• Journal of Chest Surgery
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• v.20 no.2
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• pp.223-229
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• 1987

Doppler echocardiography provides valuable information regarding prosthetic heart valve function rather than structure. There are three methods of expressing the severity of mitral valve obstruction: the transvalvular pressure gradient, effective valve area, and pressure half-time. Of these, the transvalvular pressure gradient [~p] can be determined by the measurement of maximum transvalvular blood flow velocity [V] according to the modified Bernoulli`s equation [gp=4V*]. Eleven patients, who underwent mitral valve replacement with Duromedics mechanical prostheses, and 17 normal persons were investigated. There were significantly higher calculated pressure gradients in prosthetic than normal mitral valves [9.*10*2.22mmHg-vs-3.26*0.99mmHg:p<0,01], and there was a inverse relationship between pressure gradient and prosthetic valve size [11.17*0.%mmHg in size 27mm and 29mm -v- 7.38*1.12mmHg in size 31mm and 33mm; r=0.85, p<0.01] The noninvasive Doppler technique should be useful in the diagnosis of prosthetic valve obstruction.

• 제어로봇시스템학회:학술대회논문집
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• 1999.10a
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• pp.226-229
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• 1999

We have been developing a method to build models for time series using Genetic Programming. The proposed method has been applied to various kinds of time series e.g. computer-generated chaos, natural phenomena, and financial market indices etc. Now we apply the prediction method to time histories of seismic ground motion i.e. one-step-ahead prediction of seismographic amplitude. Waves of earthquakes are composed of P-waves and S-waves. They propagate in different speeds and have different characteristics. It is believed that P-waves arrive firstly and S-waves arrive secondly. Simulations were performed based on real data of Hyuganada earthquake which broke out at southern part of Kyushuu Island in Japan. To our surprise, prediction model built using the earthquake waves in early time can enough precisely predict main huge waves in later time. Lots of experiments lead us to conclude that every slice of data involves P-wave and S-wave. The simulation results suggest the GP-based prediction method can be utilized in alarm systems or dispatch systems in an emergency.

• The Journal of Advanced Prosthodontics
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• v.16 no.1
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• pp.25-37
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• 2024

PURPOSE. To investigate the effect of sintering programs and surface treatments on surface properties, phase transformation and flexural strength of monolithic zirconia. MATERIALS AND METHODS. Zirconia specimens were sintered using three distinct sintering programs [classic (C), speed (S), and superspeed (SS)] (n = 56, each). One sample from each group underwent scanning electron microscopy (SEM) and grain size analysis following sintering. Remaining samples were divided into five subgroups (n = 11) based on the surface treatments: control (CL), polish (P), glaze (G), grind + polish (GP), and grind + glaze (GG). One sample from each subgroup underwent SEM analysis. Remaining samples were thermally aged. Monoclinic phase volume, surface roughness, and three-point flexural strength were measured. Monoclinic phase volume and surface roughness were analyzed by Kruskal-Wallis and Dunn tests. Flexural strength was analyzed by two-way ANOVA and Weibull analysis. The relationships among the groups were analyzed using Spearman's correlation analysis. RESULTS. Sintering program, surface treatment, and sintering × surface treatment (P ≤ .010) affected the monoclinic phase volume, whereas the type of surface treatment and sintering × surface treatment affected the surface roughness (P < .001). Type of sintering program or surface treatment did not affect the flexural strength. Weibull analysis revealed no significant differences between the m and σ_o values. Monoclinic phase volume was positively correlated with surface roughness in the SGG and SSP groups. CONCLUSION. After sintering monolithic zirconia in each of the three sintering programs, each of the surface treatments can be used. However, for surface quality and aging resistance, G or GG can be recommended as a surface finishing method.

• Journal of the Korean Institute of Gas
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• v.3 no.2 s.7
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• pp.53-61
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• 1999

The safety of gas utilities is intimidated by many causes. Among them, subsidence is a dominant cause to decrease the safety of gas utilities. So it is very important to monitor the displacement of subsidence. The purpose of this study is to on-line monitor the subsidence of gas utilities using Static GPS(Global Positioning System)technique. Static GPS technique, which is one of various GPS techniques and originally applied to monitor the crustal activity, was applied for two gas station in Korea Gas Corporation. Prior to applying this technique to the field, i.e, gas station, a preliminary test was peformed to confirm the accuracy of this technique. As a result, it was proved that this technique can measure the displacement of gas utilities three dimensionally by sub-millimeter. After getting confirmation of GPS technique, we applied this technique for two gas stations and monitored the amount of subsidence during 5 months. As a result of field test, we can conclude that the gas stations was subsiding several millimeters in a year.

• The Journal of Korean Society of Virology
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• v.28 no.4
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• pp.383-391
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• 1998

A murine monoclonal antibody (mAb) specific for the envelope glycoprotein gp120 of human immunodeficiency virus type-I (HIV -1) was chemically coupled to pokeweed antiviral protein (PAP) from Phytolacca americana. The immunotoxin was purified by FPLC using S200 colum. The purified immunotoxin efficiently bound to HIV-infected T cells as evidenced by fluorescenceactivated cell sorter analysis. The immunotoxin selectively killed human T lymphoid lines infected with $HIV-1_{IIIB}$ at less than 250 pM of the immunotoxin cells, while PAP or mAb alone did not have any significant effect on infected cells. The uninfected control T cell lines were not affected. Human cells infected with HIV-2 or other HIV-1 strains were not killed, suggesting that the killing depends completely on the antibody used for coupling. These in vitro results suggest that the PAP-mAb conjugate may be used to selectively remove cells expressing viral antigens from individuals infected with HIV.

• Preventive Nutrition and Food Science
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• v.16 no.3
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• pp.230-235
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• 2011

Roasted and retorted (RR) chestnuts develop green pigment spots on their surface during storage. The purpose of this study was to evaluate the cytotoxicity of the green pigment using RAW 264.7, MOLT-4, KATOIII and HT-29 cells. The pigment scraped from RR chestnuts (GP), whole RR chestnuts with green pigment spots (GC), whole RR chestnuts without green pigment (WC) and roasted and frozen stored chestnuts (FC) were extracted in 10% DMSO. MOLT-4 cells were less resistant to the cytotoxicity of the chestnut extracts than the RAW 264.7 cells. The GP extracts did not show different responses against $H_2O_2$-induced oxidative stress and LPS-induced NO production compared to the other extracts. The chestnut extracts did not have proliferative activity on either of the KATOIII or HT-29 cells (p>0.05). Our results from the comparison of the green pigment produced on the surface of the RR chestnuts to chestnuts that do not develop the green pigment suggest that the pigment may not be harmful in terms of either cytotoxicity towards immune cells or proliferation of gastrointestinal cancer cells.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.215-215
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• 2017

The preference for domestic cereal crop of Setaria Italica has been increased with the recent interest in healthy foods. However, the productivity of Korean domestic produce, which has been decreasing due to the lack of cultivation technology and the low rate of mechanization during cultivation. Increase of germination ability will have a positive effect on the cultivation by reducing the labor of the manpower consuming and weeding work. Therefore, red light, ultrasonication, liquid priming and liquid smoke treatment that are effective for the germination of the seeds evaluated. The seeds of 1.4mm or more were used for the experiment. The priming solution used in the experiment was 1% $KH_2PO_4$ (74mM). During the priming, the light treated seeds at 2000 lux for 15, 30, 60 and 120 minutes. Ultrasonicationd treatment was performed for 5, 10, and 20 minutes at exposures of 60%, 80%, and 100% of ultrasound up to 21.6 kHz during priming. Light or ultrasound treated seeds transferred to priming treatment at $15^{\circ}C$ for 24 hours. The treatment of the liquid smoke was divided into the treatment of the liquid smoke alone and the treatment of the liquid smoke with the priming. The liquid smoke alone was diluted with distilled water without priming solution and the treatment of the liquid smoke was diluted with the salt priming solution. Both treatments were performed at 0.0%, 0.5%, 1.0%, 5.0%, and 10.0% of the liquid smoke (pH7) concentration at $15^{\circ}C$ for 6 hours. After each treatment, the seeds were dried to moisture content ranged 5-8% at $25^{\circ}C$ for 24 hours. All treatments showed better results than the non-treated control. Light treatment for 120 minutes improved for germination percentage (GP), Germination uniformity (GU) and heath seed percentage (HS). Ultrasonication treatment was most effective when treated with ultrasound at 21.6 kHz for 5 minutes in all germination characteristics. Ten % of the liquid smoke increase in 92% GP, 1.8 days MGT, $54%{\cdot}day^{-1}GR$, 0.76 GU and 88% HS comparing to non-treated control (72% GP, 2.3 days MGT, $45%{\cdot}day^{-1}GR$, 1.48 GU, and 63 % HS). This study showed that it is possible to obtain high germination by adding liquid smoke treatment to the seeds supplied to the farmers. The efficacy of light, ultrasonication, inorganic salt priming, and liquid smoke treatment on the seeds found in the experiment will be a positive alternative to labor force problems in the cultivation by improving germination.

• Journal of Microbiology and Biotechnology
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• v.20 no.6
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• pp.1022-1026
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• 2010

The different cleavage patterns of pYBamy59 plasmid isolated from E. coli $DH5{\alpha}$ and B. longum MG1 by the cell extract of B. longum MG1 suggested that the main reason for its low transformation efficiency was related to the restriction modification (R-M) system. To confirm the correlation between the R-M system and transformation efficiency, in vitro methylation and site-directed mutagenesis were performed in pYBamy59. Sequence analysis of pYBamy59 fragments digested by the cell extract of B. longum MG1 revealed that all fragments were generated by restriction of the sequence recognized by SacII endonuclease. When pYBamy59 from E. coli was methylated in vitro by CpG or GpC methyltransferase, it was protected from SacII digestion. Site-directed mutagenesis, which removed SacII sites from pYBamy59, or in vitro methylation of pYBamy59 showed 8- to 15-fold increases in the transformation efficiency over intact pYBamy59. Modification of the SacII-related R-M system in B. longum MG1 and in vitro methylation in pYBamy 59 can improve the transformation efficiency in this strain. The results showed that the R-M system is a factor to limit introduction of exogenous DNA, and in vitro modification is a convenient method to overcome the barrier of the R-M system for transformation.

• Korean Journal of Environmental Agriculture
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• v.24 no.2
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• pp.159-163
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• 2005

This study was conducted to investigate the effect of simulated acid rain (SAR) on growth and antioxidant system in french marigold (Tagetes patula L.). Plants were subjected to four levels of SAR (pH 5.6, 4.0, 3.0, 2.0) in the growth chambers for 2 weeks. SAR decreased both plant height and plant dry weight of french marigold. As the pH levels decreased from 5.6 to 2.0, the content of MDA highly increased linearly. The ratios of dehydroascorbate/ascorbate and oxidized glutathione/reduced glutathione were significantly increased with decreasing pH levels. The enzyme (superoxide dismutase, ascorbate peroxidase etc.) activities of the plant affected by SAR were increased as the pH decreased. Based on the results, SAR caused oxidative stress in french marigold and resulted in significant reduction in plant growth. Biochemical protection responses might be activated to prevent the plant from damaging effects of oxidative stress generated in SAR.

• YAKHAK HOEJI
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• v.54 no.4
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• pp.252-257
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• 2010

The aim of this study was to investigate the effect of resveratrol on the pharmacokinetics of nifedipine in rats. The pharmacokinetic parameters of nifedipine were measured after the oral administration of nifenipine (6 mg/kg) in the presence or absence of resveratrol (0.5, 2.5 and 10 mg/kg, respectively). The effect of resveratrol on the P-glycoprotein (Pgp), CYP 3A4 activity was also evaluated. Resveratrol inhibited CYP3A4 enzyme activity in a concentration-dependent manner with 50% inhibition concentration ($IC_{50}$) of 0.94 ${\mu}M$. In addition, resveratrol significantly enhanced the cellular accumulation of rhodamine 123 in MCF-7/ADR cells overexpressing P-gp. Compared to the control groups, the presence of 2.5 mg/kg and 10 mg/kg of resveratrol significantly (p<0.05, p<0.01) increased the area under the plasma concentrationtime curve (AUC) of nifedipine by 49~75%, and the peak concentration ($C_{max}$) of nifedipine by 48~66%. The absolute bioavailability (AB%) of nifedipine was significantly (p<0.05) increased by 22.9-34.8% compared to the control (19.8%). The terminal half-life ($T_{1/2}$) of nifedipine was significantly (p<0.05) increased compared to the control. While there was no significant change in the time to reach the peak plasma concentration ($T_{max}$) of nifedipine in the presence of resveratrol. It might be suggested that resveratrol altered disposition of nifedipine by inhibition of both the CYP3A and P-glycoprotein efflux pump in the small intestine of rats. In conclusion, the presence of resveratrol significantly enhanced the oral bioavailability of nifedipine, suggesting that concurrent use of resveratrol or resveratrol-containing dietary supplenment with nifedipine should require close monitoring for potential drug interation.