• 생명과학회지
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• 제24권3호
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• pp.260-265
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• 2014

귤나무(Citrus unshiu)의 과피를 말린 한약재인 진피(Aurantii Nobilis Pericarpium; ANP)는 오래 전부터 대한민국을 비롯한 동아시아에서 위장관 운동 관련 질환의 치료에 전통적으로 쓰여 왔다. 본 연구에서는 진피 주정 추출물(ANP-E)을 제조하여 실험하였는데, 우선 ANP-E는 5 g/kg의 고용량을 mouse에 경구 투여하였을 때에도 급성독성을 나타내지 않았다. ANP-E가 위장관 운동 기능에 미치는 영향을 파악하고 이를 cisapride의 효과와 비교하기 위하여, mouse를 대상으로 위장관 이송률을 측정하는 실험을 수행하였다. Cisapride는 20세기 말까지 다양한 위장관 운동 저해 상황에서 임상적으로 광범위하게 적용되었던 최고의 위장관 운동 촉진제였으나, 치명적인 부작용으로 인하여 2000년 이후 시장에서 철수된 약물이다. 실험 결과, ANP-E는 정상 및 위장관 운동 저해 상황에서 모두 용량 의존적으로 위장관 운동을 촉진시키는 것으로 나타났다. ANP-E의 위장관 운동 촉진 효과를 cisapride와 비교해 보면, 정상 mouse에서는 cisapride와 거의 대등한 위장관 이송률 수치를 나타내었으며, 특히 위장관 운동 저해 상황에서는 cisapride보다 약효 및 안전성 측면에서 모두 비교 우위를 점하는 강력한 위장관 운동 기능개선 효과를 보였다. 이상과 같은 결과들은, ANP-E가 인간의 위장관 운동 기능 저해 상황을 개선할 수 있는 새롭고 강력한 신약 후보 물질이자, 아직 시장에 출현하지 않고 있는 cisapride의 대체 의약품으로서 개발 가능함을 시사하고 있다.

• 대한교통학회지
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• 제25권2호
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• pp.121-132
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• 2007

본 연구는 대중교통 통행배정을 위한 수단 및 경로선택의 기준으로서 도보시간, 대기시간(환승대기시간 포함), 차내시간, 환승시간(환승도보시간), 요금 및 각 요소별 가중치로 구성된 일반화비용 모형을 제시하였다. 모형의 정산을 위해 현실상황에 직면하도록 설계된 선호도 조사를 실시하여 자료를 수집/분석 하였으며, 한계대체율 및 임금율법을 적용하여 일반화비용 모형의 각 변수별 가중치를 도출하였다. 그 결과 서울시내간 통행의 경우 차내시간 대비 도보시간의 가중치는 1.507, 대기시간은 1.749, 환승시간은 1.474, 요금은 1.476이며, 서울경기간의 경우, 각각 1.827, 1.967, 1.015, 0.857로 도출되었다. 통계검정 결과 두 모형간에는 차이가 있는 것으로 나타났으며, 각 변수는 유의미 한 것으로 나타났다. 이 결과를 활용, 서울시 대중교통체계 개편 이후의 통행지표를 거시적 정량적으로 분석한 결과 서울시내간, 서울경기간 평균총통행시간은 30.23분, 63.29분으로 나타났으며, 일반화비용은 각각 2,510원, 3,880원으로 추정되었다.

• 동의생리병리학회지
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• 제27권2호
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• pp.225-232
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• 2013

Delayed gastrointestinal (GI) motility is frequent adverse effect associated with chemotherapy, and induced by serotonin releases from enterochromaffin cells. Ijintang-gamibang (IJG) is a digestive polyherbal formula has been traditionally used in Korea and consisted of 8 types of medicinal herbs. This study was conducted to determine whether or not IJG aqueous extracts can prevent delayed GI motility induced by the antineoplastic drug cisplatin chronically administered, once per week for five consecutive weeks (2 mg/kg). 200, 100 and 50 mg/kg of IJG extracts were orally administered, once a day for 14 days from fourth cisplatin treatment, and the changes in body weight gain, fecal parameters, gastrointestinal transit ratio and histopathology were observed. In addition, pylorus gastrin and serotonin contents were also measured with immunohistochemical observations of enterochromaffin cells contains gastrin and serotonin, as compared with ondansetron, a serotonin 5-HT3 receptor antagonist, 1 mg/kg. Cisplatin treatment related body weight decreases, delayed GI motility, decreases of fecal water contents were significantly and dose-dependently inhibited by oral treatment of IJG extracts, and they also inhibited the pylorus gastrin and serotonin changes induced by cisplatin treatment. The overall effects of IJG 100 mg/kg were similar to that of ondansetron 1 mg/kg. The present results supported that IJG aqueous extracts have favorable ameliorating effect on the delayed GI motility induced by chemotheraphy, modulated the GI enterochromaffin cells, serotonin and gastrin-producing cells with antioxidant effects. This effect of IJG may help improve accompanying gastrointestinal symptoms by chemotherapy.

• 약학회지
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• 제37권5호
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• pp.511-519
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• 1993

The short and variabke transit of drug throught GI tracj and the inter-and intra-subject variations of the transit restrict the sustained drug absorption after oral adminstration. These restrictions may be solved by retaining the dosage forms in the stomach. Then the dosage form will act as a platform which releases the drug slowly and makes the GI absorption occur for a long time. In this study, as the platforms, PVP hydrogels were synthesized by chemical and y-irradiation method in the cylindrical test tube. The chemical method means the synthesis of the hydrogel by heating the mixed solution of N-vinyl-2-pyrrolidone [monomer], acrylated albumin [crosslinking agent], 2, 2'-agobis(2-methylpropionitrile) [initiator] and proxyphylline [drug] at $65^{\circ}C$ for 5 hr. The $\gamma$-irradiation method means the synthesis of the hydrogel by irradiation with $^{60}$ Co $\gamma$-ray of the mixed solution of the monomer, acrylated albumin, and flurbiprofen [drug] at room temperature with total 0.2 Mrad for 3 hr. Our intention is to design the hydrogel tablet (diameter : 1.20 cm, thickness : 0.60 cm) which swells in the gastric fluid after oral administration to such a size that passing through the pylorus could be inhibited during the period of drug release. After releasing drug, the hydrogel should be degraded by the enzymeatic digestion in the stomach, or by hydrolysis and eventually solubilized. Thus, in votro tests were performed to examine the factors that affect swelling and drug release from the PVP hydrogels. Experimental results show that the hydrogels swell to a size larger than the diameter of the pylorus(l.3$\pm$0.7 cm) and the hydrogel prepared by the chemical method is digested by pepsin. But the hydrogel prepared by the $\gamma$-irradiation method was not digested by the pepsin and just collapsed with time. Thus, the swelling of the hydrogel synthesized by $\gamma$-irradiation was independent albumin acrylation time and pepsin concentration. But drug content and radiation dose affected the swelling and drug release kinetics of the hydrogel. Drug release from the hydrigels was prolonged up to about 24 hr. Therefore, it was concluded that by adjusting these factors, the albumin-crosslinked PVP hydrogel synthesized by $\gamma$-irradiation method is expected to be retained in the stomach for up to 60hr and be a potential platform of drugs for long-term GI absorption.

• Journal of Nutrition and Health
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• 제29권3호
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• pp.286-295
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• 1996

The present study was conducted to evaluate the usefulness of four kinds of seaweeds (mixture of purple laver & sea lettuce, sea tangle, sea mustard, agar agar) as a high- fiber supplment in the therapeutic deit for the diabetic patients. Seven groups of normal and streptozotocin-induced diabetic rats were fed dietary fiber-free control diet or one of experimental diets containing 7% of one of the four seaweeds for 6 weeks. The effect of seaweeds supplementation on the body weight change, gastrointestinal function, and the control of diabetic symptoms were examined and compared with the effect of fiber-free diet or pectin diet used as references. The body weight gains of all the diabetic groups were significantly suppressed compared to the normal group. Feed efficiency ratios and body weight gains of seaweed groups were relatively higher than those of the pectin group. Sea tangle appeared to have an effect of alleviating the typical diabetic symptoms such as polyphasia, polydipsia, polyuria, urinary glucose excretion and hyperglycemia indicating its beneficial acition of improving glucose metabolism even though the degree of effectiveness was less than that with pectin. All the supplemntations of seaweeds and pectin ressulted in the significant changes in gastronitestinal functins ; shortening of GI transit time, increase of fecal volume and the length of intestine. Based on their effects of the significant changes in GI function in may be suggested that seaweeds may influence the process of digestion and absorption of nutrients in diabetic animals.

• Integrative Medicine Research
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• 제6권2호
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• pp.149-155
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• 2017

Background: Naringenin (NRG) is a common dietary polyphenolic constituent of fruits. NRG has diverse pharmacological activities, and is used in traditional medicine to treat various diseases including gastrointestinal (GI) disorders. Interstitial cells of Cajal (ICCs) are pacemaker cells of the GI tract. In this study, the authors investigated the effects of NRG on ICCs and on GI motility in vitro and in vivo. Methods: ICCs were dissociated from mouse small intestines by enzymatic digestion. The whole-cell patch clamp configuration was used to record pacemaker potentials in cultured ICC clusters. The effects of NRG on GI motility were investigated by calculating percent intestinal transit rates (ITR) using Evans blue in normal mice. Results: NRG inhibited ICC pacemaker potentials in a dose-dependent manner. In the presence of tetraethylammonium chloride or iberiotoxin, NRG had no effect on pacemaker potentials, but it continued to block pacemaker potentials in the presence of glibenclamide. Preincubation with SQ-22536 had no effect on pacemaker potentials or on their inhibition by NRG. However, 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one blocked pacemaker potential inhibition by NRG. In addition, L-NG-nitroarginine methyl ester blocked pacemaker potential inhibition by NRG. Furthermore, NRG significantly suppressed murine ITR enhancement by neostigmine in vivo. Conclusion: This study shows NRG dose-dependently inhibits ICC pacemaker potentials via a cyclic guanosine monophosphate/nitric oxide-dependent pathway and $Ca^{2+}$-activated $K^+$ channels in vitro. In addition, NRG suppressed neostigmine enhancement of ITR in vivo.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 정기총회 및 추계학술대회 논문집
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• pp.2731-2734
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• 2011

Korean-Automated Guideway Transit (K-AGT) was successfully developed through Light Rail System Development Project. Since then, the domestic development rate of on-board signalling system of light rail has been improved up to 90% by Practical Utilization Project of Light Rail. After utilization project, furthermore, POSCO ICT has developed the wayside signalling system of CBTC, including wireless communication equipment. KRRI carried out the performance test of the wireless communication, interfacing and using the other CBTC equipments of KyungSan Test Line so as to see whether it conforms IEEE 802.11x, international communication standard in view of operational concept of CBTC. In this paper, we presents the test plan, test items, and the analysis results of maximum communication distance tests between on-board and wayside radio sets.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2010년도 하계학술대회 논문집
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• pp.78-78
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• 2010

Fiber Reinforced Plastic (FRP) insulator has a higher performance than porcelain. It is only used in domestic AC 25 kV electric railway system. Seoul Metro has developed DC 1500 V polymer insulator since 2008. The test of moisture infiltration is carried out. The test results showed that all result values satisfy the test standard.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2009년도 춘계학술대회 논문집
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• pp.2005-2009
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• 2009

Urban transit consists of signaling system, railway systems, power facilities systems, information and communication system and the other complicated facilities. There are many new technologies to analysis the requirement of for information and communication system. The more system is complicate, the more system design error occur frequently in development of information and communication system. Now, we need to reduce the error by analysis the behavior of the requirements of it. Thus in this paper, we suggest the way to analysis the behavior of the requirements by using the computer aided design tools.

• Journal of Information Display
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• 제4권3호
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• pp.22-25
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• 2003

In this paper, we propose the bistability the bistability in a chiral-splay nematic liquid crystal cell, which is obtained by adding a chiral additive to a splay cell and introduce a novel switching method for the bistable chiral-splay nematic cell in order to transit the LC director between the non-twisted state with splay and the 180$^{\circ}$ twist state.