• Korean Journal of Plant Resources
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• v.35 no.1
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• pp.71-99
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• 2022

This study was conducted to investigate the vascular flora of Masan, located in Goseong-gun, Gangwon-do, and to comprehend the distribution of remarkable plants such as rare and Korea endemic plants and invasive alien plants. The survey was carried out the distribution of vascular plants 11 times per season from 2010 to 2018. A total of 619 taxa in 93 families, 328 genera, 529 species, 6 subspecies, 78 varieties and 6 forms were identified on mt. Masan. Among them, Korean endemic plants are 21 taxa including Saussurea diamantica Nakai and are plants designated by the Korea Forest Service are 20 taxa counting Saxifraga octopetala Nakai. Invasive alien plants were classified a total of 35 taxa inclusive of Trifolium pratense L. (WS), Aster pilosus Willd. (SS), Coreopsis lanceolata L. (SR), Rumex obtusifolius L. (SC) and Lindernia dubia (L.) Pennell (CS). The naturalization rate was 5% and the urbanization index was 10.0%, respectively. Although this study identified the diverse distribution of major plants such as rare and endemic plants around Masan, it was confirmed that invasive alien plants, which pose a great threat to forest biodiversity conservation and promotion, spread and distributed in a specific section Therefore, it is urgent to establish a conservation strategy and countermeasures.

• Korean Journal of Plant Resources
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• v.35 no.2
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• pp.317-345
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• 2022

This study carried out a survey to utilize basic data for the conservation of northern lineage plants that are vulnerable to climate change, targeting algific talus slope of a specific forest biodiversity region in Yeotan-ri, Jeongseon-eup, Jeongseon-gun, Gangwon-do. The survey was conducted by dividing the wind hole into 625 m² inside and 6,925 m² outside based on the wind hole. The vascular flora were identified as 84 families, 203 genera, 296 species, 6 subs., 27 var., 2 for., and a total of 331 taxa. This was found to be about 7% of 4,724 species of vascular plants in Korea. Plants endemic to the Korean peninsula were identified as 19 taxa, including Syringa fauriei, and 11 taxa for rare plants designated by IUCN. Critically endangered grade (CR) was Paeonia obovata 1 taxa, Endangered grade (EN) was Forsythia saxatilis and Prunus choreiana 2 taxa. A total of 78 taxa were florisitc target species, and 19 taxa were classified for indicator plants in the limestone area. As for alien plants, 20 taxa such as Taraxacum officinale were identified, and the naturalization rate was 6.04% and the urbanization rate was 5.33%. Geographical plants of the study area are 2 taxa of Syringa fauriei and Syringa villosa subsp. wolfii.

• Analytical Science and Technology
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• v.21 no.3
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• pp.183-190
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• 2008

PFOS (Perfluorooctane sulfonate) and PFOA (Perfluorooctanoic acid) are environmental hormones which belong to potential future persistent organic pollutants (POPs), and it is easy to exposure to human because they are used in a wide variety of consumer products. We studied exposure route and the relativity through determining and monitoring of PFOS and PFOA in Korean plasma of metropolis, small town, rural area and industrial area. And we monitored the concentration of PFOS and PFOA regarding the gender and age. The older age is, the higher concentration of PFOS is. The mean concentration of PFOS and PFOA in men (4.74 ng/mL, 2.20 ng/mL) was higher than that in women (3.53 ng/mL, 1.17 ng/mL). In the comparison of residential areas, the mean concentration of PFOS and PFOA was the lowest in metropolitan plasma (2.47 ng/mL, 0.79 ng/mL) whereas it was the highest in the industrial area (6.57 ng/mL, 2.19 ng/mL).

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.13 no.2
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• pp.112-120
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• 2008

A series of experiments were conducted to establish a marine ecotoxicological standard method using marine primary producers, Skeletonema costatum, Heterosigma akashiwo, Prorocentrum micans, Isochrysis galbana, Tetraselmis suecica as candidate test species. Marine diatom, S. costatum was selected as standard test species in terms of the ecological roles and international uses as test species. Test methods and test acceptability criteria are as follows; $72{\sim}96$ hr population growth inhibition $EC_{50}$ as endpoint. Static non-renewal method, and population growth rates over 0.04/hr in control as test acceptability criterium. S. costatum is widely distributed in the world ocean and used for standard species of marine toxicity test method by ISO (International Standardization Organization). Possible salinity ranges for this test method are $20{\sim}35\;psu$, and reproducibility and interlaboratory test results were consistent through the calibration tests. Sensitivity of the test method was comparable or better than other toxicity tests such as rotifer neonate mortality, bioluminescent bacterial inhibition, seaweed sporulation and sea urchin fertilization tests.

• Journal of Environmental Impact Assessment
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• v.31 no.1
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• pp.11-46
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• 2022

This study was carried out to examine vascular plants and invasive alien plants in Gyodong Island, located at the northwestern Civilian Control Line (CCL) of Ganghwa-gun, Incheon, and to use them as basic data for systematic management of identified plants and establishing biodiversity conservation measures. The survey was conducted 13 times from April 2019 to August 2021. The vascularflora in Gyodong Island was identified as 109 families, 378 genera, 641 species, 15 subspecies, 49 variants, 8 forma, a total of 713 taxa. This was found to be about 15.36% of the total 4,641 taxa of vascular plants in Korea. The northern linage plants on the Korean Peninsula appearing in the Gyodong Island area were identified in 83 classification groups, including Red-based leaf edge (Carex erythrobasis H.Lev. & Vaniot). Korea endemic plants were identified as 16 taxa such as Seoul wild-ginger [Asarum heterotropoides var. seoulense (Nakai) Kitag.], and a total of 20 taxa of rare plants designated by IUCN were observed, including the endangered grade Beardless iris (Iris ruthenica Ker Gawl.). Floristic target species were classified with a total of 99 taxa. For V grade, Beardless iris 1 taxon was found. and also IV grade and III grade were identified in 8 taxa and 20 taxa respectively. The invasive alien plants identified as 75 taxa, such as Verbesina alternifolia (L.) Britton ex Kearney. The naturalization rate was 10.51%, and the urbanization index was calculated as 23.29%. Since large-scale construction has been currently underway on Hwagae Mt. in Gyodong Island as the target of survey area, the influx of invasive plants will be expected to promote. Therefore, it is urgent to establish in-situ protection and conservation measures for notable plants such as Beardless iris and Water smartweed [Persicaria amphibia (L.) S.F.Gray].

• Korean Journal of Environment and Ecology
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• v.20 no.3
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• pp.345-351
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• 2006

This study investigates the toxic effects of $Cd^{2+}$on frog (Rana dybowskii) by the determination of oocyte maturation and development of embryo exposure to different concentrations of the toxicant. The results show that $Cd^{2+}$ concentration of 0.1ppm suppressed the maturation of the oocytes. To examine the reversibility of the inhibitory effects, the oocytes were exposed to the $Cd^{2+}$ only for 3 hours, and then transferred to plain medium and cultured further for 17 hours. The oocytes were recovered from the toxic effect of the $Cd^{2+}$ when they were exposed to 1ppm, but not to 2.5ppm of the $Cd^{2+}$. The development of 2 cell embryos to 32 cell was completely suppressed at 0.1ppm and the longer the embryos were exposed to the $Cd^{2+}$, the more damage appeared to the embryos and the cytolysis of the 32 cell was induced by $Cd^{2+}$ at 0.1ppm. On the other hand, the embryos of blastula stage were cultured 96 hours in presence of the $Cd^{2+}$ at various concentrations and were examined. The rates of mortality and malformed larvae were investigated by probit analysis. From the results of LC$_{50}$ of 0.1ppm and EC$_{50}$ of 0.08ppm, Tl of 5.0 was derived, which indicates $Cd^{2+}$ is to be considered a teratogenic compound. Such specific malformations occurred in 14.3% as spine deformations at the 0.05ppm, in 75.0% as tail deformations at the 0.1ppm, in 66.7% as abdominal deformations at the 0.01ppm and in 26.0% as profound deformations at the 0.1ppm of $Cd^{2+}$ concentration which living embryos were exposed to. $Cd^{2+}$ suppressed growth to head-tail length at 0.1ppm. In conclusion, The study results reveal that $Cd^{2+}$ must be considered highly toxic effect to oocyte maturation and embryonic development.

• Korean Journal of Environmental Agriculture
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• v.36 no.3
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• pp.175-183
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• 2017

BACKGROUND:The Aromatic rice which is characterized by the flavor of Nurungji when cooked rice, and consumption is increasing recently. The purpose of this study was to investigate the physicochemical characteristics and aroma components of five aromatic rice cultivars according to transplanting time. METHODS AND RESULTS: Quantitative analysis of protein, fat, fatty acid and essential amino acid for five aroma rice cultivars(Hyangmibyeo 2 ho, Aromi, Mihyang, Aranghyangchal, Heughyang)and transplanting time was analyzed by crude protein analyzer, gas chromatography (GC), liquid chromatography (LC) and viscosity analysis was done by using rapid viscosity analyzer (RVA). The content of 2-acetyl-1-pyrroline (2AP) was determined by gas chromatography mass spectrometer. (GC-MS) As a result, the average protein and lipid contents were 6.5% and 2.4%, respectively. The content of essential amino acid showed the highest content at 104.4mg/g. There was no significant change in normal nutrients during the transplanting time. By RVA, cv.Hyangmibyeo 2 ho showed the highest peak and total setback viscosities and lowest breakdown viscosity in early transplantation. The content of 2AP in flavor varieties and transplanting time was quantitatively analyzed by GC-MS. Among the cultivars, Aromi showed the highest 2AP contents at $66.7{\mu}g/100gin$ normal transplanting time. CONCLUSION: cv.Aromi and Hyangmibyeo 2 ho were excellent physicochemical properties and 2AP components contents amongaromatic rice cultivars tested. Theiroptimaltime to transplant was at the beginning of June in the area of Miryang.

• Korean Journal of Food Science and Technology
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• v.39 no.3
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• pp.237-245
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• 2007

We tested for residual pesticide levels in agricultural products purchased from 5 provinces within the middle region of Korea during 2006. A Total of 488 samples of 23 different types of agricultural products were analyzed by GC/MS, GC-NPD, and LC/MS/MS. We used multi-analysis methods to analyze for 231 different pesticide types; a single residual pesticides were detected in 92 samples (18.9%), of which 9 samples (1.9%) exceeded the Korea Maximum Residue Limits (MRLs). we detected pesticide residue in more than 50% of the pepper leaf and welsh onion samples. For the welsh onions, 16 among the 30 analyzed samples contained pesticide residue, and 4 samples exceeded the Korea MRLs. Among the 234 kinds of pesticides we tested for, 42 were detected, and 21 of them were detected more than twice. Six pesticide residue types, including cypermethrin, iprodione, fludioxonil, ethoprophos, flutolanil, and lufenuron, exceeded the MRLs. No residual pesticides were detected in 396 of the samples (81.1%), and the residual pesticide levels in 83 samples (17.0%) were lower than the Korea MRLs, indicating that 98.1% of the samples were relatively safe.

• Clinical and Experimental Pediatrics
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• v.46 no.12
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• pp.1235-1241
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• 2003

Purpose : We assessed the dynamic characteristics of 16 nebulizer/compressor combinations currently available in Korea. Methods : The 16 nebulizer/compressor combinations(Pariboy Type 38/Long life, Pariboy Type N/Long life, Pariboy Type N/Salter 8900, Pariboy Type N/LC, Devilbiss pulmoaid-LT/Hudson, Devilbiss pulmoaid/Hudson, Mesmed neb-300/Own, San-up 3040/Hudson, Midas(Basic)/Own, AirJolie 2/Hudson, Thomas 1127/Salter 8900, Noel NE-2000/Salter 8900, Omron CX3/Hudson, Chang Woo CWN-100/Salter 8900, Voyage/Mefar, Chang Woo ASI-Pro/Medel jet pulse) were evaluated in terms of particle size and mass output. In addition, we determined the effects of nebulizer fill volume on mass output. Results : Pariboy Type N/Long life has the highest respirable mass of 0.184 mg/min and Mesmed Neb-300/Own has the lowest 0.019 mg/min. Pariboy Type N/Long life has the highest mass output of 0.68 mg/min and the shortest mass median aerodynamic diameter(MMAD) of $3.76{\mu}m$. All combinations other than Pariboy Type N/Long life produced a MMAD of over $5{\mu}m$. MMAD over a 5 min nebulization ranged 3.76 to $9.83{\mu}m$. There were no significant effects of fill volume on mass output. Conclusion : We concluded that there is a wide variation in performance of nebulizer/compressor combinations. The characteristics of nebulizer/compressor combinations should be considered in selecting products.

• Restorative Dentistry and Endodontics
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• v.30 no.3
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• pp.158-169
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• 2005

This study was done to evaluate the shear bond strength between light-cured glass ionomer cement (GIC) base and resin cement for luting indirect resin inlay and to observe bonding aspects which is produced at the interface between them by SEM. Two types of light cured GIC (Fuji II LC Improved, GC Co. Tokyo, Japan and Vitrebond$^{TM}$, 3M, Paul Minnesota U.S.A) were used in this study. For shear bond test, GIC specimens were made and immersed in 37$^{\circ}C$ distilled water for 1 hour, 24 hours, 1 week and 2 weeks. Eighty resin inlays were prepared with Artglass$^{(R)}$ (Heraeus Kultzer Germany) and luted with Variolink$^{(R)}$ II (Ivoclar Vivadent, Liechtenstein). Shear bond strength of each specimen was measured and fractured surface were examined. Statistical analysis was done with one-way ANOVA. Twenty four extracted human third molars were selected and Class II cavities were prepared and GIC based at axiopulpal lineangle. The specimens were immersed in 37$^{\circ}C$ distilled water for 1 hour, 24 hours, 1 week and 2 weeks. And then the resin inlays were luted to prepared teeth. The specimens were sectioned vertically with low speed saw. The bonding aspect of the specimens were observed by SEM (JSM-5400$^{(R)}$, Jeol, Tokyo, Japan) .There was no significant difference between the shear bond strength according to storage periods of light cured GIC base. And cohesive failure was mostly appeared in GIC On scanning electron micrograph, about 30 - 120 $\mu$m of the gaps were observed on the interface between GIC base and dentin. No gaps were observed on the interface between GTC and resin inlay.