• 한국환경과학회지
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• 제31권4호
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• pp.311-318
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• 2022

In this study, we analyzed the relationships between weather factors and photosystem II activity (F_v/F_m), as a measure of photochemical efficiency, in three cool-season turfgrasses commonly planted on golf courses in Jeju, South Korea: perennial ryegrass (Lolium perenne L.), Kentucky bluegrass (Poa pratensis L.), and creeping bentgrass (Agrostis palustris Huds.). In all three turfgrasses, F_v/F_m was higher during late summer than during early summer. However, in late summer, F_v/F_m was significantly lower in perennial ryegrass than in the other two species. In early summer, F_v/F_m in perennial ryegrass and Kentucky bluegrass was positively correlated with mean low temperature and extreme minimum temperature, whereas, in late summer, this parameter in Kentucky bluegrass and creeping bentgrass was positively correlated with relative humidity, and in creeping bentgrass was negatively correlated with mean high temperature, mean low temperature, and extreme maximum temperature. These results indicate that raising low temperatures is favorable for perennial ryegrass and Kentucky bluegrass in early summer, whereas, in late summer, the lowering of high temperatures proves to be beneficial for creeping bentgrass, and raising relative humidity is conducive to the growth of Kentucky bluegrass and creeping bentgrass. These findings will contribute to improving the selection and management of turfgrasses on golf courses and sports fields.

• Journal of Microbiology and Biotechnology
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• 제11권4호
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• pp.720-723
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• 2001

The effect of long-term storage on garlic antibacterial activity was investigated. A concentration of 5% or more garlic was found to be necessary to completely inhibit Eschrichia coli growth in tryptic soy broth. This value is substantially higher than the minimum inhibitory concentration of 1% for E. coli reported previously. pH-modified garlic extract was stored at different temperatures to investigate the impact of storage conditions (i.e., temperature, pH, period of storage) on the stability of the antibacterial activity of the garlic extract used against E. coli B34. The antibacterial effectiveness of the garlic extract against E. coli remained stable when both the storage temperature and the pH of the extract were kept low. When the garlic extract was stored at $40^{\circ}C and above, most or all of the garlic antibacterial activity disappeared after a 24-h storage period, regardless of the storage pH. The antibacterial activity was weakened when the pH of the garlic extract was adjusted to 8, and at low temperatures.

• 한국토양비료학회지
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• 제31권2호
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• pp.158-161
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• 1998

본 연구는 벼의 저온발아중 생채내의 ${\alpha}$-amylase 활성, 유리 proline함량, 생육특성 등 몇가지 실험을 수행하였던 바 얻어진 결과를 요약하면 저온발아시 초장은 품종간에 차이를 보이지는 않았지만 저온발아성이 다소 강한 대야벼가 3.9cm로 가장 우세하였으며 근장은 동진벼에서 4.8cm로 매우 양호한 생육현상을 보이는 것으로 나타났다. 벼 품종간 발아일수에 따른 ${\alpha}$-amylase 활성은 발아 후 3일째 고시히까리가 가장 낮은 65.4 mg인 반면에 동진벼는 80.9 mg 으로 매우 높은 활성을 보였다. 유리 proline 함량변화는 발아 후 3일째 저온발아능력이 다소 약한 품종인 상주벼와 고시히까리가 각각 $1.807{\mu}mole$, $1,800{\mu}mole$인 것보다 다소 강한 품종인 동진벼와 대야벼가 각각 $1,933{\mu}mole$, $1,895{\mu}mole$로 높은 함량변화를 보였다.

• Journal of Plant Biology
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• 제32권4호
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• pp.235-245
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• 1989

The contents and the compositions of total free amino acids were investigated in the rice(Oryza sativa L. cv. Chuncheong) seedlings under low temperatures. Activities of some enzymes associated with the markedly changed amino acid content were also investigaetd. Under low temperature, the contents of soluble protein and the total free amino acids increased, while the content of total nitrogen decreased. Although asparagine＋glycine were the most abundant amino acid speceis in the rice seedlings at the control temeprature, low temperature treatment for 3days brought about the decrease in their amount to about 60% level of the control plants. On the other hand, alanine showed the highest increase in the content among all the free amino acids, though glutamine, proline, asprtic acid, valine and tyrosine also increased after low temperature treatment. To eludicate the decrease of asparagine＋glycine level under low temperature, the activities of asparagine aminotransferase and asparaginase which metabolize asparagine were investigated in the rice seedlings under low temperature. The activity of asparaginase increased markedly, while that of asparagine aminotransferase decreased under low temperatures. Therefore, it was suggested that asparaginase metabolizes asparagine predominatly in the rice seedlings under low temperatures.

• 대한본초학회지
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• 제22권4호
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• pp.177-185
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• 2007

Objectives : The present study purposed to compare the anti-oxidative effect of Fructificatio Inonoti Obliqui aqueous extract according to extraction temperature. Methods : We measured the total phenol content and anti-oxidative activity of Fructificatio Inonoti Obliqui total extract and $50^{\circ}C$ low-temperature leachate. Results : Anti-oxidative activity of Fructificatio Inonoti Obliqui total extract and $50^{\circ}C$ low-temperature leachate was different according to extraction temperature, concentration, and antioxidant effect measuring method. In all experiments, the total extract showed higher antioxidant than n-BuOH fraction. The total phenol content was higher in Fructificatio Inonoti Obliqui total extract than $50^{\circ}C$ low-temperature leachate. Conclusions : Both Fructificatio Inonoti Obliqui total extract and Fructificatio Inonoti Obliqui $50^{\circ}C$ low-temperature leachate have significant anti-oxidative effect.

• 대한본초학회지
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• 제22권4호
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• pp.187-199
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• 2007

Objectives : The present study purposed to compare the antioxidant effect, anti inflammatory effect and cancer cell multiplication inhibition effect of Fructificatio Inonoti Obliqui aqueous extract according to extraction temperature. Methods : We medicated animal models, which had experimental oxidation, with Fructificatio Inonoti Obliqui total extract and $50^{\circ}C$ low temperature leachate, and performed hematological analysis and blood chemical analysis with measuring SOD, GSH, catalase, NO and MDA content in the liver. In addition, we made comparative observation of anti inflammatory effect and anti-cancer effect. Results : Compared to the control group, both the group medicated with Fructificatio Inonoti Obliqui total extract and with $50^{\circ}C$ low-temperature leachate were found to decrease the number of thrombocytes in blood plasma and NO content while to increase SOD activity and catalase activity significantly. Both groups also showed anti-inflammatory effect against THP-1 cells and a multiplication inhibition effect against liver cancer cells and stomach cancer cells significantly. Conclusions : Both Fructificatio Inonoti Obliqui total extract and Fructificatio Inonoti Obliqui $50^{\circ}C$ low-temperature leachate have significant antioxidant effect, anti inflammatory effect and anti cancer effect.

• International Journal of Industrial Entomology and Biomaterials
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• 제41권2호
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• pp.36-44
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• 2020

Mulberry root bark is one of potential plant sources for antioxidant materials which can be used for the relief of oxidative stress. To explore the effects of solvent type and temperature on the structural characteristics and antioxidant activity of the root bark extracts, we prepared various extracts of mulberry root bark (Morus alba L.) using 0 - 100 % ethanol (EtOH) at RT - 100℃. EtOH concentration and temperature critically affected the extraction yields, the content of bioactive components, and antioxidant activity of the extracts. Use of high content of EtOH solvent and low temperature resulted in the low extraction yield. Meanwhile, it was revealed that the extract prepared using absolute EtOH at room temperature contained polyphenols and flavonoids with the highest contents among other extracts. Interestingly, the temperature differently affected the polyphenol and flavonoid contents according to the solvent types. In the case of 30% EtOH solvent, polyphenol and flavonoid contents increased with an increase in temperature, whereas in the case of 70 and 100 % EtOH, these contents decreased. Using the radical scavenging assay, it was confirmed that the 100% EtOH extracts had higher antioxidant activity compared to distilled water (DW) extracts regardless of temperature. Also, heating might extract more antioxidant components from the root bark. Especially, the extract prepared using 30% EtOH solvent at 100℃ showed the highest antioxidant activity. Taken together, these experimental results imply that the extraction parameters should be designed carefully considering the productivity, the extracted bioactive components, and antioxidant activity.

• 한국환경과학회지
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• 제13권6호
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• pp.537-542
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• 2004

$V_{2}O_{5}/TiO_{2}$ catalysts promoted with Mn were prepared and tested for selective catalytic reduction of NOx in $NH_3.$ The effects of promoter content, degree of catalyst loading were investigated for NOx activity while changing temperatures, mole ratio, space velocity and $O_2$ concentration. Among the various $V-{2}O_{5}$ catalysts having different metal loadings, $V-{2}O_{5}$(1 wt.%) catalyst showed the highest activity(98%) under wide temperature range of $200-250^{\circ}C.$ When the $V-{2}O_{5}$ catalyst was further modified with 5 wt.% Mn as a promoter, the highest activity(90-47%) was obtained over the low temperature windows of $100-200^{\circ}C.$ From Mn-$V_{2}O_{5}/TiO_{2}$, it was found that by addition of 5 wt.% Mn on $V_{2}O_{5}/TiO_{2}$ catalyst, reduction activity of catalyst was improved, which resulted in the increase of catalytic activity and NOx reduction. According to the results, NOx removal decreased for 10%, but the reaction temperature down to $100^{\circ}C.$

• 대한환경공학회지
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• 제22권3호
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• pp.511-521
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• 2000

디젤자동차와 같이 희박연소 상태에서 많이 배출되는 질소산화물을 선택적 촉매환원(SCR)으로 제거하기 위하여 제올라이트와 금속산화물을 조합한 촉매를 석영 반응로에서 설험하였다. 환원제는 자동차 배출가스에 포함되어 있어 실용 가능성이 크다고 판단되는 탄화수소 중 안전성 및 환원효율이 좋은 올레핀계 탄화수소인 프로필렌을 사용하였다. 본 연구에서는 제올라이트 및 금속산화물계의 단일촉매 상태에서의 NOx 전환율을 파악하고, 저옹 및 고온에서 활성이 다른 촉매를 기계적으로 조합하여 NOx 전환 활성 온도창(Temperature Window)을 확대하고 내구성이 좋은 촉매를 찾고자 하였다 0.55wt%Pt-$TiO_2$/5wt%Cu-ZSM-5 촉매와 0.28wt%Pt-$TiO_2$/$Al_2O_3$ 촉매 및 1.1 wt%Pt-$TiO_2$/$Mn_2O_3$ 촉매 모두 $400^{\circ}C$를 변곡점으로 저온과 고온에서 NOx 제거활성이 있었는데, 저온에서 활성이 가장 큰 것은 0.28wt%Pt-$TiO_2$/$Al_2O_3$ 촉매이었고, 고온에서는 1.1wt%Pt-$TiO_2$/$Mn_2O_3$(21) 촉매가 제일 높은 활성을 보였다. 그러나 수분 및 아황산가스 공존시와 열적 내구성 면에서는 0.55wt%Pt-$TiO_2$/5wt% Cu-ZSM-5 촉매가 가장 우수하게 나타났다.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2017년도 9th Asian Crop Science Association conference
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• pp.229-229
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• 2017

This research study was conducted to analyze the characteristics of different rice cultivars in abnormal temperature conditions (low temperature) for ripening period abnormalities, and to investigate the physiological causes behind the abnormalities. Four Korean high quality japonica-type rice cultivars, Jinbu (JB), Junamjosaeng (JJ), Geumyoung (GY), Hwawang (HW) were used in the experiment. The following day after flowering, they were then moved into two phytotrons under natural daylight with 65% RH but controlled at different temperatures - one at $19/29^{\circ}C$ (night/day) and the other at $13/23^{\circ}C$ as the low - temperature study on ripening. For the cultivars at $13/23^{\circ}C$ (low temperature study), JB and JJ had a ripening rate of 93% which is similar to the ripening rates of cultivars at $19/29^{\circ}C$ at 45 days after heading (DAH). In contrast, GY and HW recorded lower ripening rates of 86% and 57% respectively. However, when the cultivars at $13/23^{\circ}C$ were harvested at 61 DAH (when the accumulated temperature reached $1100^{\circ}C$), the difference in ripening rates compared to the 4 cultivars of $19/29^{\circ}C$ harvested at 45 DAH was not obvious (JB 94%, JJ 97%, GY 97%, HW 88%). Starch content showed little difference among the 4 cultivars at different temperature conditions while amylose content was higher for cultivars at $13/23^{\circ}C$ compared to those at $19/29^{\circ}C$. In addition, the enzyme activities of starch biosynthesis were about 5~10 days slower in cultivars at $13/23^{\circ}C$ compared to cultivars at $19/29^{\circ}C$. The grain-filling rate showed highly significant correlations with the enzyme activities of Sucrose synthase ($R^2=0.70^{***}$), ADP glucose pyrophosphorylase ($R^2=0.63^{***}$), UDP glucose pyrophosphorylase ($R^2=0.36^{***}$), Starch synthase ($R^2=0.51^{***}$), and Starch branching enzyme ($R^2=0.59^{***}$). Among the enzymes, Sucrose synthase activity had the highest correlation coefficient with grain-filling rate. In conclusion, the activity of enzymes such as Sucrose synthase, UDP glucose pyrophosphorylase, ADP glucose pyrophosphorylase, Starch synthase, Starch branching enzyme in starch biosynthesis is proven to be highly related to the grain filling process. Notably, the decrease in the activity of Sucrose synthase and Starch branching enzyme and the late increase in ADP glucose pyrophosphorylase activity at low temperature in the ripening stage are considered to be disadvantageous as they delay ripening and increased amylose content.