• 한국식품과학회지
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• 제53권3호
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• pp.304-312
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• 2021

참당귀로부터 열수추출 및 에탄올 침전법을 이용해 조다당을 분리하고 DEAE-Sepharose FF와 Sephadex G-100을 이용하여 얻은 정제 다당 AGE-2c-I을 대상으로 선천 면역 활성 및 항종양 전이 효과를 확인하고자 하였다. 인체의 초기 면역 반응에 있어 중추적인 역할을 수행하는 보체계 활성화 및 활성화 경로를 확인한 결과, AGE-2c-I은 운지버섯 유래 시판 면역증강제인 PSK에 준하는 우수한 활성을 나타내는 것으로 확인되었으며. 본 활성은 주로 고전경로를 통하여 활성화되며 일부 부경로를 경유하는 것으로 최종 확인되었다. 또한 AGE-2c-I은 mouse 복강 유래 대식세포에 대해 직접적인 독성을 나타내지 않으며 종양세포주 YAC-1 및 B16BL6에 대한 직접적인 독성 또한 나타나지 않음을 확인함으로써 시료의 직접적인 독성에 근거한 항암 효과는 없는 것으로 확인되었다. 반면에 비장으로부터 분리한 림프구는 8 ㎍/mL의 AGE-2c-I 처리에 의해 증식능이 관찰되었다. AGE-2c-I이 대식세포의 cytokine 분비능에 미치는 효과를 확인한 결과, 우수한 IL-6, IL-12 및 TNF-α 분비능을 보였으며 시료를 200 ㎍ 및 1,000 ㎍의 고농도로 처리한 실험군에서 IL-10이 분비된 것으로 보아 AGE-2c-I은 immune-stimulator의 역할뿐만 아니라 immune-suppressor로서의 작용 또한 가능한 것으로 확인되었다. 한편 종양 및 암세포에 대하여 직접적인 살해 활성을 나타내는 NK cell 활성을 확인한 실험에서는 농도 의존적인 종양 세포 살해능을 확인할 수 있었으며 100 ㎍/mouse 농도에서 NC 대비 약 1.5배 높은 NK cell 활성을 나타냈을 뿐만 아니라, 폐에 대한 고전이성 종양세포주인 B16BL6 melanoma 세포를 이용한 실험동물 종양 전이 모델에선 100 ㎍/mouse 농도로 처리한 실험군이 NC 대비 58%의 colony가 감소한 것을 확인할 수 있었다. 이상의 결과로 부터 참당귀 유래 RG-I 구조의 다당은 높은 선천면역계 자극 활성, 특히 보체계, 대식세포, 림프구 증식, NK cell의 활성화를 통해 우수한 항종양 전이 효과를 갖는 것으로 최종 확인되었으며 건강기능성식품 소재로의 개발가치가 우수한 것으로 판단되었다.

• 대한의용생체공학회:의공학회지
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• 제38권1호
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• pp.16-24
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• 2017

For the development of feasible retinal prosthesis, one of the important elements is acquiring proper judging tool if electrical stimulus leads to patient's visual perception. If evoked potential to electrical stimulus is recorded in primary visual (V1) cortex, it means that the stimulus effectively evokes visual perception. Therefore, in this study, we established VEP recording system on V1 cortex using BioPAC modules as the judging tool. And the measuring system was evaluated by recording VEP of mice. After anesthesia, normal mice (C57BL/6J strain; n = 6) were secured to stereotaxic apparatus (Harvard Apparatus, USA). For the recording of VEP, the stainless steel needle electrode (impedance: $2-5k{\Omega}$) was positioned on the surface of the cortex through the burr hole at 2.5 mm lateral and 4.6 mm caudal to bregma. DA 100C and EEG 100C BioPAC modules were used for the trigger signal and VEP recording, respectively. When left eye was blocked by black cover and right eye was stimulated by flash light using HMsERG (RetVet Corp, USA), VEP response at left V1 cortex was detected, but there was no response at right V1 cortex. Amplitudes and latencies of P2, N3 peaks of VEP recording varied according to the depths of the electrodes on V1 cortex. From the surface upto $600{\mu}m$ depth, amplitudes of P2 and N3 increased, while deeper than $600{\mu}m$, those amplitudes decreased. The deeper the insertion depth of the electrode, the latency of N1 peaks tends to be delayed. However, there was no statistically significant difference among the latencies of P2 and N3 peaks (P > 0.05, ANOVA). Our VEP recording data such as the insertion depth and the latency and amplitudes of peaks might be used as guidelines for electrically-evoked potential (EEP) recording experiment in near future.

• 대한의용생체공학회:의공학회지
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• 제38권1호
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• pp.49-55
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• 2017

The prevalence of obesity has noticeably increased worldwide over several decades with various complication. Even though anti-obesity drug treatments have been spotlighted by resulting in effective mean weight losses, its adverse effects cannot be overlooked. Thus, this study aimed to evaluate the effects of multi-frequency whole body vibration, one of the mechanical stimulus, as a countermeasure against obesity. Thirty-two-6-week-old C57BL/6J male mice were equally assigned to four groups: the Control group (CON, n = 8), the Sham group (Sham, n = 8), the sham with single frequency whole body vibration (S+V, n = 8), and the sham with multi frequency whole body vibration (S+MV, n = 8). After 4 weeks, morphologic changes in the adipose tissue were evaluated from three-dimensional images using in vivo micro-computed tomography. At 4 weeks, the volume of the abdominal adipose tissue, which had the highest value in Sham group, noticeably reduced in S+MV group compared to it in S+V group. These results implied that the accumulation of abdominal adipose tissue can be effectively reduced through applying multi-frequency whole body vibration.

• 폴리머
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• 제37권3호
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• pp.393-398
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• 2013

본 실험에선 미녹시딜을 함유한 수용성 고분자 젤로부터 solvent casting 방법으로 250과 $750{\mu}m$ 두 가지 길이의 미녹시딜이 함유된 용융형 고분자 마이크로 니들(micro-needle)을 제작하였다. 제작된 미녹시딜을 함유한 용융형 고분자 마이크로 니들은 기계적 강도가 입증된 고분자 니들과 동일한 형태 및 기계적 강도를 나타냈으며, 성공적으로 피부를 투과함을 확인하였다. 제조된 고분자 마이크로 니들의 경우 피부 적용 후 최소 30분 이상은 부착되어야 전체 니들의 50% (v/v) 이상이 피부 내로 용융되었으며, 니들 적용부위에서 서서히 약물의 방출 및 확산을 확인할 수 있었다. 또한 C57BL/6 동물 모델을 통해 미녹시딜이 함유된 250, $750{\mu}m$ 길이의 고분자 마이크로 니들이 무처리군 혹은 미녹시딜 처리군에 비해 발모에 긍정적인 영향을 나타냄을 확인할 수 있었다.

• 한국의학물리학회:학술대회논문집
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• 한국의학물리학회 2002년도 Proceedings
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• pp.411-414
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• 2002

The CdTe semiconductor detector has a higher detection efficiency for x-rays and $\square$amma rays and a wider energy band gap compared with Si and Ge semiconductor detectors. Therefore, the size of the detector element can be made small, and can be operated at room temperature. The interaction between a CdTe detector and incident x-rays is mainly photoelectric absorption in the photon energy range of up to 100 keV. In this energy range, Compton effects are almost negligible. We have developed a 256 channel CdTe array detector system for monochromatic x-ray CT using synchrotron radiation. The CdTe array detector system, the element size of which is 1.98 mm (h) x 1.98 mm (w) x 0.5 mm (t), was operated in photon counting mode. In order to improve the spatial resolution, we tilted the CdTe array detector against the incident parallel monochromatic x-ray beam. The experiments were performed at the BL20B2 experimental hutch in SPring-8. The energy of incident monochromatic x-rays was set at 55 keV. Phantom measurements were performed at the detector angle of 0, 30 and 45 degrees against the incident parallel monochromatic x-rays. The linear attenuation coefficients were calculated from the reconstructed CT images. By increasing the detector angle, the spatial resolutions were improved. There was no significant difference between the linear attenuation coefficients which were corrected by the detector angle. It was found that this method was useful for improving the spatial resolution in a parallel monochromatic x-ray CT system.

• JSTS:Journal of Semiconductor Technology and Science
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• 제7권2호
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• pp.67-75
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• 2007

To improve low sense margin at low voltage, we propose a negatively driven sensing (NDS) scheme and to solve the problem of WL-to-BL short leakage fail, a variable bitline reference scheme with free-level precharged bitline (FLPB) scheme is adopted. The influence of the threshold voltage offset of NMOS and PMOS transistors in a latch type sense amplifier is very important factor these days. From evaluating the sense amplifier offset voltage distribution of NMOS and PMOS, it is well known that PMOS has larger distribution in threshold voltage variation than that of NMOS. The negatively-driven sensing (NDS) scheme enhances the NMOS amplifying ability. The offset voltage distribution is overcome by NMOS activation with NDS scheme first and PMOS activation followed by time delay. The sense amplifier takes a negative voltage during the sensing and amplifying period. The negative voltage of NDS scheme is about -0.3V to -0.6V. The performance of the NDS scheme for DRAM at the gigabit level has been verified through its realization on 1-Gb DDR2 DRAM chip.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2013년도 제44회 동계 정기학술대회 초록집
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• pp.456-456
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• 2013

We report the modifications in the electronic structureof ZnO thin films induced by swift heavy ion (SHI) irradiated ZnO thin films by using near edge X-ray absorption fine structure (NEXAFS) spectroscopy at O K-edge was performed at BL10D XAS-KIST beamline at Pohang Accelerator Lab (PAL). ZnO films of 250 nm thickness oriented in [200] plane deposited by RF magnetron sputtering using equal $Ar:O_2$ atmosphere and air annealed at $500^{\circ}C$ for 6 hours for stability were irradiated with 120 MeV Au and 100 MeV O beams separately with different doses ranging from $1{\times}10^{11}$ to $5{\times}10^{12}$ ions/$cm^2$. High Resolution X-ray diffraction and NEXAFS analysis indicates significant changes in the electronic structure and the SHI effect is different for Ag and O-beams. The NEXAFS measurements provide direct evidence of O 2p and Zn 3d orbital hybridization. The NEXAFS results will be presented in detail.

• Journal of Microbiology and Biotechnology
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• 제27권7호
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• pp.1216-1222
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• 2017

To develop starters for the production of functional foods or materials, lactic acid bacteria producing ${\gamma}-aminobutyric$ acid (GABA) were screened from jeotgals, Korean fermented seafoods. One isolate producing a high amount of GABA from monosodium $\text\tiny{L}$-glutamate (MSG) was identified as Enterococcus avium by 16S rRNA gene sequencing. E. avium M5 produced $18.47{\pm}1.26mg/ml$ GABA when incubated for 48 h at $37^{\circ}C$ in MRS broth with MSG (3% (w/v)). A gadB gene encoding glutamate decarboxylase (GAD) was cloned and overexpressed in E. coli BL21 (DE3) using the pET26b (+) expression vector. Recombinant GAD was purified through a Ni-NTA column and the size was estimated to be 53 kDa by SDS-PAGE. Maximum GAD activity was observed at pH 4.5 and $55^{\circ}C$and the activity was dependent on pyridoxal 5'-phosphate. The $K_m$ and $V_{max}$ values of GAD were $3.26{\pm}0.21mM$ and $0.0120{\pm}0.0001mM/min$, respectively, when MSG was used as a substrate. Enterococcus avium M5 secretes a lot of GABA when grown on MRS with MSG, and the strain is useful for the production of fermented foods containing a high amount of GABA.

• 생명과학회지
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• 제13권3호
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• pp.308-313
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• 2003

식중독 병원균인 장염비브리오균 (V. parahaemolyticus)의 세포외 분비 효소 중 콜라겐분해효소를 발현벡터인 pET-29b에 클로닝시키고 대장균에서 발현시킨 다음, 부분정제하여 그 특성을 조사하였다. V. parahaemolyticus collagenase는 $(NH_4)_2So_4$침전, affinity adsorption, 그리고 Sephacryl S-100 gel filtration 과정을 통하여 부분정제 되었다. 이 collagenase는 73%의 회수율과 43.7의 정제도를 나타내었으며, 전기영동시 분자량은 약 35 kDa로 나타났다. 이 효소의 최적 pH 및 온도는 6~12와 $35^{\circ}C$이었고, 온도안정성 조사에서 $55^{\circ}C$까지는 90% 잔존 찬성을 유지하였으나 $60^{\circ}C$이상에서는 급격하게 효소활성이 실활되었다. 기질특이성조사에서 type I collagen과 콜라겐분해효소의 합성기질로 알려진 Z-GPGGPA에서 gelatin과 casein에 비해 높은 활성을 보이는 것으로 보아 이 효소가 진정한 콜라겐분해효소라는 것을 알 수 있었다.

• Journal of Applied Biological Chemistry
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• 제44권4호
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• pp.167-172
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• 2001

A cDNA fragment encoding the chloroplastic fructose-1, 6-bisphosphatase (FBPase) was cloned via PCR from the cDNA library of pea leaves. The cloned cDNA, about 1.05 kbp without signal sequence, was introduced into a pET-28a vector for expression in E. coli strain BL21(DE3)pLysS. The recombinant FBPase was purified through $Ni^+-NTA$ affinity chromatography and characterized. Molecular mass of the monomer was about 42,000. Enzymatic activity of the purified enzyme as the native pea chloroplastic FBPase was the highest at alkaline pH (pH 9.0). The recombinant enzyme was activated by a reducing agent DTT and was insensitive to AMP. The activation energy (Ea) and Arrehenius frequency factor were 42.67 kcal/mol and $2.65{\times}10^{14}/s$, respectively, slightly higher than those of the native enzyme. $K_M$ and $V_{max}$ were $99.98{\mu}M$ and $52.9{\mu}M/min$, respectively, which were comparable with the native enzyme.