• Journal of Pharmaceutical Investigation
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• 제19권4호
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• pp.179-183
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• 1989

Drug release experiments were performed based on pH-sensitive swelling behaviors of polymethacrylic acid. 5-Fluorouracil as a nonionic model drug revealed release patterns depending solely on pH-dependent swelling kinetics of polymethacrylic acid. In contrast, release of propranolol hydrochloride as a cationic model drug was significantly affected by ionic drug-polymer interaction as well as the swelling kinetics. Accordingly, a zero-order release pattern was obtained at pH 7, which was distinguished from the general matrix type drug release pattern.

• 전기전자학회논문지
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• 제27권1호
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• pp.85-92
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• 2023

최근 4차 산업혁명 시대가 다가오면서 휴대성을 강조한 IoT 기기가 늘고 있다. 동시에 배터리 사용량도 급증하고 있다. 배터리 사용량이 증가하면서 배터리 안전과 관련된 이슈는 피할 수 없는 문제가 되었고, 많은 연구가 이뤄졌다. 본 논문은 다양한 배터리 문제 중 팽창으로 인한 폭발 문제를 다루고 있으며, 저항 변화를 파악하여 배터리 팽창을 감지하는 시스템의 연구 및 개발을 포함하고 있다. 이번 연구의 핵심기술은 배터리가 팽창할 때 발생하는 부피 변화를 배터리에 그려진 전선의 저항 변화를 이용해 배터리 폭발을 방지하는 시스템을 개발하는 것이다. 또한 패턴분석을 통해 어떤 형태로 전선을 구성하여야 저항 변화가 많이 일어나는지 분석하였다.

• 대한상한금궤의학회지
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• 제13권1호
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• pp.61-79
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• 2021

Objective : The objective of this study was to explore the meaning of "man (滿)" in Shanghanlun through the analysis of four cases. Methods : We analyzed four cases treated with modified Soshiho-tang, which is administered when 滿 aggravates chief complaints. All cases were diagnosed by the disease pattern identification diagnostic system based on the Shanghanlun provisions. Results : All 4 patients' chief complaints were improved after administration of modified Soshiho-tang. Swelling symptoms were reduced in all 4 cases. Through the etymological research and clinical treatment results, the clinical meaning of 滿 was deduced as "swelling." Conclusions : The etymological and clinical analysis suggest that the concept of "滿" may be defined as "swelling" in the Shanghanlun provisions.

• Macromolecular Research
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• 제14권2호
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• pp.132-139
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• 2006

The dispersion of organoclay in ethylene propylene diene terpolymer (EPDM) matrix was correlated with the rheological and swelling properties of nanocomposites. X-ray diffraction pattern (XRD) and transmission electron microscopic (TEM) analysis exhibited the disordered-intercalated structure of EPDM/organoclay nanocomposite. The extent of the disordered phase increased with increasing organoclay content up to a limiting value of 3 wt% after which equilibrium tended towards intercalation. The dispersion effect of organoclay in EPDM matrix was clarified by the physicochemical properties like rheological response and swelling thermodynamics in toluene. The increase in viscoelastic properties of EPDM nanocomposite with increasing organoclay content up to 3 wt%, followed by a subsequent decrease up to 4 wt%, was correlated in terms of the disordered and ordered states of the dispersed nano-clay sheets. Swelling measurements revealed that the change in entropy of the swelling increased with the increase in disorder level but decreased with the increase in intercalation level of organoclay in the disordered-intercalated nanocomposite. The increase in solvent uptake was comparable with the free volume in EPDM matrix upon inclusion of silicate particles, whereas the inhibition in solvent uptake for higher organoclay loading was described by bridging flocculation.

• Clinical and Experimental Reproductive Medicine
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• 제46권4호
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• pp.147-151
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• 2019

Objective: The aim of this study was to investigate DNA fragmentation status in human spermatozoa according to specific tail swelling patterns determined via hypo-osmotic swelling test (HOST). Methods: Frozen semen samples from 21 healthy donors were thawed and prepared by the swim-up technique for use in intracytoplasmic sperm injection. The semen samples were treated for 5 minutes as part of the HOST procedure and then underwent the sperm chromatin dispersion test using a Halosperm kit. DNA fragmentation status (large halo, medium halo, small halo, no halo, or degraded) and the specific tail swelling pattern ("a"-"g") were assessed at the level of a single spermatozoon. A total of 42,000 spermatozoa were analyzed, and the percentage of spermatozoa without DNA fragmentation (as evidenced by a large or medium halo) was assessed according to the specific tail swelling patterns observed. Results: The HOST examinations showed that > 93% of spermatozoa across all types displayed no DNA fragmentation. The percentage of spermatozoa without DNA fragmentation was 100% in type "d", 98.67% in type "g", and 98.17% in type "f" spermatozoa. Conclusion: We found that the type "d" spermatozoa displayed no DNA fragmentation, but the other types of spermatozoa also displayed very low rates of DNA fragmentation. This result may be associated with the processing of the spermatozoa by density gradient centrifugation and the swim-up technique.

• Structural Engineering and Mechanics
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• 제50권5호
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• pp.575-588
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• 2014

Gel materials have recently gained more attention due to its unique capability of large and reversible volumetric changes. This study explores the possibility of mimicking the pattern formation of certain natural fruits during their growing process and leaves during drying processes through the swelling and de-swelling of gel materials. This will hopefully provide certain technical explanations on the morphology of fruits and plants. We adopt the inhomogeneous field gel theory to predict the deformation configurations of gel structures to describe the morphology of natural fruits and plants. The growing processes of apple and capsicum are simulated by imposing appropriate boundary conditions and field loading via varying the chemical potential from their immature to mature stages. The drying processes of three types of leaves with different vein structures are also investigated. The simulations lead to promising results and demonstrate that pattern formation of fruits and plants may be described from mechanical perspective by the behavior of gel materials based on the inhomogeneous field theory.

• 한국광물학회지
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• 제30권2호
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• pp.71-81
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• 2017

회백색 응회암으로 구성된 경주 골굴암 마애불의 효과적인 보존처리를 위하여 구성암석의 특징과 보존처리제 적용에 따른 효과를 살펴보았다. 구성암석은 팽윤성 광물인 몬모릴로나이트를 3-5% 함유하고 있으며, 물과 반응 후 팽윤성 광물의 층간간격이 증가함을 보였다(1.54-2.69%). 에틸실리케이트 암석강화제를 적용한 후 시편의 표면 경도, 흡수율, 공극률 등의 물성은 향상되었으나 팽윤성 광물의 층간간격이 감소하였으며(4.23-12.12%), 팽윤성 광물의 함량이 많을수록 그 정도는 컸다. 팽윤저지제를 선 처리한 후 강화제를 적용하였을 때 물성은 강화제만을 처리하였을 때와 거의 유사한 결과를 보였다. 팽윤저지제만의 처리로는 팽윤성 광물의 층간간격이 거의 변화되지 않았으며, 팽윤저지제 처리 후 강화제를 처리하였을 때는 XRD 패턴에서 팽윤성 광물의 세기는 줄어들었으나 층간간격의 변화는 강화제만을 처리하였을 때와 유사하여 팽윤저지제의 효과는 거의 없었다(4.10-11.85%). 따라서 팽윤성 광물을 함유하고 있는 골굴암 마애불 구성암석을 강화시키기 위한 보존처리제로서 에틸실리케이트 계열의 암석강화제는 적절치 않으며 이를 보완하기 위해 사용한 팽윤저지제도 효과적이지 못하다. 우수의 접촉으로 구성광물이 팽윤되어 풍화가 급속히 진행되기 때문에 현재로서는 하부와 측면 등 풍화가 심한 부분에 우수접촉을 저지시키는 조치가 필요하다.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2003년도 생물공학의 동향(XII)
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• pp.739-742
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• 2003

생분해성인 Curdlan을 이용하여 pH 의존성 약물 전달계 개발을 위한 실험을 수행한 결과, pH 1,4에서 약물 방출 보다 pH 7.4에서 약물 방출이 10배 이상 증가하였다. 이러한 결과로 curdlan acetate microsphere는 pH 의존성 약물 전달계로 유용하다고 판단된다.

• 한국산학기술학회논문지
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• 제21권3호
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• pp.215-222
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• 2020

메트포르민은 제2형 당뇨병의 1차 치료제로 사용되는 약물로 다른 당뇨병 치료제에 비해 투여 용량이 크고 용해도는 높으나 위장관 투과도가 낮은 특성을 갖고 있으며 주로 위장관 상부에서만 흡수되는 이유로 생체이용률이 40~60%로 낮은 편이다. 따라서 본 연구를 통해 위체류 약물전달시스템을 적용하여 제제가 위에 머무르는 시간을 증가시키고 제제로부터 방출된 약물을 서서히 소장으로 이동시킨다면 생체이용률을 증가시킬 수 있을 것으로 기대된다. 팽윤성 시스템은 다른 위체류 약물전달시스템에 비해 안정성이 높아 개발목표기술로 선정하였고, 팽윤성 기제로는 기존의 연구와 다르게 카라기난과 히프로멜로오스를 병용하여 차별성을 확보하였다. 카라기난과 히프로멜로오스 병용 시스템은 각각의 함량이 15/110 질량분율일 때 가장 높은 팽윤성과 적절한 서방성 용출패턴을 나타내었다. 또한 각각의 함량이 15 %와 14 %가 되도록 제조한 메트포르민 정제를 시판 정제와 비교 시 더 우수한 팽윤성이 나타남을 확인하였다. 결론적으로 본 연구 결과에 의해 메트포르민의 서방출을 위한 새로운 팽윤성 위체류 약물전달시스템이 개발되었으며 다양한 주성분에 대한 추가적인 연구가 수행되면 의약품, 화장품, 건강기능식품 등의 분야에서 효과적인 약물전달시스템으로 응용될 수 있을 것으로 기대된다.

• Journal of Korean Neurosurgical Society
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• 제42권2호
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• pp.97-102
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• 2007

Objective : The authors attempted to evaluate the pattern of the airway narrowing due to prevertebral soft tissue swelling after surgery of the anterior cervical spine and their clinical significances using plain cervical X-ray images. Methods : Twenty-four patients undergoing anterior cervical spine surgery were reviewed from January 2004 to December 2005. Postoperatively, in daily basis, lateral radiograph of the neck was obtained in neutral position. We measured the upper airway diameter above and below the epiglottis level and prevertebral soft tissue diameter every day for a week and finally 2 weeks after surgery using their simple lateral cervical X-ray films. Results : Both airway narrowing and prevertebral soft tissue swelling were maximum in postoperative 2 days, and decreased rapidly in postoperative 7 days. Airway narrowing was aggravated postoperatively but slowly decreased as prevertebral soft tissue swelling diminished. But, the severity of airway narrowing showed no clinical correlations with clinical symptom and radiologic severity. Conclusion : Not all patients who show severe airway narrowing and prevertebral soft tissue swelling on their plain cervical X-ray film complain respiratory insufficiency. But, the patients with undergoing anterior cervical spine surgery should be monitored carefully for respiratory insufficiency, especially during several days following operation because both airway narrowing and prevertebral soft tissue swelling become peak at postoperative 2-3 days.