. 6. The results of multiple regression showed that the risk factors related to the subjective fatigue symptoms of farmers in the greenhouse group were ages, levels of education, sex and for the comparison group, were sex. years of farming, and hours of sleep. The R-square were 12.5% in the greenhouse group and 12.1% in the comparison son group. The differences between the greenhouse and open field farmers in the degrees of fatigue symptoms were found not to be statistically significant even if the working conditions of the greenhouse farmers were poor. This may be attributed to non-work related factors, i.e., social, economical, and psychological factors among greenhouse farmers.

• Environmental Analysis Health and Toxicology
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• 제29권
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• pp.14.1-14.8
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• 2014

Objectives Some plants were placed in indoor locations frequented by asthmatics in order to evaluate the quality of indoor air and examine the health benefits to asthmatics. Methods The present study classified the participants into two groups: households of continuation and households of withdrawal by a quasi-experimental design. The households of continuation spent the two observation terms with indoor plants, whereas the households of withdrawal passed the former observation terms with indoor plants and went through the latter observation term without any indoor plants. Results The household of continuation showed a continual decrease in the indoor concentrations of volatile organic compounds (VOCs) during the entire observation period, but the household of withdrawal performed an increase in the indoor concentrations of VOCs, except formaldehyde and toluene during the latter observation term after the decrease during the former observation term. Peak expiratory flow rate (PEFR) increased in the households of continuation with the value of 13.9 L/min in the morning and 20.6 L/min in the evening, but decreased in the households of withdrawal with the value of -24.7 L/min in the morning and -30.2 L/min in the evening in the first experimental season. All of the households exhibited a decrease in the value of PEFR in the second experimental season. Conclusions Limitations to the generalizability of findings regarding the presence of plants indoors can be seen as a more general expression of such a benefit of human-environment relations.

• 생물환경조절학회지
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• 제25권1호
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• pp.71-75
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• 2016

본 연구는 비가림하우스 재배에서 정식시기가 여주의 생육 및 과실 수량에 미치는 영향을 조사하기 위하여 수행되었다. 여주의 정식시기는 각각 6월, 7월, 8월에 정식하는 3처리로 하였으며, 품종은 '드레곤'을 이용하여 재배하였다. 여주의 유인방법은 원줄기를 적심처리하고 아들줄기를 4개로 유인하여 재배하였다. 여주 식물체의 생육조사 결과 절간장은 정식시기에 따른 유의적인 차이가 없었다. 그러나 여주 식물체의 지제부 경경은 정식시기에 유의적인 차이가 있었다. 또한, 여주의 정식시기는 과실의 수량과 수확개수 증가에 효과적이었다. 과실의 상품과 수량은 6월 정식처리구에서 6,439kg/10a으로 가장 많았으며, 반면 8월 정식처리구에서 870kg/10a으로 가장 적었다. 과실의 상품과 수확개수도 6월 정식처리구에서 8월 정식처리구에 비하여 유의성 있게 증가하였다. 그러나, 과실의 과장과 과경은 정식시기에 따른 유의한 차이가 없었다. 따라서, 여주의 적정 정식시기는 6월에 정식하는 방법이 가장 적합하였다.

• 한국콘텐츠학회논문지
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• 제21권3호
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• pp.47-67
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• 2021

본 연구는 MZ세대가 추구하는 가치 소비가 패션 하우스의 코스메틱 소비 상황을 고려해 가치 소비에 대한 이해와 이들의 성향에서 관찰되는 양면적 소비 의도에 영향을 미치는 선행요인을 파악하기 위한 목적으로 하였다. 본 연구에서 제안하는 연구 모형과 연구 가설을 통계적 유의수준에서 검증하기 위해 MZ세대를 대상으로 설문조사를 실시하였고, 표본(총 286명)으로부터 수집된 자료는 구조방정식 모형 분석을 사용하였다. 그 결과, 감정적, 사회적 소비 가치는 MZ세대의 소비 의도에 큰 영향을 미치는 변수로 나타났다. 첫째, 자아존중감은 감정적 소비 가치에 영향을 미치는 것으로 통계적 유의수준에 나타났다. 둘째, 물질주의는 감정적, 사회적 소비 가치에 유의미한 영향을 주는 것으로 나타났다. 셋째, 공적 자기의식은 사회적 소비 가치에 영향을 미치는 것으로 나타났다. 즉, MZ세대들은 패션 하우스의 뷰티 브랜드에서 제시하는 뷰티 트렌드를 추구하고, 높은 소비 가치로 지각하며, 패션 하우스의 코스메틱을 사용함으로써 사회적으로 차별화될 수 있다는 과시적 소비성향을 가지고 있는 것으로 나타났다.

• 마이크로전자및패키징학회지
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• 제17권4호
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• pp.41-48
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• 2010

본 연구에서는 일액형 이방 도전성 페이스트(anisotropic conductive paste, ACP) 혼합 조성의 상온 보관성을 향상시키기 위해 2-methyl imidazole 경화 촉매제를 5종의 각기 다른 물질로써 encapsulation하였다. Encapsulation용 분말 물질들은 DSC를 통해 그 융점을 관찰하였으며, 이를 통해 encapsulation용 분말 물질들을 액상으로 용융시켜 encapsulation하는 공정이 가능함을 확인할 수 있었다. Encapsulation된 2-methyl imidazole 분말을 포함한 ACP 혼합물질의 상온 보관성을 평가하기 위하여 시간에 따른 점도 변화가 관찰되었다. 그 결과, stearic acid와 carnauba wax로 encapsulation된 2-methyl imidazole 분말을 포함한 혼합물질에서 향상된 상온 보관성을 관찰할 수 있었으며, 이러한 formulation은 기본 혼합물질과도 유사한 경화 거동을 보임을 확인할 수 있었다. 최종적으로 stearic acid와 carnauba wax로 encapsulation된 2-methyl imidazole 분말을 포함한 혼합물질을 사용하여 RFID 칩을 제조된 안테나 패턴이 형성된 PET 기판에 고속 플립칩 본딩을 실시하였다. 이 경우 측정된 접합 강도는 기본 혼합물질에 비해 약 37%의 수준인 것으로 측정되었다.