• 동아시아식생활학회지
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• 제25권4호
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• pp.681-690
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• 2015

In this study, gluten-free noodles were developed and the physicochemical quality of gluten-free noodles added with nondigestible maltodextrin (NMD) was also investigated. The gluten-free noodles were prepared by addition of 0, 5, 7, and 9% NMD of total ingredients except water. Inhibition activities for ${alpha}$-amylase and ${alpha}$-glucosidase according to the addition amounts of NMD were evaluated. As a result, activities of carbohydrate-digestive enzymes decreased with an increase of the added NMD amounts. Water binding capacity and solubility of raw noodles increased upon NMD addition. Swelling power also increased as temperature rose. L value of raw noodles decreased with the addition of NMD, but b value increased. Texture profile analysis of cooked noodles showed reduction of hardness, springiness, and chewiness of noodles with NMD. On the other hand, tensile strength of cooked noodles containing up to 7% NMD was not significantly different from that of noodle without NMD. In the sensory evaluation, elasticity of noodles with 9% NMD was lower than that of other noodles, whereas other characteristics of noodles were not significantly different among noodles. Therefore, it was confirmed that the addition of 5~7% NMD had little effect on the sensory quality of noodles.

• BMB Reports
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• 제50권4호
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• pp.175-185
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• 2017

Nonsense-mediated mRNA decay (NMD) is a surveillance mechanism ensuring the fast decay of mRNAs harboring a premature termination codon (PTC). As a quality control mechanism, NMD distinguishes PTCs from normal termination codons in order to degrade PTC-carrying mRNAs only. For this, NMD is connected to various other cell processes which regulate or activate it under specific cell conditions or in response to mutations, mis-regulations, stresses, or particular cell programs. These cell processes and their connections with NMD are the focus of this review, which aims both to illustrate the complexity of the NMD mechanism and its regulation and to highlight the cellular consequences of NMD inhibition.

• BMB Reports
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• 제50권4호
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• pp.160-161
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• 2017

Proper maintenance of biological components is crucial for longevity and healthy aging. Although the role of homeostatic maintenance systems for DNA and protein in longevity is established, it remains largely unknown for RNA. In our recent work, we show that nonsense-mediated mRNA decay (NMD) promotes longevity in the roundworm C. elegans by enhancing RNA quality control. We find that the activity of NMD decreases during aging, raising the possibility that RNA quality declines in old animals. We then show that key components of NMD complex are required for prolonged lifespan in C. elegans. In addition, animals with reduced insulin/insulin-like growth factor-1 (IGF-1) signaling (IIS), a representative longevity model, display increased NMD activity. Thus, up-regulation of NMD appears to play crucial roles in longevity conferred by reduced IIS via enhancing mRNA quality control. As both IIS and NMD pathways are evolutionarily conserved, mammals including humans may be equipped with similar RNA quality control systems to achieve longevity.

• BMB Reports
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• 제56권12호
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• pp.625-632
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• 2023

Nonsense-mediated mRNA decay (NMD) is both a quality control mechanism and a gene regulation pathway. It has been studied for more than 30 years, with an accumulation of many mechanistic details that have often led to debate and hence to different models of NMD activation, particularly in higher eukaryotes. Two models seem to be opposed, since the first requires intervention of the exon junction complex (EJC) to recruit NMD factors downstream of the premature termination codon (PTC), whereas the second involves an EJC-independent mechanism in which NMD factors concentrate in the 3'UTR to initiate NMD in the presence of a PTC. In this review we describe both models, giving recent molecular details and providing experimental arguments supporting one or the other model. In the end it is certainly possible to imagine that these two mechanisms co-exist, rather than viewing them as mutually exclusive.

• 청정기술
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• 제2권1호
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• pp.60-68
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• 1996

고정층 반응기에서 망간광석을 이용하여 저농도의 일산화탄소 산화제어반응에 대하여 고찰하였다. 고려된 실험변수는 일산화탄소 농도 (500ppm~10000ppm), 산소 농도(500ppm~99.8%)와 촉매의 온도($50{\sim}750^{\circ}C$)이다. 또한 망간광석의 특성은 Thermogravimetric Analysis(TGA), 일산화탄소에 의한 환원, Temperature Programmed Reduction(TPR)실험을 이용하여 규명하였다. 망간광석의 일산화탄소 산화력은 순수이산화망간에 비해서 단위 면적당 높은 산화력과 $750^{\circ}C$까지 가열된 후에도 산화력이 유지될 수 있는 안정된 촉매작용을 보였다. Temperature Programmed Desorption(TPD), TPR 실험과 TG 등의 분석결과 산소의 농도가 낮거나 무산소하에서 망간광석의 격자내 산소가 쉽게 제공될 수 있음을 알 수 있었다. 일산화탄소의 농도가 500~3500ppm일 때 일산화탄소의 반응차수는 0.701이며 3500~10000ppm구간에서 일산화탄소의 농도에 무관한 0차 반응이었다.

• Journal of Korean Neurosurgical Society
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• 제29권7호
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• pp.861-867
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• 2000

Purpose : Neuronal migration disorder(NMD) is a major underlying pathology of patients with intractable epilepsy. The role of NMD on seizure susceptibility or epileptogenecity, however, has not been documented. Methods : External irradiation of total amount of 250 cGY was performed to the fetal rats on days 16(E16) and 17(E17) of gestation. After delivery, the rats of 230-260g were decapitated for the histopathologic study. Epileptog-enecity of the NMD was studied by observing electroclinical events after intraperitoneal kainic acid(KA) injection in the control rats and NMD rats. Results : Histopathologic findings revealed focal and/or diffuse cortical dysplasia consisting of dyslamination of the cerebral cortex and appearance of the cytomegalic neurons, neuronal heterotopia in the periventricular white matter, dispersion of the pyramidal layer and the dentate gyrus of the hippocampus, and agenesis of the corpus callosum. Abnormal expression of neurofilaments protein(NF-M/H) was characteristically observed in the dysplastic neurons of the neocortex and hippocampus. Early ictal onset and prolonged ictal activity on EEG and clinical seizures were observed from the NMD rats unlike with the control rats. Conclusions : Exteranl irradiation on the fetal rats produced NMD. And the rats with NMD were highly susceptible to kainic acid provoked seizures. This animal model would be useful to study the pathophysiology of clinically relevant NMDs.

• Molecules and Cells
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• 제42권4호
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• pp.301-312
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• 2019

Post-transcriptional regulation underlies the circadian control of gene expression and animal behaviors. However, the role of mRNA surveillance via the nonsense-mediated mRNA decay (NMD) pathway in circadian rhythms remains elusive. Here, we report that Drosophila NMD pathway acts in a subset of circadian pacemaker neurons to maintain robust 24 h rhythms of free-running locomotor activity. RNA interference-mediated depletion of key NMD factors in timeless-expressing clock cells decreased the amplitude of circadian locomotor behaviors. Transgenic manipulation of the NMD pathway in clock neurons expressing a neuropeptide PIGMENT-DISPERSING FACTOR (PDF) was sufficient to dampen or lengthen free-running locomotor rhythms. Confocal imaging of a transgenic NMD reporter revealed that arrhythmic Clock mutants exhibited stronger NMD activity in PDF-expressing neurons than wild-type. We further found that hypomorphic mutations in Suppressor with morphogenetic effect on genitalia 5 (Smg5) or Smg6 impaired circadian behaviors. These NMD mutants normally developed PDF-expressing clock neurons and displayed daily oscillations in the transcript levels of core clock genes. By contrast, the loss of Smg5 or Smg6 function affected the relative transcript levels of cAMP response element-binding protein B (CrebB) in an isoform-specific manner. Moreover, the overexpression of a transcriptional repressor form of CrebB rescued free-running locomotor rhythms in Smg5-depleted flies. These data demonstrate that CrebB is a rate-limiting substrate of the genetic NMD pathway important for the behavioral output of circadian clocks in Drosophila.

• 아태비즈니스연구
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• 제8권1호
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• pp.33-44
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• 2017

The present study aims to examine the role of market orientation as an international partnership property. This property, labeled export-venture market orientation, is at the inter-firm level and is related to the new market development (NMD) activities of export-ventures. Specifically, this article is to define the export-venture market orientation; to argue that it is a major factor in NMD export-venture success; and to argue that the resource-advantage (R-A) theory of competition can provide a theoretical foundation for this concept and explain its contribution to export-ventures' international expansion success. This manuscript is conceptual in approach. In their efforts to strengthen relationships, export-ventures may tend to focus so much time on the partnership factors that they miss market opportunities. As a spanning process, NMD should be informed by both external and internal activities. In an export-venture, market orientation helps guide NMD activities from outside to inside and vice versa. As a dynamic and disequilibrium provoking process, the R-A theory can theoretically ground the concept of export-venture market orientation and explain its role in NMD export-venture success. The current study contributes to business marketing theory in three ways: it extends the concept of intra-organizational market orientation to an inter-organizational context; contributes to understanding the role of idiosyncratic resources in export-ventures; and theoretically explains the concept of export-venture market orientation. The present study is the first to extend the concept of market orientation into inter-organizational NMD framework and to examine the role of export-venture market orientation in NMD export-venture success.

• 한국지하수토양환경학회지:지하수토양환경
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• 제10권4호
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• pp.62-69
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• 2005

본 연구에서는 천연 망간산화물에 의한 4-클로로페놀 화합물의 제거효과를 평가하였으며 자연유기물질과 용액의 pH에 의한 분해율 변화를 살펴보았다. 천연망간산화물은 4-클로로페놀 화합물의 제거에 효과적이었으며 실험결과의 분석을 통하여 반응계수 및 차수에 대한 정량적인 값을 도출하였다. 그 결과, 전체적인 반응은 2차반응으로서 4-클로로페놀 화합물에 대하여 1차, 망간산화물에 대하여 1차에 비례하는 반응이었다. 망간산화물에 의한 4-클로로페놀 화합물의 산화반응은 표면에서 일어나며 pH에 큰 영향을 받았다. 용액의 pH가 망간산화물의 영가전위(PZC) 값보다 클 경우 반응율은 급격히 감소하였으며 PZC 보다 pH가 작은 경우에도 반응율은 감소하였다. 휴믹산을 첨가한 경우 4-클로로페놀 화합물의 산회중합 반응은 다소 증가하는 경향을 보여 휴믹산이 중합반응에 관여하고 있다고 평가할 수 있다. 본 연구 결과, 경제적인 비용으로서 천연망간산화물을 이용하여 페놀계 오염물의 제거에 효과적으로 사용 할 수 있는 방안을 제시하였다.

• 한국균학회지
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• 제51권3호
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• pp.205-217
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• 2023

비병원성 야생 색소 효모로부터 건강 소재를 생산하기 위하여 대전광역시 월평공원 등에서 분리, 동정한 야생 효모들 중 비병원성 색소 효모들을 선별한 후 각종 생리활성과 효소활성들을 조사하였다. 최종적으로 항산화활성 우수 균주로 Rhodosporidium paludigenum HHGG35-1 와 항통풍성 xanthin 산화효소 저해물질 생산 우수 균주로Rh. diobovatum NMD18-1를 선발하였다. Rh. paludigenum HHGG35-1의 항산화물질은 초기 pH를 6.5로 조정한 YPD 배지에 선발 균을 접종하여 30℃에서 24시간 배양하였을 때 76.9%의 최대 활성을 보였다. Rh. diobovatum NMD18-1의 xanthin 산화효소 저해물질은 선발 균주를 YPD 배지에 접종하여 30℃에서 96시간동안 배양하였을 때 91.6%의 최대 활성을 보였다. 항산화활성과 xanthin 산화효소 저해활성 우수 균주들의 균학적 특성을 조사하였다. Rh. paludigenum HHGG35-1는 타원형으로 포자를 형성하였고 YPD, YM, PD 배지 및 비타민을 첨가하지 않은 YPD배지에서 잘 생육하였으며 40% 포도당을 함유한 YPD 배지와 10% NaCl을 함유한 YPD 배지에서도 잘 생육하여 강한 내당성과 호염성을 보였다. 항통풍성 xanthin 산화효소 저해물질 생산 우수 균주인 Rh. diobovatum NMD18-1은 구형으로 포자를 형성하였고 YPD, YM, PD 배지에서 잘 생육하였으며 40% 포도당을 함유한 YPD 배지와 10% NaCl을 함유한 YPD 배지에서 생육하여 내당성과 내염성을 보였다. 그러나 비타민을 함유하지 않은 배지에서는 생육하지 못하였고 pH 5.0-8.0, 20-37℃에서 잘 생육하였으며 포도당, fructose, maltose를 자화 시켰다.