• Bulletin of the Korean Chemical Society
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• 제27권5호
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• pp.672-678
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• 2006

A new approach to fabricate an enzyme electrode was described based on the immobilization of horseradish peroxidase (HRP) on dithiobis-N-succinimidyl propionate (DTSP) self-assembled monolayer (SAM) formed on gold-nanoparticles (Au-NPs) which were electrochemically deposited onto glassy carbon electrode (GCE) surface. The overall surface area and average size of Au-NPs could be controlled by varying deposition time and were examined by Field Emission-Scanning Electron Microscope (FE-SEM). The $O_2$ reduction capability of the surface demonstrated that Au-NPs were thermodynamically stable enough to stay on GCE surface. The immobilized HRP electrode based on Au-NPs/GCE presented faster, more stable and sensitive amperometric response in the reduction of hydrogen peroxide than a HRP immobilized on DTSP/gold plate electrode not containing Au-NPs. The effects of operating potential, mediator concentration, and pH of buffer electrolyte solution on the performance of the HRP biosensor were investigated. In the optimized experimental conditions, the HRP immobilized GCE incorporating smaller-sized Au-NPs showed higher electrocatalytic activity due to the high surface area to volume ratio of Au-NPs in the biosensor. The HRP electrode showed a linear response to $H_2O_2$ in the concentration range of 1.4 $\mu$M-3.1 mM. The apparent Michaelis-Menten constant ($K _M\; ^{app}$) determined for the immobilized HRP electrodes showed a trend to be decreased by decreasing size of Au-NPs electrodeposited onto GCE.

• 환경생물
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• 제18권1호
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• pp.105-111
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• 2000

1998년 11월부터 1999년 12월까지 13개월 동안 대형 수생식물인 애기부들의 분해와 분해 과정에 따른 각 기관별 영양염류 함량의 변화를 조사하였다. 13개월 후 잎, 줄기, 지하경의 잔존량은 각각 34.7%, 59.2%, 7.2%로 줄기의 분해가 가장 느렸고 지하경의 분해가 빠른 것으로 나타났다. 분해상수는 잎, 줄기, 지하경이 각각 1.06, 0.52, 42.63yr^{-1}$이었다. 잎, 줄기, 지하경의 초기 영양염류 함량은 질소 11.5, 9.0, 14.5 mg/g, 인 0.30, 0.27, 0.47 mg/g, 칼륨 20.7, 26.9, 26.6 mg/g, 칼슘 14.50, 4.77, 3.25 mg/g, 그리고 마그네슘이 1.99, 1.32, 2.07 mg/g이었다. 애기부들 각 기관의 분해과정 중 부동화 기간은 없었으며, 각 영양염류의 60% 이상이 5개월 이내에 물 속으로 방출되는 것으로 나타났다.

• Korean Journal of Chemical Engineering
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• 제35권11호
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• pp.2220-2231
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• 2018

Lipase from Candida rugosa was immobilized on $MgO{\cdot}SiO_2$ hybrid grafted with amine, thiol, cyano, phenyl, epoxy and carbonyl groups. The products were analyzed using Fourier transform infrared spectroscopy, nuclear magnetic resonance, low-temperature $N_2$ sorption and elemental analysis. Additionally, the degree of coverage of the oxide material surface with different functional groups and the number of surface functional groups were estimated. The Bradford method was used to determine the quantity of immobilized enzyme. The largest quantity of enzyme (25-28 mg/g) was immobilized on the hybrid functionalized with amine and carbonyl groups. On the basis of hydrolysis reaction of p-nitrophenyl palmitate to p-nitrophenol, it was determined how the catalytic activity of the obtained biocatalysts is affected by pH, temperature, storage time, and repeated reaction cycles. The best results for catalytic activity were obtained for the lipase immobilized on $MgO{\cdot}SiO_2$ hybrids with amine and carbonyl groups. The biocatalytic system demonstrated activity above 40% in the pH range 4-10 and in the temperature range $30-70^{\circ}C$. Lipase immobilized on the $MgO{\cdot}SiO_2$ systems with amine and epoxy groups retains, respectively, around 80% and 60% of its initial activity after 30 days of storage, and approximately 60-70% after 10 reaction cycles.

• Journal of Ginseng Research
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• 제47권2호
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• pp.255-264
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• 2023

Background: Red ginseng (RG) alleviates psychiatric disorders. Fermented red ginseng (fRG) alleviates stress-induced gut inflammation. Gut dysbiosis causes psychiatric disorders with gut inflammation. To understand the gut microbiota-mediated action mechanism of RG and fRG against anxiety/depression (AD), we investigated the effects of RG, fRG, ginsenoside Rd, and 20(S)-β-D-glucopyranosyl protopanaxadiol (CK) on gut microbiota dysbiosis-induced AD and colitis in mice. Methods: Mice with AD and colitis were prepared by exposing to immobilization stress (IS) or transplanting the feces of patients with ulcerative colitis and depression (UCDF). AD-like behaviors were measured in the elevated plus maze, light/dark transition, forced swimming, and tail suspension tests. Results: Oral gavage of UCDF increased AD-like behaviors and induced neuroinflammation, gastrointestinal inflammation, and gut microbiota fluctuation in mice. Oral administration of fRG or RG treatment reduced UCDF-induced AD-like behaviors, hippocampal and hypothalamic IL-6 expression, and blood corticosterone level, whereas UCDF-suppressed hippocampal BDNF⁺NeuN⁺ cell population and dopamine and hypothalamic serotonin levels increased. Furthermore, their treatments suppressed UCDF-induced colonic inflammation and partially restored UCDF-induced gut microbiota fluctuation. Oral administration of fRG, RG, Rd, or CK also decreased IS-induced AD-like behaviors, blood IL-6 and corticosterone and colonic IL-6 and TNF-α levels, and gut dysbiosis, while IS-suppressed hypothalamic dopamine and serotonin levels increased. Conclusion: Oral gavage of UCDF caused AD, neuroinflammation, and gastrointestinal inflammation in mice. fRG mitigated AD and colitis in UCDF-exposed mice by the regulation of the microbiota-gut-brain axis and IS-exposed mice by the regulation of the hypothalamic-pituitary-adrenal axis.

• 멤브레인
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• 제22권4호
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• pp.280-283
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• 2012

본 연구는 이산화탄소를 효율적으로 분리하기 위한 이온성액체 지지분리막 제조를 목적으로 한다. 공칭크기 0.1 ${\mu}m$ PVDF 정밀여과막에 이온성액체인 [bmim][${PF_6}^-$] (1-butyl-3-methylimidazolium hexafluorophosphate)를 분리막 세공내로 흡입시켜 고정화하였다. 제조된 이온성액체 지지막에 대한 $N_2$, $H_2$, $CO_2$ 기체의 투과도는 0.075, 0.203, 1.380 GPU로 측정되었으며 $CO_2/N_2$, $H_2/N_2$의 선택도는 각각 14.2와 2.69이었다. 또한 이온성액체 지지분리막은 이온성 액체가 운전압력 2.0 bar까지 세공 내에 고정되어 안정적으로 운전 가능하였다.

• 청정기술
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• 제8권3호
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• pp.167-172
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• 2002

제지슬러지를 지렁이에게 급이하여 생산된 분변토의 하 폐수 고도처리용 담체로의 적용 가능성에 대하여 알아보았다. 먼저 폐수를 일반 활성슬러지법으로 운전한 후 이를 담체와 유입수의 조건을 달리하여 영양 염류의 제거 효율을 알아보았다. 담체를 적용하기 전엔 T-P및 T-N의 제거율은 각각 평균 52%와 31%정도로 나타났다. Pellet 형 및 pack 형으로 제조된 두 종류의 분변토 담체를 적용한 후에는 T-P의 경우는 제거효율이 약 1.3~1.4배 증가하였으며 T-N의 제거효율은 약 1.9 ~ 2.0 배 증가하여 상당히 뛰어난 영양염류의 제거 효율을 보여주었다. 또한, T-N 및 T-P의 제거효율은 담체의 종류에는 큰 영향을 받지 않아 다양한 미생물이 서식하는 분변토는 성형 방법에 관계없이 뛰어난 성능을 보임을 알 수 있었다. 반면, 담체 적용 전후의 BOD 및 COD의 제거 효율은 큰 차이가 없었다. 본 연구를 통하여 분변토로 제조된 담체는 하 폐수 고도처리용 담체로의 활용 가능성이 매우 높은 것으로 사료된다.

• 생명과학회지
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• 제9권3호
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• pp.268-275
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• 1999

고저화된 Rp.palustris균을 이용한 양식장 폐수주으이 질산염 제거를 위하여 Rp.palustris균의 고정화를 위한 담체를 조사하였는데, 탈질능력과 내구성을 실험한 결과 agar,k-carrageenan,그리고 PVA 3종의 담체주우 3% agar가 가장 적합한 담체이었다.Agar bead 내부로의 기질 이동 및 sheer stress를 고려해볼 때 최적 bead 크기는 직경 4mm 였고,접종되는 세포의 양은 25mg dry $cells/cm^2$gel 이었다. 탄소원으로 ethanol이 가장 적합하였고,최적 C:N ratio는 1.5이며,온도와 pH는 각각$31^{\circ}C$,PH 6 이었다. 이러한 조건에서의 최대 탈질율은 인공합성폐수의 경우 $345{\MU}{\ell};N_2/Cm^3 gel{\cdot}hr;이었으며,;modifed MYC 배지의; 경우는; 450{\MU}{\ell}};N_2/Cm^3 gel{\cdot}hr $이었다.

• 분석과학
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• 제13권1호
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• pp.49-54
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• 2000

5단계 반응을 통하여 실리카겔의 8-hydroxyquinoline 유도체를 제조하였으며, 각 단계에서 얻은 생성물들을 IR과 NMR을 이용하여 분석하였다. 실리카겔 자체에 관한 IR 스펙트럼으로부터, 자유 hydroxyl기와 수소 결합된 hydroxyl기가 존재하는 것을 확인할 수 있었다. 첫 단계 반응에서는 N-H와 C-H의 IR 밴드와 APTS기에 있는 메틸렌 탄소의 NMR peak을 확인하였다. 둘째 단계에서는 카보닐, nitro, 방향족 탄소의 IR 밴드와 지방족, 방향족, 카보닐 탄소의 NMR peak을 관찰하였으며, 셋째 단계에서 $NO_2$가 $NH_2$로 환원되는 것을 IR과 NMR로 확인할 수 있었다. 마지막 단계에서는 4번째 단계에서 생성된 $N{\equiv}N$ IR peak이 사라지는 것으로부터 8-quinolinol이 고정화되는 것을 확인할 수 있었다.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2003년도 생물공학의 동향(XIII)
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• pp.209-213
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• 2003

Self-assembled monolayers of spinach ferredoxin immobilized to Au substrate were investigated. Ferredoxin was immobilized onto the chemically modified Au surface. Au surface were modified to $NH^{3+}$ by the 4-aminothiphenol and then modified by N-succinimidyl-3-[2-pyridyldithio]propionate for the ferredoxin immobilization. To verify the electrochemical activity of immobilized ferredoxin molecules, cyclic-voltammetry was measured. Finally, to verify the memory application, reduction potential was applied to ferredoxin molecules as for the write function, and then current transients observed from the reduced ferredoxin layers were measured for the read function of memory applications.

• Journal of Life Science
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• 제9권2호
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• pp.67-71
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• 1999

1. The analgesic effect of Haeuljowitang by acetic aced method was revealed significantly. 2. The anti-inflammatory effect of Haeuljowitang by yeast method was revealed significantly 3. The degree of occurrence of gastric ulcer in sample group insignificantly decreased compared with control group. 4. The plasma epinephrine contents of sample group significantly decreased compared with control group. 5. The plasma norepihrine contents of sample group significantly decreased compared with control group. 6. The plasma dopamine contents of sample group significantly decreased compared with control group. According to the above results, it is concluded that Heaujowitang has a anti-stress effect.