• 분석과학
• /
• 제16권3호
• /
• pp.179-184
• /
• 2003

극성이 다른 여러 가지 용매를 사용하여 느릅나무의 뿌리 껍질(이하 유근피)을 추출하였다. MeOH 추출물이 SK-Hep-1에서 분리된 matrix metalloproteinase-9(MMP-9)의 zymography에서 저해능을 나타내었다. 분리 정제한 물질의 분자량은 GC-MS spectrum에서 $M^+=281$인 것으로 나타났고 MMP-9의 활성은 $314.7{\mu}g/g$에서 47% 억제되는 것으로 나타났다. 그리고 SK-Hep-1 세포주는 $31.47{\mu}g/g$에서 60%의 생존율을 나타났다.

• International Journal of Advanced Culture Technology
• /
• 제9권4호
• /
• pp.9-17
• /
• 2021

This is a descriptive investigative study which attempts to confirm the mediating effect of learning motivation in the relationship between self-directed learning, learning commitment, and learning persistence intention of university students in an online learning environment. The questionnaires were randomly distributed online and the agreed questionnaires were retrieved, with a total of 338 copies used for analysis. The following is the summary of the findings. First, there were significant differences in learning persistence intention according to general characteristics depending on age, major, part-time job, and academic level. Second, the results showed a positive correlation between self-directed learning, learning commitment, learning motivation, and learning persistence intentions of the subjects were statistically significant. Third, after checking the mediating effect of learning motivation in relation to self-directed learning, learning commitment and learning motivation, the learning motivation has a partial mediating effect on learning and 23% explanatory power, and the learning commitment was found to have a complete mediating effect on the impact of learning motivation on learning intentions with 21% explanatory power. Based on these results, it is necessary to provide a more diverse educational environment, such as operating a motivation semester program that can improve learning motivations along with learning commitment, and the use of a variety of contents that can focus the learner's interest or attention.

• Asian-Australasian Journal of Animal Sciences
• /
• 제13권1호
• /
• pp.6-9
• /
• 2000

The purpose of this study was to evaluate the effect of lower numbers of sperm $(3{\times}10^9)$ per dose liquid semen and type of semen used in artificial insemination (AI) on sow reproductive performance in subtropical area. Semen was supplied by two commercial AI centers. A total of 671 female pigs from seven farms were inseminated with either $3{\times}10^9$ or $5{\times}10^9$ sperm per dose. Two types of semen were used: heterospermic semen from two boars of the same breed and homospermic semen from a single boar. After insemination, conception rate, farrowing rate, total litter size, and number of dead piglets were recorded. The analysis of variance indicated that there was no significant effect of interactions between pig farm, type of semen, or number of sperm on any of the traits measured. There were significant differences in conception rate, farrowing rate, and total litter size among pig farms (p<0.05). The effect of number of sperm per dose liquid semen ($3{\times}10^9$ or $5{\times}10^9$) was not significant. Sows inseminated with homospermic semen showed significantly higher conception and farrowing rates but significantly lower total litter size (p<0.05). In conclusion, the number of sperm per dose liquid semen for AI could be lowered to $3{\times}10^9 $ without affecting reproductive performance in subtropical areas like Taiwan.

• Journal of Microbiology and Biotechnology
• /
• 제9권4호
• /
• pp.398-403
• /
• 1999

In our previous studies, we reported that hybridoma B-lymphocytes can be used to determine the virulence of Listeria species in an in vitro cytotoxicity assay. Here, we examined the cytopathic effect, i.e., membrane damage and the nature of cell death induced by Listeria monocytogenes on murine hybridoma B-lymphocytes (Ped-2E9). Membrane damage was assessed by microscopic analyses and by measuring the release of intracellular alkaline phosphatase(AP) and lactate dehydrogenase (LDH). Cell death was determined by DNA fragmentation analyses using agarose gel electrophoresis. Infection by listeriolysin O (LLO)-producing L. monocytogenes strains induced substantial amounts of AP and LDH release from Ped-2E9 hybridoma B-cells, suggesting severe membrane damage in these cells, while an LLO-negative L. monocytogenes mutant strain had no effect. An LLO-producing recombinant L. innocua ($prifA^+hly^+$) strain also induced high AP and LDH release and cytopathic changes in Ped-2E9 cells. Light or scanning electron microscopic examination revealed L. monocytogenes mediated membrane destabilization, pore formation, intense cytoplasmic granulation, bleb formation, and lysis of Ped-2E9 cells. LLO-producing L. monocytogenes and L. innocua ($prifA^{+}hly{^}+$) also induced ladder-like DNA fragmentation in Ped-2E9 cells. Collectively, these results suggest that L. monocytogenes, specifically LLO-producing strains, can induce a severe cytopathic effect leading to apoptosis in hybridoma B-lymphocytes (Ped-2E9).

• Journal of Animal Science and Technology
• /
• 제46권6호
• /
• pp.967-974
• /
• 2004

본 연구는 여 러 conjugated linoleic acid(CLA) 이성체가 돼지 지방전구세포의 분화에 미치는 영향을 구영하기 위해 수행하였다. 돼지 지방전구세포는 갓난 돼지의 등 지방에서 분리해서 성숙지방세포로 분화될 때 까지 배양했다. 여러 CLA 이성체를 배양중의 세포에 처리했다. 세포분화는 세포배양이 끝난 후 세포의 glycerol-3-phosphate의 활성도를 측정함으로써 구명했다. 20$\mu$M과 50$\mu$M의 transto-cis12 CLA 이성체는 돼지 지방천구세포의 분화를 억제했고，한펀 cis9-cisl1 이성체는 세포분화를 촉진했다. cis9-trans 11 과 trans9-trans11 이생체는 세포분화에 아무런 영향을 마치지 않았다. CLA의 세포분화에 미치는 작용은 배양후기 (day8${\sim}$14) 보다 배양전기(day 0${\sim}$ 8)에 더 두드러지게 나타냈다. 위의 결과는 여러 CLA 이성체는 돼지 지방천구세포 분화에 각각 다른 작용을 가짐을 나타낸다.

• 한국전자통신학회논문지
• /
• 제16권2호
• /
• pp.347-354
• /
• 2021

화학공장과 같은 장치산업은 고온·고압·유독성 유체가 배관을 통하여 각종 설비들 사이를 이동한다. 온도변화, 진동, 지진, 지반침하와 같은 주변환경의 변화에 의한 배관의 위치 이동과 파손은 인명피해를 수반하는 큰 사고로 연결되는 경우가 많다. 이러한 사고를 방지하기 위하여 배관에 가해지는 각종 충격을 흡수하고, 보완하여 사고를 미연에 방지하기 위한 여러 가지 종류의 익스펜션 조인트(Expansion Joint)를 사용한다. 따라서 사용된 익스펜션 조인트의 변형을 측정하고, 수명을 예측하는 것은 대형사고를 방지하기 위하여 매우 중요하다. 본 논문에서는 익스펜션 조인트의 변형을 일종의 모션으로 이해하고, Hall Effect Sensor와 9-Axis Sensor를 사용하여 변화를 측정하였다. 그리고 범용의 마이컴보드 아두이노와 C언어를 사용하여 측정된 데이터를 모으고, 분석하여 익스펜션 조인트의 변형을 예측할 수 있는 시스템에 대하여 연구하였다.

• 지식경영연구
• /
• 제10권3호
• /
• pp.115-132
• /
• 2009

This paper makes an analysis of economic spillover effects of credit guarantee by linking the remainder of guarantee according to industries from 2003 to 2006 in this study. Specifically, total remainder of guarantee in 2006 is approximately 3922 billion and 600 million won on the basis of unchangeable price in 2003, and each funds becomes the input of the last demand in 27 industries over the cow1try and, thereby, induces production, added value, and the effect of employment. The last demand according to industries shows that a lot of funds have been supported to the manufacturing industry for about 1200 billion won, the wholesale and retail for about 1299 billion and 500 million won, food and lodging industry for about 144 billion and 100 million won, education and health care industry for about 132 billion and 600 million won, and social and other service industry for about 339 billion and 300 million won. The spillover effect about the remainder of guarantee in 2006 classified by industries over the country on the basis of production shows the high effects on the manufacturing industry for 37.8%, 2625 billion and 90 million won, the wholesale and retail for 20.7%, 1439 billion and 290 million won, food and lodging industry for 9.4%, 654 billion and 570 million won, real estate and business service industry for 9.2%, 637 billion and 310 million won, social and other service industry for 5.3%, 369 billion and 90 million won, and education and health care industry for 2.9%, 199 billion and 300 million won of the effect causing production over the country, 6945 billion won in order. The effect causing added value shows high spillover effect on the wholesale and retail for 36.7%, 1186 billion and 830 million won, the manufacturing industry for 25.8%, 831 billion and 500 million won, food and lodging industry for 14.9%, 480 billion and 980 million won, social and other service industry for 9.3%. 300 billion and 160 million won, and real estate and business service industry for 4.2%, 135 billion and 36 million won of the effect causing added value over the country in order. Finally, the effect causing employment shows a lot of employment have occurred in the wholesale and retail for 37.4%, 23,060 people, the manufacturing industry for 18.9%, 11,637 people, food and lodging industry for 13.7%, 8,429 people, social and other service industry for 7.9%, 4,866 people, and real estate and business service industry for 5.6%, 3,429 people of 61,617 people in order.

• 전기학회논문지P
• /
• 제59권2호
• /
• pp.191-196
• /
• 2010

The electricity distribution system in Korea is adopting a multi-grounding system. Protection of this distribution system against lightning is performed by installing overhead ground wires over the high voltage wires, and connecting the overhead ground wires to the ground every 200 m. The ground resistance in this system is limited not to exceed $50\Omega$ and overhead ground wire and neutral wire are multiple parallel lines. Although overhead ground wire and neutral wire are installed in different locations on the same pole, this circuit configuration has duplicated functions of providing a return path for unbalanced currents and protecting the distribution system against induced lightning. Therefore, the purpose of this study is to analyze the induced lightning shielding effect according to the neutral wire installation structure of a 22.9kV distribution line in order to present a new 22.9kV distribution line structure model and characteristics. This study calculated induced lightning voltage by performing numerical analysis when an overhead ground wire is present in the multi-grounding type 22.9kV distribution line structure, and calculated the induced lightning shielding effect based on this calculated induced lightning voltage. In addition, this study proposed and analyzed an improved distribution line model allowing the use of both overhead wire and neutral wire to be installed in the current distribution lines. The result of MATLAB simulation using the conditions applied by Yokoyama showed almost no difference between the induced lightning voltage developed in the current line and that developed in the proposed line. This signifies that shielding the induced lightning voltage through overhead wire makes no difference between current and proposed distribution line structures. That is, this study found that the ground resistance of the overhead wire had an effect on the induced lightning voltage, and that the induced lightning shielding effect of overhead wire is small.

• 대한한의학회지
• /
• 제23권2호
• /
• pp.211-224
• /
• 2002

Background and Objective : In order to investigate the effects of Gilgyunglwedok-tang (GRT) on antitumor activity and antimetastatic activity, studies were done experimentally. Materials and Methods : Experimental studies were perfonned for the cytotoxic effect on BALB/c mouse lung fibroblast cells, the proliferating effect of splenic lymphocyte, the expression of CD3e/CD4, CD3e/CD8, and B220 in peripheral blood mononuclear cells (PBMCs), the cytotoxic effect on A549, SK-OV-3, SK-MEL-2, MCF-7 cells, the inhibitory effect on the activity of DNA topoisomerase I, the T/C% in ICR mice bearing S-180, the inhibitory effect of Cell adhesive of A549 Cells and SK-OY-3 Cells to complex extracellular matrix, the inhibitory effect on lung colonies, the change of lung tissue, the antiangiogenic activity, and the effect on MMP-2 and MMP-9 gene expression in the RT1080 cell line. Results and Conclusion : The results were obtained as follows : 1. In the cytotoxic effect on BALB/C mouse lung fibroblast Cell, GHT didn't show the significant cytotoxic effect on BALB/C mouse lung fibroblast cell compared to the control group. 2. In thymidine uptake assay, GHT showed the significant proliferating effect of splenic lymphocyte in proportion to the concentration. 3. In the expression of CD3e/CD4, CD3e/CD8, and B220 in peripheral blood mononuclea cells (PBMCs) of mice, GRT had no significant change to the normal group in CD4. However, GRT showed an increase to the normal group in CD8 and GHT in the only $1\mu\textrm{g}/ml$ category showed an increase to the normal group in B220. 4. In the cytotoxic effect of GRT on A549, SK-OY-3, SK-MEL-2 and MCF-7 cells, there was no significant cytotoxic effect compared to the control group. 5. In the inhibitory effect on the activity of DNA topoisomerase I, GHT in the $10\mu\textrm{g}/ml$ category showed the inhibitory effect on the activity of DNA topoisomerase I in proportion to the concentration. 6. In the T/C% in ICRmice bearing S-180, GHTtreated group showed 123.7% of T/C% compared to the control group. 7. In the inhibitory effect of cell adhesive of A549 Cells and SK-OV-3 Cells to complex extracellular matrix, GRT in the only $100\mu\textrm{g}/ml$ category showed the significant inhibitory effect compared to the control group. 8. In the inhibitory effect on lung colonies, GHT showed the significant inhibitory effect on lung colonies compared to the control group. 9. In the change of lung tissue, GHT showed a significant decrease of lung cancer growth, interalveolar fibrosis and hyaline material compared to the control group. In the development of lymphocyte around lung cancer cells and lung parenchymal, GHT showed the significant inducement efficacy compared to the control group. 10. In CAM assay, the antiangiogenic activity of GHT showed 30%. 11. In the effect on MMP-2 and MMP-9 gene expression in the RT1080 cell line, GHT had no significant inhibitory effect on MMP-2 and MMP-9 gene expression compared to the control group. According to the above results, it could be suggested that GHT has an antitumor activity and antimetastatic activity.

• 한국기후변화학회지
• /
• 제9권4호
• /
• pp.407-421
• /
• 2018

In this paper, I analyze the GHG (greenhouse gas) emission factor of the domestic railway transportation sector using the LMDI (Log Mean Divisia Index) methodology. These GHG factors are the emission factor effect, energy intensity effect, transportation intensity effect, and economic activity effect. The analysis period was from 2011 to 2016, and the analysis objects were an intercity railway, wide area railway, and urban railway. The results show that the GHG emission of railway transportation sector decreased during these 6 years. The factors decreasing the GHG emission are the emission factor effect, energy intensity effect, and transportation intensity effect, while the factor increasing the GHG emission is the economic activity effect.