• 한국염색가공학회지
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• 제25권1호
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• pp.18-24
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• 2013

A water soluble spironaphthoxazine (SPO) was synthesized, and its spectral properties were determined. Under UV irradiation, colorless SPO shows intensive blue color while the intensity of its initial fluorescence decreased. In addition, SPO also exhibited high sensitivity to pH stimuli both in colorimetry and fluorometry distinguishing from the spectral appearance observed under UV irradiation. Further, integrating these two optical characteristics a three-state switching system can be established, and all interconversions can be observed by naked-eye.

• 대한의용생체공학회:의공학회지
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• 제12권1호
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• pp.1-7
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• 1991

This paper describes and discusses the employment of HMG pattern analysis to provide upper-motor-neuron paraplegics with patient-responsive control of FES ( functional electrical stimulation) for the purpose of walker-supported walking. The use of above-lesion EMG signals as a solution to the control problem is considered. The AR(autoregressive)parameters are identified by time-varying nonstationary Kalman filler algorithm using DSP chip and classified by fuzzy theory. The control and stimuli part of the below-lesion are based on micro-processor(8031). The designed stimulator is a 4-channel version. The experiments described above have only attempted to discriminate between standing function and sit-down function A further advantge of the this system Is applied for motor rehabilitation of social readaption of paralyzed humans.

• 한국응용과학기술학회지
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• 제30권3호
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• pp.411-422
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• 2013

Polymers in cosmetics are used to deliver desired attributes to skin and hair. Precisely constructed block and graft copolymers widen the range of available mechanical properties and compatibilities. Stimuli responsive hydrophobic polymers can be triggered to become hydrophilic by changes in their environment and this can confer waterproof properties at low temperature and easy water removal at higher temperatures. Transfer-resistant cosmetics can be possible due to silicone resins. The control of rheology properties in cosmetics gradually continue to be easy with copolymers. Durability of colors and fragrances for rinse-off products can be enhanced by delivery systems from complex coacervates. Polymeric anti-microbials promise product preservation while minimizing the concern of skin permeation. This article reviews recent trends in the use of polymers in cosmetics.

• 한국고분자학회:학술대회논문집
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• 한국고분자학회 2006년도 IUPAC International Symposium on Advanced Polymers for Emerging Technologies
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• pp.329-329
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• 2006

Various new active ester monomers based on (meth)acrylates and 4-vinylbenzoic acid have been prepared. Investigation of the controlled radical polymerization behavior of the respective monomers resulted in excellent polymerization control, thus, opening synthetic routes to reactive block copolymers. Polymer analogous reactions with amines yielded functional polymers. In the case of the copolymer poly(N-isopropylacrylamide-co-acetone oxime acrylate) a lower critical solution temperature could be measured at $52^{\circ}C$. Thus, the reactive copolymer features two characters: reactive AND stimuliresponsive behavior.

• 한국임상수의학회지
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• 제1권1호
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• pp.49-52
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• 1984

Ponies were administered at the level of 0.1mg per kg of body weight of acetylpromazine malate through the jugular vein. Sedative effect, clinical signs such as body temperature, and changes of red blood cell counts and serum glucose concentration were investigated. Sedation was induced 5 to 6 minutes after injection of acepromazine and sedative effect was lasted for 30 to 40 minutes. Responsive reactions, however, to external stimuli were remained. Change of body temperature was not observed and heart beat was increased at the stage of induction and respiratory rate was decreased during the sedative period. Red blood cell count was considerably decreased during sedation, and concentration of serum glucose showed a tendency to increase gradually from the induction.

• Bulletin of the Korean Chemical Society
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• 제25권11호
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• pp.1629-1630
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• 2004

• 한국진공학회:학술대회논문집
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• 한국진공학회 2013년도 제45회 하계 정기학술대회 초록집
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• pp.90.1-90.1
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• 2013

Nature utilizes various of the colorization process. Some species of birds can express their mood of tempers by changing their collagen structures on skin. For example, turkey can change their skin color by expansion of the collagen structures, which are associated with the distinct color changes. Here, we developed bioinspired virus-based colorimetric sensors which can be genetically tuned for target molecule. Using M 13 bacteriophage, we fabricated responsive self-assembled color matrices composed of quasi-ordered fiber bundle structures. These virus matrices can exhibit color change by stimuli through fiber bundle structure modulation. Upon exposure of volatile organic compounds, the resulting multi-colored matrices exhibited distinct color changes with different ratios that can be recognized by the naked eyes. Using the directed evolutionary approaches, we genetically engineered the virus matrix to incorporate binding motif for explosive detection (i.e., trinitrotoluene (TNT)). Through utilizing a common handheld device (i.e., iPhone), we could distinguish TNT molecules down to 20 ppb in a selective manner. Our novel biomimetic virus colorimetric sensor can overcome current limitation for low response selectivity.

• Journal of Forest and Environmental Science
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• 제35권3호
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• pp.141-149
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• 2019

Nanocellulose, which can exist as either cellulose nanocrystals or cellulose nanofibrils, has been used as a biomaterial for drug delivery owing to its non-immunogenicity, biocompatibility, high specific area, good mechanical properties, and variability for chemical modification. Various water-soluble drugs can be bound to and released from nanocelluloses through electrostatic interactions. The high specific surface area of nanocellulose allows for high specific drug loading. Additionally, a broad spectrum of drugs can bind to nanocellulose after facile chemical modifications of its surface. Controlled release can be achieved for various pharmaceuticals when the nanocellulose surface is chemically modified or physically formulated in an adequate manner. This review summarizes the potential applications of nanocelluloses in drug delivery according to published studies on drug delivery systems.

• 한국고분자학회:학술대회논문집
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• 한국고분자학회 2006년도 IUPAC International Symposium on Advanced Polymers for Emerging Technologies
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• pp.101-101
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• 2006

We have studied the micellisation of poly(n-butyl acrylate)-block-poly(acrylic acid) and poly(n-butyl acrylate)-graft-poly(acrylic acid) in aqueous solution. The size and structure of the formed micelles was elucidated by scattering and imaging techniques. The micelle structure depends on pH, composition, and topology: graft copolymers form much smaller micelles that block copolymers of similar composition. We have also synthesized block copolymers of acrylic acid and N-isopropylacrylamide (NIPAAm) or N,N-diethylacrylamide (DEAAm). Due to the LCST of polyNIPAAm and polyDEAAm, these block copolymers spontaneously form micelles upon heating and they form inverse micelles upon decreasing pH below 4. If the LCST block is much longer than the PAA one, this presents a very convenient way to prepare crew-cut micelles. The polymers have been successfully used as stabilizers in emulsion polymerization. They also have been conjugated to streptavidin. The conjugates reversibly form mesoscopic particles on heating.

• 공업화학
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• 제30권6호
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• pp.698-706
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• 2019

지난 수십 년 동안, 외부 자극에 대한 응답성이 우수하면서도 인체에 적용할 수 있는 소프트 액추에이터 개발을 위한 많은 노력이 이어졌다. 본 연구에서는 동역학적 정밀 제어가 가능한 의료용 소프트 액추에이터를 개발하기 위해, 유해한 화학적 첨가제나 개시제 없이 방사선을 이용하여 전기 자극 반응성과 물리적 특성이 우수한 3차원 가교 구조의 poly(acrylic acid) (PAAc)/poly(vinyl alcohol) (PVA)/poly(ethylene glycol) (PEG) 하이드로겔을 합성하였다. 방사선 조사 후, 모든 하이드로겔은 75% 이상의 겔 분율을 나타내었고, 표면 반사 적외선 분광법을 통해 PAAc/PVA/PEG 하이드로겔이 성공적으로 합성되었음을 확인하였다. 또한 PAAc/PVA/PEG 하이드로겔의 겔 분율, 평형 수분 함량, 압축 강도를 측정하여 감마선의 총 조사 선량과 구성 성분의 함량비 조절에 따른 하이드로겔의 물리적 특성 변화를 확인하였다. 조사된 감마선의 선량이 증가하거나 poly(ethylene glycol) diacrylate (PEGDA)의 함량이 많을수록 PAAc/PVA/PEG 하이드로겔은 높은 가교 밀도와 우수한 기계적 강도를 나타내었다. 또한 PAAc/PVA/PEG 하이드로겔은 3 V의 저전압에서도 전기적인 자극에 반응하였고, 전기장 하에서 이동성 이온의 움직임에 따른 하이드로겔의 밴딩 거동은 하이드로겔의 가교 밀도, 이온기의 함량, 인가 전압 및 전해질 용액의 이온 농도 등을 조절함으로써 제어할 수 있음을 확인하였다.