• Journal of Pharmaceutical Investigation
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• 제32권4호
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• pp.267-275
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• 2002

A self-microemulsifying drug delivery system (SMEDDS) was developed to increase the dissolution rate, solubility, and ultimately bioavailability of a poorly water soluble drug, lovastatin. SMEDDS was thε mixtures of oils, surfactants, and cosurfactants, which emulsify under conditions of gentle agitation, similar to those which would be encountered in the gastro-intestinal (GI) tract. Various types of self-emulsifying formulations were prepared using four types of oil (Capryol 90, Lauroglycol 90, Labrafil M 1944 CS and Labrafil M 2125), two surfactants (Cremophor EL and Tween 80), and three cosurfactants (Carbitol, PEG 400 and propylene glycol). Thε efficiency of emulsification was studied using a laser diffraction size analyzer to determine particle size distributions of the resultant emulsions. Optimized formulations selected for bioavailability assessment were Carpryol 90 (40%), Cremophor EL (30%) and Carbitol (30%). SMEDDS containing lovastatin (20 mg and 5 mg) were compared to a conventional lovastatin tablet $(Mevacor^{\circledR},\;20\;mg/tab)$ by the oral administration as prefilled hard gelatin capsules to fasted beagle dogs for in vivo study. The arεa under the serum concentration-time curve from time zero to the last measured time in serum, $AUC_{0{\rightarrow}24h}$, was significantly greater in SMEDDS, suggesting that bioavailability increase 130% and 192% by the SMEDDS, respectively. The self-emulsifying formulations of lovastatin afforded the improvement in absolute oral bioavailability relative to previous data of lovastatin tablet formulation. These data indicate the utility of dispersed self-emulsifying formulations for the oral delivery of lovastatin and potentially other poorly absorbed drugs.

• The Korean Journal of Ecology
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• 제24권2호
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• pp.101-109
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• 2001

We created an environmental forest on the basis of ecological design around the incineration plant of Jindo Engineering and Construction Co., Ltd., which is located in Jeongwang-dong, Siheung-si, Kyunggi-do. To get ecological information of this site, physico-chemical properties of soil on salt marsh, which is located close to the syudy site and of forest soil transported from other sites for ecological restoration were analyzed. Texture of salt marsh and transported soils were loam and sandy loam, respectively. pH, organic matter, T-N, available P, and exchangeable K and Na contents of salt marsh and transported forest soils were 6.7 and 5.4, 4.1 and 0.4%, 1.0 and 0.3mg/g, 46.7 and 6.8ppm, 521 and 207ppm, and 3.8 and 0.5mg/g, respectively. Introduced plants were selected among the dominant species of forests and the species composing the potential natural vegetation around the present study site. Those plants were selected again by considering the tolerances to air pollution and to salt, and their availability. Selected trees were Pinus thunbergii, Sophora japonica, Celtis sinensis, Quercus aliena, Q. serrata, Q. dentata, and Q. acutissima. Selected sub-trees were Albizzia julibrissin, Koelreuteria poniculata, and Styrax japonica and shrubs were Rhododendron yedoense var. poukhanense, R. mucronulatum, Callicarpa japonica, Euonymus alatus, E. japonica, and R. schlippenbachii. On the other hand, introduction of herbs was not considered except for Liriope platyphylla, which was ornamentally planted in one site. Planting bed of mound type was adopted to provide the fine drainage system. Mound was designed to furnish litter, A, B, and C layers simuating the profile of forest soil. Slope of mound was mulched by rice straw of 2cm in thickness to prevent for sliding of litter and soil in cases of strong wind or heavy rain. Height of mound was designed to secure more than 1 m by combining A and B layers. Narrow zones, in which mound with stable slope degree cannot be prepared, was designed to equip the standard soil depth with the introduction of stone for supporting. On the other hand, plants with shallow root system were arranged in some zones, in which satisfactory soil depth cannot be ensured. Plants were arranged in the order of tree, sub-tree, and shrub from center to edge on the mound to make a mature forest of a dome shape in the future. Dispersion of plants was designed to be random pattern rather than clumped one. Problems on creation of the environmental forest by such ecological design were found to be management or inspection by non-specialized project operators and inspecting officers, and regulations for construction without ecological background. Alternative plans to solve such problems were suggested.

• 한국축산시설환경학회지
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• 제8권2호
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• pp.99-106
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• 2002

This study was conducted to improve utilization efficiency of slurry and choose a suitable type of tractor power which can be attached by manure spreader in the paddy field. In the paddy field, the pulling force for the spreader was measured by using a measurement system installed between tractors with and without the spreader. The soil moisture contents at the 0${\sim}$10cm and 10${\sim}$20cm depth of test soil(SiCL) were 28.45% d.b. and 23.47% d.b., respectively in average while Cone Index at l0cm and 15cm depth were 14.5kPa and 16.2kPa, respectively. It was impossible to measure the soil moisture contents and Cone Index below 20cm depth of the soil because the hardness of the soil increased greatly. Thereafter, hard pan of the sampled soil was found at 15${\sim}$20cm depth. While the required power only for the dragged tractor was found to be 3.44kW in the test field, the required pulling powers of tractor considering the pumping were 8.48${\sim}$12.48kW, 12.19${\sim}$16.19kW, 16.96${\sim}$20.96kW, respectively for 2 tons, 3 tons, and 4 tons of tank capacity. As the tank capacity increased, the sinkage of soil were also increased to 7cm, l0cm, and 12cm, respectively for the tractors with 2 tons, 3 tons and 4 tons of tank capacity. Considering about 60% of pulling efficiency of tractor, a tractor which had lower than 25.74kW of pulling power was suitable to pull the spreader and spread the slurry simultaneously for manure spreader with 2 tons of tank capacity. 29.42kW${\sim}$36.78kW of pulling power was found to be optimum for the tractor with 3 tons of tank capacity while over 40.45kW for 4 tons of tank capacity.

• 자원환경지질
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• 제26권1호
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• pp.67-81
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• 1993

This dissertation is a basic research on the degradation of rocks and aims at clarifying the relations between the progression of degree of weathering and the variation of chemical composition. The author wants to make clear the degradation of rocks and the process of formation of sedimentary rocks from a standpoint of elucidation of migration of elements. This study is considered to be significant not only as a part of research on the distribution of earth crust materials but as the petrogenesis of rocks. The chemical studies on the weathered rocks have been started relatively early and there are not a few researches on them: Goldich, 1938; Harris, et al., 1966; Ruxton, 1968; Berner, et al., 1982; Kanuss, 1983; Lasaga, 1984; Siagel, 1984. The degree of migration of elements in weathering is the composite result of various factors. Because, at the present time, it is difficult to clarify the individual and composite effects of each factor theoretically and quanititatively, we must accumulate empirical data and use them relatively. In such consideration the author acquired some data of chemical weathering from the chemical analysis of granitic and basaltic rocks in and around Fukuoka city, Japan and granitic rocks in and around Chonju and Iri cities, Korea. Because both rock types studied can be considered as representative materials of acidic and basic rocks compsing the earth crust, it is significant to examine the phenomena of weathering of both rock types. The following results are obtained from the analysis and examinations of chemical compositions of the original and weathered rocks. The loss rate of major elements has no uniformity, but the following relation holds in general; Ca, Na> K, Si> Mg> Fe, Al. As weathering proceeds, the ratio of $Al_2O_3/CaO$ shows increasing phenomena, and that of $Na_2O/CaO$ decreasing. The range of migration of composition is broad in basaltic rocks but narrow in granitic rocks. The reason is that the chemical weathering of basaltic rocks progresses more easily than that of granitic rocks. The chemical weathering potenitial index of basaltic rocks in larger than that of granitic rocks. The reason is that the chemical weathering of basaltic rocks proceeds more easily than that of granitic rocks. In weathering, the decrease of mobile cations such as $Ca^{2+}$, $Na^{2+}$, $Mg^{2+}$ and the increase of $H_2O$ in basaltic rocks are more obvious than in granitic rocks.

• Korean Journal of Acupuncture
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• 제32권3호
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• pp.108-115
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• 2015

Objectives : Acupuncture is frequently used as an alternative therapy for Parkinson's disease(PD) in Korea. Using 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine(MPTP)-induced Parkinson's disease mouse model, the present study investigated a possible role of acupuncture stimulation at GB34 in suppressing dopaminergic neuronal death and regulating the phosphorylation of protein kinase B(Akt) in substantia nigra(SN) and striatum(ST). Methods : Eight-week-old male C57BL/6 mice were administered intraperitoneally with 30 mg/kg of MPTP at 24-h intervals for 5 days. Acupuncture stimulation at GB34 or SI3 was performed once a day for 12 days consecutively from the first MPTP injection. After the last acupuncture stimulation, pole test was performed to assess the effect of the acupuncture stimulations. Dopaminergic neuronal survival in the SN and the ST, dopamine transporter( DAT) and caspase-3 expression in the ST were evaluated by immunohistochemistry. The phosphorylations of Akt in the SN and the ST were measured by Western blotting. Results : MPTP administration caused behavioral impairment and dopaminergic neuronal death in the SN and the ST. It also decreased DAT expression and increased caspase-3 expression in the ST. Acupuncture stimulation at GB34 alleviated these MPTP-induced impairments. Moreover, MPTP suppressed Akt phosphorylation in the SN and the ST, whereas acupuncture stimulation at GB34 alleviated the phosphorylation in the SN. Conclusions : These results indicate that acupuncture stimulation at GB34 can inhibit MPTP-induced dopaminergic neuronal death and alleviate the Akt phosphorylation in the SN, suggesting a possible role for acupuncture in the treatment of PD.

• Molecules and Cells
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• 제42권11호
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• pp.763-772
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• 2019

Periodontitis is characterized by the loss of periodontal tissues, especially alveolar bone. Common therapies cannot satisfactorily recover lost alveolar bone. Periodontal ligament stem cells (PDLSCs) possess the capacity of self-renewal and multilineage differentiation and are likely to recover lost alveolar bone. In addition, periodontitis is accompanied by hypoxia, and hypoxia-inducible $factor-1{\alpha}$ ($HIF-1{\alpha}$) is a master transcription factor in the response to hypoxia. Thus, we aimed to ascertain how hypoxia affects runt-related transcription factor 2 (RUNX2), a key osteogenic marker, in the osteogenesis of PDLSCs. In this study, we found that hypoxia enhanced the protein expression of $HIF-1{\alpha}$, vascular endothelial growth factor (VEGF), and RUNX2 ex vivo and in situ. VEGF is a target gene of $HIF-1{\alpha}$, and the increased expression of VEGF and RUNX2 proteins was enhanced by cobalt chloride ($CoCl_2$, $100{\mu}mol/L$), an agonist of $HIF-1{\alpha}$, and suppressed by 3-(5'-hydroxymethyl-2'-furyl)-1-benzyl indazole (YC-1, $10{\mu}mol/L$), an antagonist of $HIF-1{\alpha}$. In addition, VEGF could regulate the expression of RUNX2, as RUNX2 expression was enhanced by human VEGF ($hVEGF_{165}$) and suppressed by VEGF siRNA. In addition, knocking down VEGF could decrease the expression of osteogenesis-related genes, i.e., RUNX2, alkaline phosphatase (ALP), and type I collagen (COL1), and hypoxia could enhance the expression of ALP, COL1, and osteocalcin (OCN) in the early stage of osteogenesis of PDLSCs. Taken together, our results showed that hypoxia could mediate the expression of RUNX2 in PDLSCs via $HIF-1{\alpha}$-induced VEGF and play a positive role in the early stage of osteogenesis of PDLSCs.

• 헤리티지:역사와 과학
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• 제47권1호
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• pp.18-31
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• 2014

관룡사 약사전에 사용된 단청안료에 대해 과학적 분석을 실시하여 사용안료의 종류와 특성을 밝혀내고, 이를 약사전 벽화 뿐만아니라 대웅전 단청에 사용된 안료와도 비교하고자 하였다. 분석결과, 적색과 녹색, 백색계열의 안료는 채색 부위에 따라 전혀 다른 종류의 안료를 사용한 것으로 나타났으며, 여러 가지 색상구현을 위해 2종류 이상의 안료를 혼합하여 일부 사용하였다. 확인된 안료의 색상별 원료광물은 적색계열의 경우, 진사(Cinnaba)와 연단(Minium), 석간주(Hematite)이며, 백색계열은 합분(Oyster shell white)과 백토(White Clay), 녹색계열은 녹염동광(Atacamite)과 뇌록석(Celadonite)이었다. 또한 흑색계열은 먹(Carbon)이나 카본블랙(Carbon Black), 황색은 황토(Yellow Ocher)이며, 청색계열은 청람석(Lazulite)으로 확인되었다. 이러한 분석결과를 관룡사 내 약사전 벽화나 대웅전 단청에 사용된 안료의 연구결과와 서로 비교했을 때, 전체적으로는 비슷한 원료광물을 사용했으나 녹색이나 백색, 황색 등의 안료들에서 서로 다른 원료광물이 가감되어 사용되었음을 일부 확인하였다. 결국 같은 시기, 같은 사찰내에서도 회화의 종류나 대상건물에 따라 안료의 원료광물은 선택적으로 사용될 수 있다는 것을 보여주는 결과이다.

• 한국산림과학회지
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• 제70권1호
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• pp.91-102
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• 1985

굴참나무림(林)의 밀도(密度) 차이(差異)에 따른 생장(生長) 및 물질생산(物質生産)을 비교분석(比較分析)하여 천연림(天然林)의 무육시업자료(撫育施業資料)를 얻고자 경남산청지역(慶南山淸地域)의 해발(海拔) 900 m (A임분(林分) : 6,600본(本)/ha, $15.84m^2/ha$, $\frac{19}{17-20}$년생(年生))와 800 m (B임분(林分) : 4,300본(本)/ha, $16.65m^2/ha$, $\frac{20}{17-21}$년생(年生))의 위치(位置)에 $20m{\times}20m$ 표본점(標本點)을 각각(各各) 설치(設置)하여 조사(調査)한 바를 다음과 같이 요약(要約)할 수 있었다. 조사구내임목(調査區內林木)을 매목조사(每木調査)하고 경급별(徑級別) 평균목(平均木)을 12본(本)씩 벌채(伐採)하여 $W_S$, $W_B$, $W_L$, $W_{Ba}$ 등(等)의 건중량(乾重量)을 측정(測定), $D^2H$와의 상대생장식(相對生長式)에 의(依)해 현존량(現存量)과 물질생산량(物質生産量)을 추정(推定)하였다. 생산구조면(生産構造面)에서 광합성부위(光合成部位)는 A임분(林分)이 지상(地上) 2.2 m, B임분(林分)이 지상(地上) 1.2 m 높이서 시작(始作)되었고, 최대광합성부위(最大光合成部位)는 A, B 임분(林分)에서 각각(各各) 4.2 m, 6.2 m 높이였으며 엽면적지수(葉面積指數)는 각각(各各) 4.25 ha/ha, 389 ha/ha로 나타났다. 지상부현존량(地上部現存量)은 A, B임분(林分)에서 각각(各各) 49.51 ton/ha, 59.20 ton/ha이고, 순생산량(純生産量)은 각각(各各) 6.75 ton/ha/yr., 8.99ton/ha/yr.로 B임분(林分)이 더 컸었으나, 현존량(現存量)에 대(對)한 순생산량(純生産量)의 구성비(構成比)에 있어서는 A, B임분(林分)이 각각(各各) 17.5%, 16.7%로 A임분(林分)이 더 컸다. 잎의 순동화율(純同化率), 간재생산능률(幹材生産能率) 및 수피생산능률(樹皮生産能率)을 A, B임분별(林分別)로 추정(推定)한바 NAR은 2.75kg/kg/yr., 3.58kg/kg/yr이고, 간재생산능률(幹材生産能率)은 1.46kg/kg/yr., 2.09kg/kg/yr로 B임분(林分)이 크게 나타나 효과적(効果的)인 공간이용(空間利用)을 하고 있음을 시사(示唆)하고 있으나, 수피생산능률(樹皮生産能率)은 0.60kg/kg/yr., 0.34kg/kg/yr.로 A임분(林分)이 크게 추정(推定)되었다. 이상(以上)의 결과(結果)로서 임분(林分)의 밀도조절(密度調節)을 통(通)하여 생산성(生産性)을 높일 수 있는 굴참나무천연림무육시업(天然林撫育施業)의 자료(資料)와 생산물(生産物) 목표(目標)에 따른 경영(經營)의 지침(指針)을 얻을 수 있을 것으로 생각된다.

• 청정기술
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• 제22권3호
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• pp.190-195
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• 2016

회전식 소각공정은 고에너지 물질의 폐기처리를 위해 현재 상용화 되고 있는 기술로 열풍을 이용하여 대상물질을 열분해하는 공정이며 TNT, RDX 및 Composition B를 통한 열분해 공정의 사전연구가 진행되었다. 본 연구의 대상물질은 나이트로셀룰로스(nitrocellulose, NC)와 나이트로글리세린(nitroglycerine, NG)의 혼합물인 더블베이스 추진제(M8)로 선정하였다. M8 추진제의 열분해 반응은 응축상 반응(condensed phase reaction, CPR)과 기체상 반응(gas phase reactions, GPRs)로 구성되어 있다. CPR의 경우 흡열반응으로 4가지 화합물을 생성하며, GPRs의 경우 59개의 가스화합물 및 365개의 흡열·발열 반응으로 구성되어 있다. 본 연구는 gPROMS 소프트웨어를 이용하여 관형반응기의 수학적 모델링을 완성하였으며, 운전온도 및 유속 변화에 따른 케이스스터디를 진행하였다. 상대적으로 낮은 유속 및 높은 공정온도는 반응기의 내부온도(Case3: 953 K, Case6: 1300 K)를 상승 시켰으며, CO₂와 H₂O 몰농도 값 상승을 통해 완전연소율이 증가하는 것을 확인할 수 있었다. 본 연구 내열형 소각로 설계, 운전조건을 도출하는데 있어 기초 자료로 활용될 수 있을 것으로 사료된다.

• 원예과학기술지
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• 제33권2호
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• pp.298-301
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• 2015

무궁화 '다솜'은 1993년에 채종한 '홍순' 종자를 이듬해에 한국원자력연구원 감마선 저준위조사시설에서 감마선 100Gy를 조사하여 1998년에 가로수용으로 유망한 우수한 화색을 가진 개체를 1차 선발하였다. 2005년부터 2010년까지 6년에 걸쳐 선발 계통의 균일성과 안정성을 검정하였다. 무궁화 '다솜'의 주요특성으로 초장은 106cm로 길며, 분지수는 19개로 많은 편이고 가지는 상향으로 갈색을 띈다. 꽃은 홍단심계 반겹꽃으로 옅은 적색을 띄고, 꽃잎의 길이(4.0cm)와 폭(3.3cm)은 중간 정도이나 꽃잎의 겹침 정도가 강하여 전체적인 꽃의 직경(5.8cm)은 다소 작은 편이다. 개화시간은 17시간 정도로 다른 품종들과 유사하나, 개화일수는 105일로 대조품종인 '홍순'(111일)에 비해 짧은 편이다. 잎의 모양을 비롯한 주요 특성은 '홍순'과 유사하다.