• Journal of Microbiology and Biotechnology
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• 제15권4호
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• pp.749-755
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• 2005

The ccpA gene encoding catabolite control protein A (CcpA) of Leuconostoc mesenteroides SYl, a strain isolated from kimchi, was cloned, sequenced, analyzed for transcript, and overexpressed in Escherichia coli. The ccpA ORF (open reading frame) is 1,011 bp in size, which can encode a protein of 336 amino acid residues with a molecular mass of 36,739 Da. The transcription start site was mapped at a position 49 nucleotides upstream of the start codon, and promoter sequences were also identified. The putative cre site overlapped with the -35 promoter sequence. The deduced amino acid sequence of the CcpA contained the helix-turn-helix motif found in many DNA-binding regulatory proteins. CcpA from 1. mesenteroides SY1 had $54.6\%$ identity with CcpA from Lactobacillus casei. The Northern blot experiment showed that ccpA was transcribed as a single 1.1 kb transcript, and transcription was repressed when grown on media containing glucose. CcpA was overproduced in E. coli BL21(DE3) cells using the pET expression vector, and purified to an apparent homogeneity. Gel Mobility Shift Assay with purified CcpA and a DNA fragment containing the ere sequence of the $\alpha$-galactosidase gene (aga) from L. mesenteroides SY1 revealed that CcpA bound specifically to the cre site of aga.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2015년도 춘계학술대회
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• pp.63-66
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• 2015

스마트폰의 대중화에 따라 무선 데이터 트래픽이 기하급수적으로 증가하고 있으며, 이러한 데이터 트래픽을 원활히 수용하기 위하여 차세대 이동통신 네트워크에 대한 연구가 활발히 진행 중이다. 특히, 매크로 셀과 소형 셀을 활용하여 공간 재활용성을 높임으로써 네트워크 용량을 획기적으로 개선할 수 있는 이종 이동 통신망이 많은 관심을 끌고 있다. 이종 이동 통신망에서는 매크로 기지국과 소형 기지국 간의 송신전력의 차이로 인하여 부하 불균형과 간섭 등의 문제가 발생하며, 이를 해결하기 위하여 cell range expansion (CRE) 기술을 활용한다. 본 논문에서는, 초밀집 이종 이동 통신망에서 CRE bias를 적응적으로 적용하는 새로운 셀 선택 방식을 제안하고 시스템 레벨 시뮬레이션을 통하여 셀 평균 전송률을 분석하고, 기존의 셀 선택 방식과 비교 한다.

• 대한의생명과학회지
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• 제12권3호
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• pp.131-137
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• 2006

RGS is a negative regulator of G-protein signaling and can be identified by the presence of a conserved $120{sim}125$ amino acid motif, which is referred to as the RGS box. A number of RGSs are induced in response to a wide variety of stimuli. Increased levels of RGSs lead to significant decreases in GPCR responsiveness. To obtain further evidence of a role of RGS proteins in rat C6 astrocytoma cells, we first determined the expression profile of RGS-specific mRNA in C6 cells using reverse transcription-polymerase chain reaction (RT-PCR) with a poly dT18 primer and transcript-specific primers. We found that RGS2, RGS3, RGS6, RGS9, RGS10, RGS12, and RGS16 were differentially expressed in C6 astrocytoma cells. The highest expression rate was found for RGS3, followed by RGS16, RGS10 and RGS9, whereas the expression level for RGS2 was barely detectable. We next assessed whether forskolin regulated the expression of RGSs expressed in C6 astrocytoma cells. The present study found that forskolin dose-dependently stimulated the expression of RGS2 transcripts. This up-regulation of RGS2 gene was abrogated by H-89, potent and broad-spectrum protein kinase A (PKA) inhibitors. Actinomycin D completely inhibited the up-regulation of RGS2 gene induced by forskolin $(10{\mu}M)$, indicating that the regulation of RGS2 gene is controlled at the transcriptional level. In addition, forskolin did significantly activate transcriptional cAMP response element (CRE) in either HEK 293 cells or C6 cells and did not modulate the $NF-{\kappa}B$ and AP-l activity as measured by luciferase reporter gene assay. Finally, forskolin induced the expression of RGS2 mRNA in C6 astrocytoma cells, which depend on the PKA pathway and CRE transcriptional pathways.

• 전자공학회논문지
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• 제50권8호
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• pp.39-44
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• 2013

LTE(Long Term Evolution)-Advanced에서는 저전력 피코셀(picocell)과 같은 소형셀을 중첩하여 배치해 시스템 성능을 향상시키기 위한 HetNet(Heterogeneous Network)에 대한 연구가 활발히 진행되고 있다. 또한 HetNet에서 데이터 오프로딩 효과를 증대시키기 위해 셀 영역 확장(CRE: Cell Range Expansion) 기술이 소개되었다. 본 논문에서는 최적의 오프로딩 효과를 위해 SINR(Signal to Interference plus Noise Ratio) 기반 셀 선택 기법을 제안한다. 셀 확장 영역에 존재하는 사용자의 간섭 관리를 위해 ABS를 사용하며, 스펙스럼 효율을 증가시키기 위하여 동적인 ABS 비율을 사용한다. 모의실험 결과, 제안한 기법에서 피코셀뿐만 아니라 매크로셀 사용자의 스펙트럼 효율이 향상되어 전체적인 사용자의 성능이 향상 된 것을 볼 수 있다.

• 한국식품조리과학회지
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• 제13권5호
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• pp.639-647
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• 1997

The hypoglycemic effects of five Korean wild vegetables, Aralia continentalis (A. con.), Castanea crenata (C. cre.), Xanthium strumarium (K, str.), Alisma canaliculatum (A. can,) and Eupatorium chinense var. simplicifolium for tripartium (E. tri) which have been utilized for the traditional remedies were investigated in this study. Diabetes mellitus was induced in male Sprague-Dawley rats by injections of streptozotocin (STZ) into the tail veins at a dose of 45 mg/kg. Five groups of STZ-induced diabetic rats were fed one of each experimental diet containing 10% of the Korean wild vegetable powder and normal and STZ-control rats were fed the control diet for five weeks. The body weight change, feed efficiency ratio (FER) and organ weights were compared. The plasma levels of glucose, protein, cholesterol, HDL-cholesterol, triglyceride, free fatty acid, and aminotransferase activity were determined. Mineral (Ca, K, Mg, Na, Cu, Fe, Mn and Zn) contents of the Korean wild vegetables were analyzed. The body weight gain was higher in normal, C. cre., A. can. and E. tri. groups than in the diabetic control group. The FER of C. cre., A. can. and E. tri. groups was significantly higher (p.＜0.05) than that of diabetic control group. Liver weight was heavier in A. con., X. str. and A. can. groups compared with the diabetic control group. The weights of kidney were lighter in all five Korean wild vegetable groups than in the diabetic control group. After five weeks, the plasma glucose level tends to be decreased in A. con., A. can. and E. tri. groups. Plasma cholesterol level was decreased the Korean wild vegetables except for X. str. group. Plasma HDL- cholesterol level was significantly higher in A. con., A. can. and E. tri. groups compared with the diabetic control group. Plasma triglyceride and free fatty acid levels were significantly higher in X. str. group compared with the diabetic control group. Mineral contents were higher in E. tri. (Ca, K, Na and Fe). The results suggest that the intakes of A. con., A. can. and E. tri. have a hypoglycemic effect in diabetic rats showing the possibility as the valuable food resources for the prevention of diabetic mellitus.

• 대한치과기공학회지
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• 제40권1호
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• pp.41-47
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• 2018

Purpose: The purpose of this study was to analyze the biomechanical properties of the dental implants on the supporting bone using three-dimensional finite element method when three different abutment materials were applied to the implant system. Methods: Three different dental implant models were fabricated by applying Ti, PEEK, and CRE-PEEK (60% carbon-reinforced PEEK) to abutment material. The abutment and connecting screw from the fixture was applied with a tightening torque of 20 Ncm. And then, total loads of 150 N were applied in an $30^{\circ}oblique$ direction (to the vertical). The structural stability of dental implants on the supporting bone was analyzed using Von Mises stress and principal stress values. Results: The maximum tensile stress of the cortical bone was highest at 12.6 MPa in the PEEK abutment (Model-B). Ti abutment (Model-A) and CRE-PEEK abutment (Model-C) showed similar stress distributions (10.6 and 10.3 MPa, respectively). And the maximum compressive principal stress was similar in all models. The Von Mises stress value delivered to the bone around the implant was highest at 16.5 MPa in Model-B. On the other hand, Model-A and C showed similar stress distributions (14.0 and 13.8 MPa, respectively). In addition, the maximum equivalent stress applied to the abutment was highest at 629.8 MPa in Model-A. The stress distribution in Model-C was 573.9 MPa. Whereas, Model-B showed the lowest value at 165.6 MPa. Conclusion : The dental implant supporting bone system using PEEK material seems to have the possibility of supporting bone fracture. It was found that the CRE-PEEK abutment can reduce the elastic deformation and reduce the stress value of the interfacial bone.

• Journal of Microbiology and Biotechnology
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• 제31권10호
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• pp.1383-1392
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• 2021

Carbapenem-resistant Enterobacteriaceae (CRE) that produce Klebsiella pneumoniae carbapenemase are increasingly reported worldwide and have become more and more resistant to nearly all antibiotics during the past decade. The emergence of K. pneumoniae strains with decreased susceptibility to carbapenems, which are used as a last resort treatment option, is a significant threat to hospitalized patients worldwide as K. pneumoniae infection is responsible for a high mortality rate in the elderly and immunodeficient individuals. This study used Lactobacillus fermentum as a candidate probiotic for treating CRE-related infections and investigated its effectiveness. We treated mice with L. fermentum originating from the vaginal fluid of a healthy Korean woman and evaluated the Lactobacilli's efficacy in preventive, treatment, nonestablishment, and colonization mouse model experiments. Compared to the control, pre-treatment with L. fermentum significantly reduced body weight loss in the mouse models, and all mice survived until the end of the study. The oral administration of L. fermentum after carbapenem-resistant Klebsiella (CRK) infection decreased mortality and illness severity during a 2-week observation period and showed that it affects other strains of CRK bacteria. Also, the number of Klebsiella bacteria was decreased to below 5.5 log₁₀ CFU/ml following oral administration of L. fermentum in the colonization model. These findings demonstrate L. fermentum's antibacterial activity and its potential to treat CRE infection in the future.

• 한국어병학회지
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• 제24권3호
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• pp.247-254
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• 2011

이 연구는 FUJI DRI-CHEM 3000의 건식 자동생화학 분석기를 이용하여 조사한 어류 혈액검사 항목 가운데, 적용할 수 있는 분석항목의 활용도를 평가함과 동시에 어류 혈액학적 건강진단에 필요한 분석항목의 참고자료를 얻고자 하였다. 국립수산과학원 내 수면양식연구센터에서 사육 중인 육안적으로 보아 건강한 무지개송어 (Onchorhynchus mykiss), 이스라엘잉어 (Cyprinus carpio), 틸라피아 (Oreochromis niloticus) 및 뱀장어 (Anguilla japonica) 총 200마리를 대상으로 실시하였다. Hemoglobin (Hb), 총단백 (TP), 알부민 (ALB), 알칼리성포스파타제 (ALP), 요소질소 (BUN), 젖산탈수소효소 (LDH), 중성지방 (TG), 총콜레스테롤 (TCHO), 크레아티닌 (CRE), aspartate aminotransferase (AST), alanine aminotransferase (ALT), 포도당 (GLU) 은 FUJI DRI-CHEM 3000 기종을 이용하였다. 그 결과, 이 장비의 검출범위 (detectable range)에서 최고값 (maximum) 과 최저값 (minimum) 을 벗어난 분석항목들 (ALT, TG, LDH, ALB, TCHO, AST, ALP) 이 출현하였다. 이러한 검출범위를 초과한 평균비율을 살펴보면, ALT 및 TG가 67%~61.5%, LDH, ALB 및 TCHO는 36%~17%, AST 및 ALP는 5.5%~0.5%로 나타났다. 반면에, BUN, CRE, GLU, Hb 및 TP의 분석값은 모두 검출범위의 영역 안에서 벗어나지 않았다.

• 대한본초학회지
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• 제35권4호
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• pp.25-36
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• 2020

Objective : Reflux esophagitis is a disease caused by the reflux of gastric acid and inflammation due to unstable gastroesophageal sphincter. The aim of the present study was to clarify the effect of Phellodendri Cortex (PC) on chronic reflux esophagitis (CRE) in rats. Methods : The anti-oxidant activity of PC was measured by total polyphenol, total flavonoid contents, 1, 1-diphenyl-2-picrylhydrazyl (DPPH), and 2, 2'-azinobis-3-ethyl-enzothiazoline-6-sulfonic acid (ABTS) radical scavenging activity. A CRE was established surgically in SD rats. And then CRE rats were treated with water or PC 200 mg/kg body weight for 14 days. Besides, the anti-oxidant and inflammatory protein levels were evaluated using western blotting. Results : PC reduced esophagus tissues injury. The total polyphenol (36.05 ± 0.25 mg/g) and total flavonoid (72.90 ± 0.61 mg/g) of PC showed a high content. PC strongly reduced radical scavenging activities (DPPH IC₅₀ 43.58 ± 1.54 ㎍/㎖; ABTS IC₅₀ 36.75 ± 0.35 ㎍/㎖). Moreover, reactive oxygen species (ROS) and peroxynitrite (ONOO^-) levels in serum, the protein expression of inducible nitric oxide synthases (iNOS) were significantly reduced. In addition, the protein expression of NADPH oxidases related to oxidative stress were significantly reduced in PC compared to CRE control. PC effectively reduced inflammatory factors including, TNF-α, and IL-6 via NF-κBp65 inactivation through the inhibition of p-IκBα and increased anti-oxidant enzyme such as HO-1, SOD, catalase, and GPx-1/2 via Nrf2 activation. Conclusions : Taken together, these results show that PC can alleviate the esophageal mucosal ulcer though the inhibition of NF-κB inflammatory and the enhancement of Nrf2 anti-oxidant pathway.

• Animal cells and systems
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• 제13권3호
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• pp.289-295
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• 2009

Cyclic AMP-mediated signaling pathways regulate a number of cellular functions. In this study, we examined the regulatory role of cAMP signaling pathways in chondrogenesis of chick limb bud mesenchymal cells in vitro. Forskolin, which increases cellular cAMP levels by the activation of adenylate cyclase, enhanced chondrogenic differentiation. Inhibition of PKA with specific inhibitors (H89 or KT5720) blocked pre-cartilage condensation stage, indicating that chondrogenesis is regulated by the increase in cellular cAMP level and subsequent activation of PKA. Downstream signaling pathway of PKA leading to gene expression was investigated by examination of several nuclear transcription factors. Forskolin treatment increased transcription level for a cartilage-specific marker gene Sox9. However, inhibition of PKA with H89 led to restore expression of Sox9, indicating PKA activity was required to regulate the expression of Sox9 in chondrogenesis. In addition, CREB was highly phosphorylated at early stage of mesenchyme culture, and followed by progressive dephosphorylation. CBP and ATF, another CRE related proteins were transiently expressed at the early stage of chondrogenesis with a pattern similar to CREB phosphorylation. Electrophoretic mobility shift assays confirmed that the binding activity of CREB to the CRE is closely correlated to the phosphorylation pattern of CREB. Therefore, cAMP-mediated signal transduction to nuclear events for the induction of genes appeared to be required at the early stage of chick limb bud chondrogenesis.