• Horticultural Science & Technology
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• v.16 no.2
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• pp.213-214
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• 1998

This study was conducted to provide useful information for improvement on the efficency of transformation mediated by Agrobacterium tumefaciens. The result from the sensitivity test of cotyledon explants of tomato to kanamycin suggested that 50mg/L could be a proper concentration for selection media. Two hundred mg/L of cefotaxime was selected as a proper concentration to remove Agrobacteria from media without any negative effect on explants. Both callus formation and shoot regeneration from cotyledon explants of tomato were significantly suppressed by the cocultivation with Agrobacterium. Three days of cocultivation was effective on callus formation and shoot regeneration in all of tomato cultivars tested. Confirmation of transformation for regenerated shoots was carried out by histochemical GUS assay and PCR analysis using NPTII primer, and transgenic shoots were obtained from all of 3 tomato cultivars tested.

• Korean Journal of Food Science and Technology
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• v.12 no.2
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• pp.88-96
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• 1980

Reaction conditions in the amino-carbonyl reaction, and the effect of amino acids on the reactivity of amino-carbonyl reaction were investigated. Results obtained are as follows : 1. When the pH of the reaction mixture was increased above the isoelectric point of an amino acid, a significant increase in the color intensity was observed. 2. The color intensity increased gradually up to 1 : 1 of the molar ratio of reactants. This result was interpreted to show that sugar and free amino group combined in 1 : 1 ratio. 3. Amino-carbonyl reaction showed a significant time and temperature-dependences. The activation energy at 0.2 M glucose and 0.2 M glycine system was 37.5 Kcal/mole. 4. Among amino acids tested, glycine, lysine and $\beta$-alanine caused a significant increase in the color intensity, but acidic amino acids showed the least color intensity. The latter was interpreted to show that one of carboxyl groups of acidic amino acid has an inhibiting effect on the reactivity of the amino group. 5. The color intensity of sugars tested was in the order of xylose>arabibose>fructose>glucose>maltose>lactose.

• Safety and Health at Work
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• v.1 no.1
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• pp.80-86
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• 2010

Objectives: We investigated the genotoxicity of two chemicals, methyl formate and 2-methylbutane, using male ICR mice bone marrow cells for the screening of micronucleus induction. Although these two chemicals have already been tested numerous times, a micronucleus test has not been conducted and the amounts used have recently been increased. Methods: 7 week male ICR mice were tested at dosages of 250, 500, and 1,000 mg/kg for methyl formate and 500, 1,000, and 2,000 mg/kg for 2-methlybutane, respectively. After 24 hours of oral administration with the two chemicals, the mice were sacrificed and their bone marrow cells were prepared for smearing slides. Results: As a result of counting the micronucleated polychromatic erythrocyte (MNPCE) of 2,000 polychromatic erythrocytes, all treated groups expressed no statistically significant increase of MNPCE compared to the negative control group. There were no clinical signs related with the oral exposure of these two chemicals. Conclusion: It was concluded that the two chemicals did not induce micronucleus in the bone marrow cells of ICR mice, and there was no direct proportion with dosage. These results indicate that the two chemicals have no mutagenic potential under each study condition.

• YAKHAK HOEJI
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• v.41 no.4
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• pp.421-432
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• 1997

A new lectin was partially purified from starfish,Asterina pectinifera by means of physiological saline extraction, salt fractionation, ion exchange chromatography and hy droxyapatite chromatography, and it was named APL. The biochemical properties of the APL were characterized. In addition, its effects on lymphocyte mitogenicity and cancer cell agglutinability were tested. The APL agglutinated nonspecifically human erythrocytes and rabbit blood cells. Agglutinability was decreased to 30% of control activity below pH 5 and above pH 9 and was relatively unstable at increasing temperatures above 60$^{\circ}C$. The activity was reduced by addition of two kinds of metal ions, $Ba^{2+},\;Mn^{2+}$ and chelating agent, EDTA. APL was proved to be glycoproteins containing 9% sugars. For carbohydrate specificity, it was found that the activity of APL was inhibited by D(+)-glucosamine, D(+)-galactosamine, stachyose, N-acetyl-galactosamine and methyl-${\alpha}$-D-galactopyranoside among 35 sugars tested. In amino acid composition, the contents of acidic amino acids such as aspartic acid and glutamic acid were relatively high. This result suggest that the isoelectric point would be in a lower range. APL was found that it promotes the division of human lymphocytes. APL was proved to be a potent agglutinin for cancer cells such as HeLa, L929 and L1210 cells. Significant changes on the HeLa cell surfaces affected by APL were observed under the electron microscope.

• Wind and Structures
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• v.29 no.1
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• pp.75-84
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• 2019

A steady slot suction near the free-end leading edge of a finite-length square cylinder was used to control its aerodynamic forces and vortex-induced vibration (VIV). The freestream oncoming flow velocity ($U_{\infty}$) was from 3.8 m/s to 12.8 m/s. The width of the tested cylinder d = 40 mm and aspect ratio H/d = 5, where H was the height of the cylinder. The corresponding Reynolds number was from 10,400 to 35,000. The tested suction ratio Q, defined as the ratio of suction velocity ($U_s$) at the slot over the oncoming flow velocity at which the strongest VIV occurs ($U_{\nu}$), ranged from 0 to 3. It was found that the free-end slot suction can effectively attenuate the VIV of a cantilevered square cylinder. In the experiments, the RMS value of the VIV amplitude reduced quickly with Q increasing from 0 to 1, then kept approximately constant for $Q{\geq}1$. The maximum reduction of the VIV occurs at Q = 1, with the vibration amplitude reduced by 92%, relative to the uncontrolled case. Moreover, the overall fluctuation lift of the finite-length square cylinder was also suppressed with the maximum reduction of 87%, which occurred at Q = 1. It was interesting to discover that the free-end shear flow was sensitive to the slot suction near the leading edge. The turbulent kinetic energy (TKE) of the flow over the free end was the highest at Q = 1, which may result in the strongest mixing between the high momentum free-end shear flow and the near wake.

• The Journal of Korean Institute of Information Technology
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• v.17 no.4
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• pp.87-97
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• 2019

SRS was proposed for immediate processing of the meaning of sensor data on mobile devices independent from specific sensor networks and sensor type. However, each time new sensor data is received, sensor data inspection operations are performed repeatedly, and it cause resulting in low performance. App profile-based SRS has been proposed to resolve the problem. The app profile-based SRS has improved the SRS problem through the profile, but has been tested in a virtual simulation environment. After that the test was experimented in a real-time environment, but has not been tested with a variety of dynamic factors. Therefore, this paper experiment considering such as user mobility and sensor density in real-time environment. And this paper also evaluate performance of the App profile-based through analysis of the results of the experiment. As a result, app profile-based SRS is high influence by density and sensor type, and the number of sensor node is not influence.

• Mass Spectrometry Letters
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• v.12 no.1
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• pp.16-20
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• 2021

We aimed to compare the content of ginsenosides and the pharmacokinetics after the oral administration of four different ginseng products at a dose of 1 g/kg in rats. The four different ginseng products were fresh ginseng extract, red ginseng extract, white ginseng extract, and saponin enriched white ginseng extract prepared from the radix of Panax ginseng C.A. Meyer. The ginsenoside concentrations in the ginseng product and the rat plasma samples were determined using a liquid chromatography-tandem mass spectrometry (LC-MS/MS). Eight or nine ginsenosides of the 15 tested ginsenosides were detected; however, the content and total ginsenosides varied depending on the preparation method. Moreover, the content of triglycosylated ginsenosides was higher than that of diglycosylated ginsenosides, and deglycosylated ginsenosides were not present in any preparation. After the single oral administrations of four different ginseng products in rats, only four ginsenosides, such as 20(S)-ginsenosides Rb1 (GRb1), GRb2, GRc, and GRd, were detected in the rat plasma samples among the 15 ginsenosides tested. The plasma concentrations of GRb1, GRb2, GRc, and GRd were different depends on the preparation method but pharmacokinetic features of the four ginseng products were similar. In conclusion, a good correlation between the area under the concentration curve and the content of GRb1, GRb2, and GRc, but not GRd, in the ginseng products was identified and it might be the result of their higher content and intestinal biotransformation of the ginseng product.

• Journal of Appropriate Technology
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• v.7 no.1
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• pp.26-32
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• 2021

In the process of vaccine delivery and vaccination, temperature is mostly controlled by an insulated containers containing ice. Moreover, amount of wasted vaccine is significant because the temperature of the vaccine is not properly controlled. A core challenge of vaccination is temperature data monitoring, since it is critical for managing and operating strategical vaccination by health organizations. In this research, a real-time monitoring vaccine carrier system was developed. Temperature, location, and power consumption data of the vaccine carrier were monitored and working performances of the vaccine carrier were tested in both Korea and Tanzania (Arusha and Kilimanjaro regions). For both places, Short Message Service (SMS) communication method was used to send information of the carrier's status. As a result, the monitoring system was able to transmit and receive real-time data of the vaccine carrier status while the vaccine carrier was tested. The vaccine status data can be accessed from any location through the cloud server and web-based user interface.

• Journal of Information Technology Services
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• v.21 no.6
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• pp.1-19
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• 2022

This study empirically analyzed the effects of immersion and self-efficacy on the intention to continuously use realistic media. To this end, we used an extended technology acceptance model that includes not only the perceived ease of use and usefulness, but also the perceived joy as important factors. We collected data from 595 participants through an online questionnaire survey and tested the research model using a covariance-based SEM. As a result, we found that a user's immersion significantly increased perceived usefulness, ease of use, and joy of realistic media; and self-efficacy increased perceived usefulness and ease of use. Although the effect of perceived usefulness was relatively stronger than that of perceived joy, we found that the effect of perceived joy on the intention to use was also quite large. The effect of perceived ease of use on intention to use was found to be completely mediated by perceived usefulness and joy. In addition, the differences according to the types of media were tested by comparing two groups: augmented reality and virtual reality. The effects of perceived ease, usefulness, and joy on the intention to use were very similar regardless of the type of immersive media. However, it was found that self-efficacy increases usefulness only in augmented reality. Based on our findings, we have discussed the implications of our study, as well as the scope for future research.

• Analytical Science and Technology
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• v.35 no.1
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• pp.15-23
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• 2022

Food delivery is gaining popularity due to changes in lifestyle and dietary patterns. However, packages used to delivery food may contain contaminants including heavy metals, or additives added during manufacturing process which may migrate into food during processing and transportation. In this study, a total of 58 food packages for delivery were collected and tested for migration of heavy metals (lead, cadmium and arsenic), bisphenol A and phenol into food simulants. The method was validated by evaluating linearity of calibration curve, limit of detection, limit of quantification, recovery and precision. Result of heavy metal migration showed that lead was the most frequently migrated metal and the highest concentration was detected in a polypropylene sample. Although there are no specific migration limits for bisphenol A and phenol in packaging materials tested in this study, migrations of bisphenol A and phenol were detected in some packages. This may due to contamination or additives added during manufacture of packages. Risk (%) was calculated to analyze the risk associated with the migration of heavy metals, bisphenol A and phenol, and was always below 1 %. These results showed that food packages for delivery are safe in terms of heavy metals, bisphenol A and phenol migration.