• Animal Bioscience
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• 제36권3호
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• pp.429-440
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• 2023

Objective: 12-oxo-5Z,8Z,10E,14Z-eicosatetraenoic acid (12-KETE), a metabolite of arachidonic acid, is a strong candidate signal for placenta separation following calf discharge at delivery. In the present study, the effects of 12-KETE on bovine trophoblast cells were investigated to determine its function in the placentome at delivery. Methods: Bovine trophoblast cells derived from blastocysts were used. They were cocultured with or without fibroblasts derived from bovine placentome and/or bovine uterine epithelial cells. 12-KETE was added to the culture medium. Results: Bovine trophoblast cells contained binucleate cells and strongly expressed caudal type homeobox 2 (CDX-2) genes. Addition of 12-KETE to the trophoblast cell colony without feeder cells or that on a fibroblast monolayer induced rapid exfoliation of the colony. After 12-KETE addition, trophoblast cells emitted strong fluorescence caused by the degradation of dye-quenched collagen, indicating that 12-KETE activated matrix metalloproteinase of the trophoblast cells. Exfoliated cell colonies were stained with YOPRO-1, but not propidium iodide (PI). Moreover, DNA fragmentation and Bcl-2 associated X protein (Bax) gene (apoptosis stimulator) upregulation were observed in exfoliated cells, indicating that 12- KETE induced trophoblast cell apoptosis. These results were consistent with previous in vivo observations; however, even a lower concentration of 12-KETE activated trophoblast protease. Meanwhile, fibroblasts derived from the bovine placentome converted arachidonic acid to 12-KETE. Conclusion: These observations indicate that 12-KETE may serve as a signal for placenta separation at delivery.

• 대한화학회지
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• 제43권6호
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• pp.707-719
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• 1999

본 연구는 중학교 3학년 학생들의 산${\cdot}$염기 개념에 대한 이해 정도를 알아보는 것이다. 중학교 학생들의 산${\cdot}$염기 개념에 대한 사전 지식을 고려하여 순환학습 모형을 기초로 한 학습 전략을 개발한 후 실험반에 투입하였다. 비교반에는 오개념을 고려하지 않은 전통적 수업 전략을 사용하였다. 실험반과 비교반에 대한 사전, 사후 개념 검사 문항을 분석한 결과 실험반이 비교반에 비해 수업 처치 효과가 유의미하게 높은 것으로 나타났다. 그러나 수업 후에도 강산, 약산, 강염기, 산의 세기 개념에 대한 학생들의 이해 성춰도는 두 그룹 모두 별로 높지 않은 것으로 나타났다. 따라서 미시적 관점의 산${\cdot}$염기 개념은 중학생들에게는 이해하기 어려운 개념이라고 해석할 수 있다. 본 연구에서 얻어진 두 집단간의 수업 전${\cdot}$후에 나타나는 학생들의 이해 정도를 강산, 약산, 강염기, 산의 세기의 네 범주로 분류하여 범주별로 과학자적 유형과 오개념 유형을 자세하게 논의하였다. 이 분석 자료는 산${\cdot}$염기 개념에 대한 보다 효과적인 수업 전략을 개발하는데 유용한 자료가 될 수 있을 것이다.

• KSBB Journal
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• 제9권5호
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• pp.506-511
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• 1994

천연자원에서 향균성 물질을 찾고자 수종의 식용 식물을 검색하는 과정에서 쑥(Artemisia princeps var. orientalis)의 추출물이 항균활생이 비교적 높았다. 쑥의 메탄올 추출물을 겨l통분획한 ethyl acetate 분획물(EtOAc)은 agar diffusion법에셔 항균활성이 가장 높았으며, EtOAc로부터 분리된 화합물 중 0­C coumaric acid(200 -600ppm)는 B. subtilis(12.6 ~ -18.0mm)와 s. typmηwrium( 12.6-16.6mm)에 대하 여 우수한 항균활성을 나타내였고, 그 유도체인 p­C coumanc a디d는 약 1.2 -1.7배 정도의 항균활성을 증가시켰다 Coumaric acid의 3가지는 액체배양에 서 B. subtilis 증식응 모두 강하게 억제하였으며, S. typmmuriuη2, P. aeruginosa 및 s. aureus의 증식 억제에는 각각 0-, m- 및 p-coumaric a디d가 효과적 이었다. B. subtilis의 반고체 agar 배양에셔 pc coumaric acid의 MID는 $\100∼200mu\textrm{g}$/disk였다.

• Archives of Pharmacal Research
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• 제19권1호
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• pp.36-40
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• 1996

The effect of glycyrrhetinic acid(18.betha.-glycyrrhetinic acid, GA) on histamine synthesis and release was investigated in cocultured mast cells with Swiss 3T3 fibroblasts. GA has strong dose dependent inhibitory activity for histamine synthesis and release in cocultured mast cells. GA(50 .mu.M) inhibited about 85% of histidine decarboxylase (HDC) activity. The appearance of cells staining positively with berberine sulface was also decreased in the presence of GA. It indicates that transdifferentiation of cultured mas cells (CMCs) was also inhibited.

• Bulletin of the Korean Chemical Society
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• 제22권3호
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• pp.263-266
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• 2001

Isopropylation of phenol with 2-propanol has been carried out over Na-exchanged ZSM-5 zeolites to determine the effect of catalyst acidity on phenol conversion and product selectivity. The acid type and strength of the catalyst such as Lewis, weak and strong Bronsted acid sites are measured by pyridine adsorbed XPS and the catalytic properties are interpreted in terms of the acid properties. The active site and mechanism for the reaction are suggested based on evidence of study from the reactant adsorbed FT-IR.

• Journal of Microbiology and Biotechnology
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• 제26권1호
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• pp.61-65
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• 2016

From the lees of bokbunja wine (LBW) made from Rubus coreanus Miquel, we have identified six compounds (1: trans-4-hydroxycinnamic acid; 2: trans-4-hydroxy-3-methoxycinnamic acid; 3: 3,4-dihydroxycinnamic acid; 4: 4-hydroxy-3-methoxybenzoic acid; 5: 3,5-dimethoxy-4-hydroxybenzoic acid; and 6: 3,5-dimethoxy-4-hydroxycinnamic acid (sinapic acid)) through silica gel chromatography and UHPLC-MS. The compounds 1-6 showed strong anticoagulation and platelet aggregation inhibitory activities without hemolytic effect against human red blood cells. To date, this is the first report of the in vitro anti-thrombosis activity of sinapic acid. Our results suggest that different cinnamic and benzoic acid derivatives are closely linked to the anti-thrombosis activity of LBW, and sinapic acid could be developed as a promising anti-thrombosis agent.

• 분석과학
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• 제13권2호
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• pp.151-157
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• 2000

수소화물 발생법-원자흡수 분광계를 이용한 비소의 분석에서 금속이온의 은폐제로 사용되는 L-cysteine, thiourea, KI/ascorbic acid 등의 예비 환원제와 염산, 질산, 황산 및 이들의 1:1 혼산의 종류 및 농도가 비소의 분석에 미치는 영향을 비교 연구하였다. 대부분의 예비 환원제의 경우 3-5M 이상의 고농도 산 용액에서 비소에 대한 높은 흡괌도를 나타냈으나, 0.1M 이하의 낮은 산 용액에서는 L-cysteine을 제외하고는 극히 저조한 흡광도를 나타내었다. 질산 산성용액에서는 흡광도 신호의 불안정성이 심하였다. 방해물질로서 $Cr^{6+}$, $Br^{5+}$ 이온의 방해영향이 크게 관찰되었지만, 이때 예비 환원제는 수소화물 생성을 크게 증가시켰다.

• 대한수의학회지
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• 제40권4호
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• pp.701-706
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• 2000

This study was carried out to select the lactic acid bacteria(Lactobacillus, Streptococcus and Bifidobacterium) and yeast for probiotic use in pigs. Acid-tolerant 536 strains were isolated from the feces of 30 pigs. To select useful strains, the first screened strains were treated with strong acid solution(pH 2.5 to 3.0) for 3 hours and subsequentely treated with the anaerobic diluent solution containing 0.15% Oxgall for 3 hours. Among these strains, 151 strains showed strong tolerance to both acid and bile. Lactobacillus and Streptococcus tolerant to the acid and bile were treated with heat at $80^{\circ}C$ for 15 min, and at $70^{\circ}C$ for 5 min in Bifidobacterium and yeast. As a result of heat treatment, 38 strains were obtained as heat-tolerant strains. All of heat-tolerant strains were tested for antibiotic resistance against virginiamycin, sulfathiazole, aureomycin, neomycin, linsmycin, tiamulin and ASP250 which were used as feed additives for growth promotion in pigs. Finally, one strain each from Lactobacillus, Streptococcus, Bifidobacterium and yeast that showed resistance to acid, bile, heat and antibiotics was selected for probiotic use in pigs.

• Journal of the Korean Wood Science and Technology
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• 제14권1호
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• pp.55-60
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• 1986

Discoloration sensitivities of woods grown in this country haven't reported yet. Therefore we examined discoloration sensitivities of domestic wood specimens to iron (0.1 %, $FeCl_3.6H_2O$), alkali (pH 12.0, NaOH). acid (pH 1.0, $C_2H_2O_4$) and exposing to sunlight (40 hrs), Thirty-six hardwood species were collected and examined. All specimens were prepared from heartwoods of the collected species. But the specimens of 4 Betula species were divided into sapwoods and heartwoods. By iron stain, the color differences (${\Delta}E$) of 21 wood specimens including one Betula sapwood showed above 12.0, which means strong discoloration sensitivities, and of 3 specimens including one Betula sapwood showed below 2.5, which means weak discolorations. The most strong iron discoloration species was Jungkukgulpi-namu (Pterocarya stenoptera). By alkali stain, the color differences (${\Delta}E$) of 3 wood specimens showed above 9.0, which means strong discoloration sensitivities, and of 18 wood specimens including 4 Berula sapwoods showed below 2.5, which means weak discolorations. By acid stain, the color differences (${\Delta}E$) of 6 wood specimens showed above 10.0 which means strong discoloration sensitivities, and of 12 wood specimens including one Betula sapwoods showed below 2.5, which means weak discolorations. By exposing to sunlight, the color differences (${\Delta}E$) of 31 wood specimens including one Betula sapwoods showed below 6.5, which means, strong discoloration sensitivities, and of only one specimens showed below 2.5, which means weak discoloration. The most strong discoloration species by exposing to sunlight was Guirung-namu (Prunus padus). In general, it was shown that hardwoods grown in Korea were most subject to change of color by exposing to sunlight and next were by iron stain. Domestic hardwoods showed some differences in discoloration sensitivities from domestic softwoods previously reported.

• 한국축산식품학회지
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• 제31권3호
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• pp.349-355
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• 2011

Russian deer velvet antlers were divided into three parts and subjected to a extraction process using hot water at 100, 110, and $120^{\circ}C$ or an extraction with 70% ethanol. Each extract was analyzed for its biochemical components, including uronic acid, sulfated-glycosaminoglycans (sulfated-GAGs), and sialic acid, and the antioxidant and anti-acetylcholinesterase activities were investigated. Different levels of uronic acid and sulfated-GAGs were observed in the extracts according to the water temperature used for the extraction, and contents decreased with increasing extraction temperature. The upper layer of each extract showed high amounts of uronic acid and sulfated-GAGs, followed by the middle and base layers. Ethanol extraction was more effective for recovering uronic acid than sulfated-GAGs. Sialic acid content was the highest in the $110^{\circ}C$ extracts but was not observed in the ethanol extracts. Velvet antler extracts showed strong antioxidant activities against DPPH and hydrogen peroxide as well as strong reducing power in a dose-dependent manner. However, the antioxidant activities were different in each layer and according to the extraction method. Additionally, velvet antler extracts exhibited inhibitory activity against acetylcholinesterase, which is associated with Alzheimer's disease, in a dose-dependent manner. These results suggest that velvet antler extracts are useful as a functional food ingredient and/or a pharmaceutical.