• Korean Journal of Heritage: History & Science
• /
• v.49 no.2
• /
• pp.56-69
• /
• 2016

Flame resistant treatment has been applied since 1973 for fire prevention in historical wooden buildings, but several problems, such as whitening and discoloration are constantly occurring in some Dancheong, in spite of evaluation criteria. It is supposed that these phenomena are caused by the stability issue of flame retardant, Dancheong production methods, the residue of chemicals, which were applied in the past, building location environments, etc., but no evaluation and cause inspection has been performed. Therefore, this study aims to verify the effect of flame retardant on Dancheong by producing Pseudo-samples and setting spatial and temporal environment conditions. Pseudo-samples of Dancheong were produced using three methods; the method specified in the Standard Specification of Properties; the method, which is generally used in the site and the traditional method. For different environment conditions of pseudo-samples, the areas were classified into a coastal area and an inland area and the places were classified into a sunny place and a wetland. After applying a flame retardant, annual variations were inspected for 12 months and change aspects were observed through scan and regular observation. In annual variation inspection, various variations like whitening, decolorization, dissolution and exfoliation were found and especially, whitening was most dominant. When the effect of flame retardant depending on the production methods was analyzed, whitening occurred in all the three production methods. It is supposed that this is because calcium(Ca) was contained in the coloring material of each production method and it reacted with phosphorous(P) of flame retardant. When the effect of flame retardant depending on the environment conditions was analyzed, whitening occurred more in the coastal area than in the inland area and it reduced in the building in a sunny place, which was constructed using the traditional method. It is supposed that this results from the humidity change and the difference of glue used in each production method. In conclusion, for using a flame retardant containing phosphorous(P), there is a need to check if calcium components including Oyster Shell White were used in Dancheong in advance and to conduct various preliminary studies on place conditions and Dancheong construction conditions.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.66 no.2
• /
• pp.146-154
• /
• 2021

This study was conducted to determine the degree of reduction in the yield of sweetpotato subjected to different shading treatments according to the growing season of the typical viscous sweetpotato 'Hogammi' and the powdery sweetpotato 'Jinyulmi'. Shading was provided using commercially available shading nets (55% and 75% shading level), and the treatments were applied at the following stages of storage root growth: SFS: the storage root formation stage (planting-50^th day), SSS: the storage root swelling stage (50-90^th day), and SAS: the storage root actively swelling Stage (90-120^th day). The growth characteristics according to shading treatments during each growth period, the number of tubers obtained at harvest, and sugar contents were investigated. For both assessed cultivars, there was no significant difference between the control group and the 55% shading treated group with respect to the maximum quantum yield (Fv/Fm) of photosystem II under different shading treatments, whereas the 75% shading group showed slightly higher values than the control group. In both cultivars, the contents of chlorophyll a and b tended to increase in plants subjected to shading treatments compared with the control plants, particularly that of chlorophyll b. Compared with the control group, the chlorophyll b content of 'Hogammi' subjected to 55% and 75% shading increased by 47% and 41%, respectively, whereas that of 'Jinyulmi' increased by 39% and 34%, respectively. We also detected reductions in the dry weights of the above- and belowground parts of the two varieties in response to shading compared with the control, with the reduction in the dry weight of belowground parts being significant. Furthermore, in both varieties, the T/R rate tended to increase in response to shading treatment. Owing to the lack of sunlight, both cultivars tended to suppress the formation and enlargement of tuber roots. Consequently, post-harvest yield analysis revealed that under shading treatments, both cultivars were characterized by poor tuber root growth according to growing season, with the yield of 'Hogammi' showing a greater reduction compared with that of 'Jinyulmi'. In addition, we found that the higher shading level also significantly reduced yields. Compared with the storage root formation and storage root actively swelling stages, shading treatments during the storage root swelling stage significantly affected yield reduction in both varieties.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.64 no.3
• /
• pp.165-175
• /
• 2019

In response to elevated temperature, a shift in the rice planting period was proposed as a promising option in temperate regions. To understand the yield response of early maturing rice to different transplanting dates and to analyze the related agronomic traits in the central plain area, we performed a two-year study using different transplanting dates and six varieties in Suwon, Korea. The maximum head rice weight was achieved in the treatments transplanted between June 14 and 29, depending upon the varieties. The optimal mean temperature during the 40 days from heading stage for attaining the maximum head rice weight was $21.8^{\circ}C$ on the average of six varieties. The index of head rice weight was positively correlated with the indices of both the milled rice weight and head rice percentage, the latter showing a higher coefficient of determination. The highest milled rice weight was commonly achieved from the treatment transplanted on June 29, where the head rice weight was also the highest. The index of milled rice weight was significantly correlated with the indices of grain filling percentage and number of spikelets per area, but not correlated with the index of 1000-brown rice weight. The transplanting date with the highest milled rice yield produced the largest number of spikelets per area, greatest biomass at the heading and harvesting stages, and highest level of harvest index. We suggest that the optimal transplanting date for early maturing rice varieties in the central plain area is from June 14 to 29. High head rice yield in this study was attributed to increased spikelets owing to the increased biomass production at the heading stage, enhanced grain filling due to the high biomass production and harvest index at maturity, and improved head rice percentage.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.41 no.2
• /
• pp.102-109
• /
• 2021

In this study, the effect of forage sources in the total mixed ration (TMR) on in vitro goat rumen fermentation was investigated. Rice straw (RS), Italian ryegrass (IRG), timothy (TIM), and alfalfa (ALF) were used as forage sources. Each forage source was mixed with a commercial goat concentrate diet in the ratio of 1:1. Total 4 TMR were prepared. Rumen simulated in vitro fermentation using goat rumen fluid collected from the slaughterhouse was conducted until 72^th. For fermentation parameters, gas production (GP), volatile fatty acids (VFAs), and ammonia nitrogen (NH₃-N) were examined. All assays were performed at 24^th, 48^th, and 72^th h of incubation individually. Contents of crude protein and non-fibrous carbohydrate were greater in the order of RS < IRG < TIM < ALF. Significant treatment effects were found in valerate and NH₃-N at 24^th h of incubation (p<0.05). ALF showed the greatest contents of them and RS was the lowest. At 48^th incubation, a significant effect was detected at GP (p<0.05) and RS was greater than others. However, GP of RS was lower than others at 72^th. Significant effects on Total VFA, butyrate, and valerate productions were found at 72^th h of incubation (p<0.05). ALF showed the greatest production. Methane production from all treatments was not significantly different for each incubation time (p>0.05). The present study provided primary information on how goat rumen fermentation responds to different nutrient contents and forage sources of TMR. And the information could be used for the design or optimizing economical diet formulation for goats.

• Journal of Korean Society of Forest Science
• /
• v.110 no.1
• /
• pp.53-63
• /
• 2021

Sophora koreensis Nakai is an indigenous plant in Koreawith a restricted natural range, part of which is in Gangwon province. The species is known to contain phytochemicals that have beneficial effects on human health, and it is economically important in bioindustry. Because of the limited number of plants in a small range of habitats, the mass-propagation method should be developed for use and conservation. In vitro tissue culture is a reliable method in terms of mass propagation from selected clones of the species. We investigated the optimal conditions of the medium in this process, especially focusing on the concentrations of plant growth regulators(PGRs) in the culture of stem-containing axillary buds. Three statistical methods, i.e., ANOVA, response surface method(RSM), and fuzzy clustering were used to analyze the plant growth, number of shoots induced, and shoot length with various combinations of PGRs. Results from the RSM differed from those of the other two methods; thus, the method was not suitable. ANOVA and fuzzy clustering showed similar results. However, more accurate results were obtained using fuzzy clustering because it provided a probability for each treatment. On the basis of the fuzzy clustering analysis, stem tissue produced the greatest number of shoots(11.03 per explant; 63.33%) on a medium supplemented with 5-��M 6-benzylaminopurine and 2.5-��M thidiazuron(TDZ). Proliferation of shoots(2.18 ± 0.21 cm, 63.33%) was attained on a medium supplemented with 2.5-��M BA, 2.5-��M TDZ, and 2.5-��M gibberellic acid.

• Journal of Life Science
• /
• v.32 no.4
• /
• pp.271-278
• /
• 2022

The detailed mechanism by which cancer upregulated gene 2 (CUG2) overexpression induces cancer stem cell-like phenotypes is not fully understood. The downregulation of FBXW7 E3 ligase, a tumor suppressor known for its proteolytic regulation of oncogenic proteins such as cyclin E, c-Myc, Notch, and Yap1, has been frequently reported in several types of tumor tissues, including those in the large intestine, cervix, and stomach. Therefore, we investigated whether FBXW7 is involved in CUG2-induced oncogenesis. In this study, the decreased expression of FBXW7 was examined in human lung adenocarcinoma A549 (A549-CUG2) and human bronchial BEAS-2B cells (BEAS-CUG2) overexpressing CUG2 and compared with control cells stably expressing an empty vector (A549-Vec or BEAS-Vec). Treatment with MG132 (a proteosome inhibitor) prevented the degradation of FBXW7 and Yap1 proteins, which are substrates of the FBXW7 E3 ligase. To address the role of Fbxw7 in the development of cancer stem cell (CSC) phenotypes, we suppressed Fbxw7 protein levels using its siRNA. We observed that decreased levels of FBXW7 enhanced cell migration, invasion, and spheroid size and number in A549-Vec and BEAS-Vec cells. The enforced expression of FBXW7 produced the opposite results in A549-CUG2 and BEAS-CUG2 cells. Furthermore, the downregulation of FBXW7 elevated the activities of EGFR, Akt, and ERK1/2 and upregulated β-catenin, Yap1, and NEK2, while the enforced expression of FBXW7 generated the opposite results. We thus propose that FBXW7 downregulation induced by CUG2 confers CSC-like phenotypes through the upregulation of both the EGFR-ERK1/2 and β-catenin-Yap1-NEK2 signaling pathways.

• The Korea Journal of Herbology
• /
• v.37 no.5
• /
• pp.89-96
• /
• 2022

Objectives : This research was performed to analyze the components in the different parts of Lythrum salicaria L. and to compare which parts of L. salicaria L. are appropriate for food development. Methods : L. salicaria L. was extracted in 20% EtOH at 100 ℃ for 4 hours. Cytotoxicity was investigated in 3T3-L1 cells after treatment of 10-500 ㎍/ml L. salicaria L. for 24 hours. Total polyphenol content (TPC) was estimated using 1 N Folin-ciocateu reagent. 2,2-Diphenyl-1-picryhydrazyl (DPPH) radical scavenging activity was estimated using DPPH reagent and gallic acid. The chemical composition was analyzed by high-performance liquid chromatography (HPLC). 1) Results : The half maximal inhibitory concentration (IC50) in the extracts of the whole plant, aerial parts, and root parts was 350 ㎍/ml, over 500 ㎍/ml, and 150 ㎍/ml, respectively. The TPC in the extracts of the whole plant, aerial parts, and root parts was 527.1 mg/g, 422.6 mg/g, and 781.1 mg/g, respectively. The averages of vitexin contents in the aerial parts, and root parts were 256.7 ± 154.9 ㎍/g and 266.1 ± 63.2 ㎍/g, respectively. The averages of TPC in the leaves, roots, flower stalks and stems were 224.0 ± 53.7 tannin acid (TA) mg/g, 221.8 ± 70.2 TA mg/g, 249.8 ± 34.4 TA mg/g, and 67.7±8.9 TA mg/g, respectively. The averages of DPPH radical scavenging activity in the leaves, roots, flower stalks, and stems were 282.01 ± 43.3 gallic acid equivalent (GAE) 𝜇mole/g, 260.16 ± 44.1 GAE 𝜇mole/g, 288.0 ± 9.3 GAE 𝜇mole/g, and 97.6 ± 10.7 GAE 𝜇mole/g, respectively. Conclusions : There were no significant differences in the content of components or antioxidant activity in the aerial parts compared to those in the whole plant of L. salicaria L. Furthermore, the root parts had low extract yield, cytotoxicity, and quality control problems, therefore our results suggest that the use of the aerial part of L. salicaria L. would be the most appropriate for food development.

• Pediatric Infection and Vaccine
• /
• v.28 no.3
• /
• pp.133-143
• /
• 2021

Purpose: This study aimed to determine the incidence of central line-associated bloodstream infection (CLABSI) in the neonatal intensive care unit (NICU), evaluate the patients' clinical characteristics, and identify the etiologic agents for guidance in prevention and treatment. Methods: A retrospective chart review study of infants classified as having CLABSI was conducted at the NICU of Seoul National University Bundang Hospital from January 2016 to December 2020. Results: Of the 45 infants, 53 had CLABSIs within a follow-up period of 18,622 catheter days. The incidence of CLABSIs was 2.85 per 1,000 catheter days. The most common catheter type was a peripherally inserted central catheter (n=47, 81%). A total of 57 pathogens were isolated, of which 57.9% (n=33) were Gram-positive bacteria, 36.8% (n=21) were Gram-negative bacteria, and 5.3% (n=3) were Candida spp. The most common pathogens were Staphylococcus aureus (n=12, 21%) and coagulase-negative staphylococci (n=12, 21%), followed by Klebsiella aerogenes (n=8, 14%). The median duration of bacteremia was 2 days, and 19 episodes showed bacteremia for 3 days or more. The mortality rate of infants within 14 days of CLABSI was 13.3% (n=6). Conclusions: This study analyzed the incidence of CLABSI and the distribution of pathogens in the NICU. Continuous monitoring of CLABSI based on active surveillance serves as guidance for empiric antibiotic use and also serves as a tool to assess the necessity for implementation of prevention strategies and their impact.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.68 no.1
• /
• pp.27-33
• /
• 2023

Several domestically consumed sweetpotato derivatives, such as sweetpotato starch for processing raw materials, frozen and refrigerated paste, and powder are dependent on imports. This study was conducted to examine the suitability of sweetpotato cultivars of twelve varieties (powdery-type and viscous type) cultivated in paddy fields, for use in starch, chips, dried products, and beverages. The two-year average yield results of the four cultivars suitable for starch (in order of highest to lowest yield) was as follows: Gogeonmi (4,018 kg/10a); Daeyumi (3,615 kg/10a); Jinhongmi (3,426 kg/10a); Singeonmi (2,837 kg/10a). The starch content was 20.2%, 18.2%, 21.2%, and 20.6% in Daeyumi, Gogeonmi, Singeonmi, and Jinghongmi, respectively. The total amount of starch was higher in Daeyumi (730 kg/10a) and Gogeonmi (731 kg/10a) than that in Singeonmi and Jinghongmi. The yield of Pungwonmi and Shinjami were 4,443 and 3,602 kg/10a, respectively. Powdery-type sweetpotatoes (Daeyumi and Gogeonmi) showed the low decay rates of all cultivars (0.8 and 0%, respectively). The yield of the storage root formation and storage root swelling stages by water-logging treatment decreased by 16.5% and 15.4% for Pungwonmi, and by 17.2% and 10.0% for Shinjami. Drainage management of paddy fields is necessary to reduce the damage caused by water-logging. Our results suggest that cultivation of sweetpotato varieties suitable for processing raw materials in paddy fields will enable stable yields of sweetpotato with a high starch content.

• Korea Science and Art Forum
• /
• v.19
• /
• pp.281-292
• /
• 2015

For this study, I conducted a survey investigating current situation, user preference, and field experiment. Hospitals utilizing digital sign systems at least five years were selected, which are connected with visual elements (layout, typo, color) used in waiting areas and elements of the systems (time, video time line). The results obtained from the field survey showed that digital sign systems used the color of typo and background contrasted to one another to increase explicitness and to ensure easy understanding of contents. In addition, the Gothic typo with relatively high legibility was adopted. Time and video timeline, which characterize digital sign systems, showed the advertising screens of the hospitals and the guidance of medical treatment at regular intervals. Moreover, survey results on user satisfaction showed that a majority of respondents indicated they had difficulty in understanding digital information conveyed from digital sign systems due to time setting for rotational speed or the small size of typo although most of the users had previous experience with digital sign systems. The highest proportion of respondents (n=86, 86%) answered that information related to medical departments was what they sought most frequently and that this kind of information should be importantly considered in digital sign systems. For the experiment, new samples with restructured contents of current digital sign systems were created and tested while keeping its design unchanged as well as applying these new samples. Study participants were in their 20s through 50s. When the size of typo was larger under the same conditions for all age groups, study participants found the desired information approximately 3.5 seconds faster. In addition, those in their 20-30s and 40-50s showed the time difference of 4.7 seconds for small typo and 6 seconds for large typo, which suggested that there was a difference by age in the amount of time taken in the experiment to find the desired information from the rotating digital sign system regardless of age and the size of typo.