• Title/Summary/Keyword: K-12

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Characteristics of antimicrobial activity of Streptococcus salivarius K12 by culture condition (Streptococcus salivarius K12의 배양조건에 따른 항균활성의 특징)

  • Song, Young-Gyun;Lee, Sung-Hoon
    • Journal of Dental Rehabilitation and Applied Science
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    • v.37 no.4
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    • pp.244-250
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    • 2021
  • Purpose: The purpose of this study was to examine effects of culture conditions on the growth and antibacterial activity of Streptococcus salivarius K12. Materials and Methods: S. salivarius K12 was cultivated in medium containing animal and plant protein or in medium of neutral and acidic conditions. The growth of S. salivarius K12 was measured every 2 hours by a spectrophotometer. The antimicrobial activity of S. salivarius K12 against Streptococcus mutans and Porphyromonas gingivalis was investigated by the susceptibility assay using the spent culture medium. Results: the growth of S. salivarius K12 showed faster in medium containing plant protein and neutral pH condition. The antimicrobial and antifungal activity of S. salivarius K12 appeared stronger in medium containing plant protein than animal proteins. Conclusion: For application of S. salivarius K12 to bacterial oral disease, co-substances may be needed for S. salivarius K12 to colonize in the oral cavity and enhance the antimicrobial activity.

Absolute Configuration of Di-(2-Picolyl) sulfur Dichloro Zinc(II) with an Enantiomorphic Space Group $P4_12_12$ (Enantiomorphic 공간군 $P4_12_12$을 갖는 Di-(2-Picolyl) sulfur Dichloro Zinc(II)의 Absolute Configuration)

  • Choi Ki-Young;Lee Han-Hyoung;Kim Min-Hee;Whang Min-Ah;Kang Sang Ook;Son Ho-Jin;Son Ki-Chul;Han Won-Sik;Suh Il-Hwan
    • Korean Journal of Crystallography
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    • v.16 no.1
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    • pp.21-29
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    • 2005
  • The crystal structure of an enantiomeric compound di-(2-picolyl)sulfur dichloro zinc(II), $C_{12}H_{12}N_2SCl_2Zn$, could be elucidated with two space groups $P4_12_12\;and\;P4_32_12$. However, its absolute configuration with the space group $P4_12_12$ was confirmed by means of the effect of anomalous dispersion.

Preparation of EPDM/Polyamide12 Elastomers through Electron Beam Irradiation (전자선 조사를 통한 EPDM/Polyamide12 탄성체의 제조에 관한 연구)

  • Jung, Hyo Shin;Park, Jung Il;Kang, Phil-Hyun;Choi, Myung Chan;Chang, Young-Wook;Hong, Sung Chul
    • Polymer(Korea)
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    • v.37 no.5
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    • pp.571-578
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    • 2013
  • Polyamide12 (PA12) is blended with ethylene propylene diene rubber (EPDM) at various compositions in the presence of maleated EPDM (mEPDM) to afford blend materials having the characteristics of thermoplastic elastomer (TPE). The EPDM/PA12 melt-blends are further irradiated with electron-beam (e-beam) at 0~100 kGy dosage, yielding selective crosslinking between EPDM chains while retaining melt-processibility originated from PA12 phase. mEPDM acts as a compatibilizer and affords additional improvements in mechanical properties of the EPDM/PA12 blend. With 25 kGy of e-beam irradiation and mEPDM, the EPDM/PA12 blends successfully exhibit TPE behaviors with reasonable elastomeric and mechanical properties.

Tudor Domain Containing Protein TDRD12 Expresses at the Acrosome of Spermatids in Mouse Testis

  • Kim, Min;Ki, Byeong Seong;Hong, Kwonho;Park, Se-pill;Ko, Jung-Jae;Choi, Youngsok
    • Asian-Australasian Journal of Animal Sciences
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    • v.29 no.7
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    • pp.944-951
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    • 2016
  • Tdrd12 is one of tudor domain containing (Tdrd) family members. However, the expression pattern of Tdrd12 has not been well studied. To compare the expression levels of Tdrd12 in various tissues, real time-polymerase chain reaction was performed using total RNAs from liver, small intestine, heart, brain, kidney, lung, spleen, stomach, uterus, ovary, and testis. Tdrd12 mRNA was highly expressed in testis. Antibody against mouse TDRD12 were generated using amino acid residues SQRPNEKPLRLTEKKDC of TDRD12 to investigate TDRD12 localization in testis. Immunostaining assay shows that TDRD12 is mainly localized at the spermatid in the seminiferous tubules of adult testes. During postnatal development, TDRD12 is differentially expressed. TDRD12 was detected in early spermatocytes at 2 weeks and TDRD12 was localized at acrosome of the round spermatids. TDRD12 expression was not co-localized with TDRD1 which is an important component of piRNA pathway in germ cells. Our results indicate that TDRD12 may play an important role in spermatids and function as a regulator of spermatogenesis in dependent of TDRD1.

CONSTRUCTION EDUCATIONAL GAME FOR K-12

  • Youjin Jang;Moonseo Park;Hyun-Soo Lee;Chanhyuk Park
    • International conference on construction engineering and project management
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    • 2013.01a
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    • pp.546-552
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    • 2013
  • The future competitiveness of construction industry is dependent on K-12 students. However, unfavorable images of construction industry have negative influence on K-12 students' decision-making of their career. This negative image makes them not want to find out what actually happens in construction industry. Consequently, it is important to give K-12 students the opportunity to know what construction employees actually do in their job. Studies show that K-12 students who encounter the job early-on are more likely to choose it as their career. In this context, this paper proposes construction educational game in which it can serve as a medium for capturing K-12 students' interest in Construction Management (CM). Based on the literature reviews, challenges of construction educational game for K-12 students which are edutainment, hands-on experience and social interaction, are derived. To address these issues, conceptual model and scenario are designed. Based on designed scenario, prototype of Simulation based Construction Game in Virtual World (SCGVW) is developed in Second Life (SL) and applicability test to K-12 students are implemented. This paper concludes with a discussion of the lessons learned and the future development steps of the construction educational game for K-12 students.

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Genomic characteristics of natural recombinant infectious bronchitis viruses isolated in Korea

  • Moon, Hyun-Woo;Sung, Haan Woo;Kwon, Hyuk Moo
    • Korean Journal of Veterinary Research
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    • v.59 no.3
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    • pp.123-132
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    • 2019
  • Two infectious bronchitis virus (IBV) K046-12 and K047-12 strains were isolated and the nearly complete genomes of them were sequenced. Sequence comparisons showed that the K046-12 genome was most similar to Korean IBV strains, and the K047-12 genome was most similar to QX-like IBV strains. Phylogenetic analysis showed that nearly all K046-12 and most K046-12 genes were placed in the same cluster as Korean IBV isolates, but the S1 region was placed in the same cluster as Mass-type IBVs. For K047-12, nearly all K047-12 and most K047-12 genes were located in the same cluster as QX-like IBVs, but the M region was located in the same cluster as Korean IBV isolates with K047-12. Recombination analysis confirmed that K046-12 is a recombinant strain with the primary parental sequence derived from Korean IBVs and minor parental sequence derived from Mass-type IBV, and K047-12 is a recombinant strain with the major parental sequence derived from QX-IBV and minor parental sequence derived from Korean IBVs. This study showed that new IBV recombinants are constantly generated among various IBVs, including those used for vaccination. Therefore, genetic analysis of new virus isolates should be performed for effective infectious bronchitis control and appropriate vaccine development.

Effects of K-MBSR Program according to the Length of the Training Period on Emotional Response of College Students (수행기간에 따라 K-MBSR 프로그램이 대학생의 정서반응성에 미치는 영향)

  • Bae, Jae-Hong
    • The Journal of the Korea Contents Association
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    • v.10 no.11
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    • pp.198-208
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    • 2010
  • The purpose of this study was examined the effects of the K-MBSR program according to the length of the training period. Three versions of the K-MBSR program were compared: a 4-week program composed of formal meditation an 8-week program with official meditation and a 12-week program that combined the 4-week and 8-week programs. The 4-week K-MBSR program did not result in a significant decrease in depression, anxiety, or negative emotion. The 8-week and 12-week K-MBSR programs decreased the score of depression significantly, and the effect continued until 8 months. The effect of the 12-week K-MBSR program was greaterthan the effect of the 8-week program, but not significantly. The result of this study indicates that the effect of the 4-week K-MBSR program appears insignificant. The effects of the 8-week and 12-week programs are almost the same, but the effect of 12-week K-MBSR program showed a slightly greater effect in the post-test and 8-month test. The findings were discussed the effect of k-MBSR Program and recommendations for further research.

Enzymatic Formation of 13,26-Dihexyl-1,14-dioxacyclohexacosane-2,15-dione via Oligomerization of 12-Hydroxystearic Acid

  • Lee, Chan-Woo;Kimura, Yoshiharu;Chung, Jin-Do
    • Macromolecular Research
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    • v.17 no.11
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    • pp.919-925
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    • 2009
  • The enzymatic polymerization of 12-hydroxystearic acid (12-HSA) was carried out with Lipase $CA^{(R)}$ in benzene to produce poly(12-hydroxystearate) (PHS) with a low molecular weight. When this polymerization was continued for a long reaction time, the PHS once formed was depolymerized into a cyclic diester, 13,16-dihexyl-1,14-dioxacyclohexacosane-2,15-dione (12-HSAD). Similar polymerization and depolymerization were observed when 12-hydroxyoleic acid (12-HOA) was treated with Lipase $CA^{(R)}$, whereas only polymerization occurred when 12-hydroxydodecanoic acid (12-HDA) was treated in a similar manner. The preferential formation of cyclic diesters for 12-HSA was attributed to the structural requirements due to the bulky n-hexyl side groups stemming from the ring systems.

Electrical and Optical Properties of Bi12(Si,Ge)O20 Single Crystals (Bi12(Si,Ge)O20 단결정의 전기 및 광학적 특성)

  • Kim, Douk Hoon;Mun, Jung Hak;Lee, Chanku;Lee, Sudae
    • Journal of Korean Ophthalmic Optics Society
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    • v.1 no.2
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    • pp.37-42
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    • 1996
  • The $Bi_{12}(Si,Ge)O_{20}$ single crystals were prepared by Czochralski method and the study of electrical and optical properties were carried out. The activation energy of the electrical conductivity was $E_g$=1.12 eV. The optical energy gap measured in the room temperature is found to be 2.3 eV. A.c. conductivity of crystal $Bi_{12}(Si,Ge)O_{20}$ was measured at temperatures from 290 K to 570 K in the frequency range from 50 kHz to 30 MHz. The a.c. conductivity is proportional to ${\omega}^s$. In view of this it should be hopping conduction mechanisms. At high frequencies, the power exponent was s=2. The low frequency dielectric constants were 54 for $Bi_{12}(Si,Ge)O_{20}$ and 41 for $Bi_{12}(Si,Ge)O_{20}$ single crystals.

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In Situ Localization of Rice dwarf phytoreovirus P12 Protein in Infected Rice Plant (벼오갈병 바이러스 P12 단백질의 벼 감염세포 내 소재양식)

  • Lee Bong-Choon;Hong Yeon-Kyu;Hong Sung-Jun;Park Sung-Tae
    • Research in Plant Disease
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    • v.12 no.1
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    • pp.25-27
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    • 2006
  • Rice dwarf phytoreovirus (RDV), a member of the family Reoviridae has a genome composed of 12 segmented dsRNAs designated as 51 to 512 with an increasing order of mobility in polyacrylamide gel electrophoresis (PAGE). RDV encode 12 structural and non-structural proteins, $P1{\sim}P12$ which are encoded by the $S1{\sim}S12$ segments of the dsRNA genome, respectively. In this experiment, we confirmed in situ localization of RDV particles and P12 in cytoplasm of infected rice plant. We observed specific reaction of the gold particles using virus particle and P12 protein specific antiserum with protein A-gold immunolabelling in electron microscope. It was observed that gold particles specifically react to virus particles in cytoplasm in case using the antiserum for virus particles. In the case of antiserum for P12 protein, gold particles sporadically existing on cytoplasm without existing in organelle of cytoplasm specifically. As this result, RDV P12 protein encoded by S12 located in cytoplasm.