• Journal of Life Science
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• v.31 no.8
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• pp.710-718
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• 2021

Placenta-derived mesenchymal stem cells (PD-MSCs) are promising candidates for cell-based therapy in regenerative medicine. The migration and homing potential of PD-MSCs to injured sites is a critical property of MSC engraftment. MicroRNAs (miRNAs) have recently been shown to regulate the critical functions of MSCs, such as proliferation, survival, and migration. The objective of the present study was to identify the miRNA and target genes involved in PD-MSCs homing in a bile duct ligation (BDL) rat model. We selected candidate miRNAs targeting genes for PD-MSCs homing based on microarray analysis. PD-MSC engraftment in BDL-injured rat liver was identified by immunofluorescence assay and human-specific Alu gene expression by quantitative real-time polymerase chain reaction (qRT-PCR) one week after transplantation. Compared with migrated naïve PD-MSCs under hypoxic and normoxic conditions (Hyp/Nor), the transplanted group with PD-MSCs (Tx) showed distinct differences in miRNA expressions in BDL-injured rat liver. We also validated the miRNAs and their target genes for PD-MSCs homing. The expressions of integrin α4 (ITGA4) and integrin α5 (ITGA5) target genes for miR-199a-5p and miR-148a-3p were significantly upregulated in the Tx group (p<0.05). In addition, integrin β1 (ITGB1) and integrin β8 (ITGB8) were upregulated by suppressing miR-183-5p and miR-145-5p, respectively. These results demonstrated that PD-MSCs regulate miRNA expression related to the integrin family for their homing effects on the BDL-injured rat liver. The findings further suggest that miRNA-mediated regulation of the integrin family contributes to the therapeutic efficacy of PD-MSCs in the rat hepatic fibrosis model by BDL.

• Journal of Korean Society of Forest Science
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• v.109 no.4
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• pp.371-381
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• 2020

The Ministry of Environment (ME) is planning to adopt in 2020 the IUCN regional Red List for "Guidelines for listing and delisting rare & endangered species and management of endangered Species System". The ME designated 377 species of vascular plants on the regional Red List. In a previous study it had been suggested that 103 species from this list are candidates for the regional Red List. With respect to a possible Red List, we assessed 59 species (after excluding 34 additional NA species and ten endemic species). These assessments indicated that 16 species are at the "threatened" level. Of those, one species is Critically Endangered, ten are Endangered, and five are Vulnerable. A further four species are classified as Near Threatened, 30 as Of Least Concern, and nine as Data Deficient. We found that most of the assessments proposed by the Ministry of Environment were not supported by scientific data, including quantitative geographic data (over 70%) in Criteria B. In order to determine the endangered species belonging to the orchid family, it is necessary to obtain records of illegal activities or data on overcollection. The current problem with the Ministry of Environment Red List has been the lack of management of scientific data on species showing a trend in decreasing population in the mid- to long-term; thus, there is a lack of critical resources for policy-makers. The ME legally designated categories and assessment, and the lack of expertise in failing to comply with the legal law by itself. The key to presenting an accurate overview of the state of Korean flora is to fill the information gaps with respect to significant geographical and taxonomical biases in the quality and quantity of data. By regularly updating the qualified data, we will be able to track the changes in the conservation status of the flora and inform the necessary conservation policies.

• Korean Journal of Environment and Ecology
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• v.34 no.6
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• pp.601-609
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• 2020

This study aims to draw suggestions for establishing the Post-2020 national policy direction and goals related to protected areas in Korea by analyzing the trends of major discussion issues on protected areas in the Convention on Biological Diversity (CBD) and reviewing the achievement progress of the Aichi target-11. Regarding the CBD decisions on protected areas, two decisions (Decisions II/7 and II/8) were adopted in 1995, and then the Program of Work on Protected Areas (PoWPA), which presented an ideal blueprint for protected areas, was adopted at the 7th Conference of the Parties (COP) in 2004. At the 10th COP in 2010, the "Strategic Plan for Biodiversity 2011-2020 and the Aichi Biodiversity Target" (Decision X/2) was adopted along with the Decision X/31, which presented ten key issues related to protected areas. The global outcomes of the Aichi Target-11 include 15% of the earth's land area and 7.4% of the ocean being designated as protected areas. In Korea, 16.63% of the land and 2.12% of the ocean have been designated as protected areas. However, the outcomes of the effective and equitable management, protection of areas important to biodiversity and ecosystem services, and identifying "Other effective area-based conservation measures" (OECMs) and linking them with protected areas have been found to be significantly short of global goals. The first draft of the Post-2020 Global Biodiversity Framework (Post-2020 GBF) prepared in January 2020 presented multi-step objectives. They included protecting at least 60% of particularly important sites for biodiversity through protected areas and other effective area-based conservation measures, at least 30% of the entire land and sea areas, and at least 10% of them under strict protection by 2030. The Updated Zero drafted in August 2020 concisely set out one quantitative goal of at least 30% of the globe by 2030, adding qualitative goals that these areas should be protected and conserved through "well connected and effective system of protected areas and OECMs at least 30 % of the planet with the focus on areas particularly important for biodiversity." Based on the draft Post-2020 GBF's targets related to protected areas and Korea's national targets reflecting the current state of Korea and established national plans, we suggest the national targets "to protect and conserve at least 30% of the land area and 10% of the marine area and to strengthen the means of qualitative achievement by establishing sub-targets through an effective system of protected areas and OECMs by 2030.".

• Journal of Korean Society of Forest Science
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• v.110 no.2
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• pp.129-140
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• 2021

The study investigates the correlation between the seasonal changes in the absorption of fine dusts and the fine structure of surface on each type of street tree, such as Quercus myrsinifolia, Quercus glauca, Quercus salicina, Camellia japonica, and Prunus × yedoensis in the southernareas of Korea. The absorption ranges of fine dust were 31.51~110.44 ㎍/cm² in January, 23.20~79.30 ㎍/cm² in November, 22.68~76.90 ㎍/cm² in May, and 9.88~49.91 ㎍/cm² in August. The absorption value was about 54.4% higher in January than in May. With the grooves and hairs on the leaf surface and lots of wax, Q. salicina seems related to the high absorption rate of fine dust for each fine dust particle size. The one with gloss and smooth leaf surface has a low amount of wax. C. japonica Prunus × yedoensisshowed a low absorption rate of fine dust in each season. Whereas the increase in porosity density, length, and leaf area size can be related to the reduced PM and increasedabsorption rate, the leaf surface roughness, total wax amount, and porosity width can be related to the increase in the PM absorption rate. There was also a high correlation between the total wax amount and absorption rate of the leaf surface at the size of PM_0.2 than PM₁₀ and PM_2.5. These results imply that the quantitative and qualitative trais of leaf, such as wax amounts and leaf surface,can increase the absorption of fine dusts, and the small-sized particles seem to be highly adsorbed with the high wax amounts.

• Korean Journal of Mineralogy and Petrology
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• v.35 no.1
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• pp.65-73
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• 2022

The proper estimation of physical and chemical properties of Earth materials and their structures at high pressure and high temperature conditions is key to the full understanding of diverse geological processes in Earth and planetary interiors. Multi-anvil press - high-pressure generating device - provides unique information of Earth materials under compression, mainly relevant to Earth's upper mantle. The quantitative estimation of the relationship between the oil load within press and the actual pressure conditions within the sample needs to be established to infer the planetary processes. Such pressure-load calibration has often been based on the phase transitions of crystalline earth materials with known pressure conditions; however, unlike at high temperature conditions, phase transitions at low (or room) temperatures can be sluggish, making the calibration at such conditions challenging. In this study, we explored the changes in Al coordination environments of permanently densified pyrope glasses upon the cold compression using the high-resolution ²⁷Al MAS and 3QMAS NMR. The fractions of highly coordinated Al in the cold compressed pyrope glasses increase with increasing oil load and thus, the peak pressure condition. Based on known relationship between the peak pressure and the Al coordination environment in the compressed pyrope glasses at room temperature, we established a room temperature pressure-load calibration of the 14/8 HT assembly in 1,100-ton multi-anvil press. The current results highlight the first pressure-load calibration of any high pressure device using high-resolution NMR. Irreversible structural densification upon cold compression observed for the pyrope glasses provides insights into the deformation and densification mechanisms of amorphous earth materials at low temperature and high pressure conditions within the subducting slabs.

• Journal of the Korean Electrochemical Society
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• v.24 no.4
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• pp.120-132
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• 2021

Although the development of high-Nickel is being actively carried out to solve the capacity limitation and the high price of raw cobalt due to the limitation of high voltage use of the existing LiCoO₂, the deterioration of the battery characteristics due to the decrease in structural stability and increase of the Ni content. It is an important cause of delaying commercialization. Therefore, in order to increase the high stability of the Ni-rich ternary cathod material LiNi_0.6Co_0.2Mn_0.2O₂, precursor Ni_0.6Co_0.2Mn_0.2-x(OH)₂/xTiO₂ was prepared using a nanosized TiO₂ suspension type source for uniform Ti substitution in the precursor. It was mixed with Li₂CO₃, and after heating, the cathode active material LiNi_0.6Co_0.2Mn_0.2-xTi_xO₂ was synthesized, and the physical properties according to the Ti content were compared. Through FE-SEM and EDS mapping analysis, it was confirmed that a positive electrode active material having a uniform particle size was prepared through Ti-substituted spherical precursor and Particle Size Analyzer and internal density and strength were increased, XRD structure analysis and ICP-MS quantitative analysis confirmed that the capacity was effectively maintained even when the Ti-substituted positive electrode active material was manufactured and charging and discharging were continued at high temperature and high voltage.

• Journal of Food Hygiene and Safety
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• v.37 no.2
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• pp.87-96
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• 2022

Recently, the purchase of fresh-cut produce and meal kits has increased. Ready-to-eat (RTE) fresh-cut products have potentially hazard of cross-contamination of various microorganisms in the processes of peeling, slicing, dicing, and shredding. There are frequent cases of protozoa food poisoning, such as Cyclospora and Cryptosporidium, caused by fresh-cut products. The objective of the study is to investigate the microbiological qualities of various types of RTE fresh-cut products in the domestic on/offline markets. RTE fresh-cut fruits cup (n=100), fresh-cut vegetables (n=50), and vegetables in meal kits (Vietnamese spring rolls and white radish rolls kits, n=50) were seasonally analyzed. The contamination levels of hygienic indicator organisms, yeast and mold (YM), and foodborne pathogens (Bacillus cereus, Staphylococcus aureus, Listeria monocytogenes, Salmonella spp., and Escherichia coli O157:H7) were monitored. Overall, the lowest microbiological qualities of meal kits vegetables were observed, followed by RTE fresh-cut fruits cup and fresh-cut vegetables. Contamination levels of total aerobic bacteria, coliforms, and YM in meal kits vegetables were 5.91, 3.90, and 4.71 logs CFU/g, respectively. From the qualitative analysis, 6 out of 200 RTE fresh-cut products (3%) returned positive result for S. aureus. From the quantitative analysis, the contamination levels of S. aureus in purple cabbage from a meal-kit and fresh-cut pineapple were below the acceptable limit (100 CFU/g). Staphylococcus enterotoxin seg and sei genes were detected in RTE fresh-cut celery and red cabbage from meal-kits, respectively. S. aureus contamination must be carefully controlled during the manufacturing processes of RTE fresh-cut products. Neither Cyclospora cayetanensis nor Cryptosporidium parvum was detected in the samples of RTE fresh-cut products and vegetables from meal-kits from the Korean retail markets.

• Korean Journal of Remote Sensing
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• v.38 no.6_2
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• pp.1691-1707
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• 2022

Cheonji Lake, the caldera of Baekdu Mountain, located on the border of the Korean Peninsula and China, alternates between melting and freezing seasonally. There is a magma chamber beneath Cheonji, and variations in the magma chamber cause volcanic antecedents such as changes in the temperature and water pressure of hot spring water. Consequently, there is an abnormal region in Cheonji where ice melts quicker than in other areas, freezes late even during the freezing period, and has a high-temperature water surface. The abnormal area is a discharge region for hot spring water, and its ice gradient may be used to monitor volcanic activity. However, due to geographical, political and spatial issues, periodic observation of abnormal regions of Cheonji is limited. In this study, the degree of ice change in the optimal region was quantified using a Landsat -5/-7/-8 optical satellite image and a Modified U-Net regression model. From January 22, 1985 to December 8, 2020, the Visible and Near Infrared (VNIR) band of 83 Landsat images including anomalous regions was utilized. Using the relative spectral reflectance of water and ice in the VNIR band, unique data were generated for quantitative ice variability monitoring. To preserve as much information as possible from the visible and near-infrared bands, ice gradient was noticed by applying it to U-Net with two encoders, achieving good prediction accuracy with a Root Mean Square Error (RMSE) of 140 and a correlation value of 0.9968. Since the ice change value can be seen with high precision from Landsat images using Modified U-Net in the future may be utilized as one of the methods to monitor Baekdu Mountain's volcanic activity, and a more specific volcano monitoring system can be built.

• Journal of Nutrition and Health
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• v.55 no.2
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• pp.227-239
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• 2022

Purpose: This study investigated the effects of water-soluble mulberry leaf extract (ME) on hepatic lipid accumulation in high-fat diet-fed rats via the regulation of hepatic microRNA (miR)-221/222 and inflammation. Methods: Male Sprague-Dawley rats (4 weeks old) were randomly divided into 3 groups (n = 7 each) and fed with 10 kcal% low-fat diet (LF), 45 kcal% high-fat diet (HF), or HF + 0.8% ME for 14 weeks. Lipid profiles and cytokine levels of the liver and serum were measured using commercial enzymatic colorimetric and enzyme-linked immunosorbent assay, respectively. The messenger RNA (mRNA) and miR levels in liver tissue were assayed by real-time quantitative reverse-transcription polymerase chain reaction. Results: Supplementation of ME reduces body weight and improves the liver and serum lipid profiles as compared to the HF group. The mRNA levels of hepatic peroxisome proliferator-activated receptor-gamma, sterol regulatory element binding protein-1c, fatty acid synthase, and fatty acid translocase, which are genes involved in lipid metabolism, were significantly downregulated in the ME group compared to the HF group. In contrast, the mRNA level of hepatic carnitine palmitoyl transferase-1 (involved in fatty acid oxidation) was upregulated by ME supplementation. Furthermore, administration of ME significantly downregulated the mRNA levels of inflammatory mediators such as hepatic tumor necrosis factor alpha (TNF-α), interleukin 6 (IL-6), monocyte chemoattractant protein-1, and inducible nitric oxide synthase. The serum levels of TNF-α, IL-6, and nitric oxide were also significantly reduced in ME group compared to the HF group. Expression of hepatic miR-221 and miR-222, which increase in the inflammatory state of the liver, were also significantly inhibited in the ME group compared to the HF group. Conclusion: These results indicate that ME has the potential to improve hepatic lipid accumulation in high-fat diet-fed rats via modulation of inflammatory mediators and hepatic miR-221/222 expressions.

• Analytical Science and Technology
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• v.34 no.6
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• pp.259-266
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• 2021

Cannabis (Marijuana) is one of the most widely used drugs in the world, and its distribution has been controlled in South Korea since 1976. Identification of 11-nor-Δ⁹-carboxy-tetrahydrocannabinol (THCCOOH) in urine can provide important proof of cannabis use, and it is considered scientific evidence in the forensic field. In this study, we describe a simultaneous quantitative method for identifying THCCOOH and THCCOOH-glucuronide in urine, using simple liquid-liquid extraction (LLE), and liquid chromatography-tandem mass spectrometry (LC-MS/MS). THCCOOH-D₃ and THCCOOH-glucuronide-D₃ were used as internal standards. Validation results of the matrix effect, as well as recovery, linearity, precision, accuracy, process efficiency, and stability were all satisfactory. No carryover, endogenous or exogenous interferences were observed. The limit of detection (LOD) of THCCOOH and THCCOOH-glucuronide were 0.3 and 0.2 ng/mL, respectively. The developed method was applied to 28 authentic human urine samples that tested positive in immunoassay screening and gas chromatography/mass spectrometry (GC/MS) tests. The ranges of concentrations of THCCOOH and THCCOOH-glucuronide in the samples were less than LOQ~266.90 ng/mL and 6.43~2133.03 ng/mL, respectively. The concentrations of THCCOOH-glucuronide were higher than those of THCCOOH in all samples. This method can be effectively and successfully applied for the confirmation of cannabinoid use in human urine samples in the forensic field.