• 에너지공학
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• 제21권3호
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• pp.237-242
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• 2012

이 연구에서는 초음속 연소에서 발생하는 열폐색의 다양한 현상을 규명하기 위해 확대 축소 노즐 내부에서 열폐색에 의해 형성되는 2차원의 초음속의 비정상 유동장에 대한 수치해석 결과를 제시한다. 열폐색에 의해 야기되는 이동 충격파를 수치계산하기 위해 TVD 스킴을 이용하며, 노즐의 확대부의 일정영역에 가열을 통하여 열폐색이 발생할 수 있는 조건을 형성하고, 이 때 발생하는 천이현상을 분리부가 있는 경우와 없는 경우에 대해 불시동현상 발생속도, 비추력의 불안정성 등을 통해 비교, 설명한다. 분리부가 있는 경우가 없는 경우에 비해 열폐색에 의해 발생한 경사 충격파가 느린 속도로 상류측으로 이동하여 분리부의 설치가 엔진 불시동의 지연효과가 있음을 제시하였다.

• Biomolecules & Therapeutics
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• 제6권2호
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• pp.171-181
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• 1998

DA-3585, a biosynthetic recombinant human erythropoietin has been developed as a treatment for anemia associated with chronic renal failure in Dong-A pharmaceutical Co. Ltd. This study was carried out to assess its acute and subacute toxicities in rabbits. DA-3585 was intravenously administered to rabbits at dose levels of 6250, 12500 or 25000 lU/kg for single dose toxicity study and at dose levels of 100, 500 or 2500 lU/kg/day for 4-week repeated dose toxicity study. In the acute toxicity study, dose up to 25000 lU/kg had no adverse effect on the behavior or body weight gain. Pathological examinations revealed no abnormal gross lesions related to DA-3585. In the subacute toxicity study, all animals survived until termination of treatment. DA-3585 had no influence on clinical signs, food and water intake or on body weight changes. Hematological examination showed increases in the number of RBC, hemoglobin contents and hematocrit values with a dose dependent manner in the animals treated with DA-3585. Histopathological examination revealed erythroid hyperplasia in the bone marrow and extramedullary hematopoiesis in the liver. The changes detected in the hematological and histopathological examination presumably represent exaggerated pharmacological effects of erythropoietin. The NOAEL (no-observed-adverse-effect-level) of DA-3585 was estimated to be 100 lU/kg/ day under this study condition.

• Journal of Veterinary Science
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• 제22권4호
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• pp.54.1-54.13
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• 2021

Background: Hypoxia causes oxidative stress and affects cardiovascular function and the programming of cardiovascular disease. Melatonin promotes antioxidant enzymes such as superoxide dismutase, glutathione reductase, glutathione peroxidase, and catalase. Objectives: This study aims to investigate the correlation between melatonin and hypoxia induction in cardiomyocytes differentiation. Methods: Mouse embryonic stem cells (mESCs) were induced to myocardial differentiation. To demonstrate the influence of melatonin under hypoxia, mESC was pretreated with melatonin and then cultured in hypoxic condition. The cardiac beating ratio of the mESC-derived cardiomyocytes, mRNA and protein expression levels were investigated. Results: Under hypoxic condition, the mRNA expression of cardiac-lineage markers (Brachyury, Tbx20, and cTn1) and melatonin receptor (Mtnr1a) was reduced. The mRNA expression of cTn1 and the beating ratio of mESCs increased when melatonin was treated simultaneously with hypoxia, compared to when only exposed to hypoxia. Hypoxia-inducible factor (HIF)-1α protein decreased with melatonin treatment under hypoxia, and Mtnr1a mRNA expression increased. When the cells were exposed to hypoxia with melatonin treatment, the protein expressions of phospho-extracellular signal-related kinase (p-ERK) and Bcl-2-associated X proteins (Bax) decreased, however, the levels of phospho-protein kinase B (p-Akt), phosphatidylinositol 3-kinase (PI3K), B-cell lymphoma 2 (Bcl-2) proteins, and antioxidant enzymes including Cu/Zn-SOD, Mn-SOD, and catalase were increased. Competitive melatonin receptor antagonist luzindole blocked the melatonin-induced effects. Conclusions: This study demonstrates that hypoxia inhibits cardiomyocytes differentiation and melatonin partially mitigates the adverse effect of hypoxia in myocardial differentiation by regulating apoptosis and oxidative stress through the p-AKT and PI3K pathway.

• 한국의류산업학회지
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• 제19권2호
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• pp.166-179
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• 2017

Fashion industry have been emphasizing on eco-friendly business to enhance their public image. Due to the lack of consumers' awareness and experience of eco fashion advertising, this have resulted in adverse outcomes. Therefore, it is required to develop eco fashion advertisement that meets the public interest of Koreans. This study aims to obtain practical implications which can be applied to further eco fashion advertising. The study examines the public opinion towards eco fashion using Twitter as big data analysis and the protracted implication was provided to consumers as consumer vocabulary to see the advertising effect of consumer vocabulary. In addition, this study focuses on the environmental claim types to identify the most effective advertisement in eco fashion. The results are as follow. Associative claim types had a more positive influence on advertising attitude than substantive claim types. Substantive claim types had a more positive influence on brand cognition than associative claim types. In addition, the moderating effects of consumer vocabulary on advertising attitude and brand cognition were supported in substantive claim types. Advertisement attitude shows positive effects to both brand cognition and brand attitude. It has been proved that brand cognition leads to positive influence towards brand attitude and brand attitude eventually increases consumers' urge to buy products. This study has implication when providing a guideline for eco fashion advertisements.

• Nuclear Engineering and Technology
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• 제26권2호
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• pp.168-178
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• 1994

사고관리란 사고발생시에 이용가능한 모든 자원, 즉 인원과 설비를 효율적으로 활용함으로써 발전소를 안전상태로 회복시키거나 사고의 피해를 완화시키기 위한 제반 활동을 말한다. 사고관리의 접근방식은 첫째, 후보사고관리방안의 사전 평가, 둘째, 효과적으로 적절한 조치를 수행하게 하는 세부 절차서의 개발, 그리고 셋째, 그러한 조치수행에 필요한 도구와 자원의 준비, 실현 가능한 원전 시스템의 변경등을 포함한다. 사고관리 전략을 평가할 때에는 그 전략의 효율성분만 아니라 부작용, 타당성, 필요한 정보, 기존 절차서와의 양립성 등을 종합적으로 고려하여야 한다. 이 논문의 목적은 여러가지 사고관리 전략을 모델링하고 평가하기위한 체제를 개발하기 위한 의사결정 수목과 영향도의 해석도구를 소개하는 것이다. 이 해석도구와 관련한 여러가지 특징들이 제시되었으며 이 해석도구에 근거하여 세워진 사고관리전략의 평가체제가 간단한 예제문제에 적용되었다.

• Asian Pacific Journal of Cancer Prevention
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• 제15권17호
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• pp.7303-7307
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• 2014

Objective: To explore the clinical efficacy of gemcitabine concomitant with nedaplatin and drug resistance in the treatment of non-small cell lung cancer (NSCLC) and associated molecular predicators. Materials and Methods: A total of 68 patients diagnosed with NSCLC by histology served as the study objects and were randomly divided into an observation group treated with gemcitabine concomitant with nedaplatin and a control group with cisplatin concomitant with gemcitabine, 34 cases for each group. Short-term and long-term efficacies, adverse responses as well as the expression of nucleotide excision repair cross complementing 1 (ERCC1), ribonucleotide reductase subunit M1 (RRM1) and lung resistance-related protein (LRP) in NSCLC tissues in both groups were assessed. Results: The short-term objective response rate (ORR) and disease control rate (DCR) were 35.3% (12/34) and 76.5% (26/34) in the observation group and 38.2% (13/34) and 85.3% (29/34) in the control group, respectively, the differences not being statistically significant. The time to progression (TTP) in both groups were 1~12 months, while the median TTP was 135 d and 144 d, respectively. Though the survival was slightly higher in the control group, there were no significant differences in TTP and survival time. The rates of decreased hemoglobin, vomiting and nausea as well as renal toxicity were evidently lower in the observation group, while other adverse responses demonstrated no significant difference. The positive expression rates of ERCC1, RRM1 and LRP were 47.1% (16/34), 61.8% (21/34) and 64.7% (22/34) in the observation group, respectively. Compared with negative ERCC1 expression, ORR had decreasing trend and the overall survival time (OS) decreased significantly in patients with positive ERCC1 expression, which were markedly decreased by the positive expressions of RRM1 and LRP. Conclusions: Gemcitabine concomitant with nedaplatin has significant effects in the treatment of NSCLC, with an adverse response rate obviously lower than for cisplatin concomitant with gemcitabine, suggesting that wider use in the clinic is warranted. Additionally, the positive expressions of ERCC1, RRM1 and LRP may increase patient drug resistance, so they can be applied as the chemotherapeutic predicators to guide individualized therapy of NSCLC patients.

• Journal of Animal Science and Technology
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• 제65권1호
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• pp.132-148
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• 2023

Ruminants are the main contributors to methane (CH₄), a greenhouse gas emitted by livestock, which leads to global warming. In addition, animals experience heat stress (HS) when exposed to high ambient temperatures. Organic trace minerals are commonly used to prevent the adverse effects of HS in ruminants; however, little is known about the role of these minerals in reducing enteric methane emissions. Hence, this study aimed to investigate the influence of dietary organic trace minerals on rumen fermentation characteristics, enteric methane emissions, and the composition of rumen bacteria and methanogens in heat-stressed dairy steers. Holstein (n=3) and Jersey (n=3) steers were kept separately within a 3×3 Latin square design, and the animals were exposed to HS conditions (Temperature-Humidity Index [THI], 82.79 ± 1.10). For each experiment, the treatments included a Control (Con) consisting of only basal total mixed rations (TMR), National Research Council (NRC) recommended mineral supplementation group (NM; TMR + [Se 0.1 ppm + Zn 30 ppm + Cu 10 ppm]/kg dry matter), and higher concentration of mineral supplementation group (HM; basal TMR + [Se 3.5 ppm + Zn 350 ppm + Cu 28 ppm]/kg dry matter). Higher concentrations of trace mineral supplementation had no influence on methane emissions and rumen bacterial and methanogen communities regardless of breed (p > 0.05). Holstein steers had higher ruminal pH and lower total volatile fatty acid (VFA) concentrations than Jersey steers (p < 0.05). Methane production (g/d) and yield (g/kg dry matter intake) were higher in Jersey steers than in Holstein steers (p < 0.05). The relative abundances of Methanosarcina and Methanobrevibacter olleyae were significantly higher in Holstein steers than in Jersey steers (p < 0.05). Overall, dietary organic trace minerals have no influence on enteric methane emissions in heat-stressed dairy steers; however, breed can influence it through selective alteration of the rumen methanogen community.

• 한국건축시공학회지
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• 제18권4호
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• pp.313-319
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• 2018

전 세계적으로 폭발성 물질 사용 증가와 폭탄테러 등으로 인명 및 재산 피해가 증가하고 있는 추세이다. 이에 중요 건축물이나 군사시설에 방호 방폭 성능을 향상시킬 목적으로 섬유보강 고성능 시멘트 복합체(HPFRCC)에 대한 연구가 진행되고 있다. 그러나, HPFRCC의 자기수축 문제를 해결하기 위해 ERCO를 혼입하게 되면 높은 점성 및 지방분의 시멘트 알칼리와의 조기반응으로 유동성, 공기량 및 강도 등 품질저하의 문제점이 발생한다. 이에 본 연구에서는 기존에 도출된 HPFRCC의 최적 배합에 ERCO 혼입시기 및 혼입율 변화에 따른 HPFRCC의 자기수축저감 및 기초적 특성에 대해 분석하였다. 그 결과 모르타르 믹싱완료 후 ERCO를 0.5% 혼입하는 후혼입 방법이 유동성, 강도 및 자기수축저감 등의 HPFRCC의 품질 향상에 가장 효과적인 것으로 밝혀졌다.

• 한국유통학회지:유통연구
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• 제11권2호
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• pp.97-122
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• 2006

유통업체는 다양한 상품구색을 갖는 것이 좋다는 생각이 일반적이다. 그리나 최근 연구들은 선택대안의 수를 증가시키는 것이 오히려 소비자 선택을 떨어뜨린다고 한다. 본 연구는 선택대안의 수가 늘어나는 맥락에서 소비자 구매결정에 영향을 미치는 요인을 파악하는 데 목적이 있다. 연구 결과, 본 연구에서는 선택대안의 수가 실제 고려제품군의 크기에 해당하는 $3{\sim}9$개인 경우, 선택대안의 수가 늘어남에 따라 비선택 비율이 줄어드는 것(선택 비율이 증가하는 것)을 알 수 있었다. 특히 선택대안의 수가 선택여부에 미치는 영향은 지배적 대안이 없을 때보다는 있을 때 더 높게 나타났다. 그리고 대안의 수와 함께 소비자의 제품에 대한 친숙도가 선택여부에 어느 정도 영향을 미치는 것으로 나타났다. 지배적 대안이 있을 경우에는 친숙도가 선택여부에 영향을 미치지 않았으나, 지배적 대안이 있을 경우에는 소비자의 제품에 대한 친숙도는 자체적으로는 선택여부에 영향을 미치지 않고, 대안의 수와 상호작용을 통해 선택여부에 영향를 미치는 것으로 나타났다. 마지막으로 이러한 결과를 바탕으로 실무적 시사점과 연구의 한계점에 대해 논의하였다.

• Journal of Nutrition and Health
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• 제26권2호
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• pp.145-155
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• 1993

A factorial experiment was conducted to determine the influence of phytate(0 or 10g/kg diet) and calcium (Ca)(3 or 10g/kg diet) intakes on Ca, P and Zn metabolism by growing female rats. Food intake and weight were similar for the all groups, however, phytate ingestion for six weeks depressed femur growth. The low Ca plus phytate group showed the lowest Ca content of total femur and this was related to a significant decrease of Ca retention. Phytate intake depressed zinc(Zn) absorption in the first metabolic collection. This inhibitory effect of phytate on Zn absorption was improved in the low Ca plus phytate group after several weeks. Impared Zn absorption however remained in the high Ca plus phytate group which was reflected in the lowest Zn content of femur, phytate intake with high Ca also depressed phosphorous(P) absorption and serum and urinary P. These adverse effects of phytate on Zn and P absorption when the dietary Ca was high could explain reduced femur weight despite the highest concentration of femur Ca(mg/g ash) in this group. Results suggest that phytate can adversely affect not only Ca metabolism but Zn and P utilization. Thus, for the normal bone growth when phytate intake is high, the ingesion of Ca, P, Zn and other minerals should be enhanced.