• 한국전산구조공학회논문집
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• 제27권2호
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• pp.121-128
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• 2014

본 논문에서는 새로운 형상의 GFRP 판으로 전단보강된 플랫 플레이트의 전단거동에 관하여 실험적으로 연구하였다. GFRP 판은 개구부가 있는 판의 형태로서 콘크리트와의 일체화 거동을 위하여 콘크리트에 매립하여 사용한다. 총 7개의 시험체에 대한 뚫림 전단실험을 수행하였고, 실험 변수로는 전단보강재의 종류와 전단보강량을 선택하였다. 실험결과를 시험체의 균열 및 파괴양상, 변형률, 하중변위곡선으로 분석하였다. 또한 GFRP 판으로 전단 보강된 플랫 플레이트의 ACI 318-11 기준식에 의한 계산값과 실험에 의한 결과값을 비교하였다. 실험 결과 GFRP 판이 플랫 플레이트의 전단보강재로써 뚫림 전단에 효과적으로 적용함을 확인하였다.

• 대한의생명과학회지
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• 제5권2호
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• pp.209-212
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• 1999

라임병의 원인균인 Borrelia burgdorferi에 대하여 각 균종의 표준균주와 진드기에서 추출한 DNA를 template로 PCR을 실시한 후 그 증폭산물을 Alu I으로 처리한 restriction fragment length polymorphism (RFLP) 방법으로 각 균종의 연관성을 조사하고자 하였다. 표준균주로 RFLP를 실시한 결과 B. burgdorferi sensu stricto와 B. garinii의 RFLP 형태 (50 bp, 70 bp, 150 bp)가 유사하였으며 B. afzelii에서는 다른 RFLP 형태 (50 bp,110 bp,150 bp)를 관찰하였다. 그 중 B. afzelii KK-1과 B. garinii HPI은 새로운 RFLP형태를 보여 B. afzelii자 B. garinii는 각각 2 type의 subgroup으로 분류할 수 있었다. 진드기 DNA에서는B. afzelii를 포함한 각 균종에 대하여 모두 유사한 RFLP형태를 보였는데, 진드기 DNA에서 확인된 B. afzelii는 KK-1과 같은 군에 속하는 것으로 사료되었다.

• BMB Reports
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• 제33권6호
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• pp.483-492
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• 2000

The Herpes simplex virus type 1 (HSV-1) strain F glycoprotein H (gH) gene in the pHLB-4 plasmid was recombinated into a baculovirus expression vector (lacZ-HcNPV) to construct a recombinant virus GH-HcNPV expressing gH. The sequences of gH and its expression were analyzed. The gH gene was located in the 6.41 kb BglII fragment. The open reading frame (ORF) of the gH gene was 2,517 bp and codes 838 amino acid residues. Insect cells infected with this recombinant virus synthesized a high level of the matured and gX-gH fusion protein with approximately 112 kDa. The fusion gH protein was localized on the membrane of the insect cells as seen by using immunofluorescence assay and accumulated in the cultured media by the SDS-PAGE and immunoprecipitation assays. The amino acid sequence presents additional characteristics compatible with the structure of a viral glycoprotein: signal peptide, putative glycosylation sites and a long C-terminal transmembrane sequence. Antibodies raised in mice to this recombinant protein recognized viral gH and neutralized the infectivity of HSV-1 in vitro. These results demonstrate that it is possible to produce a mature protein by gene transfer in eukaryotic cells, and indicate the utility of the HcNPV-insect cell system for producing and characterizing eukaryotic proteins. Furthermore, the neutralizing antibodies would appear to protect mice against HSV; accordingly, this particular recombinant protein may be useful in the development of a subunit vaccine.

• 대한기계학회논문집A
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• 제27권9호
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• pp.1562-1570
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• 2003

The prediction of the inelastic behavior of the structure is an essential part of reliability assessment procedure, because most of the failures are induced by the inelastic deformation, such as creep and plastic deformation. During decades, there has been much progress in understanding of the inelastic behavior of the materials and a lot of inelastic constitutive equations have been developed. The complexity of these constitutive equations generally requires a stable and accurate numerical method. The radial return mapping is one of the most robust integration scheme currently used. Nonlinear kinematic hardening model of Armstrong-Fredrick type has recovery term and the direction of kinematic hardening increment is not parallel to that of plastic strain increment. In this case, The conventional radial return mapping method cannot be applied directly. In this investigation, we expanded the radial return mapping method to consider the nonlinear kinematic hardening model and implemented this integration scheme into ABAQUS by means of UMAT subroutine. The solution of the non-linear system of algebraic equations arising from time discretization with the generalized midpoint rule is determined using Newton method and bisection method. Using dynamic yield condition derived from linearization of flow rule, the integration scheme for elastoplastic and viscoplastic constitutive model was unified. Several numerical examples are considered to demonstrate the efficiency and applicability of the present method.

• Journal of Magnetics
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• 제16권3호
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• pp.211-215
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• 2011

The dynamic magnetostriction characteristics of an Fe-based nanocrystalline FeCuNbSiB alloy are investigated as a function of the dc bias magnetic field. The experimental results show that the piezomagnetic coefficient of FeCuNbSiB is about 2.1 times higher than that of Terfenol-D at the low dc magnetic bias $H_{dc}$ = 46 Oe. Moreover, FeCuNbSiB has a large resonant dynamic strain coefficient at quite low Hdc due to a high mechanical quality factor, which is 3-5 times greater than that of Terfenol-D at the same low $H_{dc}$. Based on such magnetostriction characteristics, we fabricate a new type of transducer with FeCuNbSiB/PZT-8/FeCuNbSiB. Its maximum resonant magnetoelectric voltage coefficient achieves ~10 V/Oe. The ME output power reaches 331.8 ${\mu}W$ at an optimum load resistance of 7 $k{\Omega}$ under 0.4 Oe ac magnetic field, which is 50 times higher than that of the previous ultrasonic-horn-substrate composite transducer and it decreases the size by nearly 86%. The performance indicate that the FeCuNbSiB/PZT-8/FeCuNbSiB transducer is promising for application in highly efficient magnetoelectric energy conversion.

• IMMUNE NETWORK
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• 제14권6호
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• pp.307-320
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• 2014

Mycobacterium scrofulaceum is an environmental and slow-growing atypical mycobacterium. Emerging evidence suggests that M. scrofulaceum infection is associated with cervical lymphadenitis in children and pulmonary or systemic infections in immunocompromised adults. However, the nature of host innate immune responses to M. scrofulaceum remains unclear. In this study, we examined the innate immune responses in murine bone marrow-derived macrophages (BMDMs) infected with different M. scrofulaceum strains including ATCC type strains and two clinically isolated strains (rough and smooth types). All three strains resulted in the production of proinflammatory cytokines in BMDMs mediated through toll-like receptor-2 and the adaptor MyD88. Activation of MAPKs (extracellular signal-regulated kinase 1/2, and p38, and c-Jun N-terminal kinase) and nuclear receptor (NF)-${\kappa}B$ together with intracellular reactive oxygen species generation were required for the expression of proinflammatory cytokines in BMDMs. In addition, the rough morphotypes of M. scrofulaceum clinical strains induced higher levels of proinflammatory cytokines, MAPK and NF-${\kappa}B$ activation, and ROS production than other strains. When mice were infected with different M. scrofulaceum strains, those infected with the rough strain showed the greatest hepatosplenomegaly, granulomatous lesions, and immune cell infiltration in the lungs. Notably, the bacterial load was higher in mice infected with rough colonies than in mice infected with ATCC or smooth strains. Collectively, these data indicate that rough M. scrofulaceum induces higher inflammatory responses and virulence than ATCC or smooth strains.

• 한국전산구조공학회논문집
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• 제32권6호
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• pp.401-408
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• 2019

본 연구는 헤테로코어 광파이버 센서를 활용하여 콘크리트 내부에서 발생되는 변형률의 측정을 통해 콘크리트의 프리스트레스를 직접 평가할 수 있는 새로운 매립형 센서모듈 개발을 최종 목표로 하고 있다. 이를 위하여 노출형 센서모듈을 이용한 성능발현 실험결과는 가력속도 0.12, 1.80mm/min일 때 52.1, 2.6sec로 최대 약 19배의 계측 지연현상이 발생하였다. 계측 지연현상은 구조물의 실시간 변화 상태를 계측하지 못하는 경우로 실시간 계측이 가능한 센서모듈의 개발을 위해서 추가실험이 필요한 것으로 판단하였다. 계측 지연현상 원인규명 실험은 3가지의 실험을 계획하였으며, 실험결과는 마찰저항에 의한 계측 지연이 지배적으로 확인되었다. 마찰이 제거된 장치를 이용한 센서모듈의 실험결과에서는 계측 지연현상이 나타나지 않은 것으로 확인되었다.

• Journal of Periodontal and Implant Science
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• 제37권4호
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• pp.681-690
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• 2007

Mini implants had been used provisionally for the healing period of implants in the beginning. But it becomes used for the on-going purpose, because it is simple to use, economic and especially suitable for the overdenture. But there is few studies about the stability of mini implants, that is most important factor for the on-going purpose, and particularly the implant parameters affecting the initial stability. The purpose of this study was to evaluate the stress and the strain distribution pattern of immediate-loaded screw type orthodontic mini-implant and the parameters affecting the initial stability of immediate-loaded mini-implant. Two dimensional finite element models were made and contact non-linear finite element analysis was performed. The magnitude and distribution of Von Mises stresses were evaluated. The obtained results were as follows: 1. The stress was concentrated on the thread tip of an implant in the cortical bone. 2. The direction of load is the most important factor for the stress distribution in cortical bone. 3. The diameter of an implant is the most important factor for the stress distribution in the trabecular bone. In conclusion, if the horizontal load vector is successfully controlled, mini-implants, which diameter is under 3mm, can be used for the on-going purpose.

• Clinical and Experimental Reproductive Medicine
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• 제27권3호
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• pp.275-282
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• 2000

Objective: This study was to determine the effect of different concentration of calcium III medium on the preimplantational development of zygotes and early 2 cell embryos. Methods: Female mice of ICR strain ($5{\sim}8$ weeks old) were superovulated and mated with fertile males. Zygotes or early 2-cell embryos were collected by flushing the oviducts $31{\sim}32$ hours after hCG injection. The embryos were cultured in various concentrations of $Ca^{2+}$ in medium or with EDTA, EGTA and $Ni^{2+}$. Result and Conclusion: Treatment of high concentraion of $Ca^{2+}$ (3.42 mM $(2X){\sim}17.l$ mM (10X)) in medium didn't develop well compared to the control. Low concentrations of $Ca^{2+}$ (0.214mM $(1/8X){\sim}0.855$ mM (1/2X) were deterimental to development beyond 2-cell stage. EDTA, $Ca^{2+}$ chelating agent was treated with ranged concentrations of EDTA (0.014 $mM{\sim}0.107$ mM) to medium contaning 1.71 mM $Ca^{2+}$ showed beneficial effect to development to blastocyst compared to the control. EGTA, extracellular $Ca^{2+}$ chelator, was treated with ranged concentrations of EGTA ($0.014{\sim}0.107$ mM) to the medium contaning 1.71 mM $Ca^{2+}$. There is no significant difference with the control. $Ni^{2+}$ (50 ${\mu}M$), T-type $Ca^{2+}$-channel blocker was treated to medium contaning low concentration of $Ca^{2+}$. It overcame 2-cell block significantly. Rate of degenerated embryos decreased and developmental rate to morula and blastocyst increased more than low $Ca^{2+}$ concentration alone. Further studies are needed for the overcoming effect of 2-cell block by $Ni^{2+}$.

• Journal of Ginseng Research
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• 제41권3호
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• pp.277-283
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• 2017

Background: The ginseng berry has various bioactivities, including antidiabetic, anticancer, antiinflammatory, and antioxidative properties. Moreover, we have revealed that the active antiaging component of the ginseng berry, syringaresinol, has the ability to stimulate longevity via gene activation. Despite the many known beneficial effects of ginseng, its effects on skin aging are poorly understood. In this study, we investigated the effects of ginseng and the ginseng berry on one of the skin aging processes, melanogenesis, and age-related pigment lipofuscin accumulation, to elucidate the mechanism of action with respect to antiaging. Methods: The human melanoma MNT1 cell line was treated with ginseng root extract, ginseng berry extract, or syringaresinol. Then, the cells were analyzed using a melanin assay, and the tyrosinase activity was estimated. The Caenorhabditis elegans wild type N2 strain was used for the life span assay to analyze the antiaging effects of the samples. A lipofuscin fluorescence assay was performed during 10 passages with the syringaresinol treatment. Results: A 7-d treatment with ginseng berry extract reduced melanin accumulation and tyrosinase activity more than ginseng root extract. These results may be due to the active compound of the ginseng berry, syringaresinol. The antimelanogenic activity was strongly coordinated with the activation of the longevity gene foxo3a. Moreover, the ginseng berry extract had more potent antiaging effects, caused a life span extension, and reduced lipofuscin accumulation. Conclusion: Taken together, our results suggest that these antimelanogenic effects and antiaging effects of ginseng berry mediate the activation of antioxidation-FoxO3a signaling.