• Journal of Korean Society of Forest Science
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• v.99 no.6
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• pp.836-842
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• 2010

Hovenia dulcis var. koreana Nakai has been reported to liver function improvement effect as functional materials for food and medicine. On these facts, biological activity and safety test were conducted to evaluate biological activities of the fruit petiole and root extracts of H. dulcis as a potential cosmeceutical ingredient. Cosmeceutica activities of different extracts were examined by l.l-diphenyl-2-picrylhydrazyl (DPPH) radical generation, the ABTS+ cation decolorization, tyrosinase activity, collagenase activity and elastase activity compared with the properties of the commercial antioxidant butylated hydroxytoluene (BHT) and L-ascorbic acid (AA). The antioxidant activities HDFW, HDFE, HDRW and HDRE were 83.6%, 39.6%, 85.9% and 74.5% in DPPH assay, 99.5%, 13.7%, 96.4% and 88.6% in ABTS assay. Tyrosinase inhibitiory activities HDFW were 56.0% at 1,000 ppm. Measured the inhibition effect of the H. dulcis about collagenase and elastase where break the peptide bonds in collagen and enzyme from the class of proteases where exists in the dermis. The H. dulcis was inhibition the two kind enzymesm, collagenase activities being on a high scale inhibition, was same concentration. Uses the anti oxidation effect and a anti-wrinkle effect of this resultant H. dulcis and with the functional cosmetics use is thought with the fact that will be possible.

• Journal of dental hygiene science
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• v.15 no.4
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• pp.437-444
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• 2015

Due to the attractive benefits with regard to bone health, digestion, and hydration, carbonated water consumption have rapidly grown over the past few years. However, the acidic drink has latent potential for enamel erosion. The most experimental studies about the enamel erosion have focused on the carbonated beverages with sugar and artificial sweeteners. Here, we determined the enamel erosion potential by commercially available carbonated waters with bovine teeth. The erosion was verified by pH value, calcium concentration, and scanning electron microscope. Then plaque accumulation by bacterial adhesion was determined on the enamel erosion surface to measure roughness. In the present study, we observed that the increased calcium content after being immersed in carbonated waters result from the overall enamel erosion. There were no significant differences between general carbonated waters and mineral waters for erosive capacity. Therefore, commercially available carbonated waters are potentially erosive. In addition, oral bacteria strongly adhered to the erosive enamel surfaces thereby facilitating the development of dental plaque. Thus, it is urgently necessary to provide food safety information on the carbonated water as acidic drink to prevent the enamel erosion.

• Korean Journal of Plant Resources
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• v.27 no.5
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• pp.518-533
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• 2014

The flora in the region of Daeheuksando ($N34^{\circ}37^{\prime}{\sim}34^{\circ}42^{\prime}$, $E125^{\circ}23^{\prime}{\sim}125^{\circ}38^{\prime}$) was surveyed from June 2010 to October 2011. The vascular plants from 22 field surveys were revealed to total of 496 taxa: 113 families, 316 genera, 446 species, four subspecies, 43 varieties and three forms. 124 taxa were the first records from this region. This field study discovered significant plants in various categories. Korean endemic plants numbered 7 taxa, and 6 taxa designated by Korean Forest Service as rare plants were investigated in this region. The taxa in the category II of rare and endangered plants and higher than the third degree among the floristic regional indicator plants designated by Korean Ministry of Environment were one taxon and 47 taxa, respectively. Especially, it was proved that Spiraea chartacea, Hosta yingeri, Hemerocallis hongdoensis and Saussurea polylepis were endemic to Heuksan-myeon including Daeheuksando in Korean peninsular. In addition, the naturalized plants of 46 taxa were recorded.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.254-254
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• 2017

This study evaluated the grain quality of local brand rice from 6 major rice exporting countries which are anticipated to export their rice to Korea. Recently, with the end of the postponement of rice import tariffs in 2014, Korea is in a very easy environment to import foreign rice. Therefore, the quality evaluation of local brand rice in those countries is needed to secure the quality competitiveness of Korean rice, also to protect the rice industry in Korea. We provided total 38 local brand rice from USA(7), China(16), Australia(4), Thailand(3), Vietnam(5) and India(3), and 2 imported brand rice through MMA from USA and China to find out the status of the grain quality for each country. For the quality evaluation, we analyzed the physicochemical properties, milling and palatability-related characteristics. The amylose content on country average ranged from 24.4(India)~16.2%(Thailand). The protein content was 6.66% by overall average, and was higher in order of India(7.86), Australia(6.80), Vietnam(6.61), Thailand(6.59), China(6.28), USA(5.82). In Toyo glossiness value, it ranged from 75.7~45.2, and the figures in USA and China were the highest level. The head rice ratio ranged from 95.2~72.4%, and the figures in Thailand, USA and China were distinctly high. When we analyze the palatability of boiled brand rice with Chucheongbyeo as check variety by expert panelists, several rice brands from USA and China showed equal or better scores in shape, smell, taste, stickiness, texture and overall score, although most rice brands showed a tendency to decrease significantly in the taste characteristics compared with Chucheongbyeo. From the above results, it can be seen that the grain quality of USA and China rice is very competitive when imported into Korea. The results will provide basic information for the quality control of foreign rice which will be imported into Korea in the near future, also for the quality information which could be applied on the development of high-quality Korean rice varieties. Continuous monitoring about the foreign brand rice is advisable to improve the quality competitiveness of Korean rice.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.104-104
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• 2017

Sorghum (Sorghum bicolor (L.) Moench.) is one of the most important crops for human and animal nutrition. Nonetheless, sorghum has a cyanogenic glucoside compound which can be degraded into hydrogen cyanide, toxic to humans and animals even with tiny amount. In consequence, breeding materials with a low cyanide level has been a top priority in sorghum breeding programs. To fulfill our long-term goal, we are screening sorghum accessions with low cyanide level, which would be an important breeding material for food safety. We collected seeds of various sorghum accessions and analyzed relevant metabolites to find useful breeding materials of sorghum accessions containing low cyanide. Fourteen wild relatives were obtained from the University of Georgia in US, a reference accession BTx623, and three local varieties from National Agrobiodiversity Center of Rural Development Administration in Korea, and one wild species from the Wild Plant Resources Seed Bank of Korea University in Korea. Sorghum plants were grown in plastic greenhouse under natural conditions. After growing, leaf samples were harvested at different developmental stages: seedling phase, vegetative phase (right before flowering), and reproductive phase (ripening). Using collected samples, quantification analysis were performed by an HPLC system for three metabolites (dhurrin, 4-hydroxybenzaldehyde, and 4-hydroxyphenylacetic acid) in sorghum plants. Prior to metabolome analysis, specific experimental condition for HPLC system was set to be able to separate three metabolites simultaneously. Under this condition, these metabolites were quantified in each accession by HPLC system. We observed that the metabolite contents were changed differently by developmental stages and accessions. We clustered these results into five groups as patterns of their contents by developmental stages. Most of accessions showed that 4-hydroxybenzaldehyde content was very high at seedling stage and decreased rapidly at vegetative phase. Interestingly, the patterns of dhurrin content were very different among clusters. However, 4-hydroxyphenylacetic acid content was maintained at low levels by developmental stages in most accessions. The results would demonstrate how dhurrin and alternative degradation pathways are differentiated in each accession.

• Korean Journal of Environmental Biology
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• v.37 no.2
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• pp.189-195
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• 2019

In this study, we performed an analysis of the accumulation of inorganic arsenic and growth rate with changes in phosphate concentration in Hizikia fusiforme. When exposed to inorganic arsenic for fourteen days, we found that the collection of inorganic arsenic hardly increased at high phosphate concentrations (2 mg L^-1). However, when the phosphate concentration was low (0.02 mg L^-1), accumulation of inorganic arsenic increased. Additionally, H. fusiforme decreased in a growth rate of 14.5% in low phosphate concentration (0.02 mg L^-1) and fell in a growth rate of 30% when exposed to inorganic arsenic (10 ㎍ L^-1). H. fusiforme cannot distinguish between phosphate and inorganic arsenic. Thus, when phosphate concentration was lower, the inorganic arsenic accumulation increased, and accumulated inorganic arsenic inhibited photosynthesis and cell division, reducing the growth rate. H. fusiforme is known to have higher inorganic arsenic accumulation than other seaweeds. Therefore, various studies are needed to secure the food safety of H. fusiforme which is an essential aquaculture species in Korea.

• Korean Journal of Weed Science
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• v.32 no.3
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• pp.211-221
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• 2012

The fourth leaves (younger leaves) amongst extended 4-upper leaves in 18 squash cultivar were the highest tolerance to the paraquat application, followed by third, the second, and the first leaves (older leaves). The forth leaves in Joongangaehobak showed more than three times higher tolerance to the paraquat application than did the first leaves. When the combining of water extract from the fourth leaves with paraquat were applied to the leaves and stems of maize, the paraquat phytotoxicity in maize was reduced compared to the paraquat application alone. Therefore, this study continued to investigate if the phytotoxicity inhibitor exist in the fourth leaves. The water extract in the fourth leaves were isolated by silica gel column chromatography, Sephadex LH-20 column chromatography, TLC, and HPLC, and the substance in the extract was speculated as a malic acid by identifying through NMR. The mixture malic acid and paraquat were applied to the maize to verify the application effect of malic acid on paraquat toxicity. The 100 ${\mu}M$ of paraquat application alone showed 62% of paraquat toxicity to the corn leaves, while the combined application of 100 ${\mu}M$ paraquat with malic acid at 0.1, 0.3, 0.5, and 1.0% did not show the symptom.

• Weed & Turfgrass Science
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• v.2 no.4
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• pp.341-347
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• 2013

The survey of weed occurrence was conducted to identify problematic weed species on the paddy field. Total 524 sites of the 17 regions in Chungnam Province in Korea were investigated from June to August, 2013. In the whole region, 23 weed species were identified including 19 annuals and 4 perennials. The most dominant weed species in Chungnam paddy fields were Echinochloa crus-galli (25.3%), followed by Monochoria vaginalis (11.9%), Eleocharis kuroguwai (10.3%), Bidens tripartite (9.3%) and Aneilema japonicum (8.5%). The 95.2% of the investigation sites was determined under dominance value 1 (range of cover <10: numerous individuals) by Braun-Branquet indicating proper weed control in the paddy fields. This information could be useful for estimation of future weed occurrence, weed population dynamics and establishment of weed control methods in Chungnam Province in Korea.

• Journal of Environmental Health Sciences
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• v.41 no.3
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• pp.203-215
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• 2015

Objectives: This study was designed to evaluate the filtration efficiencies and pressure drops of five commercial cloth masks (4 plate type, 1 cup type) in comparison to the performance of a class 1 disposable respirator (reference respirator). A further objective was to evaluate the effects of the number of layers and wash treatment independently on filtration efficiencies and pressure drops. Methods: Polydisperse NaCl aerosols were generated in an aerosol chamber and their concentrations were measured by an optical particle counter (OPC) in the size range of $0.3{\sim}10{\mu}m$ (five channels). Results: The filtration efficiencies of the five cloth masks and the reference respirator were D: 9.5%, C: 18.5%, E: 23.6%, A: 28.5%, B: 29.7% and R: 91.1%, respectively, and the pressure drops through them were C, D: 0.8 Pa, E: 1.7 Pa, B: 6.4 Pa, A: 42.7 Pa and R: 19.3 Pa, respectively. The filtration efficiencies of the cloth masks and reference respirator were below the class 1 respirator criterion (${\geq}94.0%$) of the Ministry of Employment and Labor (MOEL) and Ministry of Food and Drug Safety (MFDS). The pressure drops satisfied the class 1 respirator criterion (${\leq}70Pa$) of MOEL and MFDS. When the cloth masks were folded into two and four layers, the filtration efficiencies of cloth masks A, B, C, D (plate type) increased 1.7-4.6 times, and 2.3-6.8 times, respectively, compared to the efficiencies of the same products in a single layer. Pressure drops increased as the number of layers was increased. The filtration efficiency of cloth mask E with a liner was 1.3 times higher than that of the same mask without a liner, and the pressure drop was lower in the no-liner configuration. After a single washing, the filtration efficiencies of all the cloth mask products decreased 1.04-4.0 times compared to those of the same products intact. For the cloth masks C and E, their filtration efficiencies were significantly decreased after washing (p<0.05). The pressure drops of all cloth masks were 1.2-2.0 times lower after washing. Conclusions: The filtration efficiencies of the five cloth masks were below 30% and did not improve greatly by increasing the number of layers. After a single washing, their performances decreased. Considering the above and other issues identified with cloth masks, such as poor fit and stretched fibers through use, people should not expect protection against particulate matters from the cloth masks on the market.

• The Journal of Korean Medicine
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• v.38 no.2
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• pp.15-30
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• 2017

Objectives: Hwangryunhaedok-tang (HHT; Huanglianjiedu-tang, Orengedoku-to), a traditional herbal formula, is used for treating inflammation, hypertension, gastritis, liver dysfunction, cerebrovascular diseases, dermatitis and dementia. The objective of this study was to assess the sub-acute toxicity of HHT in Sprague-Dawley (SD) rats, and its effect on the activities of human microsomal cytochrome P450s (CYP450s) and UDP-glucuronosyltransferases (UGTs). Methods: Male and female SD rats were orally administered HHT once daily at doses of 0, 500, 1000 and 2000 mg/kg for 4 weeks. We analyzed mortality, clinical observations, body weight, food consumption, organ weights, urinalysis, hematology, serum biochemistry, and histopathology. The activities of major human CYP450s (CYP1A2, CYP3A4, CYP2B6, CYP2C9, CYP2C19, CYP2D6, and CYP2E1) and UGTs (UGT1A1, UGT1A4, and UGT2B7) were assessed using in vitro fluorescence- and luminescence-based enzyme assays, respectively. Results: No toxicologically significant changes related to the repeated administration of HHT were observed in both male and female SD rats. The no observed adverse effect level (NOAEL) value was more than 2000 mg/kg/day for both sexes. HHT inhibited the activities of human microsomal CYP1A2, CYP2C19, CYP2D6, and CYP2E1, whereas it weakly inhibited the activities of CYP2B6, CYP2C9, CYP3A4, and UGT1A1. In addition, HHT negligibly inhibited the activities of human microsomal UGT1A4 and UGT2B7 with $IC_{50}$ values in excess of $1000{\mu}g/mL$. Conclusions: Our findings indicate that HHT may be safe for repeated administration up to 4 weeks. In addition, these findings provide information on the safety and effectiveness of HHT when co-administered with conventional drugs.