• 한국전산유체공학회:학술대회논문집
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• 2008.08a
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• pp.47.3-47.3
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• 2008

• Advances in Traditional Medicine
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• v.4 no.1
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• pp.28-36
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• 2004

The purpose of this study was to investigate the pharmacological effects of low-esterified pectin on carbon tetrachloride $(CCL_4)-induced$ hepatotoxicity in rats. The study included two experiments. In the first experiment the animals were given daily $CCL_4$ through gavage for 7 days and then 10, 50, or 250 mg/kg b.w. of pectin for 21 days. At the end of experiment rats were killed within 24 hours. The increased bilirubin level, enhanced alanine aminotransferase and aspartate aminotransferase activity in plasma induced by $CCL_4$ were partly normalized by pectin administration in a dose-dependent manner. The pectin treatment also resulted in significant recovery of $CCL_4-induced$ decrease of the liver glycogen content. In addition, pectin significantly improved $CCL_4-induced$ alterations of pro-oxidant and antioxidant biochemical parameters in liver and plasma compared to those of rats administered $CCL_4$. In the second experiment the animals were given daily 10, 50 or 250 mg/ kg b.w. of pectin for 21 days before a 7-day administration of $CCL_4$. Rats were killed 24 hours after the end of experiment. Pretreatment with pectin before $CCL_4$ administration resulted in significantly inhibited increase of the blood enzymatic activities of alanine and aspartate aminotransferases and bilirubin level in a dose-dependent manner. Also, preliminary administration of pectin prevented elevation of malondialdehyde and conjugated diene levels in liver and plasma as well as a reduction of glutathione content in liver of rats given $CCL_4$. These results suggest that low-esterified pectin exert healing and preventive effects on $CCL_4-induced$ hepatotoxicity in rats.

• Journal of Korea Water Resources Association
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• v.54 no.1
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• pp.39-48
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• 2021

The experiment of rip current at successive ends of breaking wave crests was conducted in a laboratory wave basin, and its time-varying evolution according to incident wave durations was observed by using ortho-rectified images. The experiment utilized the generation of a quasi nodal line of the honeycomb-pattern waves (i.e., intersecting wave trains) formed by out-of-phase motion of two piston-type wave makers arranged in the transverse direction, instead of the original honeycomb pattern waves which are generated when two wave trains propagate with slightly different wave directions. The particle moving distance and velocity caused by the rip current were measured by using the particle tracking technique. As a result, the rip current was survived for a while even without incident waves after its generation due to several successive ends of wave crests, and it moved the particles further out to sea.

• Proceedings of the KIPE Conference
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• 1999.07a
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• pp.130-133
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• 1999

It is one of the most effective methods for improving the performance of electric railway vehicles to make better the wheel-railway adhesion characteristics. The purpose of this paper is to develop the equivalent reduction machine to experiment on the adhesion system. The experiment system makes it possible to change the wheel-rail adhesion force with various adhesion parameters, and therewith to test the adhesion control system with the reduction machine in a laboratory.

• Safety and Health at Work
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• v.15 no.1
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• pp.118-122
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• 2024

To understand biosafety's current situation in laboratory animal research and risk factors affecting occupational health. Compliance surveys were conducted by questionnaire via Questionnaire Star (an application app on the Internet) in Chinese. Thirty-nine anonymous questionnaires were collected. The surveyed institution has established 24 types of ABSL (Animal Biosafety Laboratory) and biosafety management organizations and systems equipped with safety equipment. Our study also suggests that the principal of the laboratory establishment fails to perform supervision and inspection responsibilities, the inappropriate design of the animal biosafety laboratory, non-standardized personnel training and health management, non-strict waste management, and insufficient emergency management. The administrative department and work units should address certain safety and occupational health risks in laboratory animal research. The author proposes control strategies based on organizational guarantee, personnel management, emergency management, etc., to help prevent risks and ensure occupational health. Due to regional limitations and small sample size, the results may not be generalisable to all parts of the world. However, some of the key common issuesmay also be present in other regions, sowe believe that this research still has some relevance.

• The Journal of Korean Association of Computer Education
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• v.11 no.1
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• pp.23-32
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• 2008

In this paper, we have investigated the education effect of a web-based virtual laboratory for digital logic circuits which consists of multimedia contents about the usages of equipments for logic circuit experiments and the experimental logic circuits. In case of the engineering experiment of the lower grades in universities, preunderstanding about the usages of experimental equipments and the experimental circuits is necessary for the learners to conduct the experiments well. But it is impossible for the learners to have access to the real experimental equipments earlier due to the lack of equipments and the difficulty in management of the equipments. We have implemented the digital logic circuit virtual laboratory which provides the same experimental environment as a real experimental lab, and the learner can conduct the same experiments as the real ones before the real laboratory class. The learners using the laboratory have reduced the experiment completion time by the average of about 8.2% during a term, compared with the learners not using the lab.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2003.10a
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• pp.130-130
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• 2003

Gummy stem blight pathogen is very difficult not only to monitor the inoculum levels prior to host infection, and also it is destructive and hard to control in field condition. We have applied RAPD technique to elucidate the genetic diversity of the genomic DNA of Didymella bryoniae and also to generate specific diagnostic DNA probe useful for identification and detection. The 40 primers produced clear bands consistently from the genomic DNA of twenty isolates of Didymella bryoniae, and two hundred seventy-three amplified fragments were produced with 40 primers. The combined data from 273 bands was analyzed by a cluster analysis using UPGMA method with an arithmetic average program of NTSYS-PC (Version 1.80) to generate a dendrogram. At the distance level of 0.7, two major RAPD groups were differentiated among 20 strains. RAPD group (RG) I included 8 isolates from watermelon except one isolate from melon. RAPD group (RG) IV included 12 isolates from squash, cucumber, watermelon and melon.. In amplification experiment with SCAR specific primer RG1F-RG1R resulted in a single band of 650bp fragment only for 8 isolates out of 20 isolates that should be designated as RAPD Group 1. However, same set of experiment done with RGIIF-RGIIR did not result in any amplified product.. Our attempts to detect intraspecific diversity of ITS region of rDNA by amplifying ITS region and 17s rDNA region for 20 isolates and restriction digestion of amplified fragment with 12 enzymes did not reveal polymorphic band. In order to develop RAPD markers for RGIV specific primer, a candidate PCR fragment( ≒1.4kb) was purified and Southern hybridized to the amplified fragment RGIV isolates. This promising candidate probe recognized only RGIV isolates

• Environmental Engineering Research
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• v.14 no.1
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• pp.41-47
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• 2009

Column experiments were performed in this study to investigate humic acid adhesion to iron oxide-coated sand (ICS) under different experimental conditions including influent humic acid concentration, flow rate, solution pH, and ionic strength/composition. Breakthrough curves of humic acid were obtained by monitoring effluents, and then column capacity for humic acid adsorption ($C_cap$), total adsorption percent (R), and mass of humic acid adsorbed per unit mass of filter media ($q_a$) were quantified from these curves. Results showed that humic acid adhesion was about seven times higher in ICS than in quartz sand at given experimental conditions. This indicates that humic acid removal can be enhanced through the surface charge modification of quartz sand with iron oxide coating. The adhesion of humic acid in ICS was influenced by influent humic acid concentration. $C_cap$ and $q_a$ increased while R decreased with increasing influent humic acid concentration in ICS column. However, the influence of flow rate was not eminent in our experimental conditions. The humic acid adhesion was enhanced with increasing salt concentration of solution. $C_cap$, $q_a$ and R increased in ICS column with increasing salt concentration. On the adhesion of humic acid, the impact of CaCl2 was greater than that of NaCl. Also, the humic acid adhesion to ICS decreased with increasing solution pH. $C_cap$, $q_a$ and R decreased with increasing solution pH. This study demonstrates that humic acid concentration, salt concentration/composition, and solution pH should be controlled carefully in order to improve the ICS column performance for humic acid removal from water.

• Biomedical Science Letters
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• v.20 no.4
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• pp.227-236
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• 2014

Ulcerative colitis (UC) is a serious gastrointestinal tract disease characterized by recurrent chronic inflammation and mucosal damage of the gastrointestinal tract. The conventional therapies of choice are anti-inflammatory agents, steroids and anti-TNF-${\alpha}$ therapy. However, inherent limitations in these therapies have steered many UC patients to supplement existing therapies with alternative medicinal products. In the current study, we tested the efficacy of Gingko bilola extract (EGb 761) in abating colonic inflammation in a DSS-induced murine model of colitis. C57BL/6 mice were administered 2% DSS in the drinking water for 7 days, then regular water for 7 days, and then 2% DSS for an additional 7 days. EGb 761 (1 mg/dose) was oral gavaged daily for the duration of the experiment. At the termination of the experiment, mice treated with EGb+DSS showed higher body weight, lower spleen weight and longer colon length compared to mice treated with DSS alone. HE-stained colon tissues also exhibited less histologic inflammation in mice treated with EGb+DSS mice compared to mice treated with DSS alone. The serum levels inflammatory cytokines, KC and TNF-${\alpha}$, were also decreased in mice treated with EGb+DSS compared to mice treated with DSS alone. Finally, addition of EGb 761 to TNF-${\alpha}$ treated colonic cell line (HT29/c1) decreased secretion of IL-8 in vitro. These results collectively suggest that EGb 761 abates induction of colitis in DSS-induced model of colitis in mice.

• Nuclear Engineering and Technology
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• v.53 no.2
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• pp.439-445
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• 2021

In view of the complex geometric structure of the rod bundle channel and the limitation of the current CHF visualization experiment technology, it is very difficult to obtain the rod bundle CHF mechanism directly through the phenomenon of the rod bundle CHF visualization experiment. In order to obtain the applicable CHF mechanism assumption for rod bundle channel, firstly, five most representative DNB type round tube CHF mechanistic models are obtained with evaluation and screening. Then these original round tube CHF mechanistic models based on inlet conditions are converted to local conditions and coupled with subchannel analysis code ATHAS. Based on 5 × 5 full-length rod bundle CHF experimental data independently developed by Nuclear Power Institute of China (NPIC), the applicability research of each model for CHF prediction performance in rod bundle channel is carried out, and the commonness and difference of each model are comparatively studied. The CHF mechanism assumption of superheated liquid layer depletion that is most likely to be applicable for the rod bundle channel is selected and two directions that need to be improved are given. This study provides a reference for the development of CHF mechanistic model in rod bundle channel.