• Journal of Ecology and Environment
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• v.43 no.2
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• pp.226-245
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• 2019

To understand the dynamics of radial growth of trees and micro-climate at a site of Korean fir (Abies koreana Wilson) forest on high-altitude area of Mt. Hallasan National Park, Jeju Island, Korea, high precision dendrometers were installed on the stems of Korean fir trees, and the sensors for measuring micro-climate of the forest at 10 minutes interval were also installed at the forest. Data from the sensors were sent to nodes, collected to a gateway wireless, and transmitted to a data server using mobile phone communication system. By analyzing the radial growth data for the trees during the growing season in 2016, we can estimate that the radial growth of Korean fir trees initiated in late April to early May and ceased in late August to early September, which indicates that period for the radial growth was about 4 months in 2016. It is interesting to observe that the daily ambient temperature and the daily soil temperature at the depth of 20 cm coincided with the values of about 10 ℃ when the radial growth of the trees initiated in 2016. When the radial growth ceased, the values of the ambient temperature went down below about 15 ℃ and 16 ℃, respectively. While the ambient temperature and the soil temperature are evaluated to be the good indicators for the initiation and the cessation of radial growth, it becomes clear that radii of tree stems showed diurnal growth patterns affected by diurnal change of ambient temperature. In addition, the wetting and drying of the surface of the tree stems affected by precipitation became the additional factors that affect the expansion and shrinkage of the tree stems at the forest site. While it is interesting to note that the interrelationships among the micro-climatic factors at the forest site were well explained through this study, it should be recognized that the precision monitoring made possible with the application of high resolution sensors in the measurement of the radial increment combined with the observation of 10 minutes interval with aids of information and communication technology in the ecosystem observation.

• The Korean Journal of Food And Nutrition
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• v.30 no.2
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• pp.378-387
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• 2017

To stabilize the supply of kimchi by extending the storage period of spring kimchi cabbage, this study manufactured kimchi from spring kimchi cabbage under varying storage conditions and periods, and analyzed their quality and sensory characteristics following the maturing period. Trimming loss was lowest in the group of plasma+reverse direction+predrying+HDPE film processing. The salting yield of spring kimchi cabbage stored for 12 weeks was lower than that of spring kimchi cabbage stored for 6 weeks, and the kimchi yield was low in the pre-treatment group of spring kimchi cabbage stored for 12 weeks. The firmness was slightly different according to the storage period from one month of maturation. From the perspective of pH and acidity, the maturation in the reverse direction+pre-drying+HDPE film processing group was slower than that in the normal group (<0.05). In the sensory evaluation, the preference was increased in the low temperature storage processing group as the maturation period was increased (<0.05).

• Polymer(Korea)
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• v.27 no.3
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• pp.265-270
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• 2003

In spite of high ionic conductivity, the polymer gels have poor mechanical properties and high reactivity with lithium metal anode. To solve these problems, the dry solid systems and polymer composites have been intensively studied, due to their good mechanical, thermal, chemical, and electrochemical stability. The objectives of this experiment were to improve ionic conductivity and mechanical properties of the solid polymer electrolytes based on PEO-LiClO$_4$. To obtain higher ionic conductivity and better mechanical properties, ceramic or rubber phase was added in the PEO-LiClO$_4$(8:1) matrix. The results showed that ionic conductivity and mechanical properties were improved. The ionic conductivity of the samples was as high as 10$\^$-5/ S cm$\^$-1/. This value is similar to the best ionic conductivity ever reported in the solid drying system. To obtain better results, we used PEO with various molecular weights (600∼8000) and changed the salt contents. By using DSC, we found that the addition of salt reduced the crystallinity of PEO. The mobility of polymer dependence on salt contents was examined by FT-IR.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.8
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• pp.298-303
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• 2020

This study examined the washing conditions for high-quality solar salt. The salinity of the washing water was set to 5 % to prevent yield loss, and the temperatures of the washing water were 5, 10, 17.5, and 20 ℃. After washing the solar salt, the moisture content, salinity, insoluble matter, and sandy powder were measured from the solar salt. In addition, the color properties, L*[lightness], a*[redness], b*[yellowness], and yield were measured. The moisture content of the salt showed a tendency to increase when the temperature of the washing water was above 10 ℃, and the salinity and yield tended to decrease as the temperature of the washing water was high. The amount of insoluble matter decreased with decreasing temperature of the washing water. In the case of sandy powder, the highest value was 0.67 % at a washing water temperature of 5 ℃, and the value was 0.57 % under the other temperature conditions. Regarding the color properties, the b* [yellowness] of the color of the solar salt increased when the washing water temperature was high. This appeared to decrease the appearance quality. According to the above results, a washing water temperature above 10 ℃ was appropriate. The development of design factors of a high-quality solar salt production system is expected with experiments to define the drying conditions after the washing process.

• Journal of the korean academy of Pediatric Dentistry
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• v.30 no.1
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• pp.143-152
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• 2003

The aims of the present study was to observe resin tag of the resin/enamel, dentin interface produced by self-etching adhesive systems and evaluate effect of additional acid etching on resin tag formation. Three self-etching primer(SE bond, AQ bond and L Pop) and an one bottle adhesive(Single bond) were used. Flat occlusal enamel and dentin disks were obtained from extracted human molars. A total of 20 surfaces were collected and divided into four groups of 5 samples. One-half of each specimen in each group was etched with 35% phosphoric acid prior to the application of each adhesive system, with the second half being kept unetched. Subsequently, resin composite was placed and polymerized. The samples were sliced and immersed into HCl and NaOCl solutions, followed by drying and sputter coating for examination with a SEM. The results were as follows; 1. Additional etching side of dentin displayed longer and thicker resin tag than unetched side in all self-etching adhesive groups. 2. In enamel, additional etching side displayed deeper and more distinct etching pattern than unetched side except L Pop. There is no difference between etched and unetched enamel in L Pop. The results obtained suggest the self-etching adhesive did not etch enamel and penetrate into dentinal tubule as deeply as did additional etching. Further research should include the evaluation of the relationship of boding strength, microleakage and resin tag morphology.

• Nuclear Medicine and Molecular Imaging
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• v.43 no.2
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• pp.91-99
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• 2009

Noninvasive imaging of molecular and biological processes in living subjects with positron emission tomography(PET) provides exciting opportunities to monitor metabolism and detect diseases in humans. Measuring these processes with PET requires the preparation of specific molecular imaging probes labeled with $^{18}F$-fluorine. In this review we describe recent methods and novel trends for the introduction of $^{18}F$-fluorine into molecules which in turn are intended to serve as imaging agents for PET study. Nucleophilic $^{18}F$-fluorination of some halo- and mesyloxyalkanes to the corresponding $^{18}F$-fluoroalkanes with $^{18}F$-fluoride obtained from an $^{18}O(p,n)^{18}F$ reaction, using novel reaction media system such as an ionic liquidor tert-alcohol, has been studied as a new method for $^{18}F$-fluorine labeling. Ionic liquid method is rapid and particularly convenient because $^{18}F$-fluoride in $H_2O$ can be added directly to the reaction media, obviating the careful drying that is typically required for currently used radiofluorination methods. The nonpolar protic tert-alcohol enhances the nucleophilicity of the fluoride ion dramatically in the absence of any kind of catalyst, greatly increasing the rate of the nucleophilic fluorination and reducing formation of byproducts compared with conventional methods using dipolar aprotic solvents. The great efficacy of this method is a particular advantage in labeling radiopharmaceuticals with $^{18}F$-fluorine for PETimaging, and it is illustrated by the synthesis of $^{18}F$-fluoride radiolabeled molecular imaging probes, such as $^{18}F$-FDG, $^{18}F$-FLT, $^{18}F$-FP-CIT, and $^{18}F$-FMISO, in high yield and purity and in shorter times compared to conventional syntheses.

• The Korean Journal of Food And Nutrition
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• v.29 no.6
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• pp.1023-1029
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• 2016

Probiotic functional foods are known to have various functional effects such as intestinal regulation, modulation of immune system, reduction of allergies, and lowering of cholesterol. The purpose of this study was to select probiotic strain that is most suitable for freeze-dried coffee for the development of functional coffee products. The survival rate of probiotics, at drinking condition of coffee, at acid, at bile and after freeze-dried in coffee were measured on 1 strain isolated from commercial freeze-dried coffee, 8 strains used as fermented milk starter, 1 Bifidobacterium and 1 Bacillus coagulans. Bacillus coagulans showed the highest survival rate from $2.4{\times}10^7cfu/g$ to $2.0{\times}10^7cfu/g$ especially after freeze-drying. The results at drinking condition of coffee, at acid tolerance, at bile tolerance and at storage test showed significantly better survival rate of Bacillus coagulans than that of control (Lactobacillus casei). Especially, Bacillus coagulans showed 3.8-fold higher survival rate at acid tolerance (pH 1, 120 minutes) than control. Thus, the lactic acid-producing Bacillus coagulans is characterized as a probiotic strain suitable for functional coffee formulation and commercialization.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.46 no.3
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• pp.219-229
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• 2020

Recently, since atopic dermatitis is sensitive to skin irritation, it has been suggested that the development of a patch that can effectively exhibit adhesion and absorption to a specific local area while minimizing skin irritation, and capable of appropriate drug release should be given priority. In this study, we tried to develop a hydrogel patch that minimizes skin irritation, adheres effectively to a specific area, and promotes absorption. The atopic patch was formulated into a super-absorbent hydrogel sheet using a freeze drying method. Cell viability assay was carried out using keratinocytes (HaCaT cell) and fibroblasts (L929 cells). In order to investigate the physical properties, FT-IR, FE-SEM, porosity analysis and swelling behavior were investigated. As a result, the newly prepared HA-Dex hydrogel patch was verified by biocompatibility and physical evaluation. In addition, the manufactured hydrogel patch has sufficient moisture absorption capacity and can relieve itching of atopic skin, and is expected to be applied to various drug delivery products for the treatment of atopic dermatitis in the future.

• Journal of Pharmacopuncture
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• v.17 no.1
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• pp.7-12
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• 2014

Objectives: The objective of this study is to investigate the effects of Salviae Miltiorrhizae Radix hot aqueous extract on nitric oxide (NO) and prostaglandin $E_2$ ($PGE_2$) production and on 1,1-diphenyl-2-picryl hydrazyl (DPPH) free-radical scavenging in macrophages. Methods: Salviae Miltiorrhizae Radix (300 g) was heated at $100^{\circ}C$ with distilled water (2 L) for 4 hours. The extract was filtered and concentrated to 100 mL by using a rotary evaporator, was frozen at $-80^{\circ}C$, and was then freeze-dried by using a freezing-drying system. The RAW 264.7 macrophage was subcultured by using $10-{\mu}g/mL$ lipopolysaccharide (LPS). In order to evaluate cytotoxicity, we performed 3-(4,5-dimrthylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assays and measured the cell viability. The NO production was measured by using Griess assays, and the $PGE_2$ production was measured by using enzyme immunoassays. The antioxidant activity, the 1,1-diphenyl-2-picryl hydrazyl (DPPH) free-radical scavenging capability, was measured by using the DPPH method. Results: Cell viability with the 1-, 5-, 25-, 125- and $625-{\mu}g/mL$ Salviae Miltiorrhizae Radix hot aqueous extract was not significantly decreased compared to the cell viability without the extract. When 125 and $625{\mu}g/mL$ of Salviae Miltiorrhizae Radix hot aqueous extract were used, nitric oxide (NO) production in LPS-stimulated RAW 264.7 macrophages was significantly inhibited compared to that in the control group. When 25, 125, and $625{\mu}g/mL$ of Salviae Miltiorrhizae Radix hot aqueous extract were used, $PGE_2$ production in LPS-stimulated RAW 264.7 macrophages was significantly inhibited compared to that in the control group. The 125- and $625-{\mu}g/mL$ Salviae Miltiorrhizae Radix hot aqueous extracts had high DPPH free-radical scavenging capabilities in RAW 264.7 macrophages. Conclusion: This study indicates that Salviae Miltiorrhizae Radix hot aqueous extract suppresses NO and $PGE_2$ production and improves DPPH free-radical scavenging capability. Thus, it seems that Salviae Miltiorrhizae Radix hot aqueous extract may have an anti-inflammation effect and antioxidant activity.

• Journal of the Korean Applied Science and Technology
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• v.31 no.4
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• pp.635-641
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• 2014

Archaeological waterlogged woods require a process of dimensional stabilization for their conservation. PEG is the most widely used in the conservation of archaeological waterlogged wood. One of the easiest and commonly used methods is the impregnation of 40% polyethylene glycol followed by vacuum freeze drying. However, the waste fluid produced from the PEG treatment is black in color and has a severe odor due to the organic matter extracted from the wood. Thus It cannot be recycled and it was just thrown out. Color of waste fluid can be decolored with oxidation reaction by hydrogen peroxide. Properties of PEG before and after preservation treatment, and after oxidation with $H_2O_2$ were not changed. Dimensional stability of archaeological waterlogged Salix koreensis Andersson was studied with pure or recycled PEG. The ratio of impregnation solutions were 10:0, 7:3, 5:5, 3:7, 0:10 (pure PEG : recycled PEG). Impregnation process was carried out by putting the wood specimens 10% PEG solution for 5days, 20% for 5 days, 30% for 5 days finally 40% for 5 days. All of the specimens showed the weight change rate of 25%. SEM results provided that the dimensional change of were less than 4% PEG impregnated specimens. Comparing with pure PEG impregnation system, conservation precess mixed PEG also showed no significant changes. Conclusively, the recycled PEG can be used for archeological waterlogged wood conservation precess.