• Korean Journal of Plant Resources
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• v.19 no.4
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• pp.537-554
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• 2006

This study aims to investigate the distribution of the useful economic plants and the flora of Maninsan. The flora of Maninsan was investigated from March to November in 2003. Vascular plants of this area consist of total 450 taxa; 5 forma, 53 varieties, 392 species, 279 genera, 95 families. It corresponds to 11.1% of totally 4,071 taxa appeared in Korea. Useful plants of this area were investigated 373 taxa. It corresponds to 82.7% of collected plants in this area under our study. Among the useful plants, there are 191 taxa of edible source, 181 taxa of pasture source, 153 taxa of medicinal source, 54 taxa of ornamental source, 18 taxa of timber. Korean endemic plants were composed 10 families, 13 genera, 9 species, 4 varieties and totaling 13 taxa.

• Korean Journal of Plant Taxonomy
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• v.39 no.4
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• pp.277-291
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• 2009

The flora in the region of Songnisan National Park ($N36^{\circ}28^{\prime}05^{{\prime}{\prime}}{\sim}36^{\circ}46^{\prime}38^{{\prime}{\prime}}$, $E\;127^{\circ}47^{\prime}06^{{\prime}{\prime}}{\sim}127^{\circ}57^{\prime}50^{{\prime}{\prime}}$) was surveyed from April 2000 to July 2006. Vascular plants in 26 collections included a total of 723 taxa: 115 families, 392 genera, 629 species, 4 subspecies, 72 varieties and 18 forms. Ninety-three of these taxa were first records for the region. In the flora of Songnisan National Park, 27 taxa were Korean endemic plants, 19 taxa were rare and endangered plants as designated by the Korea Forest Service. Forty-five of the taxa were with the levels III, IV, V in the floristic regional indicator plants which was designated by Korean Ministry of Environment, and 29 taxa were alien plants now naturalized in Korea. Owing to their unusual phytogeography and low number of populations, the taxa Crypsinus hastatus (Thunb.) Copel., Paeonia japonica (Makino) Miyabe & Takeda, Jeffersonia dubia (Maxim.) Benth. & Hook.f. ex Baker & S.Moore, Bupleurum euphorbioides Nakai, Phacellanthus tubiflorus Siebold & Zucc., Lilium cernuum Kom., Gastrodia elata Blume and Cephalanthera erecta var. subaphylla (Miyabe & Kud ) Ohwi were considered the most important. Based on these results, it is clear that appropriate plans to conserve the natural habitat of Songnisan National Park must be made immediately.

• Korean Journal of Medicinal Crop Science
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• v.25 no.4
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• pp.231-237
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• 2017

Background: Cisplatin is one of the most extensively used chemotherapeutic agents for the treatment of cancer, including bladder, and ovarian cancers. However, it has been shown to induce nephrotoxicity, despite being an outstanding anti-cancer drug. In this study, we investigated the protective effect of dopaol ${\beta}$-D-glucoside (dopaol) on cisplatin-induced nephrotoxicity. Methods and Results: To confirm the protective effect of dopaol on cisplatin-induced nephrotoxicity, HK-2 cells were treated with $20{\mu}M$ cisplatin and $80{\mu}M$ dopaol. Cisplatin increased apoptosis, caspase-3 activity and mitochondrial dysfunction; however pretreatment with $80{\mu}M$ dopaol successfully attenuated apoptosis, caspase-3 activity and mitochondrial dysfunction. To evaluate the protective effect dopaol on cisplatin-induced nephrotoxicity in vivo, we used an animal model (balb/c mice, 20 mg/kg, i.p. once/day for 3 day). The results were similar to those obtained using HK-2 cells; renal tubular damage and neutrophilia induced by cisplatin reduced following dopaol injection (10 mg/kg, i.p. once/day for 3 day). Conclusions: These results indicate that dopaol treatment reduced cisplatin-induced nephrotoxicity in vitro and in vivo, and can be used to treat cisplatin-induced nephrotoxicity. However, further studies are required to determine the toxicity high dose dopaol and the signal pathways involved in its mechanism of action in animal models.

• Korean Journal of Plant Resources
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• v.32 no.5
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• pp.615-632
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• 2019

Field surveys were conducted from May 2016 to October and from April to October 2017 in Tributary Region of Middle Stream of the Nakdong River. The survey was carried out at 66 sites including Young-gang 11, Naeseong-cheon 21, Wi-cheon 16, and Gam-cheon 9, Byeongseong-cheon 9. As a result of investigation, 474 taxa in total ; 99 familly, 288 genera, 421 species, 4 subspecies, 39 varieties and 10 forma. Among them, 5 Korean endemic plants, 7 rare plants, 31 taxa were listed as Floristic Target Species in Korea. Naturalized plants was confirmed 73 taxa, their Urbanization Ratio 22.7%, and naturalization ratio 15.4% in the investigated area. The Life form(Dormancy form) review results as follows ; Therophytes 159 taxa, Hemicryptophytes 91 taxa, Hydrophanerophytes 68 taxa, Geophyte 52 taxa, Nanophanerophytes 35 taxa, Megaphanerophytes 32 taxa, Microphanerophytes 25 taxa, Chamaephytes 12 taxa, and Epiphyten 1 taxa.

• Ocean and Polar Research
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• v.43 no.4
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• pp.279-293
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• 2021

To investigate the effect of seasonal marine environment conditions on the cyanobacteria abundance and diversity in the South Sea, four-seasonal surveys were conducted along the 127.5°E survey transect line in the central South Sea using flow cytometry and 16S-23S ITS on the Miseq platform from August 2016 to May 2017. The average abundance of Synechococcus varied from 3.3 × 10³ to 7.4 × 10⁴ cells ml^-1. The abundance was the highest in the summer and the lowest in the winter, and the abundance fluctuated according to water temperature. The abundance was high in the outer sea affected by TWC. However, in summer, the Coastal areas affected by the Yangtze River were more populated than the outer sea. Prochlorococcus was rare and could not penetrate into coastal areas due to the fronts, but showed its dominance in the waters influenced by the TWC. Synechococcus clades II, VII, IX, CRD1, and CRD2 were predominant in the outer sea area affected by the TWC. In the coastal area, clades I and IV showed higher dominance whereas clades V, VI, WPC1, and 5.3-MS3 with euryhaline characteristics, showed a high dominance rate in the water masses affected by the low-salinity water of the Yangtze River in the summer. Clade XVI, XVII, CB1, CB5, and 5.3-I/II showed high dominance in nutrient-rich waters in the summer with increased water temperature. The abundance and community composition of cyanobacteria changed in the South Sea due to the influence of the TWC and stratification. In the summer, the abundance and the community composition differed, and were mainly affected by the general influence of the TWC in addition to the influence of the Yangtze River low-salinity water.

• The Korea Journal of Herbology
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• v.33 no.4
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• pp.77-85
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• 2018

Objective : This study was intended to examine the effects of water extract of Prunellae Spica (PS), which is a herb with 'cold' nature based on hot and cold theory of traditional Korean medicine. Methods : Hyperthyroidism was induced in SD rats by LT4 (0.5 mg/kg, i.p.) daily for four weeks. After 2 weeks of LT4 injection, rats were divided randomly into four groups; normal, LT4-induced hyperthyroid control, PS extract (500 mg/kg, p.o.)-treated group, and propylthiouracil (PTU, 10 mg/kg, s.c.)-treated positive group. After 2 weeks of drug treatment, all rats were sacrificed and harvested blood samples and thyroid tissues. The changes of body weight, food and water intake, and body temperature were measured weekly. Serological markers were analyzed in sera using an enzyme-based assay, and thyroid tissues were stained with Hematoxylin & Eosin (H&E). Brain and dorsal root ganglion (DRG) tissues were isolated and analyzed the expression of transient receptor potential (TRP) channels by Western blot. Results : PS extract administration attenuated the loss of body weight and the increase of body temperature in LT4-induced hyperthyroidism rats. PS extract increased the level of thyroid stimulating hormone (TSH) and decreased tiiodothyronine (T3) and tetraiodothyronine (T4). In action mechanism, PS extract regulated the expression of transient receptor potential channel subfamily V member 1 (TRPV1) and transient Receptor Potential channel subfamily M member 8 (TRPM8), the thermoregulators. Conclusion : To conclude, PS extract can improve the symptoms of hyperthyroidism through regulation of the thyroid hormones imbalance and thermoregulation via TRP channels.

• Journal of Food Hygiene and Safety
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• v.39 no.2
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• pp.95-101
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• 2024

In this study, we investigated the migration level of items specified in the Korean Standards and Specifications for Utensils, Containers, and Packages (Ministry of Food and Drug Safety Notification) for 50 utensils and hygiene products made of biodegradable resins. Our results revealed that one Polylactide (PLA) baby tableware contained 20 mg/L in consumption of potassium permanganate, exceeding the standard of 10 mg/L or less. In all other samples, formaldehyde, lead (Pb), and arsenic (As) levels could be considered very safe and remained below the standard. Moreover, we tested the PLA baby tablewares (n = 21) for migration into a food simulant (4% v/v acetic acid) upon repeated elution at 100℃ for 30 min or UV irradiation for 2 h. We detected increased formaldehyde and As amounts at the repeated 100℃ treatment for 30 min compared to those upon repeated UV irradiation. However, the migration level was markedly low under both conditions. Furthermore, the Estimated Daily Intake (EDI) calculated on an infant-to-child basis from the formaldehyde and As migration at 100℃ for 30 min in the PLA sample was at the maximum value, i.e., 6.0×10^-4 mg/kg b.w./day and 1.3×10^-1 ㎍/kg b.w./day, corresponding to 0.40% and 10.42% of the Tolerable Daily Intake (TDI, 0.15 mg/kg b.w./day) and Provisional Tolerable Weekly Intake (PTWI, 9.0 ㎍/kg b.w./week), respectively. Therefore, in this study, we confirmed that biodegradable synthetic resins are safe to use for food.

• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.3
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• pp.389-396
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• 2014

The physiological properties of 70% ethanol extracts from Portulaca oleracea with different extraction methods (reflux extraction, RE; autoclave extraction, AE; low temperature high pressure extraction, LTPE) were investigated. The freeze-dried powder yields of RE, AE, and LTPE were 33.78%, 30.80%, and 11.05%, respectively. The color values of L and b were higher in LTPE, and the chroma values were higher in AE and LTPE compared to RE. The total polyphenolics and proanthocyanidin contents in LTPE were significantly higher than in other extracts. The amount of substances related to flavonoids contents was highest in RE (4.30 mg/g), followed by AE (4.06 mg/g), and LTPE (4.00 mg/g). DPPH radical scavenging ability with a concentration of 500 mg% (w/v) were in the following order; LTPE (88.87%)> RE (83.84%)> AE (80.67%). Further, the reducing power, ABTS radical scavenging ability, and nitrite scavenging activity was observed in the same tendency as seen with the DPPH radical scavenging ability. However, the ferrous ion chelating activity of RE (85.45%) and AE (83.88%) was significantly higher than that of LTPE (75.60%). ${\alpha}$-Glucosidase inhibitory activities of RE and LTPE with a concentration of 100 mg% were significantly higher than AE. Xanthine oxidase, and acetylcholinesterase inhibitory activities of LTPE were higher than the other extracts. These results suggest that the extracts from Portulaca oleracea have the potential to act as functional materials, and components of Portulaca oleracea could be effective in the prevention of Alzheimer's disease, and may be used to develop various functional food products.

• Publications of The Korean Astronomical Society
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• v.36 no.3
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• pp.47-63
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• 2021

Variability is one of the major characteristics of Active Galactic Nuclei (AGN), and it is used for understanding the energy generation mechanism in the center of AGN and/or related physical phenomena. It it known that there exists a time lag between AGN light curves simultaneously observed at different wavelengths, which can be used as a tool to estimate the size of the area that produce the radiation. In this paper, We present long term near-infrared variability of optically bright type 1 AGN using the Wide-field Infrared Survey Explorer data. From the Milliquas catalogue v6.4, 73 type 1 QSOs/AGN and 140 quasar candidates are selected that are brighter than 18 mag in optical and located within 5 degree around the ecliptic poles. Light curves in the W1 band (3.4 ㎛) and W2 band (4.6 ㎛) during the period of 2010-2019 were constructed for these objects by extracting multi-epoch photometry data from WISE and NEOWISE all sky survey database. Variability was analyzed based on the excess variance and the probability P_var. Applying both criteria, the numbers of variable objects are 19 (i.e., 26%) for confirmed AGN and 12 (i.e., 9%) for AGN candidates. The characteristic time scale of the variability (τ) and the variability amplitude (σ) were derived by fitting the DRW model to W1 and W2 light curves. No significant correlation is found between the W1/W2 magnitude and the derived variability parameters. Based on the subsample that are identified in the X-ray source catalog, there exists little correlation between the X-ray luminosity and the variability parameters. We also found four AGN with changing W1-W2 color.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.18 no.1
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• pp.40-46
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• 2013

The isotope ratios of $^{13}C/^{12}C$ and $^{18}O/^{16}O$ for a sample in a mass spectrometer are measured relative to those of a pure $CO_2$ reference gas (i.e., laboratory working standard). Thus, the calibration of a laboratory working standard gas to the international isotope scales (Pee Dee Belemnite (PDB) for ${\delta}^{13}C$ and Vienna Standard Mean Ocean Water (V-SMOW) for ${\delta}^{18}O$) is essential for comparisons between data sets obtained by other groups on other mass spectrometers. However, one often finds difficulties in getting well-calibrated standard gases, because of their production time and high price. Additional difficulty is that fractionation processes can occur inside the gas cylinder most likely due to pressure drop in long-term use. Therefore, studies on laboratory production of pure $CO_2$ isotope standard gas from stable solid calcium carbonate standard materials, have been performed. For this study, we propose a method to extract pure $CO_2$ gas without isotope fractionation from a solid calcium carbonate material. The method is similar to that suggested by Coplen et al., (1983), but is better optimized particularly to make a large amount of pure $CO_2$ gas from calcium carbonate material. The $CaCO_3$ releases $CO_2$ in reaction with 100% pure phosphoric acid at $25^{\circ}C$ in a custom designed, evacuated reaction vessel. Here we introduce optimal procedure, reaction conditions, and samples/reactants size for calcium carbonate-phosphoric acid reaction and also provide the details for extracting, purifying and collecting $CO_2$ gas out of the reaction vessel. The measurements for ${\delta}^{18}O$ and ${\delta}^{13}C$ of $CO_2$ were performed at Seoul National University using a stable isotope ratio mass spectrometer (VG Isotech, SIRA Series II) operated in dual-inlet mode. The entire analysis precisions for ${\delta}^{18}O$ and ${\delta}^{13}C$ were evaluated based on the standard deviations of multiple measurements on 15 separate samples of purified $CO_2$. The pure $CO_2$ samples were taken from 100-mg aliquots of a solid calcium carbonate (Solenhofen-ori $CaCO_3$) during 8-day experimental period. The multiple measurements yielded the $1{\sigma}$ precisions of ${\pm}0.01$‰ for ${\delta}^{13}C$ and ${\pm}0.05$‰ for ${\delta}^{18}O$, comparable to the internal instrumental precisions of SIRA. Therefore, we conclude the method proposed in this study can serve as a way to produce an accurate secondary and/or laboratory $CO_2$ standard gas. We hope this study helps resolve difficulties in placing a laboratory working standard onto the international isotope scales and does make accurate comparisons with other data sets from other groups.