• Journal of the Society of Cosmetic Scientists of Korea
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• v.42 no.4
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• pp.403-412
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• 2016

The tight junction, one of Intercellular junctions, performs a variety of biological functions by bonding adjacent cells, including the barrier function to control the movement of the electrolyte and water. Recent studies have revealed that unusual expression of tight junction-related genes have been shown to be related in cancer development and progression. Recently, there are many reports that control of tight junction proteins expression is closely related to the skin moisture. In this study, we are focusing on the regulating mechanism of tight junction-associated genes by the steviol and its derivatives. Steviol, used as a sweetner, is known to chemical compound isolated from stevia plant. The MTS (3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium, inner salt) assay was carried out in HaCaT cells (human keratinocyte cell line) in order to determine the cytotoxicity. As a result, while steviol showing cytotoxicity from $250{\mu}M$, steviol derivatives are not cytotoxic more than $250{\mu}M$ concentration. We have observed a change in the tight junction protein via quantitative real-time PCR. Claudin 8 among tight junction proteins is only significantly reduced up to 30% in the presence of steviol. In addition, cell migration was inhibited by steviol, not by stevioside and rebaudioside. Finally, we could observe that steviol, not stevioside and rebaudioside, is able to increase the skin barrier permeability through the transepithelial electric resistance (TEER) measurements. These results suggest that the steviol and its derivatives are specifically acts on the tight junction related gene expression, but steviol derivatives are more suitable as a cosmetic material.

• Korean Journal of Soil Science and Fertilizer
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• v.26 no.4
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• pp.241-248
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• 1993

An experiment was conducted in 1990~1991 to study the effects of various soil amelioration on the soil productivity and machine workability at tidal land paddy field of Kyewhado Substation, Homam Crop Experiment Station. The soil, Munpo Series(fine sandy loam, Typic Fluvaquents) was treated with gipsum, rice straw, rice straw compost and foreign soil(at 20cm depth) after deep ploughing. The results are surmerized as follows. 1. Sand and clay were slightly increased, while silt was slightly decreased in the rice straw and compost plots. The soil texture was changed from loam to sand loam by the addition of foreign soil 2. Soil bulk density and porosity was decreased in the rice straw, compost and foreign soil addition plots. 3. Cone penetration resistance was $12.5kg/cm^2$ at 10cm of soil depth before experiment and $12.5kg/cm^2$ at 20cm of soil depth after experiment except control, and the root zone was expended down to 20cm. 4. Soil salt content before experiment was 0.46 and 0.48% for surface soil(10cm) and subsoil(20cm), respectively ; The salt content of ameliorated plot was 0.26~0.32% and 0.16~0.31%, respectively, indicating good leaching of soil salt by the soil improvements. 5. The yields of rice in different treatments were in the order of the foreign soil addition > compost > gypsum > rice straw > control.

• Korean Journal of Food Science and Technology
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• v.33 no.5
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• pp.567-573
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• 2001

Lactobacilli have been generally recognized as an important lactic acid bacteria present in the normal human intestinal flora. Fifty two Lactobacillus isolates were recovered from the feces of healthy Koreans whose age ranged from thirteen days after birth to 37 years. Among the isolates above, 17 isolates were tentatively identified as strains of Lactobacillus acidophilus and 3 isolates as strains of Lactobacillus casei. For their characterization, these twenty isolates were subjected to the experiments for the resistance to the artificial gastric juice, pH2.5 and bile salt. Interestingly, 3 strains survived pH 2.5 after 3 hour incubation in the artificial gastric juice with more than 75% of survival rate. L. acidophilus a-4 had the highest survival rate of 100%. Four strains including L. acidophilus a-3 grew gradually in MRS broth in the presence of the artificial bile salt. Cholesterol assimilation was also tested for the 20 isolates. The result showed that cholesterol concentration of the medium was reduced by 10 Lactobacillus isolates with more than 60%, as compared to the control. L. acidophilus a-2 had the highest reduction rate of 77%. Judging from these data obtained in vitro, some isolates ware likely to reach the lower small intestine after consumption without a significant loss of viability, suggesting that they had the potential to be developed as a probiotic culture which might lower the cholesterol level in human.

• Korean Journal of Soil Science and Fertilizer
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• v.23 no.4
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• pp.259-267
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• 1990

This study was carried out by investigating the changes of physico-chemical and mechanical properties of Gwanghwal and Poseung series in order to obtain basic information on the soil improvement and management. 1. In Gwanghwal series, the content of salt in soil and ground water before rice transplanting at the 21st year after reclamation were 0.29 and 1.02 percent respectively, and the safty cultivation of paddy rice was possible after 33 years of reclamation in both soil series. 2. Clay contents. atterberg limits and clay activity according to the age of reclaimation showed negative correlation. but sand content and N-value were positive in them. 3. Cone index was lower than $3kg/cm^2$ for the first 5 years after reclaimation in both soil series, and the formation of hard pan were 33rd and 49th year after reclamation in Gwanghwal and Poseung series respectively, and its thickness was more in Poseung than in Gwanghwal series. 4. Shearing resistance decreased with the age of reclaimation in both soil series. and friction resistance increased in Gwanghwal than Poseung siries. 4. Shearig resistance decreased with the age of reclaimation in both soil series, and friction resistance increased in Gwanghwal than Poseung series. 5. Soil pH. available, $SiO_2$, $Mg^2$, $K^+$, $Na^+$ and C. E. C showed negative correlation. with the year cultivated paddy rice. but O. M. ava ilable $P_2O_5Ca^{2+}$ and T-N had positive one in both soil series. Contents of O. M and $Ca^{2+}$ and T-N had positive one in both soil series. Contents of O. M and $Ca^{2+}$ were high in Gwanghwal, but C. E. C. was in Poseung series.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.5
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• pp.618-625
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• 2018

With the passing of time, exposed concrete structures are affected by a range of environmental, chemical, and physical factors. These factors seep into the concrete and have a deleterious influence compared to the initial performance. The importance of identifying and preventing further performance degradation due to the occurrence of deterioration has been greatly emphasized. In recent years, evaluations of the target life have attracted increasing interest. During the freezing-melting effect, a part of the concrete undergoes swelling and shrinking repeatedly. At these times, chloride ions present in seawater penetrate into the concrete, and accelerate the deterioration due to the corrosion of reinforced bars in the concrete structures. For that reason, concrete structures located onshore with a freezing-melting effect are more prone to this type of deterioration than inland structures. The aim of this study was to develop a high performance mortar mixed with a mineral admixture for the durability properties of concrete structures near sea water. In addition, experimental studies were carried out on the strength and durability of mortar. The mixing ratio of the silica fume and meta kaolin was 3, 7 and 10 %, respectively. Furthermore, the ultra-fine fly ash was mixed at 5, 10, 15, and 20%. The mortar specimens prepared by mixing the admixtures were subjected to a static strength test on the 1st and 28th days of age and degradation acceleration tests, such as the chloride ion penetration resistance test, sulfuric acid resistance test, and salt resistant test, were carried out at 28 days of age. The chloride diffusion coefficient was calculated from a series of rapid chloride penetration tests, and used to estimate the life time against corrosion due to chloride ion penetration according to the KCI, ACI, and FIB codes. The life time of mortar with 10% meta kaolin was the longest with a service life of approximately 470 years according to the KCI code.

• Korean Journal of Environment and Ecology
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• v.23 no.1
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• pp.90-98
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• 2009

Every spring, Korea is always plagued by sandy dust from the western region of China and Mongolia. Yellow sand is causing an environmental problem to Japan and far into the American continent, let alone Korea. At present, the western region of China is going under desertification at a great speed due to climatic change and humans' damaging activities. To cope with this, each country including China is considering ecological restoration of deserts through planting. Accordingly, this research conducted a vegetation survey on Baicheng district which is a representative dry land of western China to obtain a basic data for ecological restoration of a desert. The survey revealed that Setaria viridis which invaded an arid land made a succession into Setaria viridis-Cannabis sativa var. fruderalis community together with Artemisia mongolica-Setaria viridis community due to the increase in salt concentration and alkalization subsequent to dryness. It was also found out that there finally formed Artemisia mongolica community on a flat intense in harsh wind and dryness with the continuous worsening of environmental conditions. There appeared a different type of vegetation on hilly districts where sporadic shade could come into being because the air humidity could be available relatively there. Frequently, typically appearing at the whole survey area, the Tributlus terrestris community was found to make succession into Tribulus terrestris-Cleisrogenes squarrosa community due to the aggravation of soil environment. In addition, with the worsening of the environment at hilly districts, there formed Clesirogenes squarrosa community resistant to dryness, salinity in soil and strong alkalinity. Further, there appeared higher plant life totalling to 62 taxa comprising 58 species and 4 varieties with 27 families and 49 genuses at the whole survey area. Among these, Compositae plants excellent in resistance to environment was surveyed the most, accounting for 27%.

• Journal of the Korean Wood Science and Technology
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• v.47 no.2
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• pp.163-177
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• 2019

This study aims to review the relations between the dyeing conditions (i.e., dye concentration, addition amounts of salt and alkali, and dyeing temperature) and dyeing properties and color fastness to light for identifying the optimal dyeing conditions when dyed regenerated woody fibers were obtained through the defibration of waste medium density fiberboard (MDF) using reactive Red H-E3B (Bis-monochlorotriazine (MCT)/MCT type) and reactive Red RB133% (Bis-MCT/Vinyl sulphone type). The dyeing yield (K/S) obtained using two types of reactive dyes increased as the dye concentration increased by 1-10% (on the weight of fiber (OWF)). In addition, the K/S of H-E3B was higher than that of RB133% irrespective of the dye concentration. The color difference of H-E3B after ultraviolet (UV) radiation was lower than that of RB133%, denoting good resistance to discoloration by UV. As the amount of sodium sulfate increased, the color difference and K/S also increased, and the adequate salt content was determined to be 50-70 g/L. Further, the color difference and K/S significantly increased only the addition of 2 g/L of sodium carbonate; however, almost no difference was observed when more than 2 g/L of sodium carbonate was added. The addition amount of sodium carbonate was adequate 5-10 g/L to dyeing the fiber and the pH at this addition level was 10. The dyeing yield of H-E3B increased when the dyeing temperature increased; however, it subsequently decreased after the dyeing temperature became $80^{\circ}C$. The dyeing yield of RB133% was almost the same up to $60-70^{\circ}C$ but declined subsequently. Thus, the adequate temperatures were $80^{\circ}C$ and $60^{\circ}C$ for H-E3B and RB133%, respectively. If the waste MDF woody fiber was dyed under the aforementioned optimal conditions, dyed regenerated woody fiber can be obtained having the following colors: 1.5 to 2.0R with the H-E3B dye and 9.6 to 10.0 PR with RB133%.

• Journal of Life Science
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• v.25 no.8
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• pp.910-916
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• 2015

Scientists have recently shown an interest in the characteristics of Bacillus mojavensis strains because of their increasing use in plants as a defense against diseases and mycotoxins. We have shown here that B. mojavensis KJS-3 possesses the typical characteristics of B. mojavensis strains including a strong resistance to high temperatures (≤50℃), tolerance to high salt concentrations (7% NaCl), ethanol tolerance (40% ethanol), and pH range for growth (pH 5-9). B. mojavensis KJS-3 has been used for the production of cyclic lipopeptides including important antifungal substances such as surfactin, iturin, and fengycin. Polymerase chain reaction analysis in this study showed that B. mojavensis KJS-3 can be used for the production of fengycin and the findings of LC-MS/MS analyses suggest that B. mojavensis KJS-3 can be used to produce iturin and surfactin. Antifungal activity analys is confirmed that B. mojavensis KJS-3 has antifungal effects on Botrytis cinerea, Rhizoctonia solani AG-4, Sclerotinia sclerotiorum, and Colletotricum goeosporioides. A microscopy assessment of the roots of wild ginseng plants planted together with B. mojavensis KJS-3 revealed that the roots contained B. mojavensis KJS-3, confirming the bacteria to be a plant growth promoting endophyte (PGPE) which acts against plant diseases and mycotoxins. Our findings lead us to conclude that B. mojavensis KJS-3 can be produced at an industrial level as a microbial pesticide or microbial fertilizer.

• Journal of Life Science
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• v.28 no.3
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• pp.376-387
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• 2018

Among a variety of environmental stresses heat, cold, chilling, high salt, drought, and so on exposed to plants, drought stress has been reported as a crucial factor to adversely affect the growth and productivity of plants. Therefore, to understand the mechanism for the drought stress signal transduction pathway in plants is more helpful to develop useful crops that display the enhanced tolerance against drought stress, and to expand crop growing areas. The signal transduction pathway for the drought stress in plants is largely categorized into two types; ABA-dependent pathway and ABA-independent pathway. It has been reported that two transcription factors, AREB/ABF and DREB2, play predominant roles in ABA-dependent and ABA-independent pathways, respectively. In addition to transcriptional regulation mediated by AREB/ABF and DREB2 transcription factors, post-translational modification (such as phosphorylation and ubiquitination) and epigenetic control are importantly involved in the signal transduction for drought stress. In this paper, we review current understanding of signal transduction pathway on drought stress in plants, especially focusing on the biological roles of a variety of signaling components related to drought stress response. Further understanding the mechanism of drought resistance in plants through this review will be useful to establish theoretical basis for developing drought tolerant crops in the future.

• Asian-Australasian Journal of Animal Sciences
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• v.29 no.10
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• pp.1490-1499
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• 2016

In this study, 69 lactobacilli isolated from Tibetan Qula, a raw yak milk cheese, were screened for their potential use as probiotics. The isolates were tested in terms of: Their ability to survive at pH 2.0, pH 3.0, and in the presence of 0.3% bile salts; tolerance of simulated gastric and intestinal juices; antimicrobial activity; sensitivity against 11 specific antibiotics; and their cell surface hydrophobicity. The results show that out of the 69 strains, 29 strains (42%) had survival rates above 90% after 2 h of incubation at pH values of 2.0 or 3.0. Of these 29 strains, 21 strains showed a tolerance for 0.3% bile salt. Incubation of these 21 isolates in simulated gastrointestinal fluid for 3 h revealed survival rates above 90%; the survival rate for 20 of these isolates remained above 90% after 4 h of incubation in simulated intestinal fluid. The viable counts of bacteria after incubation in simulated gastric fluid for 3 h and simulated intestinal fluid for 4 h were both significantly different compared with the counts at 0 h (p<0.001). Further screening performed on the above 20 isolates indicated that all 20 lactobacilli strains exhibited inhibitory activity against Micrococcus luteus ATCC 4698, Bacillus subtilis ATCC 6633, Listeria monocytogenes ATCC 19115, and Salmonella enterica ATCC 43971. Moreover, all of the strains were resistant to vancomycin and streptomycin. Of the 20 strains, three were resistant to all 11 elected antibiotics (ciprofloxacin, erythromycin, tetracycline, penicillin G, ampicillin, streptomycin, polymyxin B, vancomycin, chloramphenicol, rifampicin, and gentamicin) in this study, and five were sensitive to more than half of the antibiotics. Additionally, the cell surface hydrophobicity of seven of the 20 lactobacilli strains was above 70%, including strains Lactobacillus casei 1,133 (92%), Lactobacillus plantarum 1086-1 (82%), Lactobacillus casei 1089 (81%), Lactobacillus casei 1138 (79%), Lactobacillus buchneri 1059 (78%), Lactobacillus plantarum 1141 (75%), and Lactobacillus plantarum 1197 (71%). Together, these results suggest that these seven strains are good probiotic candidates, and that tolerance against bile acid, simulated gastric and intestinal juices, antimicrobial activity, antibiotic resistance, and cell surface hydrophobicity could be adopted for preliminary screening of potentially probiotic lactobacilli.