• Korea journal of population studies
• /
• v.33 no.3
• /
• pp.101-121
• /
• 2010

The purpose of this study is to examine the job characteristics of care workers in elderly care voucher service emphasizing a social service quality management approach. The study sample was composed of randomly-selected 233 centers which dispatched care staffs to clients' home. Descriptive analyses were performed for examining the unique aspects of relationship-based labor of care staffs, and logistic regression analyses were performed for investigating the association between service quality structure and human right violation against staffs. As the first empirical study focusing on staff-side service quality factors, this study found out that human right violation against staffs was mainly influenced by record-keeping and document management capacity of center, risk protection under insurance, compliance of standard contract procedure, and regular supervision. These results suggest particular policy attention should be given to basic protection for and set-up of core activity boundaries of care workers as well as clients-centered rights both for preventing human right violation and improving overall social service quality.

• Journal of the Society of Cosmetic Scientists of Korea
• /
• v.30 no.4 s.48
• /
• pp.491-497
• /
• 2004

Holographic quantitative structure activity relationships (HQSAR) between the melanogenesis inhibitory activities of alkyl-3,4-dihydroxybenzoate (A) and N-Alkyl-3,4-dihydroxybenzamide (B) derivatives were analyzed and discussed. The statistical results of HQSAR model for the activities showed the best predictability of the activities based on the cross-validated $r^2_{cv}\;(q^2=0.674),$ non-cross-validated, conventional coefficient $(r^2_{ncv}=0.936).$ The melanogenesis inhibitory activities and hydrolytic reactivity of (A) were slightly higher than that of (B) (A>B) and the activities depends upon the $R_1-substituents\;(R_1>R_2).$ It has been found using frontier molecular orbital (FMO) theory that the hydrolysis reactions of (A) and (B) proceeded to an orbital-controlled reactions, while the nucleophillc addition-elimination reactions $(Ad_{N-E})$ between LUMO energy of (A) and (B) and HOMO energy of water molecule are occurred.

• Journal of the Korean earth science society
• /
• v.34 no.1
• /
• pp.81-92
• /
• 2013

The purpose of this study was to investigate the communication structures that science gifted students used in small group activities, and to examine the relationship between communication styles and their achievement level. Eight small groups,5 members in each, participated in small group activities, in which they discussed how to calculate the average density of the earth. The communication structures and the achievement level presented in the group activities were analyzed using Pajek, Ucinet 6.0. As a result, we classified the communication styles of science gifted students into monopolistic type and co-ownership type according to the degree of dispersion of the interaction. We also classified it into $D_H{\cdot}N_H$ type, $D_H{\cdot}N_L$ type, $D_L{\cdot}N_H$ type, and $D_L{\cdot}N_L$ type based on the density and network centralization of interaction. The achievement levels of gifted students in their group work were affected by the density of interaction and the network centralization in small group activities, not by the dispersion of interaction among the members of the groups. Therefore, we recommend that teachers make the communication relevant to solving problem when they utilize a small group activity in science teaching.

• Analytical Science and Technology
• /
• v.6 no.1
• /
• pp.1-8
• /
• 1993

The purpose of this study is to investigate the elution behavior of monosubstituted phenols and benzenes in micellar liquid chromatographic system, $C_{18}$ column-anionic surfactant, sodium dodecyl sulfate(SDS). The partition coefficients between the micellar pseudophase-water and modified stationary phase-water are calculated by the relationship between solute retention and micellar mobile phase(SDS) composition. The free energy of transfer of solute from water to micelle is also calculated from these values. There is a direct correlation between the hydrophobicity parameters in MLC and corresponding partition data for 1-octanol-water, which indicates that the hydrophobicity of molecules plays an important role in the partition for both systems and that quantitative structure activity relationships(QSAR) are available from studies on micellar partition. The other purpose of this study is to investigate methylene selectivity of alkyl homologous series through correlation between retention and the number of carbons. The correlation between hydrophobicity parameters in MLC and 1-octanol-water partition data was also observed when n-propanol was as a modifier in the mobile phase.

• Journal of Marine Bioscience and Biotechnology
• /
• v.2 no.2
• /
• pp.102-107
• /
• 2007

Environmental contamination becomes a great public concern as our society gets industrialized rapidly. The present study examine the role of chitosan in a effort to intervene the environmental pollutant-induced toxicity. PCB-induced neurotoxicity with respect to the PKC signaling was examined. Since the developing neuron is particularly sensitive to PCB-induced neurotoxicity, we isolated cerebellar granule cells derived from 7-day old SD rats and grew cells in culture for additional 7 days to mimic PND-14 conditions. PCB showed the alteration of PKC signaling pathway. The alteration was structure-dependent. Mono-ortho-substituted congeners at a high dose showed a significant increase of total PKC activity at [$^3H$]PDBu binding assay, indicating that mono-ortho-substituted congeners are more neuroactive than non-ortho-substituted congeners in neuronal cells. PKC isoforms were immunoblotted with respective monoclonal antibodies. PKC-beta II and -epsilon were activated with mono-ortho-substituted congeners exposure. The result suggests that the position with ortho has a higher potential of altering the signaling pathway. Alteration of PKC was blocked with treatment of high molecular weight of chitosan. The study demonstrated that the ortho position in PCBs are important in assessing the structure-activity relationship. The results suggest a potential use of marine bioactive materials as a means of nutritional intervention to prevent the harmful effects of pollutant-derived toxicity.

• Applied Biological Chemistry
• /
• v.42 no.1
• /
• pp.68-72
• /
• 1999

The cytotoxicity of 1,3-diphenylpropenone derivatives known to inhibit the farnesyl protein transferase (FPTase) was examined against various established tumor cell line, A549 (lung cancer), SKMEL-2 (uterine cancer), HCT-15 (skin cancer), SKOV-3 (brain cancer) and XF-498 (colon cancer) of the 1,3-diphenylpropenone derivatives showing farnesyl protein transferase (FPTase) inhibition activity. And the structure-activity relationship (SAR) between structure of 1,3-diphenylpropenone derivatives as substrate and cytotoxicity was investigated by Free-Wilson analysis as well as Hansch method with tumor cell lines. From the result of Free-Wilson analyses, X-substituents on the benzoyl group have a more important role than Y-substituents on the styryl group. The 2,4-dichloro substituent, 15 and 2,4-dimethyl substituent, 16 showed the highest cytotoxicity (average pI_(50)=5.0). Particulary, the cytotoxicity of X-substituents increased with electronic effect $({\sigma})$ due to weak electron withdrawing group with optimum value $({\sigma}_{opt}=0.22{\sim}0.29})$ whereas that of Y-substituent resulted from various factors such as logP, $B_1$ and R constant.

• Korean Journal of Food Science and Technology
• /
• v.52 no.6
• /
• pp.595-603
• /
• 2020

To elucidate the structure-function relationship of polysaccharides obtained from Colocasia esculenta, the immuno-stimulating polysaccharide, CE-4a was purified to homogeneity from the crude polysaccharide (CE) extracted from the corms of C. esculenta by two subsequent column chromatographies using DEAE-Sepharose FF and Sephadex G-100, and analysis of their immuno-stimulatory activities and structure were conducted. CE-4a showed an increase in anti-complementary activity in a dose-dependent fashion. The molecular mass was estimated to be 182.4 kDa, which mainly consisted of galactose (43.5%) and mannose (18.2%). Methylation analysis indicated that CE-4a comprised at least 10 different glycosyl linkages, such as terminal Galp, 3-linked Galp, and 4-linked Manp, as well as a characteristic linkage, 2,4,6-branched Manp residue. To analyze the fine structure of CE-4a, it was sequentially digested using endo-α-(1→4)-polygalacturonase, exo-α-galactosidase and endo-β-1,4-D-mannanase. These analyses suggested that CE-4a is to be a highly branched galactomannan with a (1→4)-mannan backbone and galactopyranosyl oligosaccharide side chains.

• Korea Trade Review
• /
• v.48 no.2
• /
• pp.175-195
• /
• 2023

This study is for analyzing the relation between Korean Water transport and the other main countries Water transport. In the Free trade system, Maritime transport has a high impact on the global economy as well as the each countries. The division of labor through the global value chain(GVCs) has became the ordinary activity in business, and in Maritime shipping,, there are the International trade among countries. Therefore, This study analyze relation of Korean water transport and other 13 regions using World Input-Output Table(WIOT) by Asia Development Bank(ADB). The result of analysis, the proportion of intermediate goods in the input structure of Korean water transport is about 70%, and the ratio of using domestic products is higher than the major European countries. However, since 2000, intermediate inputs from foreign countries have steadily increased, and added value has decreased. Countries with a high relation with Korean Water transport industry are United States(USA) on the input structure, Singapore(SIN) and Japan(JPN) on the distribution structure. Analyzing the relation through the production inducement coefficient, Singapore(SIN) has the high relationship with Korean Water transport industry.

• The Korean Journal of Pesticide Science
• /
• v.5 no.3
• /
• pp.26-35
• /
• 2001

In order to search potent antifungal substances from domestic plants, 40 plants cultivated in Korea were collected. After extracting with methanol (MeOH) and concentrating to dryness, the MeOH extracts were screened for in vivo antifungal activity against six plant diseases at a concentration of $2000{\mu}g/mL$. Fourteen extracts showed disease-controlling activity more than 90% against at least one of the 6 plant diseases tested; eight, seven, and three extracts controlled more than 90% the development of rice blast, tomato late blight, and wheat leaf rust, respectively. However, none of the extracts exhibited in vivo antifungal activity more than 90% against rice sheath blight, tomato gray mold, and barley powdery mildew. From the MeOH extracts of Angelica gigas and A. dahurica showing potent controlling activity against rice blast, 1 and 2 antifungal substances, respectively, were isolated by solvent partitioning and column chromatography. The three compounds were identified to be coumarins, namely, decursin, imperatorin, and isoimperatorin, by mass spectrometry and NMR spectroscopy. They were examined for in vitro and in vivo antifungal activities together with umbelliferone (7-bydroxycournarin) and scopoletin (6-methoxy-7-hydroxycoumarin) containing a free hydroxyl group at position 7 to investigate the structure-activity relationship. In vitro, most of 50% growth inhibitory concentrations ($IC_{50}$) were over $200{\mu}g/mL$, indicating that they have relatively weak antifungal activity. The antifungal activity of decursin and scopoletin, containing cyclic alkoxy groups instead of free hydroxyl group at position 7, was stronger than umbelliferone and scopoletin. Especially, decursin and imperatorin showed potent antifungal activities against Pythium ultimum and Magnaporthe grisea, respectively, with $IC_{50}$ values less than $25{\mu}g/mL$. In vivo, decursin and imperatorin showed potent antifungal activity against rice blast, whereas other coumarins hardly controlled the development of 6 plant diseases tested. These results suggest that the antifungal activity of 7-hydroxycoumarin derivative is substantially increased when the hydroxyl group at position 7 is protected by a stable cyclic alkoxy grouping.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.17 no.10
• /
• pp.449-457
• /
• 2016

Adolescence is a period of transition from child to adult and is a very important period in which to think about the direction to go in the future and establish one's ego. However, the level of life satisfaction experienced by Korean youths in the adolescent period has been shown to be the lowest among OECD countries. It is very critical to understand which factors are important in determining the level of life satisfaction and how they affect it. In this study, to analyze the factors which affect the life satisfaction of youths and their learning attitude - essential school activity prior to life satisfaction in the youth period, we firstly focused on the relationships with their parents, peers and teachers as potential factors affecting their learning attitude and life satisfaction. This study found that Parenting Style, Peer Attachment and Relationship with Teachers significantly influenced Life Satisfaction either directly or indirectly. We analyzed the structural relationships among these factors using the structure equation model, discussed the analysis results and concluded with further research directions.