• Radiation Oncology Journal
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• v.28 no.4
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• pp.219-223
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• 2010

Purpose: To test the radiosensitizing effect of the newly synthesized novel histone deacetylase inhibitor, SK-7041 in vivo. Materials and Method: The RIF-l cell line was implanted into the back of a 6-week-old female C3H mouse, intradermally, The mice were grouped into control, drug, radiation (RT), and RT+drug group. SK-7041, 4 mg/kg was administered intraperitoneally for six cycles every 12 hours for mice in the drug and RT+drug group, An identical volume of phosphate buffered saline (PBS) was administered at the same frequency to mice in the control and RT groups. A single 5 Gy fraction was delivered to mice in RT and RT+drug group 6 hours after the fourth delivery. The volume of the implanted tumor was measured every 2~3 days to formulate the growth delay curve. Results: For the control, drug, RT, and RT +drug groups, the average duration for implanted tumor to reach a volume of $1,500mm^3$ was 10 days, 10 days, 9 days, and 12 days, respectively. Moreover, the tumor volume on D14 was $276.7mm^3$, $279.9mm^3$, $292.5mm^3$, and $185.5mm^3$, respectively (p=0.0004). The difference for the change in slope for the control and drug versus the RT and RT+drug groups were borderline significant (p=0.0650). Conclusion: The results of this study indicate that SK-7041 has a radiosensitizing effect for the RIF-1 cell line in vivo at a low concentration and this effect may be synergistic. Implementing this result to clinical trial is warranted.

• Proceedings of the Korean Biophysical Society Conference
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• 2003.06a
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• pp.80-80
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• 2003

${\beta}$-lapachone(${\beta}$-Lap), a natural o-naphthoquinone, presents in the bark of the Lapacho tree. ${\beta}$-Lap is cytotoxic against a variety of human cancer cells and it potentiates the anti-tumor effect of Taxol. In addition, ${\beta}$-Lap has been reported to radiosensitize cancer cells by inhibiting the repair of radiation-induced DNA damage.In the present study, we investigated the cytotoxicity of ${\beta}$-Lap against RKO human colorectal cancer cells as well as the combined effect of ${\beta}$-LaP and ionizing radiation. An incubation of RKO cells with 5 ${\mu}$M of ${\beta}$-Lap for 4 h killed almost 90％ of the clonogenic cells. An incubation of RKO cells with 5 ${\mu}$M of ${\beta}$-Lap for 4 h or longer also caused massive apoptosis. Unlike other cytotoxic agents, ${\beta}$-Lap did not increase the expression of p53 and p21 and it suppressed the NFkB expression. The expression of Caspase 9 and 3 was minimally altered by ${\beta}$-Lap. Radiation and ${\beta}$-Lap acted synergistically in inducing clonogenic cell death and apoptosis in RKO cells when ${\beta}$-Lap treatment was applied after but not before the radiation exposure of the cells. Interestingly, a 4 h treatment with 5 ${\mu}$M of ${\beta}$-Lap starting 5 h after irradiation was as effective as that starting immediately after irradiation. The mechanisms of ${\beta}$-Lap-induced cell killing is controversial but a recent hypothesis is that ${\beta}$-Lap is activated by NAD(P)H: quinone-onidoreductase (NQO1) in the cells followed by an elevation of cytosolic Ca$\^$2+/ level and activation of proteases leading to apoptosis. It has been reported that NQO1 level in cells is markedly up-regulated for longer than 10 h after irradiation. Indeed, using immunological staining of NQO1, we observed a significant elevation of NQO1 expression in RKO cells 5h after 2-4 Gy irradiation. Such a prolonged elevation of NQO1 level after irradiation may be the reasons why the ${\beta}$-Lap treatment applied S h after irradiation was as effective as that applied immediately after irradiation in killing the cells. In view of the fact that the repair of radiation-induced damage is usually completed within 1-2 h after irradiation, it is highly likely that the ${\beta}$-Lap treahment applied 5 h after irradiation could not inhibit the repair of radiation-induced damage. For in vivo study, RKO cells were injected S.C. into the hind-leg of Nu/Nu mice, and allowed to grow to 130 mm3 tumor. The mice were i.p. injected with ${\beta}$-lapachone or saline 2 h after irradiation of tumors with 10 Gy of X-rays. The radiation induced growth delay was increased by 2.4 $\mu\textrm{g}$/g of ${\beta}$-lapachone. Taken together, we may conclude that the synergistic interaction of radiation and ${\beta}$-Lap in killing cancer cells is not due to radiosensitization by ${\beta}$-Lap but to an enhancement of ${\beta}$-Lap cytotoxicity by radiation through an upregulation of NQO1. The fact that NQO1 is elevated in tumors and that radiation causes prolonged increase of the NQO1 expression may be exploited to preferentially kill tumor cells using ${\beta}$-Lap in combination with radiotherapy.

• Korean Journal of Breeding Science
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• v.43 no.6
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• pp.513-518
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• 2011

'Hongjinju', the reddish brown coloured rice variety, was developed by the rice breeding team of National Institute of Crop Science, RDA during the period from 1990 to 2006 and released in 2007. The cultivar was derived from a cross between Suwon 383, and $SR18164F_2$, a reddish brown pigmented line. 'Hongjinju' is medium maturity with 133 days of growth duration from seeding to heading and is japonica-type with about 82 cm in culm length. 'Hongjinju' has slightly less number of tillers per hill and more spikelets of panicles than those of 'Heugjinjubyeo'. It is susceptible to leaf blast, other disease and insect pests. It shows intermediate germination ratio at low temperature and similar tolerance to leaf discolor at seeding stage and heading-delay but it is resistant to spikelets-sterility type of cold damage at maturing stage compared with 'Heugjinjubyeo'. The yield performance of this variety in brown rice is about 5.07 MT/ha and is adaptable to the central and southern plain areas of Korea.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.66 no.2
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• pp.138-145
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• 2021

Perilla contains more than 60% of fatty acids. Linolenic acid is effective in preventing heart disease, improving learning ability, treating allergies, and preventing cancer. This study was carried out to improve the cultivation method to aid the stable production of perilla by developing a suitable inter-cropping system with sesame in the central region as well as to report a suitable planting time. The test results are summarized as follows. As the planting time of perilla in the inter-cropping system with sesame was delayed, the number of clusters and capsules decreased. The perilla yields in this system showed significant differences compared to that with the previous crops (sesame varieties) and planting period. The yield of perilla was significantly lower in the characteristic-Type B variety than in the characteristic-Type A variety and decreased significantly as the planting time was delayed. With regards to the quality characteristics of perilla, such as crude protein, crude fat, etc., there were no differences between previous perilla crops and those inter-cropped with sesame. The perilla composition did not show any difference during the planting period; however, with delay in the planting time, crude protein content increased but crude fat content decreased. Yield of perilla was 38% higher in a two-row (40 x 40 cm) system, compared to a single-row cultivation (110 x 20 cm) of perilla inter-cropped with sesame. These results suggest that the suitable method for inter-cropping perilla with sesame in the central region is to sow the characteristic-Type A variety in early May, and cultivate the perilla in two lines (40 x 40 cm) in mid-June. This was judged to be the best cultivation method in the central region.

• Journal of Korea Port Economic Association
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• v.37 no.3
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• pp.117-128
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• 2021

In order for the users (shipping firms and shippers) and suppliers (stevedoring firms) in the container terminal industry to win-win, it is necessary to have some appropriate diverse market conditions for the industry. This study analyses the basic conditions and demand and supply characteristics of the industry and investigates the market performance of Busan container ports. First, this article analyses the basic characteristics of demand and supply. As the demand characteristics, there are five ones such as 1) exogeneity of demand, 2) function as export/import transportation and hub for transshipment, 3) increase of users' bargaining power, 4) high substituting elasticity, 5) reduction of volume growth. As the supply characteristics, there are seven ones such as 1) inelasticity of supply, 2) homogeneity of stevedoring services, 3) over-supply, 4) adoption of cutting-edge stevedoring technology, 5) scale economy and impossibility of storage, 6) labor market rigidity, 7) enhancing port's role in SCM. In addition, this study conducts the so-called structure-conduct-performance analysis. For the structure analysis, 1) lacks of scale economy in stevedoring companies, 2) high entry barrier, 3) strengthening of shipping firms' bargaining power, 4) transitory permission scheme for tariff are analyzed. For the conduct analysis, 1) price discrimination between export/import and transshipment, 2) mid-term length of terminal use contract, 3) continuous investment in equipment, 4) low level of cooperation among terminal operating firms are derived. For the performance analysis, 1) inequality in profitability, 2) reduction of export/import cost, 3) delay in adopting cutting-edge technology, 4) idle equipment are analyzed. Following this logical flow, the hypothesis that the market structure influences the market conduct is tested based on the actual dataset. As a future agenda in the conclusion, this article recommends the so-called port industrial policy.

• Journal of Food Hygiene and Safety
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• v.38 no.2
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• pp.55-62
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• 2023

This study aimed to investigate the effect of a coating agent on pork storage. Pork was coated with a coating agent containing sodium carboxymethyl cellulose (CMC) and mandarin peel powder (M). The treatments were divided into control, a 0.1% CMC treatment, and a 0.1% CMC +5% M treatment, and pH, color, 2-thiobarbituric acid reactive substances (TBARS), volatile basic nitrogen (VBN), and the number of viable cell counts were measured. In the case of redness (a), it was found that the reduction over the storage period was less in the 0.1% CMC + 5% M treatment than in the control and the 1% CMC treatment. When stored at 4℃ and 25℃, TBARS of pork tended to increase during the storage period, followed by control, 0.1% CMC treatment, and 0.1% CMC + 5% M treatment, indicating that lipid oxidation was most suppressed in pork coated with mandarin peel powder. As a result of measuring the VBN of pork stored at 4℃ and 25℃, the 0.1% CMC + 5% M treatment showed lower values than the control and 0.1% CMC treatment. When the film-coated pork was stored at 4℃, the number of viable cell counts in the 0.1% CMC +5% M treatment area was 7.13±0.96 log CFU/g on the 12th day of storage, delaying the growth of viable cell counts for approximately 3 d more than other treatments. Therefore, coating pork with a film containing CMC and mandarin peel powder has been confirmed to delay the increase in the number of viable cell counts while reducing the quality change during pork storage, which is an effective alternative to improving the storage of fresh food as an edible film.

• Journal of Life Science
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• v.33 no.4
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• pp.357-362
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• 2023

This report looks at an agar-degrading marine bacterium and characterization of its agarase. Agar-degrading marine bacterium JS-1 was isolated with Marine agar 2216 media from seawater from the seashore of Sojuk-do, Changwon in Gyeongnam Province, Korea. The agar-degrading bacterium was named as Agarivorans sp. JS-1 by phylogenetic analysis based on 16S rRNA gene sequencing. The extracellular agarase was prepared from the culture media of Agarivorans sp. JS-1 and used for characterization. Relative activities at 20℃, 30℃, 35℃, 40℃, 45℃, 50℃, 55℃, and 60℃ were 70%, 74%, 78%, 83%, 87%, 100%, 74%, and 66%, respectively. Relative activities at pH 5, 6, 7, and 8 were 91%, 100%, 90%, and 89%, respectively. Its extracellular agarase showed maximum activity (207 units/l) at pH 6.0 and 50℃ in 20 mM Tris-HCl buffer. The residual activity after heat treatment at 20℃, 30℃, and 50℃ for 30 minutes was 90%, 70%, and 50% or more, respectively. After a 2-hour heat treatment at 20℃, 30℃, 35℃, 40℃, and 45℃, the residual activity was 80%, 68%, 65%, 63%, and 57%, respectively. At 50℃ and above, after heat treatment for 30 minutes, the residual activity was below 60%. Thin layer chromatography analysis suggested that Agarivorans sp. JS-1 produces extracellular β-agarases as they hydrolyze agarose to produce neoagarooligosaccharides such as neoagarohexaose (20.6%), neoagarotetraose (58.5%), and neoagarobiose (20.9%). Agarivorans sp. JS-1 and its thermotolerant β-agarase would be useful in the production of neoagarooligosaccharides, showing functional activity such as inhibition of bacterial growth and delay of starch degradation.

• The Korean Journal of Zoology
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• v.15 no.1
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• pp.25-33
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• 1972

Two-Cell mouse embryos were incubated in the anterior chamber of the rat eye, which has been known as the best place among other animals' for the mouse ovum maturation, in order to observe the capability of their early development. Within 120 hours after incubation, 71.0% of two-cell embryos have developed to the blastocysts in the male rat eye, while only 38.5% in the eye of the same mouse as donated two-cell embryos. Thus, the rat eye chamber provides more favourable environment to the embryos than the mouse itself. The results are consistent with those of the previous studies comparing the maturation of the mouse follicular oocytes in the mouse and the rat eye chamber. Although the aqueous humor which is filled in the anterior chamber of the eye is characterized by its specific properties, being of higher osmolarity, higher concentrations of ascorbic acid, pyruvate and lactate, but lower of proteins and lower temperature than those in blood or lymph serum, The embryos are able to under-take their cleavage as normal as in vivo or in vitro. Concerning with a number of studies in vitro on the development of the mouse embryos which are requiring a very limited condition, the fact that they are able to manage their further development under very different enviroment from our knowledges would provide us a moment to understand their behavior during the early development. The difference of the proportion of the developed blastocysts between in the mouse eye chamber and in the rat can possibly be resulted from the species specific difference in the physicochemical properties between their eye chambers. This assumption is based upon the findings by many investigators who chmpared the nature of the eye chamber of various animals. As a consequence, the rat eye chamber might consist of better properties for the embryonal growth than the mouse eye chamber. The mouse embryos cleaved with a delayed period. In normal development they complete almost the cleavage within 94 hours after fertilization. However, in the present studies, 81.1% of two-cell embryos developed to the blastocysts and the morula in 120 hours in the eye chamber, assumed to be about 154 hours after fertilization. Such delay in development would be caused mainly by the low temperature of the eye chamber. At present we can make two assumptions to explain the capability of the emtryonal development in the eye chambers. One is that the embryos would possess an ability to adapt themselves to the environment which provides unfavourable conditions. The other is that the embryos might remain for a certain duration in the eye chamber, which is filled with a new body fluid produced immediately after the loss of the aqueous humor and the fluid of which becomes similar to blood serum in component. The first assumption is highly reliable since the embryonal cells are mostly at the undifferentiated state and so they probably engage a simple metabolism during their early period. The second assumption is induced by the fact that the rabbit eye chamber produces a plasmoid humor which has mostly similar components to blood serum after loss of aqueous humor through cornea by puncturing. However, the plasmoid humor is substituted by the initial aqueous humor in eight hours. Even though this finding, production of the new fluid, could be applied to the rat eye, it is hardly reliabel that the plasmoid humor remains for such a long period as 120 hours. Consequently, the development of the embryos is more likely due to their adaptability to the new environment during their early developmental stages.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.68 no.4
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• pp.304-312
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• 2023

Plant breeding is a time-consuming process, mainly due to the limited annual generational advancement. A speed breeding system, using LED light sources, has been applied to accelerate generational progression in various crops. However, detailed protocols applicable to soybeans are still insufficient. In this study, we report the optimized protocols for a speed breeding system comprising 12 soybean varieties with various maturity ecotypes. We investigated the effects of two light qualities (RGB ratio), three levels of light intensity (PPFD), and two soil conditions on the flowering time and development of soybeans. Our results showed that an increase in the red wavelength of the light spectrum led to a delay in flowering time. Furthermore, as light intensity increased, flowering time, average internode length, and plant height decreased, while the number of nodes, branches, and pods increased. When compared to agronomic soil, horticultural soil resulted in an increase of more than 50% in the number of nodes, branches, and pods. Consequently, the optimal conditions were determined as follows: a 10-hour short-day photoperiod, an equal RGB ratio (1:1:1), light intensity exceeding 1,300 PPFD, and the use of horticultural soil. Under these conditions, the average flowering time was found to be 27.3±2.48 days, with an average seed yield of 7.9±2.67. Thus, the speed breeding systems reduced the flowering time by more than 40 days, compared to the average flowering time of Korean soybean resources (approximately 70 days). By using a controlled growth chamber that is unaffected by external environmental conditions, up to 6 generations can be achieved per year. The use of LED illumination and streamlined facilities further contributes to cost savings. This study highlights the substantial potential of integrating modern crop breeding techniques, such as digital breeding and genetic editing, with generational shortening systems to accelerate crop improvement.

• Horticultural Science & Technology
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• v.32 no.1
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• pp.53-59
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• 2014

This study aimed to determine an appropriate cooling timing in the root zone for lowering substrate temperature and its effect on physiological response of sweet pepper (Capsicum annum L. 'Orange glory') grown on coir substrate in summer, from the July 16 to October 15, 2012. Daily temperature of substrate, root activity, leaf water potential, first flowering date, and the number of fruits were measured by circulating cool water through a XL pipe in the root zone during either all day (all-day) or only night time (5 p.m. to 3 a.m.; night) from the July 23 to September 23, 2012. For comparison, no cooling (control) was also applied. Between the $23^{rd}$ of July and $31^{st}$ of August (hot temperature period), daily average temperatures in substrates were $25.6^{\circ}C$, $26.1^{\circ}C$, and $29.1^{\circ}C$ for the all-day and night treatment, and control respectively. About 1.8 to $5^{\circ}C$ lower substrate temperature was observed in both treatments compared to that of control. In sunny day ($600-700 W{\cdot}m^{-2}{\cdot}s^{-1}$), the highest temperature of substrate was measured between 4 p.m. and 5 p.m. under both the all-day and night treatments, whereas it was measured between 7 p.m. and 8 p.m. under the control. Substrate temperatures during the day (6 a.m. to 8 p.m.) and night (8 p.m. to 6 a.m.) differed depending on the treatments. During the day and night, averaged substrate temperature was lower about $3.3^{\circ}C$ and $4.0^{\circ}C$ for the all-day, and $2.1^{\circ}C$ and $3.4^{\circ}C$ for the night treatment, compared to that of control. In the all-day and night treatment, the TD [TD = temperature of (control)] was greater in bottom than that of other regions of the substrate. Between the day and night, no different TD values were observed under the all-day treatment, whereas under the night treatment there was difference with the greatest degree in the bottom of the substrate. During the hot temperature period, total numbers of days when substrate temperature was over $25^{\circ}C$ were 40, 23 and 27 days for the control, all-day, and night treatment, respectively, and the effect of lowering substrate temperature was therefore 42.5% and 32.5% for the all-day and night treatment, respectively, compared to that for the control. Root activity and leaf water potential of plants grown under the all-day treatment were significantly higher than those under the night treatment. The first flowering date in the all-day treatment was similar to that in the night treatment, but 4-5 day faster than in the control. Also, the number of fruits in both treatments was significantly higher than that in the control. However, there was no effect of root zone cooling on eliminating delay in fruiting caused by excessively higher air temperature (> $30^{\circ}C$), although the substrate temperature was reduced $18^{\circ}C$ to $5^{\circ}C$. These results suggest that the method of cooling root zone temperature need to be incorporated into the lowering growing temperature for growth and fruit set of health paprika.