• 한국동물번식학회:학술대회논문집
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• 한국동물번식학회 2003년도 학술발표대회 발표논문초록집
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• pp.77-77
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• 2003

Chimeric animals are referred to as an organism composed of tissues derived from more than one species. In order to examine if a pluripotency of embryonic stem cells can cross the limitation of a species, we tried to establish human-mouse chimeric animals. Human embryonic stem cells were genetically modified to express eGFP using eukaryonic expression vector pcDNA 3.1 (In Vitrogene) for an easy identification. After selection with neomycin, approximately 15 cells were implanted into mouse blastocoele cavity. Ten chimeric blastocysts were transferred to one of the uterine horn of 2.5 days pesudopregnent ICR female. Out of 272 blastocysts transferred to pseudopregnant recipients 20 live newborn were obtained after 20 days. When newborn were obtained, pups were quickly removed immersed into 4% PFA. By histological examination using fluorescent microscope, green fluorescence was observed from the liver, heart, and spleen in newborn mice. Three weeks after born, presence of eGFP sequence within mouse genome (tail and kidney) was reconfirmed by PCR. eGFP sequence was amplified from the progenies of the animal suggesting a genetic transmission of the transgene. These chimeric mice having human cells at the beginning of development, are expected to recognize human cells as “self”, therefore, human cells or tissues will be able to escape the immunological surveillance of the host if grafted into the animal. These animals will serve as a good model system for studying the graft rejection in tissue transplantation and the potential of the cells to work well in many human disease.

• 한국동물위생학회지
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• 제33권4호
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• pp.341-344
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• 2010

Poultry and poultry products have been implicated as a major source of Salmonella infection in human, and infection due to Salmonella serotypes continue to be a major health problem. The presence of two virulence genes, invA and spvC, in 34 Salmonella isolates obtained from duck farms was investigated. All isolates contained the invA gene, and spvC gene was found in 20 (58.8%) of 34 Salmonella isolates : S. Typhimurium (n=8), S. Fyris (n=5), S. Enteritidis (n=3), S. Typhimurium var. copenhagen (n=1), S. Haardt (n=1) and S. Mbandaka (n=1). This study showed the presence of the spvC gene was widely distributed in between different Salmonella enterica isolates.

• International Journal of Human Ecology
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• 제5권2호
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• pp.31-49
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• 2004

The purposes of the study were to examine the trend of undergraduate students' knowledges and attitudes toward elderly and aging traits, and to present the influence of undergraduate students' attitudes. The subjects were 494 undergraduate students. Statistics used such as frequency, Percentage, Mean, Standard Deviation, Cronbach's ${\alpha}$, t-test, Duncan test, ANOVA and Stepwise Multiple Regression Analysis. The results of this study were as follow: 1) Undergraduate students' knowledge level toward the elderly was low, and undergraduate students' attitudes level was middle. 2) There were meaningful differences in attitudes level according to sex, living together with elderly (the present time), living together with elderly (the past time), the presence of grandfather. It also had a significant correlation to the undergraduate students' knowledge. 3) The variables which affected the undergraduate students' attitudes were knowledge, sex, present co-residency with grandparents, past co-residency with grandparents, the presence grandfather, period of co-residency with grandparents that were explained about $24\%$. Among variables, knowledge of elderly was a very important variable on undergraduate students' attitudes.

• Journal of Oral Medicine and Pain
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• 제9권1호
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• pp.157-167
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• 1984

A human bite-mark shows special feature according to the suspect's dentition. The teeth which most frequently give useful bite-marks are six upper and lower anteriors, while the premolar teeth somtimes give marks it is often difficult to distinguish. The author tried to classify and to analize the anterior dentition which makes the bite-mark directly by means of 672 maxillary and 691 mandibular stone model taken from Korean adult aging from 17 to 40 years old. The results were as follows : 1. There was no particular correlation between the presence of six normal-shaped and correctly positioned upper and lower anteriors and the presence of rotation of teeth. 2. Inter central incisor, inter lateral incisor, inter canine width and angles of adjecent teeth were not identical eath other in studied models. 3. The results of this analysis supported the statement that any bite-mark had no same feature.

• International Journal of Knowledge Content Development & Technology
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• 제7권4호
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• pp.27-50
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• 2017

The impact of social networking is varied from good to bad. Online activities have also been categorized into pros and cons of social networking, either as reported as hiding Internet activities among teenagers or killing loneliness among elderly. In terms of relationships, there have been argument over its closeness and quality of an online relationship in Internet settings. Looking at the contradiction in an innovative interaction between classic community communication and social media, there is an unknown scent of the future struggling and challenging both human communication and relationships in the presence of digital culture. This research uses Diffusion of Innovation to study the wide and continuous spread of digital culture in human communication; and, Media Dependency in learning and structuring the cognitive, affective and behavioral effects of social media on each person uses the media in different ways. This research will be using online survey to gain opinions from a social network site as an update of views and reflection of self-awareness to all levels of people. Social media like Facebook (FB) is perceived as a good tool of communication that it is able to bring closeness among the family members. The results show that social media like FB brings positive impact towards family members; it would help to build a better and harmonic society; and, relationships among family members and communication shall be improved and enhanced to the level of a united society.

• 대한화학회지
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• 제51권4호
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• pp.352-355
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• 2007

Efficient stereoselective synthesis of α,β-Unsaturated acids, α-Cyanoacrylonitriles and α-Cyanoacrylates has been carried out in the presence of NaHSO4·SiO2 under solvent?free conditions with an E-geometry.

• 대한한의학회지
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• 제27권4호
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• pp.162-173
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• 2006

The water-extracts of Scutellaria barbata Don (SBDE) were isolated from Chinese medicinal plant sources. The extracts showed strong growth-inhibitory activity and cancer chemopreventive activity on the growth and DNA incorporation of MG63 human osteosarcoma and K562 human leukemia cell lines. The growth of human cancer cells was inhibited in the presence of the extracts (20, 50 and 100 ${\mu}$g/ml), and the effects were concentration-dependent and incubation time-dependent up to 8 days. When 50 ${\mu}$g/ml of the extracts was added to the media of MG63 and K562, cell growth after 8 days or 6 days of incubation was retarded by 93.2 to 97.3% of the control group. Morphological changes of MG63 and K562 cell lines were observed. As the concentration of the extracts increased up to 50 ${\mu}$g/ml, degree of cell aggregation decreased. Moreover, the DNA incorporation of the cells which were labeled with [3H] thymidine was significantly reduced after 3 days of incubation at $37^{\circ}C$ with the extract. Therefore, it is suggested that the extract is highly effective on inhibition of cancer cell growth. The extract also inhibited gene expression of IGF-II in transcriptional level. Since IGF-II works as a mitogenic effector on MG63 and K562 cell lines, these results suggest that the growth inhibition is in part mediated through the inhibition of IGF-II gene expression.

• Clinical and Experimental Reproductive Medicine
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• 제16권1호
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• pp.15-21
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• 1989

An in vitro fertilization assay employing zona-free hamster embryos was used to investigate human spermatozoal fertilitzing ability. Yanaghimarchi et al.(1976) first introduced this cross species fertilzation technique, with its application as a diagnostic tool for male infertility. Human spermatozoa were preincubated for 3 to 4 hrs in B W W medium at concentration of $4{\times}10^6$ sperm/ml prior to the addition to zona-free hamster embryos. After 3 hrs, human sperm was evaluated for fertilizing potential by the presence of swelling or decondencing sperm head in the cytoplasm. The results of penetration rates for sperm were as follow : 1. The average penetration rate of a 7 fertile donor group was $47.8{\pm}27.67%$(Range 14.3-98.0%) 2. The average penetration rate of 12 infertile patients with normal semen analysis was $21.7{\pm}26.9%$(Range 0-38.8%) 3. The average penetration rate of 10 infertile patients with semen abnormalities was $6.1{\pm}8.1%$(Range 0-25%)

• Archives of Pharmacal Research
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• 제29권9호
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• pp.721-727
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• 2006

To continue exploration of structure activity relationship of novel 1-(indoline-5-sulfonyl)-4-phenylimidazolidinones (1) reported as anticancer agent with broad spectrum, three 1-(arylsulfonyl)-4-vinylimidazolidinones (2) were synthesized from methyl serinate (3) in 8 steps. Reaction of intermediate 2-phenoxycarbonylaminobut-3-enyl p-toluenesulfonate (10) with arylsulfonamide in the presence of potassium carbonate produced corresponding 2 and N-(4-vinyloxazolidin-2-yl)arylsulfonamide 11 in approximately equal ratio. This reaction is believed to undergo through urea intermediate 16 as shown in scheme 3. 1-Arylsufonyl-4-vinylimidazolidinones 2 show much reduced activity against human colon carcinoma (Colo205), human chronic myelogenous leukemia (K562), and human ovarian adenocarcinoma (SK-OV-3) and compatible activity against human lung carcinoma (A549) compared to 1. Therefore phenyl at 4-position should be the optimum planar motif for the activity of 1.

• 대한치과교정학회지
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• 제42권5호
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• pp.249-254
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• 2012

Objective: To investigate the stem cell-like characteristics of human periodontal ligament (PDL) stromal cells outgrown from orthodontically extracted premolars and to evaluate the potential for myogenic differentiation. Methods: PDL stromal cells were obtained from extracted premolars by using the outgrowth method. Cell morphological features, self-replication capability, and the presence of cell-surface markers, along with osteogenic, adipogenic, and chondrogenic differentiation, were confirmed. In addition, myogenic differentiation was induced by the use of 5-aza-2'-deoxycytidine (5-Aza) for DNA demethylation. Results: PDL stromal cells showed growth patterns and morphological features similar to those of fibroblasts. In contrast, the proliferation rates of premolar PDL stromal cells were similar to those of bone marrow and adipogenic stem cells. PDL stromal cells expressed surface markers of human mesenchymal stem cells (i.e., CD90 and CD105), but not those of hematopoietic stem cells (i.e., CD31 and CD34). PDL stromal cells were differentiated into osteogenic, adipogenic, and chondrogenic lineages. Myotube structures were induced in PDL stromal cells after 5-Aza pretreatment, but not in the absence of 5-Aza pretreatment. Conclusions: PDL stromal cells isolated from extracted premolars can potentially be a good source of postnatal stem cells for oromaxillofacial regeneration in bone and muscle.