• Journal of Biosystems Engineering
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• 제15권2호
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• pp.143-150
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• 1990

This study was conducted to estimate the ratio of Repair & Maintenance (R&M) costs to purchasing price that is one of the important factors for calculating the management costs of farm machinery. For this purpose, hour of use and R & M costs of power tiller and its attachments utilized results that were investigated with 400 sample units, 50 units by years of use from 1 to 8 years in 1988. The results obtained are summarized as follows; 1. The ratio of R & M costs per hours and annual R & M costs, accumulated R & M costs when sercice life of power tiller is 7 years were 0.017%, 5.50% and 38.52%, respectively. And in case of rotary, these ratio when its service life is 6 years were 0.072%, 7.16% and 43.0%, respectively. 2. The relationship between accumulated hours of use(t) and accumulated R & M costs(Y) of power tiller and its attachments were $Y=19.3t^{1.3}$ in power tiller, $Y=0.03t^{2.09}$ in plow, $Y=48.84t^{1.25}$ in rotary and $Y=7.45t^{1.15}$ in trailer. 3. The ratio of accumulated R & M costs to purchasing price when service life of power tiller is 7 years was 38.5%, and in case of rotary, this ratio when its service life is 6 years was 43.0%.

• 한국수학교육학회지시리즈B:순수및응용수학
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• 제17권1호
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• pp.29-38
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• 2010

We study the geometry of half light like submanifold M of a semi-Riemannian space form $\bar{M}$(c) subject to the conditions : (a) the screen distribution on M is totally umbilic in M and the coscreen distribution on M is conformal Killing on $\bar{M}$ or (b) the screen distribution is totally geodesic in M and M is irrotational.

• Animal Bioscience
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• 제35권6호
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• pp.892-901
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• 2022

Objective: This study was performed to investigate the potential effect of wheat phytase on long-chain inorganic polyphosphate (polyP)-mediated interleukin 8 (IL-8) signaling in an intestinal epithelial cell line, HT-29 cells. Methods: Cell viability and the release of the pro-inflammatory cytokine IL-8 in HT-29 cells exposed to polyP1150 (average of 1,150 phosphate residues) treated with or without wheat phytase were measured by the EZ-CYTOX kit and the IL-8 ELISA kit, respectively. Also, the activation of cellular inflammatory factors NF-κB and MAPK (p38 and ERK 1/2) in HT-29 cells was investigated using ELISA kits. Results: PolyP1150 negatively affected the viability of HT-29 cells in a dose-dependent manner. However, 100 mM polyP1150 dephosphorylated by wheat phytase increased cell viability by 1.4-fold over that of the intact substrate. Moreover, the 24 h exposure of cells to enzyme-treated 50 mM polyP1150 reduced the secretion of IL-8 and the activation of NF-κB by 9% and 19%, respectively, compared to the intact substrate. PolyP1150 (25 and 50 mM) dephosphorylated by the enzyme induced the activation of p38 MAPK via phosphorylation to 2.3 and 1.4-fold, respectively, compared to intact substrate, even though it had little effect on the expression of ERK 1/2 via phosphorylation. Conclusion: Wheat phytase could attenuate polyP1150-induced IL-8 release in HT-29 cells through NF-κB, independent of MAP kinases p38 and ERK. Thus, wheat phytase may alleviate inflammatory responses including hypercytokinemia caused by bacterial polyP infection in animals. Therefore, wheat phytase has the potential as an anti-inflammatory therapeutic supplement in animal husbandry.

• 한국가스학회지
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• 제21권5호
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• pp.56-63
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• 2017

전세계적으로 수소 충전 스테이션 구축에 많은 투자와 지원을 하고 있는 실정이다. 그러나 수소는 폭발범위가 넓고 확산이 빠른 기체이다. 본 연구에서는 액화수소를 취급하는 소규모~대규모 충전스테이션을 대상으로, 사고시 발생하는 VCE로 인한 피해영향범위를 산출하고, 프로빗 모델을 통해 주변의 인적, 물적 피해를 예측하였다. 더불어, 벤트스택 끝단에서 발생 가능한 Jet fire를 시나리오로 선정하여 최적 높이를 설정하였다. 피해영향범위는 관심과압 6.9kPa을 기준으로 하여, 소규모 저장시설의 경우 8.24m, 중규모 14.10m, 대규모 22.38m이다. 폐출혈로 인한 인체 피해는 소규모와 중규모가 각각 50m, 대규모 100m였으며, 구조물 손상에 따른 피해는 소규모 200m, 중규모 300m 및 대규모 500m이다. 벤트스택의 최적높이는 소규모 4.7m, 중규모 8.8m 및 대규모 16.9m이다.

• 한국축산식품학회지
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• 제38권6호
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• pp.1168-1178
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• 2018

The present study aimed to characterise anti-oxidant peptides from water-soluble protein extracts of Hanwoo beef and evaluate their anti-proliferative effect on human colorectal carcinoma cells (HCT116). Antioxidant peptides were purified from the low-molecular-weight fraction (<3 kDa) of Hanwoo beef extract. Antioxidant activity of peptide fractions was determined using the oxygen radical absorbance capacity (ORAC) assay. Purified peptide (P3) displayed higher ORAC activity than the low-molecular-weight fraction ($202.66{\mu}M\;TE/g$ vs $167.38{\mu}M\;TE/g$ of dry matter, respectively) (p<0.05). The peptide sequence of P3 was Cys-Cys-Cys-Cys-Ser-Val-Gln-Lys (888.30 Da). The novel peptide P3, at $250{\mu}g/mL$, also significantly inhibited HCT116 cell proliferation up to 25.24% through phosphorylation of ERK, JNK, and p38 kinase (p<0.05). Hence, antioxidant peptide P3 from Hanwoo beef extract can be used as an antioxidative and anticancer agent in the functional food industry.

• Applied Biological Chemistry
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• 제51권2호
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• pp.129-135
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• 2008

Berberine은 전통적인 중의약재로 이용되어지는 isoquinoline alkaloid로 황련, 황백과 같은 식물에서 주로 추출되며, 약리효과로는 항암, 항염, 항균과 같은 다양한 효과를 나타내는 것으로 알려져 있다. 그러나 간암세포에서 berberine의 산화적 스트레스에 의한 세포사멸기전에 대해서는 아직 밝혀진 바 없다. 따라서 본 연구는 사람의 간암세포인 HepG2 세포에서 berberien의 세포사멸기전에 reactive oxygen species(ROS)와 MAP kinase의 연관성을 조사하였다. Berberine은 HepG2 세포에서 처리 시간과 농도에 의존적으로 세포독성효과를 보였으며, $LD_{50}$은 berberine(50 ${\mu}M$) 처리 후 48시간에서 관찰 되었고, 세포고사의 특징인 핵의 응축 및 분절, DNA의 분절이 확인되었다. 또한 berberine에 의해 caspase-3, p53, p38 그리고 Bax의 발현이 현저하게 증가된 반면, anti-apoptotic 신호기전인 Bc1-2의 발현은 감소되었다. 이와 더불어 세포 내 nitric oxide(NO)와 ROS의 생성도 증가되었다. 본 연구 결과 HepG2 세포에서 berberine은 산화적 스트레스인 ROS와 NO의 생성을 유발하고 p38 MAP kinase와 p53의 인산화를 유도하였으며 미토콘드리아에서 Bcl-2의 감소와 bax의 증가, caspase-3의 활성을 경유하여 DNA의 손상을 통한 세포고사가 이루어지는 것을 확인 하였다.

• 한국작물학회지
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• 제52권2호
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• pp.134-139
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• 2007

The research was conducted with the aim of determining effects of seedling age on the yield of four fine rice varieties viz., Kalizura, Tulshimala, BRRI (Bang-ladesh Rice Research Institute)-37 and BRRI-38. The seedling of different ages such as 15, 25, 35 and 45 days were transplanted on the same day maintaining $25cm{\times}15cm$ spacing. The experiment was laid out in a randomized complete block design with three replications. The yield and yield contributing characters were influenced by seedling age, variety and their interaction. BRRI-38 gave the highest number of effective tillers $hill^{-1}$, panicle length, total spikelets $panicle^{-1}$, grains $panicle^{-1}$, 1000-grains weight and grain yield. Likewise, yield and yield contributing characters were the highest in 35 days old seedling. On the other hand, the variety (BRRI-38) with the same age as of seedlings 35 days old seedlings was found superior to other interactions, but, in the production of grains $panicle^{-1}$ and 1000-grains weight there was no significant effect in this interaction. From the findings it may be inferred that BRRI-38 with 35 days old seedlings produced the highest grain yield.

• The Korean Journal of Physiology and Pharmacology
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• 제4권5호
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• pp.339-346
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• 2000

Using murine immortalized microglial cells (BV-2), we examined the regulation of RANTES production stimulated by lipopolysaccharide (LPS), focusing on the role of mitogen-activated protein kinase (MAPK) and nuclear factor $(NF)-{\kappa}B.$ The result showed that RANTES (regulated upon activation of normal T cell expressed and secreted) was induced at the mRNA and protein levels in a dose- and time-dependent manner in response to LPS. From investigations of second messenger pathways involved in regulating the secretion of RANTES, we found that LPS induced phosphorylation of extracellular signal-regulated kinase (Erk), p38 MAPK and c-Jun-N-terminal kinase (JNK), and activated $(NF)-{\kappa}B.$ To determine whether this MAPK phosphorylation is involved in LPS-stimulated RANTES production, we used specific inhibitors for p38 MAPK and Erk, SB 203580 and PD 98059, respectively. LPS-induced RANTES production was reduced approximately 80% at $25\;{\mu}M$ of SB 203580 treatment. But PD 98059 did not affect RANTES production. Pyrrolidine-dithiocarbamate (PDTC), $(NF)-{\kappa}B$ inhibitor, reduced RANTES secretion. These results suggest that LPS-induced RANTES production in microglial cells (BV-2) is mainly mediated by the coordination of p38 MAPK and $(NF)-{\kappa}B$ cascade.

• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 2003년도 Annual Meeting of KSAP : International Symposium on Pharmaceutical and Biomedical Sciences on Obesity
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• pp.76-76
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• 2003

Mast cells accumulation can be causally related with several allergic inflammations. Previous work has demonstrated that glucocorticoids decreased tissue mast cell number and stem cell factor (SCF)-induced migration of mast cells required p38 mitogen-activated protein kinase (MAPK) activation. In the present study, we investigated the effects of dexamethasone on SCF-induced migration of rat peritoneal mast cells (RPMCs). SCF significantly induced migration of RPMCs at 4 h. Dexamethasone dose-dependently inhibited SCF-induced migration of RPMCs (about 90.1% at 100 nM, P<0.05). MAPK p38 inhibitor, SB203580 (20 ${\mu}$M) also inhibited the SCF-induced migration. The ability of SCF to enhance morphological alteration and F -actin formation was also abolished by treatment of dexamethasone. Dexamethasone inhibited SCF-induced p38 MAPK activation to near basal level and induced the MKP-1 expression. In addition, SCF-induced inflammatory cytokine production was significantly inhibited by treatment of dexamethasone or SB203580 (p<0.01). Our results show that dexamethasone potently regulates SCF -induced migration, p38 MAPK activation and inflammatory cytokine production through expression of MKP-l protein in RPMCs. Such modulation may have functional consequences during dexamethasone treatment, especially mast cell-mediated allergic inflammation disorders.

• 한국식품영양과학회지
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• 제30권3호
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• pp.395-402
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• 2001

Bacillus subtilis 돌연변이주 중 ${\gamma}-GTP$활성이 높은 SM-2와 SM-10을 융합시켜 획득한 융합주 중 ${\gamma}-GTP$활성이 높은 융합주 FG-21의 배양적 특성을 조사하였다. 융합주 FG-21에 의한 ${\gamma}-GTP$의 생산은 1% glycerol, 1% peptone, 0.1% citric acid, 5 mM $K_2HPO_4$, 1 mM $FeCl_3$, 1 mM $MgCl_2$, 1 mM $NH_4Cl$, pH 7.0의 배지에 의해 $37^{\circ}C$에서 36시간 배양했을 때 621 U/mL으로 최대한 활성을 보였다. 융합주 FG-21이 생산한 biopolymer A가 단백질함량이 38.4%이고 B. subtilis K-1이 생산하는 biopolymer B의 단백질함량은 19.3%로 융합주 FG-21이 생산하는 Biopolymer A보다 함량이 낮았다. 융합주 FG-21의 biopolymer가 모균주의 biopolymer B보다 단백질함량이 높은 것은 상대적으로 높은 ${\gamma}-GTP$활성이 높아서 생성된 PGA가 levan보다 함량이 많기 때문인 것으로 사료된다. 총당함량은 biopolymer A가 58.5%, biopolymer B가 76.5%로 나타났다. 융합주 FG-21과 모균주가 생산하는 biopolymer의 단백질함량과 총당함량비는 융합주 FG-21이 생성한 biopolymer는 38 : 59. 모균주가 생산한 biopolymer B는 19 : 78의 비율이었고 HPLC 분석에 의한 biopolymer A와 B의 fructose함량은 각각 537.7 mg/g biopolymer, 764.4 mg/g biopolymer으로 나타났다. Biopolymer A와 B의 glutamic acid함량은 각각 163.7 mg/g, 94.3 mg/g이었다. Biopolymer A와 B의 fructose와 glutamic acid의 함량비는 각각 78 : 22, 89 : 11의 비로 함유되어 있었다. 따라서 융합주에 의해 생산된 biopolymer는 모균주보다 구성상태가 변화된 biopolymer를 생산한 것으로 판단되어 fusion과 같은 균주개량을 통하여 물질의 구성적, 물질적 변화된 biopolymer를 생산할 수 있을 것이라 사료된다.