• Polymer(Korea)
• /
• v.35 no.2
• /
• pp.161-165
• /
• 2011

This study is related to the preparation of biocompatible gold nanoparticles (AuNPs) which are stable in aqueous solutions for a long time. Ultrasmall polyethyleneimine (PEI)-capped AuNPs (PEI-AuNPs) with limited agglomeration were prepared in aqueous solutions at room temperature, which were based on the roles of PEI as a reductant and a stabilizer. PEI-AuNPs with an average size of 8~12 nm formed highly stable nanocolloids with an average hydrodynamic cluster size of around 50 nm in aqueous media. At a low concentration of metal precursor hydrogen tetrachloroaurate (III), the particle size was reduced noticeably. The typical peaks of gold were observed in the X-ray diffraction pattern of AuNPs. The cell viability of 98% was obtained in the case of PEI-AuNPs, while PEI was cytotoxic. The PEI-AuNP is considered to be a potential candidate as a contrast agent for computed tomography.

• Journal of the Korean Society for Railway
• /
• v.18 no.3
• /
• pp.252-260
• /
• 2015

Ballasted track on an asphalt roadbed can be beneficial for its various effects such as (i) decreasing of roadbed thickness by dispersing train load; (ii) prevention of both strength reduction and weakening in roadbed system by preventing rainwater penetration; and (iii) reducing maintenance cost by preventing roadbed mud-pumping and frostbite. With these beneficial effects, ballasted track on asphalt roadbed has been widely used in Europe and Japan, and relevant research for applying such ballasted track on asphalt roadbed systems in Korea is ongoing. In this study, full-scale static and dynamic train load tests were performed to compare the performance of ballasted track on asphalt roadbed and ballasted track. The optimum thickness levels of asphalt and reinforced roadbeds, corresponding to the design criteria for reinforced roadbed of high-speed railway, was estimated using the FEM program ABAQUS. Test results show that the earth pressure on reinforced roadbed of ballasted track on the asphalt roadbed was relatively low compared with that of simple ballasted track. The elastic and plastic displacements of simple ballasted track on the asphalt roadbed were also lower than those of ballasted track. These test results may indicate that the use of ballasted track on asphalt roadbed is an advantageous system in view of long-term maintenance.

• Journal of Haehwa Medicine
• /
• v.10 no.1
• /
• pp.121-131
• /
• 2001

Clinical studies were carried out 62 cases of patients with lung cancer treated by Hangamdan(抗癌丹) from January 1th 1998 to September 30th 2000. The results were summarized as follows; 1. Distribution of those attached by lung cancer, by sex, showed that Male is more then Female, by age, showed that the number of sixties is majority. 2. Distribution of diagnostic stage, in descending order; stage IV(43.6%,top), stage III(35.5%), stage II(17.7%), stage I(3.2%). 3. The effects of maintenance and improvement in the symptoms with traditional oriental therapy(83.3%) and combined treatment of western and oriental therapy(84.0%) were observed. The effects of the symptoms were as follows; cough(50.0%), anorexia(48.4%), chest discomfort(31.0%), sputum(24.2%), general body weakness(11.3%), hemoptysis(9.7%) and etc. in orders. 4. Analysis of hematology attached by lung cancer, maintenance and increasing of WBC(98.4%), RBC(74.2%), Hgb(71.0%), Platelet(96.7%) were observed. After taken Hangamdan, the safety of the liver and kidney were as follows; maintenance and decreasing of AST(91.5%), ALT(93.2%), ${\gamma}-GTP$(95.0%), BUN(82.7%), Creatinine(93.3%) were observed. 5. Analysis of IL-12 and $IFN-{\gamma}$ attached by lung cancer, increasing of IL-12(31.3%), $IFN-{\gamma}$(72.7%) were observed. 6. Analysis of QOL attached by lung cancer, maintenance and improvement of combined treatment of western and oriental therapy(94.0%), traditional oriental therapy(91.7%) were observed. 7. Analysis of survival in patients with IV stage of lung cancer, above 7 months(22.2%), 12 months(70.4%). 8. Analysis of antitumor effects, maintenance of traditional oriental therapy(50.0%) and maintenance and improvement of combined treatment of western and oriental therapy(80.0%) were observed. 9. Analysis of curative valuation, maintenance and improvement of traditional oriental therapy(50.0%), combined treatment of western and oriental therapy(60.0%) were observed. From the above results, it is suggested that Hangamdan has significant effects of antitumor and immune activity, also could be usefully applied for lung cancer patients by combination with western therapy or alone.

• Journal of the Korean Chemical Society
• /
• v.25 no.6
• /
• pp.351-360
• /
• 1981

Ultraviolet spectrophotometric investigations have been carried out on the system of durene with iodine, bromine, iodine monochloride and iodine monobromide in carbon tetrachloride. The results reveal the formation of the charge transfer complexes of the type, $C_6H_2(CH_3)_4{\cdot}X_2$ or $C_6H_2(CH_3)_4{\cdot}IX$(X denotes halogen atoms). The equilibrium constant were obtained in consideration of that absorption maxima due to the formation of the charge transfer complexes shift to blue with the increasing temperatures. The thermodynamic parameters, ${\Delta}H,\;{\Delta}G\;and\;{\Delta}S$ for the formation of the charge transfer complexes were calculated from these values. These results indicate that the relative stabilities of the durene complexes at each temperature decrease in the order, $ICl>IBr>I_2>Br_2$. This order may be a measure of their relative acidities toward durene, which is explained in terms of the relative polarizabilities of halogen molecules and the relative electronegativities of halogen atoms. These results combined with previous study of this series indicated that the relative stabilities of the polymethylbenzene complexes with iodine increase in the order; Benzene

• The Korean Journal of Mycology
• /
• v.27 no.4 s.91
• /
• pp.274-279
• /
• 1999

The internal transcribed spacer regions(ITS) of the ribosomal DNA gene repeat from Coprinus and Psathyrella spp. were amplified using polymerase chain reaction (PCR) and sequenced. Sequences from 11 species including Coprinus comatus, C. atramentarius, C. micaceus, C. cinereus, C. rhizophorus, C. radians, C. echinosporus, C. disseminatus, Psathyrella candolleana, P. spadiceogrisea and Stropharia rugosoannulata were compared. The spacer region I and II were $258{\sim}301\;bp\;and\;253{\sim}275\;bp$ in length respectively and partially contained 17S, 5.8S and 25S. The reciprocal homologies of ITS sequences among these strains were in the range of $43.9{\sim}96.0%$. According to the analysis of ITS sequences, Coprinus and Psathyrella spp. were classified into three clusters. Cluster I consisted of Coprinus lagopus, C. cinereus, C. echinosporus, C. rhizophorus, and C. atramentarius. Cluster II comprised C. micaceus, C. radians, C. disseminatus, Psathyrella candolleana, and P. spadiceogrisea. On the other hand C. comatus is in Cluster III with Stropharia rugosoannulata even though this species is belonging to the section Coprinus in morphological aspect. These results suggest that taxonomic position of Psathyrella would better be inculded in genus Coprinus. Coprinus comatus, the type species of Coprinus, gives a doubt on monophyletic evolution and is assumed to be paraphyletic or polyphyletic.

• Korean Journal of Plant Resources
• /
• v.28 no.5
• /
• pp.616-634
• /
• 2015

This study was carried out to elucidate the distribution of vascular plants and their usefulness of Mt. Cheongnyangsan (870 m) in Gyeongsangbuk-do. The vascular plants that were collected 16 times 2006 and 2014 consisted a total of 614 taxa; 97 families, 330 genera, 541 species, 3 subspecies, 61 varieties and 9 forms. For the Korean endemic plants, 21 taxa were recorded and 8 taxa of Vulnerable Species (VU) and 5 taxa of Least Concerned species (LC) categorized by the Korean Forest Service as rare plants were investigated in this region. Furthermore, Ⅴ, Ⅳ, Ⅲ degrees of floristic regional indicator plants designated by the Korean Ministry of Environment included 2 taxa, 10 taxa and 18 taxa, respectively. Moreover, four species of distributional interesting plants, Aconitum austro-koreense Koidz., Allium spirale Willd., Dipsacus japonicus Miq. and Pinellia tripartita (Blume) Schott, in Mt. Cheongnyangsan were discovered by this study. Among them, edible, pasturing, medicinal, ornamental, timber, dye, fiber and unknown usefulness plants included 234 taxa, 213 taxa, 174 taxa, 62 taxa, 16 taxa, 12 taxa, 11 taxa and 167 taxa, respectively. In addition, 32 taxa of naturalized plants were observed.

• Journal of Pharmaceutical Investigation
• /
• v.19 no.2
• /
• pp.71-79
• /
• 1989

Complex formation of water-soluble polyparacyclophanes bearing two diphenylmethane or two diphenyl ether skeletons with l-anilinonaphthalene-8-sulfonate (ANS) and 2-p-toluidinylnaphthalene-6-sulfonate (TNS) was investigated quantitatively to develop useful host compounds comparing with ${\alpha}\;-\;and\;{\beta}-cyc1odextrins$$({\alpha}-\;and\;{\beta}-CyDs$) in aqueous solution. Benesi-Hildebrand type analysis of the fluorescent intensity showed that the dissociation constants (Kd) of paracyclophane-ANS complexes were $1.55\;{\times}\;10^{-4}M$ for 1,6,20,25-tetraaza[6.1.6.1]paracyclophane(CPM 44) and $1.23\;{\times}\;10^{-4}M$ for 1,7,21,27-tetraaza[7.1.7.1]paracyclophane (CPM 55), and those of paracyclophane-TNS complexes were $6.99\;{\times}\;10^{-6}M$ for CPM 44 and $6.23\;{\times}\;10^{-5}M$ for CPM 55, in 1:1 molar ratio. On the other hand, the Kd values of 1,7,21,27-tetraaza-14,34-dioxa[7.1.7.1]paracyclophane (CPE 55)-ANS, 1,8,22,29-tetraaza-15,36-dioxa[8.1.8.1]paracyclophane (CPE 66)-ANS, CPE 55-TNS, CPE 66-TNS complexes were $1.75\;{\times}\;10^{-3}M$, $3.07\;{\times}\;10^{-3}M$, $3.75\;{\times}\;10^{-3}M$ and $2.15\;{\times}\;10^{-3}M$, respectively. On the contrary, the Kd values of ${\alpha}-CyD-ANS$, ${\beta}-CyD-ANS$, ${\alpha}-CyD-TNS$ and ${\beta}-CyD-TNS$ complexes were found to be $3.98\;{\times}\;10^{-2}M$, $1.05\;{\times}\;10^{-2}M$, $1.38\;{\times}\;10^{-2}M$ and $3.52\;{\times}\;10^{-4}M$, respectively. These results mean that the complexation of CPMs with ANS or TNS is by 5.6-1,975 fold stronger than that for ${\alpha}-or\;{\beta}-CyDs$, and the complex formation of CPEs with ANS or TNS is nearly same as or somewhat stronger than that for ${\alpha}-or\;{\beta}-CyDs$. From the Kd values determined at different temperatures, thermodynamic parameters were calculated and the complexation was found to be a spontaneous exothermic reaction. The effects of pH on Kd values of CPM 44-ANS, and CPM 55-ANS complexes were negligible in the range of pH 1.2-1.8. However, the Kd values of these complexes increased significantly with increasing ionic strength.

• Environmental and Resource Economics Review
• /
• v.19 no.2
• /
• pp.361-382
• /
• 2010

In 2005, the Korean government decided to postpone the introduction of competition up to 2009 in the power plant service industry. Thus, the purpose of this study is to analyze the efficiency changes and the determinants of international competitiveness of Korean power plant service industry by the comparison between before and after 2006. The sample used in the estimation of efficiency is six firms III Korean power plant service sector for the period of 2003~2008. According to the results, technical efficiency before 2006 (2003~2005) is 0.865 and that after 2005 (2006~2008) is 0.947, which implies that efficiency has been improved after the delay of introduction of competition. In addition, according to the analyses based on the diamond model of Porter using survey data, demand condition has been ranked first in the determinants of international competitiveness. The second and the third important conditions are government and input factor ones. Firm's strategy/structure/competitiveness condition is the most weak condition. Therefore, it would be necessary for firms to improve this condition for competitiveness.

• Restorative Dentistry and Endodontics
• /
• v.15 no.1
• /
• pp.57-66
• /
• 1990

The author conducted a dental survey of college girl students and compared with that of college students 20 years and 10 years ago which based on the same criteria. The items of this survey included the prevalence of dental caries, DMFT and the kinds of restored materials. College girl students 2,294 were examined in May 1988, with the recommended criteria and method of W.H.O.. Among them, the data of 2,243 were analyzed and compared with the data of 1968 and 1978. The following results were obtained : 1. The average number of present teeth was $28.86{\pm}1.65$, which does not show much difference when compared to $29.00{\pm}1.94$ of 1968 and $28.97{\pm}1.64$ of 1978. 2. The prevalence of dental caries was 86.22%, which increased in comparison to 83.25% of 1968 and 84.92% of 1978. 3. DMF index was 19.98, which considerably increased in comparison to 14.56 of 1968 and 15.51 of 1978. 4. The number of DMFT was $5.75{\pm}5.04$ per student. Compared to $4.23{\pm}3.88$ of 1968 and $4.49{\pm}3.69$ of 1978, there is a considerable increase. I) The average number of decayed(D) teeth was $1.14{\pm}1.63$, which decreased from $1.16{\pm}1.57$ of 1968 and $2.09{\pm}2.16$ of 1978. II) The average number of missing(M) teeth was $0.23{\pm}0.73$, which also decreased from $0.69{\pm}1.11$ of 1968 and $0.32{\pm}0.79$ of 1978. III) The average number of filled(F) teeth was $4.39{\pm}4.91$, which increased from $2.38{\pm}3.33$ of 1968 and $2.09{\pm}3.17$ of 1978. 5. According to the analysis of filling material, filling baby including amalgam, gold inlay, resin, silicate cement and paladium inlay was 90.5%, which increased in comparison to 72.8% of 1968 and 83.6% of 1978. Among them, amalgam occupied 62.93%, which showed the most increase. On the other hand, crown and bridge was 6.5%, 3.0%, respectively, which showed continuous decrease from 12.1%, 15.1% of 1968 and 8.7%, 7.7% of 1978. Therefore, the prosthodontic treatment reduced due to the decrease of tooth extraction. In contrast, there is continuous increase of conservative treatment which maintaining natural tooth.

• Korean Journal of Food Science and Technology
• /
• v.36 no.5
• /
• pp.693-700
• /
• 2004

Viscometry was applied to identify irradiated corn starch (CS), sweet potato starch (SS), and potato starch (PS) from non-irradiated controls using Brookfield DV-III programmable rheometer. Effects of starch suspension concentration (7.0-9.5%) and spindle speed (25-125 rpm) were investigated. Established optimal viscosity-measuring conditions showed the highest correlation coefficient between irradiation dose (0-6.0 kGy) and corresponding viscosities for CS, SS, and PS. Threshold values for identifying irradiated starches were suggested. Viscosities of all samples significantly decreased with increasing irradiation dose (p<0.05) and spindle speed, while increased as suspension concentration increased. Optimal conditions for suspension concentration and spindle speed were 7.5% (6.7%, d.b.) and 125rpm in CS, 8.5% (7.3%, d.b.) and 125 rpm in SS, and 9.0% (7.3%, d.b.) and 100rpm in PS, respectively. Under these measuring conditions, threshold values for discriminating unknown samples were 0.313, 0.345, and 0.811 for CS, SS, and PS in 1.5 kGy-irradiated samples, compared with 0.521, 0.798, and 1.693 in non-irradiated samples, respectively, enabling identification of irradiated from non-irradiated starches.