• 국제지역연구
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• 제12권2호
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• pp.99-123
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• 2008

본 논문은 기술추종국(technology follower)으로서의 한국 제조업의 상황을 명시적으로 감안하기 위하여 기술선도국(technology frontier)과의 상대적 생산성 수준을 국제적으로 비교 가능한 방식으로 추정하고, 이러한 상대적 기술격차가 한국 제조업의 산업별 총요소생산성 증가율을 설명함에 있어 어떠한 역할을 하였는가를 분석한다. 1988~2003년 기간 중 한국의 10개 제조업을 대상으로 수행된 실증분석의 주요 결과는 다음과 같다. 첫째 기존의 연구들에서 발견되는 바와 같이 연구개발 집약도, 무역지수, 인적자본지수 등은 총요소생산성 증가에 긍정적인 영향을 미치는 것으로 나타났다. 둘째 기술선도국과의 기술격차가 클수록 그리고 기술선도국의 총요소생산성 증가율이 빠를수록 한국의 해당산업 총요소생산성 증가율이 높은 것으로 나타났다. 셋째 기술선도국과의 기술격차가 클 경우에는 기술선진국들과의 무역을 통한 기술이전이 연구개발 활동이나 인적자본의 축적 등의 경로보다 해당산업의 총요소생산성을 증가시키는 데 보다 효율적인 것으로 나타났다.

• Clinical and Experimental Pediatrics
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• 제62권8호
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• pp.307-311
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• 2019

Purpose: Necrotizing enterocolitis (NEC) is one of the most serious complications of prematurity. Many risk factors can contribute to the development of NEC. The epidermal growth factor (EGF) plays a major role in intestinal barrier function, increases intestinal enzyme activity, and improves nutrient transport. The aim of this study was to assess the role of epidermal growth factor in the development of NEC in preterm neonates. Methods: In this study, 130 preterm neonates were included and divided into 3 groups, as follows: group 1, 40 preterm neonates with NEC; group 2, 50 preterm neonates with sepsis; and group 3, 40 healthy preterm neonates as controls. The NEC group was then subdivided into medical and surgical NEC subgroups. The serum EGF level was measured using enzyme-linked immunosorbent assay. Results: Serum EGF levels (pg/dL) were significantly lower in the NEC group (median [interquartile range, IQR], 9.6 [2-14]) than in the sepsis (10.1 [8-14]) and control groups (11.2 [8-14], P<0.001), with no significant difference between the sepsis and control groups, and were positively correlated with gestational age (r=0.7, P<0.001). A binary logistic regression test revealed that low EGF levels and gestational ages could significantly predict the development of NEC. The receiver-operating characteristic curve for EGF showed an optimal cutoff value of 8 pg/mL, with 73.3% sensitivity, 98% specificity, and an area under the curve of 0.92. Conclusion: The patients with NEC in this study had significantly lower serum EGF levels (P<0.001), which indicated that EGF could be a reliable marker of NEC in preterm neonates.

• Journal of Veterinary Science
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• 제24권1호
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• pp.2.1-2.14
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• 2023

Background: Hypothermia is a crucial environmental factor that elevates the risk of cardiovascular disease, but the underlying effect is unclear. Objectives: This study examined the role of cold stress (CS) in cardiac injury and its underlying mechanisms. Methods: In this study, a chronic CS-induced myocardial injury model was used; mice were subjected to chronic CS (4℃) for three hours per day for three weeks. Results: CS could result in myocardial injury by inducing the levels of heat shock proteins 70 (HSP70), enhancing the generation of creatine phosphokinase-isoenzyme (CKMB) and malondialdehyde (MDA), increasing the contents of tumor necrosis factor-α (TNF-α), high mobility group box 1 (HMGB1) interleukin1b (IL-1β), IL-18, IL-6, and triggering the depletion of superoxide dismutase (SOD), catalase (CAT), and glutathione (GSH). Multiple signaling pathways were activated by cold exposure, including pyroptosis-associated NOD-like receptor 3 (NLRP3)-regulated caspase-1-dependent/Gasdermin D (GSDMD), inflammation-related toll-like receptor 4 (TLR4)/myeloid differentiation factor 88 (MyD88)-mediated nuclear factor kappa B (NF-κB), and mitogen-activated protein kinase (MAPK), as well as oxidative stressinvolved thioredoxin-1/thioredoxin-interacting protein (Txnip) signaling pathways, which play a pivotal role in myocardial injury resulting from hypothermia. Conclusions: These findings provide new insights into the increased risk of cardiovascular disease at extremely low temperatures.

• Journal of Interdisciplinary Genomics
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• 제5권2호
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• pp.35-41
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• 2023

Background: Ca²⁺ signaling plays a vital role in neuronal signaling and altered Ca²⁺ homeostasis in Parkinson's disease (PD). Overexpression of αSYN significantly promote the Ca²⁺-Calmodulin (CaM) activity and subsequent nuclear translocation of nuclear factor of activated T cells (NFAT) transcription factor in dopaminergic neurons of midbrain. However, the exact role of Ca²⁺-CaM and NFAT in PD pathology is yet to be elucidated. Methods: We designed the CaM-NFAT-oligodeoxynucleotide (ODN), a synthetic short DNA containing complementary sequence for NFAT transcription factor and CaM mRNA. Then, the effect of CaM-NFAT-ODN on 1-methyl-4-phenylpyridinium (MPP⁺)-mediated neurotoxicity was investigated in mimic PD model in vitro. Results: First, the expression of αSYN and CaM was strongly increased in substantia nigra (SN) of PD and the expression of tyrosine hydroxylase (TH) was strongly increased in control SN. Additionally, the expression of apoptosis marker proteins was strongly increased in SN of PD. Transfection of CaM-NFAT-ODN repressed CaM and pNFAT, the target genes of this ODN in rat embryo primary mesencephalic neurons. It also reduced ERK phosphorylation, a downstream target of these genes. These results demonstrated that CaM-NFAT-ODN operated successfully in rat embryo primary mesencephalic neurons. Transfection of CaM-NFAT-ODN repressed TH reduction, αSYN accumulation, and apoptosis by MPP⁺-induced neurotoxicity response through Ca²⁺ signaling and mitogen-activated protein kinases (MAPK) signaling. Conclusion: Synthetic CaM-NFAT-ODN has substantial therapeutic feasibility for the treatment of neurodegenerative diseases.

• 한국콘텐츠학회논문지
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• 제12권10호
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• pp.418-429
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• 2012

본 연구는 평가와 보상요인이 지식관리 시스템 도입요인(조직특성, 지식정보특성, 이용자특성)과 성과요인 간에 조절적 역할을 하고 있는지를 실증적으로 분석하였다. 분석 결과 조직 유연성, 신뢰, 지식의 적합성, 기능의 제공정도, 인지된 이익 요인은 KMS 활용도에 조절적인 역할을 하고 있는 것으로 분석되었으며, 사용 용이성, 이용자 전문성 요인은 KMS 활용도에 조절적인 역할을 하지 않는 것으로 나타났다. KMS 만족도에는 조직 유연성, 신뢰, 기능의 제공 정도, 이용자 전문성 요인은 KMS 만족도에 조절적인 역할을 하고 있는 것으로 분석되었으며, 지식의 적합성, 사용 용이성, 인지된 이익 요인은 KMS 만족도에 조절적인 역할을 하지 않는 것으로 나타났다.

• Biomolecules & Therapeutics
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• 제26권4호
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• pp.380-388
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• 2018

Neural stem cells (NSCs) have the ability to self-renew and differentiate into multiple nervous system cell types. During embryonic development, the concentrations of soluble biological molecules have a critical role in controlling cell proliferation, migration, differentiation and apoptosis. In an effort to find optimal culture conditions for the generation of desired cell types in vitro, we used a microfluidic chip-generated growth factor gradient system. In the current study, NSCs in the microfluidic device remained healthy during the entire period of cell culture, and proliferated and differentiated in response to the concentration gradient of growth factors (epithermal growth factor and basic fibroblast growth factor). We also showed that overexpression of ASCL1 in NSCs increased neuronal differentiation depending on the concentration gradient of growth factors generated in the microfluidic gradient chip. The microfluidic system allowed us to study concentration-dependent effects of growth factors within a single device, while a traditional system requires multiple independent cultures using fixed growth factor concentrations. Our study suggests that the microfluidic gradient-generating chip is a powerful tool for determining the optimal culture conditions.

• 한국생물물리학회:학술대회논문집
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• 한국생물물리학회 2003년도 정기총회 및 학술발표회
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• pp.72-72
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• 2003

The PAS factor, whose gene has been cloned from V vulnifcus, is a protein secretion factor. Although the role of the PAS factor in Vibrio is still unknown, it may be involved with the bacterial protein secretion. The PAS factor is a 76 amino acid polypeptide, and its expression in E. coli cells makes the host cell membrane leaky, resulting in the excretion of periplasmic proteins into the culture medium. Highly expressed PAS factor is harmful to the cell, this may be due to a disruption of the membrane structure or function.

• Earthquakes and Structures
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• 제16권6호
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• pp.655-664
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• 2019

Behavior factor of a structure plays a crucial role in designing and predicting the inelastic responses of it. Recently, irregular buildings have been interested in many designers. To design irregular structures, recognizing the inelastic behavior of them is necessary. The main objective of this study is to determine the behavior factor of irregular Reinforced Concrete Moment Resisting Frames (RCMRFs) via nonlinear Incremental Dynamic Analysis (IDA). To do so, first, several frames are designed according to the regulations of the Iranian national building code. Then the nonlinear incremental dynamic analysis is performed on these structures and the behavior factors are achieved. The acquired results are compared with those obtained using pushover analysis and it is shown that the behavior factors acquired from the nonlinear incremental dynamic analysis are somewhat larger than those obtained from pushover analysis. Eventually, two practical relations are proposed to predict the behavior factor of irregular RCMRFs. Since these relations are based on the simple characteristics of frames such as: irregularity indices, the height and fundamental period, the behavior factor of irregular RCMRFs can be achieved efficiently using these relations. The proposed relations are applied to design of four new irregular RCMRFs and the outcomes confirm the accuracy of the aforementioned relations.

• Biomolecules & Therapeutics
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• 제18권4호
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• pp.363-374
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• 2010

Growing evidence suggests a prominent role for leptin in human cancer progression. The intricate pattern of leptin cross-talk with other associated signaling pathways is a critical area of research that will ultimately contribute to comprehending the role of leptin in cancer progression. This review summarizes a portion of the current understanding of leptin signaling, with a critical focus on its contribution to tumor cell invasion and metastasis. Five topics are addressed in this review: (1) Leptin receptor, (2) Leptin signaling, (3) Leptin and cancer, and (4) Leptin and tumor invasion. Due to the complex cellular effects of leptin, a more precise understanding of leptin signaling pathways must still be elucidated. Leptin is clearly a major factor for stimulating tumor progression through a complex spectrum of interplay and cross-talk among various signaling molecules. An understanding of the role of leptin in invasion and metastasis will provide valuable information for establishing strategies to modulate leptin signaling, which should be a high priority for the development of anti-cancer therapeutics.

• 유통과학연구
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• 제13권11호
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• pp.31-37
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• 2015

Purpose - This study is an effort to assess the role of behavioral biases in investment decision making, specifically for mutual funds, and the moderating role of the investor. Individual investment behavior is concerned with choices about purchasing various securities. However, behavioral finance disputes the concept of perfect rationality and identifies psychological factors and their impact on decision-making. Research design, data, and methodology - A survey questionnaire was designed and used to collect responses using a judgmental sampling technique from 290 investors in the Gwalior Region. Cronbach's Alpha, factor analysis, and linear regression were all used to test the influence of behavioral biases on investment decision. Results - We found that the behavioral biases have a positive impact on investment decisions. Conclusions - This study's results identified three factors influencing investor behavior(rationale, investment skills, and profit making) and four factors influencing investor decisions (profit maker, market analysis, investment plan, seller). The overall results of the study also show that there is no significant relationship between investor behavior and investment decisions by gender in the market.