• Journal of the Korean Magnetics Society
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• v.22 no.4
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• pp.125-129
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• 2012

By employing soft x-ray absorption spectroscopy (XAS) and soft x-ray magnetic circular dichroism (XMCD), the electronic structures of molecule-based nano bioparticles, such as Helicobacter pylori ferritin (H. pylori ferritin), Heme, $NaM[Fe(CN)_6]{\cdot}H_2O$-type Prussian Blue (M=Co, Ni) analogue, have been investigated. The measured Fe 2p XAS spectra reveal that Fe ions are trivalent ($Fe^{3+}$) in H. pylori ferritins, while they are in the $Fe^{2+}-Fe^{3+}$ mixed-valent states in $NaM[Fe(CN)_6]{\cdot}H_2O$ Prussian Blue analogues (M=Co, Ni). According to the Fe 2p XMCD spectrum of high-state H. pylori ferritin, all the $Fe^{3+}$ ions have the same local symmetry and their magnetic moments are aligned in the same direction. It is also found that the Fe 3d orbitals in $NaM[Fe(CN)_6]{\cdot}H_2O$ have a strong covalent bonding to $(CN)^-$ ligands, but with a very weak bonding to the 2p orbitals of O ligands.

• Korean Chemical Engineering Research
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• v.60 no.2
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• pp.300-307
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• 2022

Time-resolved serial femtosecond crystallography (TR-SFX) is a powerful technique for determining temporal variations in the structural properties of biomacromolecules on ultra-short time scales without causing structure damage by employing femtosecond X-ray laser pulses generated by an X-ray free electron laser (XFEL). The mixing rate of reactants and biomolecule samples, as well as the hit rate between crystal samples and x-ray pulses, are critical factors determining TR-SFX performance, such as accurate image acquisition and efficient sample consumption. We here develop two distinct sample delivery systems that enable ultra-fast mixing and on-demand droplet injecting via pneumatic application with a square pulse signal. The first strategy relies on inertial mixing, which is caused by the high-speed collision and subsequent coalescence of droplets ejected through a double nozzle, while the second relies on on-demand pneumatic jetting embedded with a 3D-printed micromixer. First, the colliding behaviors of the droplets ejected through the double nozzle, as well as the inertial mixing within the coalesced droplets, are investigated experimentally and numerically. The mixing performance of the pneumatic jetting system with an integrated micromixer is then evaluated by using similar approaches. The sample delivery system devised in this work is very valuable for three-dimensional biomolecular structure analysis, which is critical for elucidating the mechanisms by which certain proteins cause disease, as well as searching for antibody drugs and new drug candidates.

• Journal of the Korean Institute of Intelligent Systems
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• v.11 no.4
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• pp.320-324
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• 2001

According to the rapid growth of computer and internet recently, A hacking to steal infonnations and the computer vinls to destroy the data in computer are now prevailing in the whole world. A study of methods to protect the data of computer is in progress. One of the study is constmction of computer immune system using biological immune system tbat has ability of removal and protection from extemal invasion. In this paper, we make a change detection algorithm which is based on ability of distinction between self and nonself in T-cytotoxic cell that is one of biological immune cell. In algorithm, MHC receptors are composed of a part of self-file that is recognized as itself and those shall distinguish self-file from the changed file. As a result of applying this algorithm to the changed self-files, we prove the efficacy of detection of the self-files changed by computer virus and hacking.

• Korean Chemical Engineering Research
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• v.48 no.3
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• pp.350-354
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• 2010

In natural world various inorganic crystals are grown with controlled shape and size in hybrid forms with organics. Such natural processes have been attempted much to mimick artificially. One of the example is calcium carbonate which has been examined a lot in the field of biomineralization. In this study, we utilize well-organized surface of polydiacetylene(PDA) films as the crystal-growing template. We devised a novel mini-arrayer device that transfers PDA films at air/water interfaces of each array well and deposit them to hydrophobized glass substrates. This technical improvement will contribute to facilitate better understandings of biomineralization mechanism.

• Horticultural Science & Technology
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• v.30 no.5
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• pp.509-518
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• 2012

The objective of this study was to determine the effect of heat shock treatments on the phytochemicals including antioxidants and anticancer materials in kale (Brassica oleracea L. var. acephala) sprouts. In study I, kale sprouts grown under the growing system for four days were soaked at 40, 50, or $60^{\circ}C$ distilled water for 10, 30, or 60 seconds, and in study II, kale sprouts were soaked at $50^{\circ}C$ distilled water for 10, 20, 30, 45, or 60 seconds. After the heat shock treatments, the sprouts were transferred into normal growing conditions and recovered there for two days. Fresh and dry weights, electrolyte leakage, total phenolic concentration, antioxidant capacity, total flavonoid concentration, phenylalanine ammonia-lyase (PAL) activity, and glucosinolates content of the sprouts were measured before and after the heat shock treatments. As a result, there was a significant decrease in the fresh and dry weight of kale sprouts treated with heat shock compared with control at harvest in study I. Especially, heat shock at $60^{\circ}C$ lead to more pronounced growth inhibition compared with heat treatments at 40 and $50^{\circ}C$. Electrolyte leakage by cell collapse was the highest in the sprouts exposed to $60^{\circ}C$ distilled water, which agreed with the growth results. Heat shock at $50^{\circ}C$ significantly induced the accumulation of phenolic compounds. In study II, fresh weight of kale sprouts at $50^{\circ}C$ heat shock showed a significant decrease compared with the control at one and two days after the treatment. However, the decrease was minimal and dry weight of kale sprouts was not significantly different from that in control. In contrast, the heat shock-treated kale sprouts had higher level of total phenolic concentration than control at harvest. Heat shock treatments at $50^{\circ}C$ for 20 seconds or more showed at least 1.5 and 1.2 times higher total phenolic concentration and antioxidants capacity than control, respectively. The change of the total flavonoid concentration was similar with that of antioxidants. PAL activity after 24 hours of heat shock was higher in all the heat shock-treated sprouts than that in control suggesting heat shock may stimulate secondary metabolic pathway in kale sprouts. Seven glucosinolates were identified in kale sprouts and soaking the sprouts with $50^{\circ}C$ water for 20 seconds had a pronounced impact on the accumulation of total glucosinolates as well as two major glucosinolates, progoitrin and sinigrin, at harvest. In conclusion, this study suggests that heat shock using hot water would be a potential strategy to improve nutritional quality of kale sprouts by inducing the accumulation of phytochemicals with antioxidant and anticancer properties.

• Proceedings of the Korean Fiber Society Conference
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• 2003.04a
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• pp.325-326
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• 2003

유기물질과 무기물질의 복합체 제조는 일찍이 1980년대 초부터 연구되어 오고 있고, 새로운 성능 및 기능 확대를 목표로 계속 이루어지고 있다[1-2]. 폴리비닐알코올(Poly(vinyl alcohol), PVA)은 분리막, 투석, 약물전달, 암세포 괴사용 색전제 등 의료 및 산업용 섬유로 널리 사용되고 있는 비닐계 고분자이다[3,4]. 또한 무기화합물인 Hydroxyapatite(HAp)는 칼슘 포스페이트계 세라믹으로, 중금속 흡착성, 항균성, 생체 친화성 등이 우수하여 의료용 소재로 사용되어 오고 있다. (중략)

• Journal of the korean veterinary medical association
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• v.39 no.7
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• pp.616-623
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• 2003

산업발전으로 인한 유해 독성물질의 대량방출은 이미 자연계에 중대한 위협요소가 되고 있다. 특히 중금속은 산업폐기물의 형태로 양산되며 자연 생태계의 자정능력으로도 쉽게 제거되지 않을뿐 아니라 생체내 축적성이 강하여 사람과 동물의 건강에 심각한 영향을 미칠 수 있다. 또한 현대 사회 발전을 주도하는 산업형태가 대부분 공해배출형이며, 문명의 고도화에 따른 에너지 다소비형의 생활형태는 자연환경을 황폐화시키고 있어 삶의 질 향상과 공중보건을 위해서 인위적인 해결방안이 마련되어야 할 중대한 시점에 와 있다. 가축의 생산기반의 축산환경은 축산물의 안전성과 직결되므로 축산현장에서 중금속 등 유해물질의 안전관리를 위하여 고도의 전문성을 갖춘 수의사의 적극적인 계도와 홍보가 절실히 요구된다.

• 동물약계
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• no.21
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• pp.5-5
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• 1995

1. 제조(수입)업허가$\cdot$변경 2. 가축전염병 발생정보 3. 축산관계관 회의 4. 안전축산물 생산을 위한 종합설명회 제 1회 수의정책 심포지움 개최 6. 가축질병 병성감정 실시기관 지정 7. 동물용의약품 사용기준 시안 작성 제출 8. 세계수의학대회 개최 9. 재해예방 특별점검 안내 10. 생체내 유해잔류물질 검사킷트 조사 11. 꿀벌 가시응애구제제 기술전수 교육 12. 임시이사회 개최

• Proceedings of the Korean Fiber Society Conference
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• 2002.04a
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• pp.455-458
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• 2002

Hydroxyapatite(HAp)는 인체의 뼈를 구성하는 주성분으로 생체친화성, 단백질 흡착성, 항균성 등이 우수하여 정형외과 분야의 골 대체제로 사용되어 오고 있다[3]. 하지만, HAp는 너무 딱딱하고 부서지기 쉬워 특별한 형태로의 성형이 어렵고, 이식된 부분으로부터 쉽게 떨어져 나오는 문제점을 갖고 있다[1,2] 따라서 HAp의 이러한 기계적인 특성을 보완할 수 있는 HAp/유기물질 복합소재 개발에 대한 관심이 증대되고 있다. (중략)

• Bioindustry News
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• v.15 no.3
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• pp.20-23
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• 2002

인간 유전체 지도가 발표 된 이후 신약 개발의 많은 부분에서 유전체 정보가 활용되고 있으며 비록 현재의 초기 단계에서는 여러 가지 실험적 장해 요인으로 인해 그 활용도가 그리 크지 않다. 하지만 대부분의 약물들이 유전자 혹은 단백질과 같은 생체 구성 물질들의 활성을 조절하는 기작을 가지고 있다는 점을 고려할 때 유전체에 대한 전반적인 이해는 빠르고 정확한 신약 개발을 위한 필수적인 선결 요건이라 볼 수 있다. 따라서 이러한 접근은 제약회사를 비롯하여 병원, 연구소 등 관련 기관들에서 계속해서 활발히 진행되고 있고 멀지 않은 미래에 유전체 연구는 효율적인 신약 개발의 핵심 기술로 자리 매김 할 것으로 예측된다