• Journal of Plant Biology
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• 제32권4호
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• pp.265-274
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• 1989

The effect of Ca2+ on auxin-induced ehtylene production in etiolated mungbean (Vigna radiata W.) hypocotyls was studied. Auxin-induced ethylene production by mungbean seedlings which had been germinated in the presence of 5-10mM Ca2+ (High Ca2+ ; HC) is greater than that by seedlings which had been germinated in distilled water (Low Ca2+ ; LC). The effect of Ca2+ on auxin-induced ethylene production was greatly increased after 12hr of incubation period. The stimulation of auxin-induced ethylene production by Ca2+ was specific, since divalent cations, such as Mg2+ and Mn2+ did not enhance auxin-induced ethylene production. Calcium also promoted ethylene evoluation induced by methionine and 1-Aminocyclopropane-1-carboxylic acid(ACC). The effect of Ca2+ on auxin-induced ethylene production was not caused by increase in free IAA or ACC contents of hypocotyl tissue. Dimethyl sulfoxide and Triton X-100, that disrupts the emembranes, inhibited ethylene production to a greater extent in LC segments than in HC segments. Addition of Ca2+ to the incubation medium for LC segments resulted in enchancement of ethylene production probalby because the membrane integrity is supported under these conditions. Comparison of activity of Ethylene Forming Enzyme(EFE) in LC and HC hypocotyl segments indicated that the enzyme activity of HC was about 2 times higher than that of L.C. It is suggested that Ca2+ increases the activity of plasma membrane-bound EFE through its stabilizing effect onn the membrane, which in turn brings about promotion of ethylene production.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 1998년도 제11회 학술강연회논문집
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• pp.25-25
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• 1998

최근의 선진국의 전략미사일에 사용되는 추진제 개발 방향은 고에너지, 저민감, 무연 및 무공해 추진제를 목표로 하고 있다. 현재까지 가장 널리 사용되어온 AP는 성능이나 기계적 특성에서 우수한 산화제이나 로켓 모타 배출기체 중에 HC1을 생성함으로써 2차 연기를 생성하며, HC1 자체가 인체에 유해한 물질이라는 단점들을 가지고 있다. 또한 RDX나 HMX는 에너지가 높은 반면 쇽(shock)에 대해 매우 민감한 단점을 가지고 있다. AN은 이러한 HC1을 생성하는 AP의 단점과 쇽에 민감한 RDX와 HMX의 단점을 해결할 수 있는 대체 산화제로 사용할 수 있으나, 성능이 대외적으로 떨어지며 상변이와 흡습성이 높은 단점이 있다. ADN은 -100~+10$0^{\circ}C$범위에서 상 변이가 없고 밀도는 1.801g/㎤, Hf는 -290cal/g이다. ADN을 산화제로 사용하면 HTPB/AP 추진제와 동등하거나 그 이상의 성능을 갖는 추진제를 만들 수가 있으며, 유해 기체인 HC1을 배출하지 않음으로 인하여 2차 연기를 없애는 장점이 있다.

• 한국자동차공학회논문집
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• 제8권2호
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• pp.33-40
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• 2000

In order to investigate the exhaust structure and secondary oxidation of unburned hydrocarbon (HC) in the exhaust port, a numerical simulation was performed with 3-dimensional flow model and oxidation mechanism optimized for port oxidation. To predict the exhaust and oxidation process with consideration of flow, mixing, and temperature, 3-dimensional flow model and HC oxidation model were used with a commercial computational program, STAR-CD. The flow model were with moving grid for valve motion, which could predict the change of flow field with respect to valve lift. Optimization was performed to predict the HC oxidation with temperature range of 1200~1500K, low HC and oxygen concentration, existence of intermediate species, as typical in port oxidation. The constructed model could predict the port oxidation process with oxidation degree of 14~48% according to the engine operation conditions.

• 생명과학회지
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• 제33권1호
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• pp.73-81
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• 2023

본 연구에서는 어성초(Houttuynia cordata, HC) 와 야관문(Lespedeza cuneata, LC)의 열수 추출물과 메탄올 추출물의 순차적 유기용매 분획물을 제조하였다. LPS를 처리한 RAW264.7세포에서 HC와 LC의 열수 추출물과 메탄올 추출물의 유기용매 분획물의 항염증 활성을 연구하였다. 어성초와 야관문의 hexane, chloroform, ethyl acetate 분획물의 처리에 의해 농도의존적으로 nitric oxide (NO) 생산을 저해하였으며, iNOS의 발현도 감소되었다. 이전 연구에서 HC와 LC의 메탄올 추출물의 ethyl acetate 분획물의 플라보노이드 함량을 분석하였다. 분석된 플라보노이드 중 HC와 LC에 공통적으로 함유된 apigenin을 선택하여 추가실험을 진행하였다. Apigenin은 세포 생존율에 영향을 주지 않으면서 NO 생산을 저해하였으며, iNOS와 COX-2의 단백질 발현도 억제하였다. 또한, apigenin은 p38 MAPK와 JNK의 인산화를 억제함으로써 항염증 활성을 가지는 것으로 생각된다. Apigenin 처리에 의해 차별적으로 발현되는 유전자 발현을 확인하기 위하여 RNA-seq 분석을 수행하였다. 발현이 감소된 유전자 중 4개의 cytokine 유전자(IL-1α, IL-1β, IL-6, CSF2)의 발현 감소를 정량적 real-time PCR을 통해 확인하였다. 종합적으로, 본 연구결과는 어성초와 야관문은 항염증 활성을 가지고 있으며, apigenin이 두 약용 작물의 항염증 활성을 담당하는 중요한 성분 중의 하나가 될 수 있다는 것을 제시한다.

• 가정∙방문간호학회지
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• 제21권2호
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• pp.127-138
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• 2014

Purpose: The objectives of this study were to analyze the state of hospital-based home care (HC) services annually and to provide basic information for research and policy regarding home care. Methods: This study is a secondary analysis of the yearly state of HC services from the Health Insurance Review & Assessment Services from 2007 to 2012. Results: The decreased by 34.6%, from 214 agencies in 2007 to 140 in 2012. The annual average number of active home care nurses was 440, which included 6.7% of the licensed home care nurses until 2012. The annual average number of HC patients were 32,000, and this number decreased by 21% in 2012, compared to that of 2008. Of the HC patients, about 70% were over 60 years of age. The chronic diseases among HC patients have been decreasing steadily since 2007. Seventy to eighty percent of the home visits were made in general hospitals or higher level hospitals. The total medical cost for HC services was 21 billion won in 2007, which consisted of 0.06% of the national medical costs, and it was 22 billion won and 0.03% in 2012. Conclusion: Based on the results of this study, further research on HC services is necessary to frame policies for the expansion of HC agencies.

• Journal of Preventive Medicine and Public Health
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• 제54권1호
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• pp.73-80
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• 2021

Objectives: Household overcrowding (HC) can contribute to both physical and mental disorders among the members of overcrowded households. This study aimed to measure the status of HC and its main determinants across the provinces of Iran. Methods: Data from 39 864 households from the 2016 Iranian Household Income and Expenditures Survey were used in this study. The Equivalized Crowding Index (ECI) and HC index were applied to measure the overcrowding of households. Regression models were estimated to show the relationships between different variables and the ECI. Results: The overall, urban, and rural prevalence of HC was 8.2%, 6.3%, and 10.1%, respectively. The highest prevalence of HC was found in Sistan and Baluchestan Province (28.7%), while the lowest was found in Guilan Province (1.8%). The number of men in the household, rural residency, the average age of household members, yearly income, and the household wealth index were identified as the main determinants of the ECI and HC. Conclusions: The study demonstrated that the ECI and HC were higher in regions near the borders of Iran than in other regions. Therefore, health promotion and empowerment strategies are required to avoid the negative consequences of HC, and screening programs are needed to identify at-risk families.

• 생명과학회지
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• 제28권12호
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• pp.1406-1415
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• 2018

본 연구는 어성초(Houttuynia cordata Thunb)의 메탄올 추출에 의한 유기 용매별 분획물에서 항산화 효과를 근거로 산화적 스트레스에 의한 HaCaT 세포보호 효과를 확인하였다. 용매별 분획물의 항산화 활성은 시료의 농도가 증가할수록 DPPH에 대한 전자공여능도 증가하였으며, $ED_{50}$은 ethyl acetate (EtOAc) 분획물에서 $175{\mu}g/ml$로 가장 높게 나타났다. $H_2O_2$에 의해 유도된 HaCaT 세포의 세포사멸($IC_{50}$)에 대하여 Hc-EtOAc 분획물은 농도 의존적으로 유의적인 세포 생존율과, $100{\mu}g/ml$ 농도에서 74%의 세포보호 효과를 나타내었다. 한편 $100{\mu}g/ml$의 Hc-EtOAc 분획물을 6 및 24시간 동안 HaCaT 세포에 처리하여 유전자 발현 양상을 분석하였다. 2 배 이상 발현이 증가된 유전자들은 신호전달, 세포분열, 항산화 활성, 상피세포 증식 등에 작용하는 것으로 나타났다. 특히 항산화 활성에 관여할 것으로 추정되는 유전자는 전염증성 사이토카인인 IL1B, TNF, 그리고 IL6 등 이었으며, 이들 유전자의 상위 조절자로써 TLR4가 확인되었다. IL1B, TNF, 그리고 IL6 유전자의 활성을 검증하기 위하여 qRT-PCR을 수행한 결과, $100{\mu}g/ml$ 이상의 Hc-EtOAc 분획물 처리군에서 2 배 이상 발현이 증가한 것으로 나타났다. 상위 조절자 TLR4 단백질의 활성 역시 Hc-EtOAc 분획물에 의해 증가되었다. 이상의 결과, Hc-EtOAc 분획물에 의한 항산화 활성은 TLR4로부터 IL1B, TNF, IL6과 같은 사이토카인을 경유하는 것으로 예측된다.

• International Journal of Industrial Entomology and Biomaterials
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• 제22권2호
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• pp.75-82
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• 2011

To elucidate the novelty of Hyphantria cunea nucleopolyhedrovirus (HcNPV) isolated in Korea, polyhedrin and inhibitor of apoptosis (iap) gene structures were determined and analyzed. The analysis of HcNPV polyhedrin showed a little difference with 97.6% at the nucleotide level but no difference at the amino acid level when compared with that of previously reported H. cunea NPV (HycuNPV). On the other hand, iap genes showed variable differences with 89.0-99.6% nucleotide and 90.0-99.6% amino acid sequence identities. Especially, the 5' and 3' non-coding flanking sequences of iap1 gene had lower degree of identity with those of HycuNPV. Although the phylogenetic analyses using polyhedrin and iap genes showed that HcNPV is closely related with HycuNPV, we could provide that HcNPV is a novel isolate having novel gene structures.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2021년도 춘계학술대회
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• pp.112-112
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• 2021

• Carbon letters
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• 제16권1호
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• pp.45-50
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• 2015

High crystallinity coke-based activated carbon (hc-AC) is prepared using a potassium hydroxide solution to adsorb carbon dioxide ($CO_2$). The $CO_2$ adsorption characteristics of the prepared hc-AC are investigated at different temperatures. The X-ray diffraction patterns indicate that pitch-based cokes prepared under high temperature and pressure have a high crystal structure. The textural properties of hc-AC indicate that it consists mainly of slit-like pores. Compared to other textural forms of AC that have higher pore volumes, this slit-pore-shaped hc-AC exhibits higher $CO_2$ adsorption due to the similar shape between its pores and $CO_2$ molecules. Additionally, in these high-crystallinity cokes, the main factor affecting $CO_2$ adsorption at lower temperature is the pore structure, whereas the presence of oxygen functional groups on the surface has a greater impact on $CO_2$ adsorption at higher temperature.