• Bulletin of the Korean Chemical Society
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• v.19 no.11
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• pp.1161-1164
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• 1998

The catalytic transformation of sterically bulky tertiary stannane n-Bu3SnH by the Cp2MCl2/Red-Al (M=Ti, Zr, Hf) and M(CO)6 (M=Cr, Mo, W) catalysts yielded two kinds of catenated products: one is a cross-linked polystannane as minor product, and the other is hexabutyldistannane (n-Bu3Sn)2 as major product. The distannane was produced by simple dehydrocoupling of n-Bu3SnH, whereas the cross-linked polystannane could be obtained via redistribution/dehydrocoupling combination process of n-Bu3SnH. The redistribution/dehydrocoupling combination process may initially produce a low-molecular-weight oligostannane with partial backbone Sn-H bonds which could then undergo an extensive cross-linking reaction of backbone Sn-H bonds, resulting in the formation of an insoluble polystannane.

• Bulletin of the Korean Chemical Society
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• v.6 no.5
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• pp.272-276
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• 1985

Various new kinds of biheterocyclic betaines were prepared by the reaction of 3-substituted-6,7-dihydro-5H-thiazolo[3,2-a]pyrimidine with electrophiles such as isothioyanates, isocyanates in aprotic solvents, respectively. The biheterocyclic betaines containing methyl group at 3-position of thiazole ring were obtained particularly in good yields at room temperature. These betaines were also reacted with alkyl halide to give quarternary ammonium salts. It was found that these betaines are dissociated in polar organic solvents depending on temperature. And new biheterocyclic compounds via ring transformation were prepared by the reaction of 8-phenyl (thiocarbamoyl)-3-phenyl-6,7-dihydro-5H-thiazolo[3 ,2-a]pyrimidinium-betaine with ${\alpha}$-halo kester ${\alpha}-halo$ ester and ${\gamma}-halo$ keto ester.

• International journal of advanced smart convergence
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• v.13 no.1
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• pp.122-128
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• 2024

This study delves into the unique transformation of South Korea's elderly population, distinctively termed 'Nomad Silver'. Characterized by individuals aged 65 and above who actively seek novel experiences and embrace new activities, this demographic shift signifies a departure from traditional perceptions of the elderly. The Nomad Silver cohort, distinguished by their significant economic influence and evolving needs, necessitates a tailored approach to healthcare services. This paper underscores the importance of comprehending both the fundamental biological needs and the personalized desires of the Nomad Silver, aiming to enhance their satisfaction and overall well-being. Hospitals, in response, should innovate their services to resonate with the emotional, psychological, and social facets of this age group. Consequently, the paper proposes a four-pronged strategy for hospitals to adapt: comprehensive healthcare provision, patient-centric service development, senior health education coupled with community engagement, and establishing a generational bridge hub. Furthermore, the paper posits that catering to the Nomad Silver not only promises substantial financial gains for hospitals but also fosters new business opportunities across various sectors.

• Asian-Australasian Journal of Animal Sciences
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• v.12 no.1
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• pp.22-27
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• 1999

Bovine oocytes with compact and complete cumulus cells were cultured in 6 groups for up to 24h in TCM199 buffered with 25 mmol/1 HEPES and supplemented with 10% FCS, 1 mg/ml $17{\beta}$-estradiol, 20 IU/ml hCG. Half of the oocytes at each group cultured in the presence of $25{\mu}g/ml$ cycloheximide at different times during maturation (0, 6, 12, 18, 20, 22 h) were fixed at 24 h of maturation to examine the nuclear progression. The rests of them were inseminated with frozen-thawed spermatozoa in medium BO with 10 mg/ml BSA and 10 mg/ml heparin and fixed after additional 18-20 h culture to evaluate the sperm head transformation. When a protein synthesis inhibitor was added at the onset of the maturation, the oocytes were prevented to proceed GVBD. A few of the oocytes (16%) were able to be penetrated and sperm head decondensation was inhibited either. Addition of cycloheximide after 6-12 h of culture resulted in an increasing percentage of GVBCD (more than 80%), but the oocytes became arrested in M-I (69.2%). More than half of the oocytes was penetrated with a decondensing sperm head. Formation of male pronucleus was first obtained at 12 h of culture in the presence of cycloheximide. When cycloheximide was added from 18 h of culture onwards, nuclear progression to M-II was increasingly restored (80.4-85.5%). The proportion of male and female pronuclear formation increased from 17.9% to 46.2%. It is concluded that protein synthesis is necessary not only for GVBD and development from M-I to M-II, but also for sperm head decendensation and male pronuclear formation in bovine oocytes.

• Physical Therapy Korea
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• v.24 no.4
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• pp.38-45
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• 2017

Background: To improve muscle flexibility, static stretch is the most common type and is considered safe and effective for improving overall flexibility of muscles. During the stretch, the intensity is more likely to be determined by the degree of an athlete's pain and practitioner's skills rather than quantitative measures of stretch. It is necessary to determine the optimal intensity for the stretch. Objects: The purpose of this study is to explore the relationship between hand held dynamometer (HHD) and verbal rating scale (VRS) in comparison of the effects of continuance time on active (walking) and inactive (sitting) movement after static stretch. Methods: A cross-sectional study was conducted with a sample (n=62) recruited from a university. Participants were randomly assigned to 2 different groups (n=31 for each group) based on participants' positions either remaining in sitting or freely walking around for a series of re-assessments. Data was collected at pre-warm up, pre-stretch, post-stretch, and additional assessments at the time of 3, 6, 9, 12, 15, 20 and 30 minutes after the stretch. Results: Relationship between VRS and HHD scores represents very weak correlation (Spearman's p=-.16, p>.05). Pearson's correlation analysis was conducted following the logarithmic transformation of the two scores. Pearson's correlation after the transformation still showed a very low relationship and a poor linear relationship between the two scores (Pearson's r=-.18, p>.05). Conclusion: The optimal intensity for stretch cannot be solely determined by the subjective pain perception. The objective measurement such as HHD could be used in conjunction with the pain perception.

• Proceedings of KOSOMES biannual meeting
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• 2007.11a
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• pp.57-60
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• 2007

The Han River is divided into North and South Korea by NLL(Northern Limit Line) and its area has been blocked by CCL(Civil Control Line) since the Korean War in 1950. Satellite remote sensing, therefore, is uniquely suited to monitoring bar transformation in the region. In river with bar, the characteristics of its physical conditions have a close relationship with bar morphology. In this paper, a monitoring approach of bar transformation in the Han River Estuary is presented using RADARSAT/SAR images from 2000 to 2005 and spatial patterns of bar morphology are presented. It could be said that in the estuary vegetated area and natural levees are developed well, but bars are shifted after an event like a flood. It is also showed that suspended solids such as silt transported through the estuary could contribute highly to a sedimentation environment around Incheon.

• Journal of the Korean Society of Costume
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• v.59 no.4
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• pp.126-142
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• 2009

Arte Povera, which was started centering around of Italy in 1960, made a great sensation using by base materials in the works that were totally different from other artists' work. Beginning of Arte Povera was just starting of Base Materialism and it was a reconsideration about the life's authenticity in material civilization. Arte Povera carried worthless materials, which were overlook or ignored in the life, into the gallery. In this study, records and Arte Povera Group's works was studied. The outcome of Arte Povera's materialism was used to an analysis of fashion designers' works. It shows how to explain Arte povera's materialism in fashion designers' works in 1960s and since 1990. Materialism in fashion is expanding from constructed materials of the clothing to the body. The expression method is getting various and complex. As if 1960s' art was, modern fashion is getting one of the testing places for the Ideology. It is getting out of the boundary of the utility as fashion art by using materials. So a function of the clothing is expending including wareing. The same expression methods of the materialism between fashion and art are as follow: First, revealing silhouette or materialism of the body or material as formless material. Second, an expression method as Base Materialism from a raw material. Third, the mobility and the transformation, which are a changeable characteristic according to a place, a space and an audience.

• Journal of Life Science
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• v.20 no.1
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• pp.97-102
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• 2010

Streptomyces platensis YK-2, newly isolated from forest soil, produces transglutaminase (TGase), which catalyses an acyl transfer reaction between the primary grade amine and protein or $\gamma$-carboxyamide group of peptide bound glutamine residues. For a molecular genetic study of S. platensis, an effective transformation method was established by using a conjugal transfer of DNA from Escherichia coli to spores of actinomycetes. The highest transconjugation frequency of S. platensis was obtained on an MS medium containing 50 mM $MgCl_2$, using $5{\times}10^7\;E$. coli as a DNA donor and $1{\times}10^8$ spores without heat treatment as a host. We also identified that S. platensis contains a single attB site within an ORF encoding a pirin-homolog, and that its attB site sequence shows high homology to that of S. logisporoflavus. In addition, it was confirmed by phenotypic analyses of exconjugants that the introduction of heterologous DNA into the attB site of the S. platensis chromosome does not affect its morphological differentiation and TGase production.

• Korean Management Science Review
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• v.31 no.1
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• pp.1-15
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• 2014

As the scarcity of natural resources has become apparent, the recycling industry has emerged as a promising one for its growth potential. Yet, the recycling industry still remains undeveloped and inefficient for various reasons. In this study, we focus on firms' recycling processes to understand the current status of recycling firms' value creation activities. With respect to the adopted recycling processes, we empirically investigate the differences in firm characteristics and firm performance. We use the data from Keco (Korea Environment Cooperation) which annually conducts a survey of recycling firms in Korea. We exclusively consider the whole group of plastic recycling industry in order to control for a possible bias in firm performance, stemming from the heterogeneity in processing and recycling of materials other than plastics. We review the descriptive statistics from the sample firms and conduct a series of hierarchical regression analyses. The results show that most of the firms in this industry adopt physical transformation processes with a low-level technology. These firms with physical transformation processes are smaller in size and produce entry level items which do not secure higher margins. The results indicate that the recycling industry largely comprises low value added firms which lack economies of scale and resources for R&D. For the stable growth of the industry, recycling firms must create sustainable values through implementation of technology-driven processes and improvement in product quality. In addition, the government should help build a reliable reverse logistic network, lower the entry barriers, and provide necessary funding for the SMEs in the recycling industry.

• The Bulletin of The Korean Astronomical Society
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• v.41 no.1
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• pp.33.1-33.1
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• 2016

Dwarf elliptical galaxies (dEs), the most abundant galaxy type in clusters, were recently shown to exhibit a wide variety in their properties. Particularly, the presence of blue cores in some dEs, what we call dE(bc), supports the scenario of late-type galaxy infall and subsequent transformation into red, quiescent dEs. While several transformation mechanisms for these dE(bc)s within cluster environment have been proposed, all these processes are able to explain only some of the observational properties of dEs. In this context, internal kinematic properties of dE(bc)s provide the most crucial evidence to discriminate different processes for the formation of these galaxies. We present Gemini Multi Object Spectrograph (GMOS) long-slit spectroscopy of two dE(bc)s in the Virgo cluster. We obtained radial profiles of velocity and velocity dispersion out to ~1.3 effective radius. We found that two dE(bc)s exhibit kinematically decoupled components as well as distinct peculiar features in velocity profiles, supporting the scenario of mergers. We also found that these galaxies are structurally compatible with low surface brightness component of blue compact dwarf galaxies. We suggest that a part of dE(bc)s in the Virgo Cluster were formed through galaxy merger in low density environment such as galaxy group or outskirt of the cluster, and then were quenched by subsequent effects within cluster environment.