• 한국식품과학회지
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• 제27권2호
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• pp.225-229
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• 1995

저칼로리 감미료로서 장내 미생물 균총을 개선한다고 알려진 대두 올리고당을 전처리 및 Steffen법을 이용하여 대두 침지액으로부터 분리, 회수하였다. 전처리로서 pH를 $3.5{\sim}4.0$으로 조절하거나, 염화칼슘을 당 대비 8%(w/w)를 첨가하여 대두 침지액 중에 함유된 단백질을 약 $25{\sim}30%$가량 제거할 수 있었다. 또한 대두 침지액에 염화칼슘과 산화칼슘 분말을 각각 당 대비 약 20%, $100{\sim}120%$씩 첨가한 후 $5^{\circ}C$에서 20분 동안 반응시키는 Steffen법을 이용하면 대두 침지액 중에 존재하는 대두 올리고당의 약 85%를 saccharate 형태로 분리, 회수할 수가 있었다. 이산화탄소로 당을 탈착시켜 회수한 결과 최종적으로 약 80%의 수율로 당을 회수할 수가 있었으며 단백질은 약 80% 정도 제거할 수가 있었다. 회수된 당액의 당조성은 대두 침지액과 유사하였다.

• Restorative Dentistry and Endodontics
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• 제3권1호
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• pp.17-21
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• 1977

After a vital pulpotomy in dogs' teeth, the responses of the remaining pulp tissue under calcium hydroxide and formocresol were studied histologically. The class I and V cavities were prepared on the teeth and the pulp was amputated. Calcium hydroxide and formocresol were placed over the amputated tissue and the cavities were sealed with zine oxide eugenol cement and zinc phosphate cement. Animals. were sacrifice after 1, 2, and 3 weeks following the operation. The teeth were decalcfied, sectioned and stained with hematoxylin and eosin. Microscopic examination reveals as follows; 1. Healing of the pulp at the amputation site did not occur in the pulps treated with formocresol. 2. At one week, a thin layer of darker staining tissues just below the necrotic zone was presented in the pulps treated with formocresol. In this stage the tissues beneath the darker staining layer were normal. 3. At two weeks, the cells of the palest staining layer were showed indistinct nucleus which suggested the karyolysis and the karyorrhexis in the pulps treated with formocoresol. As reached to the middle third of the pulp, the odontoblasts were scarcely evident or missed in this stage. 4. At three weeks, the necrotic zone was reached to the middle third of the pulp canal. The cells beneath the zone showed massive infiltration of inflammatory cells in the pulps treated with formocresol. 5. Dentin bridge in the control group was deposited below the necrotic zone from the two. weeks later. 6. Normal tissues were observed ill the apical third of all. the dental pulps in all case of calcium hydroxide and formocresol.

• 대한안전경영과학회지
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• 제16권2호
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• pp.237-246
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• 2014

Researches on the elimination of sulfur and nitrogen oxides with catalysts and absorbents reported many problems related with elimination efficiency and complex devices. In this study, decomposition efficiency of harmful gases was investigated. It was found that the efficiency rate can be increased by moving the harmful gases together with SPCP reactor and the catalysis reactor. Calcium hydroxide($Ca(OH)_2$), CaO, and $TiO_2$ were used as catalysts. Harmful air polluting gases such as $SO_2$ were measured for the analysis of decomposition efficiency, power consumption, and voltage according to changes to the process variables including frequency, concentration, electrode material, thickness of electrode, number of electrode winding, and additives to obtain optimal process conditions and the highest decomposition efficiency. The standard sample was sulfur oxide($SO_2$). Harmful gases were eliminated by moving them through the plasma generated in the SPCP reactor and the $Ca(OH)_2$ catalysis reactor. The elimination rate and products were analyzed with the gas analyzer (Ecom-AC,Germany), FT-IR(Nicolet, Magna-IR560), and GC-(Shimazu). The results of the experiment conducted to decompose and eliminate the harmful gas $SO_2$ with the $Ca(OH)_2$ catalysis reactor and SPCP reactor show 96% decomposition efficiency at the frequency of 10 kHz. The conductivity of the standard gas increased at the frequencies higher than 20 kHz. There was a partial flow of current along the surface. As a result, the decomposition efficiency decreased. The decomposition efficiency of harmful gas $SO_2$ by the $Ca(OH)_2$ catalysis reactor and SPCP reactor was 96.0% under 300 ppm concentration, 10 kHz frequency, and decomposition power of 20 W. It was 4% higher than the application of the SPCP reactor alone. The highest decomposition efficiency, 98.0% was achieved at the concentration of 100 ppm.

• The Korean Journal of Physiology
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• 제29권1호
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• pp.61-67
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• 1995

The extract of Ginkgo bibloba (EGb) is a complex mixture of natural products from the Ginkgo leaves and clinically used for the treatment of cerebral and peripheral circulatory disturbances due to its combined activity of several vasoactive principles. In this study we investigated the action of EGb and its mechanism in isolated rabbit corporal smooth muscle to evaluate the possibility of using this material as a pharmacoerecting agent. Strips of rabbit corpus cavernosum were mounted in organ chambers to measure isometric tension. EGb began to exert an relaxing effect at 1 mg/ml in the submaximally precontracted muscle strips with phenylephrine $(PHE,\;5{\times}10^{-6}\;M)$; causing concentration-dependent relaxation with maximal effect at $3{\sim}5\;mg/ml$. That relaxation was partially inhibited by removal of the smooth muscle endothelium or by pretreatment with a NO scavenger, pyrogallol $(10^{-4}\;M)$ or the guanylate cyclase inhibitor, methylene blue $(10^{-4}\;M)$. Pretreatment with EGb (3 mg/ml) inhibited PHE- $(5{\times}10^{-6}\;M)$ or KCI- (20 and 40 mM) induced contraction of muscle strip. In calcium-free high potassium solution EGb depressed the basal tone of the depolarized muscle strip and inhibited calcium-induced contraction when $CaCl_2$ $(10^{-4}\;M)$ was added. These results suggest that EGb relaxes rabbit corpus cavernosal smooth muscle through multiple action mechanisms that include increasing the release of nitric oxide from the corporal sinusoidal endothelium, sequestration of intracytosolic calcium, and maybe a hyperpolarizing action.

• 펄프종이기술
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• 제46권5호
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• pp.19-26
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• 2014

In-situ $CaCO_3$ formation on recycled wood pulp was studied to improve optical property and filler attachment to the fiber furnish in papermaking. We tried to attach calcium oxide (CaO) to the recycled fibers, old newspaper (ONP) in this case, by using selected polymers before in-situ $CaCO_3$ formation reaction on fibers, and then, $CO_2$ was injected to the furnish until all the CaO on fiber surfaces was consumed. It was found that the attachment of newly formed $CaCO_3$ to recycled fibers became stronger by attaching CaO to the fibers before in-situ $CaCO_3$ formation reaction. It was expected that the polymers used for the attachment of calcium source to the fiber furnishes helped to keep the newly formed $CaCO_3$ strongly attached to the fiber surface as well as to retain the impurities associated with calcium source and recycled fibers, if any. In-situ $CaCO_3$ formation gave higher brightness and much less ERIC value in ONP sheet than the case when the equivalent amount of GCC was added to the furnish.

• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2016년도 추계학술대회 논문집
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• pp.197-197
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• 2016

Commercially pure titanium (CP Ti) and Ti-6Al-4V alloys have been widely used for biomedical applications. However, the use of the Ti-6Al-4V alloy in biomaterial is then a subject of controversy because aluminum ions and vanadium oxide have potential detrimental influence on the human body due to vanadium and aluminum. Hence, recent works showed that the synthesis of new Ti-based alloys for implant application involves more biocompatible metallic alloying element, such as, Nb, Hf, Zr and Mo. In particular, Nb and Hf are one of the most effective Ti ${\beta}-stabilizer$ and reducing the elastic modulus. Plasma electrolyte oxidation (PEO) is known as excellent method in the biocompatibility of biomaterial due to quickly coating time and controlled coating condition. The anodized oxide layer and diameter modulation of Ti alloys can be obtained function of improvement of cell adhesion. Manganese(Mn) plays very important roles in essential for normal growth and metabolism of skeletal tissue in vertebrates and can be detected as minor constituents in teeth and bone. Radio frequency(RF) magnetron sputtering in the various PVD methods has high deposition rates, high-purity films, extremely high adhesion of films, and excellent uniform layers for depositing a wide range of materials, including metals, alloys and ceramics like a hydroxyapatite. The aim of this study is to research the Mn coatings on the micro-pore formed Ti-29Nb-xHf alloys by RF-magnetron sputtering for dental applications. Ti-29Nb-xHf (x= 0, 3, 7 and 15wt%, mass fraction) alloys were prepared Ti-29Nb-xHf alloys of containing Hf up from 0 wt% to 15 wt% were melted by using a vacuum furnace. Ti-29Nb-xHf alloys were homogenized for 2 hr at $1050^{\circ}C$. Each alloy was anodized in solution containing typically 0.15 M calcium acetate monohydrate + 0.02 M calcium glycerophosphate at room temperature. A direct current power source was used for the process of anodization. Anodized alloys was prepared using 270V~300V anodization voltage at room. Mn coatings was produced by RF-magnetron sputtering system. RF power of 100W was applied to the target for 1h at room temperature. The microstructure, phase and composition of Mn coated oxide surface of Ti-29Nb-xHf alloys were examined by FE-SEM, EDS, and XRD.

• 대한약리학회지
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• 제30권3호
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• pp.343-349
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• 1994

정신병치료제들을 장기투여하여 치료를 시도하였을 때에 생기는 여러 부작용은 그 정도 또한 매우 심각하기 때문에 그들의 치료효과와 함께 야기되는 부작용들을 따로 생각할 수가 없게 되었다. 특히 정신병치료는 그 자체에 대한 병인적 원인을 정확히 알 수 없기에 증상에 따른 대중요법이 일괄적으로 사용되므로, 이러한 현재의 치료방법으로는 부작용들이 더 치명적이 될 수 있기 때문에 일차적으로 이들의 공통적약리작용기전들을 연구하는 것은 매우 필요하다. 최근 NO(Nitric oxide)에 대한 많은 연구들에 의하면, 이들이 중추신경계에서 중요한 second messenger 또는 mediator로 신경활동에 영향을 나타내는 것으로 보고되고 있다. 그러므로 저자들은 먼저 이들 약물들과 NO와의 관계를 연구하고자, 중요한 몇종의 정신병치료제들을 택하여 NO생성에 어떤 영향을 미치는 가를 검색하여 다음과 같은 일차 결과를 얻었다 1. 정신병치료제 수종(chlorpromazine, trifluoperazine promazine, pimozide, clozapine, chlorprothixene, haloperidol)을 택하여 쥐의 소내에서 $[^3H]L-arginine$으로부터 $[^3H]L-citrulline$의 생성양을 측정하여 calmodulin antagonist(calmidazolium)와 비교하였다. 2. 이들을 N1E-115 cell에 투여하여 $[^3H]cyclic$ GMP양을 측정하고 그 결과를 calmida-zolium 과 비교하였다. 3. 이들 약물들은 citrulline과 cyclic GMP 모두의 생성양을 의의있게 억제하였으며 그 기전은 calmidazolium과 매우 유사하였다. 위의 일차적 검색결과에 의하면, 정신병치료약물들의 약리작용 기전중에 일부는 중추신경계내의 NO생성 및 cyclic GMP생성에 영향을 나타내는 것으로 사료되며, 이에는 calcium ion이 상당히 중요한 역할을 하는데, 특히 소뇌에서의 NO생성의 감소는 이들 약물들의 치명적 부작용인 tardive dyskinesia와 매우 깊은 관련을 추측할 수 있다. 그러나, 더 많은 약물들의 검색으로 일관적인 기본 결과가 필요 되고 또 각개 약물의 특정적 기전이 연구되기 위하여 현재 실험중이다.

• 해양환경안전학회지
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• 제25권1호
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• pp.67-73
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• 2019

연안지역의 오염된 저서환경을 개선 및 관리하기 위한 피복재의 성능 평가를 위하여 Mesocosm 실험을 수행하였다. 석탄회 조립물을 연안 오염 퇴적물에 피복하고 1, 3, 6개월 후의 pH, ORP(Oxidation Reduction Potential), 인산염 및 황화수소 농도 변화를 조사하였다. 석탄회 조립물에 함유되어 있는 산화칼슘은 가수분해 과정에 의해 산성화 된 퇴적물을 중화시키는 것으로 조사되었다. 또한 석탄회 조립물에서 용출되는 칼슘 및 실리카 이온은 퇴적물 간극수 중의 인산염을 침전시켜 퇴적물 내의 인산염 농도를 84.31 % 감소시키는 것으로 조사되었다. 황화수소 농도는 1개월 만에 133.5 mg/L가 감소하였으며, 이는 황화수소가 석탄회 조립물 중의 산화망간과의 화학적 반응을 통해 침전되고, 퇴적물의 투수성 향상으로 퇴적물 내부의 혐기성이 약해졌기 때문으로 판단된다. 이상의 Mesocosm 실험 결과를 통해 석탄회 조립물을 오염된 퇴적물 상부에 피복하는 기술은 저서환경 개선에 효과적인 것으로 판단된다.

• Restorative Dentistry and Endodontics
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• 제48권1호
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• pp.3.1-3.14
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• 2023

Objectives: This study evaluated the effect of different nanoparticulated zinc oxide (nano-ZnO) and conventional-ZnO ratios on the physicochemical properties of calcium aluminate cement (CAC). Materials and Methods: The conventional-ZnO and nano-ZnO were added to the cement powder in the following proportions: G1 (20% conventional-ZnO), G2 (15% conventional-ZnO + 5% nano-ZnO), G3 (12% conventional-ZnO + 3% nano-ZnO) and G4 (10% conventional-ZnO + 5% nano-ZnO). The radiopacity (R_ad), setting time (S_et), dimensional change (D_c), solubility (S_ol), compressive strength (C_st), and pH were evaluated. The nano-ZnO and CAC containing conventional-ZnO were also assessed using scanning electron microscopy, transmission electron microscopy, and energy-dispersive X-ray spectroscopy. Radiopacity data were analyzed by the 1-way analysis of variance (ANOVA) and Bonferroni tests (p < 0.05). The data of the other properties were analyzed by the ANOVA, Tukey, and Fisher tests (p < 0.05). Results: The nano-ZnO and CAC containing conventional-ZnO powders presented particles with few impurities and nanometric and micrometric sizes, respectively. G1 had the highest Rad mean value (p < 0.05). When compared to G1, groups containing nano-ZnO had a significant reduction in the S_et (p < 0.05) and lower values of D_c at 24 hours (p < 0.05). The C_st was higher for G4, with a significant difference for the other groups (p < 0.05). The S_ol did not present significant differences among groups (p > 0.05). Conclusions: The addition of nano-ZnO to CAC improved its dimensional change, setting time, and compressive strength, which may be promising for the clinical performance of this cement.

• 한국재료학회지
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• 제26권6호
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• pp.298-305
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• 2016

In this work, recent progress on graphene/metal oxide composites as advanced materials for $HgCl_2$ and $CO_2$ capture was investigated. Density Functional Theory calculations were used to understand the effects of temperature on the adsorption ability of $HgCl_2$ and water vapor on $CO_2$ adsorption on CaO (001) with reinforced carbon-based nanostructures using B3LYP functional. Understanding the mechanism by which mercury and $CO_2$ adsorb on graphene/CaO (g-CaO) is crucial to the design and fabrication of effective capture technologies. The results obtained from the optimized geometries and frequencies of the proposed cluster site structures predicted that with respect to molecular binding the system possesses unusually large $HgCl_2$ ($0.1-0.4HgCl_2g/g$ sorbent) and $CO_2$ ($0.2-0.6CO_2g/g$ sorbent) uptake capacities. The $HgCl_2$ and $CO_2$ were found to be stable on the surface as a result of the topology and a strong interaction with the g-CaO system; these results strongly suggest the potential of CaO-doped carbon materials for $HgCl_2$ and $CO_2$ capture applications, the functional gives reliable answers compared to available experimental data.