• Genes and Genomics
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• v.40 no.11
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• pp.1199-1211
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• 2018

Soil acidification is one of major problems limiting crop growth and especially becoming increasingly serious in China owing to excessive use of nitrogen fertilizer. Only the STOP1 of Arabidopsis was identified clearly sensitive to proton rhizotoxicity and the molecular mechanism for proton toxicity tolerance of plants is still poorly understood. The main objective of this study was to investigate the transcriptomic change in plants under the low pH stress. The low pH as a single factor was employed to induce the response of the wheat seedling roots. Wheat cDNA microarray was used to identify differentially expressed genes (DEGs). A total of 1057 DEGs were identified, of which 761 genes were up-regulated and 296 were down-regulated. The greater percentage of up-regulated genes involved in developmental processes, immune system processes, multi-organism processes, positive regulation of biological processes and metabolic processes of the biological processes. The more proportion of down-regulation genes belong to the molecular function category including transporter activity, antioxidant activity and molecular transducer activity and to the extracellular region of the cellular components category. Moreover, most genes among 41 genes involved in ion binding, 17 WAKY transcription factor genes and 17 genes related to transport activity were up-regulated. KEGG analysis showed that the jasmonate signal transduction and flavonoid biosynthesis might play important roles in response to the low pH stress in wheat seedling roots. Based on the data, it is can be deduced that WRKY transcription factors might play a critical role in the transcriptional regulation, and the alkalifying of the rhizosphere might be the earliest response process to low pH stress in wheat seedling roots. These results provide a basis to reveal the molecular mechanism of proton toxicity tolerance in plants.

• KSBB Journal
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• v.29 no.5
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• pp.328-335
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• 2014

Vehicle toxicity is one of the main obstacles for intracellular delivery of bioactive compounds. Silk fibroin is a natural polymer proven to have high biocompatibility since being used as suture material. In this report, fibroin microspheres were prepared without any chemical modification or cross-linking not to affect its biocompatibility. The microspheres were taken up by more than 90% of 3T3 cells. Cellular uptake continued after medium replenishment with a different-colored fluorescent microsphere, suggesting that simultaneous ingestion and exocytosis occurred. Cellular uptake of fibroin microspheres did not affect cell viability. Intracellular trafficking of the microspheres using lysosome-specific fluorescent dye revealed that fibroin microspheres were localized both in the cytoplasm and in the lysosome. Accordingly, fibroin microspheres can be a potential vehicle for intracytoplasmic delivery of large cargos, such as mixtures of proteins, nutrients or artificial organelles.

• Proceedings of the Korean Society of Sericultural Science Conference
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• 2003.10a
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• pp.55-56
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• 2003

Silk fibroin (SF) is one of the typical protein polymer produced by silkworm, Bombyx mori. SF has been used as textile fiber and surgical suture fur thousands of years due to its unique gloss, handle, and mechanical properties. Recently, SF has been intensively studied to diverse usage for biotechlological and biomedical fields because of their reproducibility, environmental compatibility, non-toxicity, and biological compatibility. Based on its biocompatibility, the possible uses of regenerated SF have been proposed including substrate for cell culture[1], enzyme immobilization[2], and matrix for drug release[3]. (omitted)

• Korean Journal of Ecology and Environment
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• v.45 no.4
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• pp.420-443
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• 2012

An Individual-Based Model (IBM) was developed by employing natural and toxic survival rates of individuals to elucidate the community responses of benthic macroin-vertebrates to anthropogenic disturbance in the streams. Experimental models (dose-response and relative sensitivity) and mathematical models (power law and negative exponential distribution) were applied to determinate the individual survival rates due to acute toxicity in stressful conditions. A power law was additionally used to present the natural survival rate. Life events, covering movement, exposure to contaminants, death and reproduction, were simulated in the IBM at the individual level in small (1 m) and short (1 week) scales to produce species abundance distributions (SADs) at the community level in large (5 km) and long (1~2 years) scales. Consequently, the SADs, such as geometric series, log-series, and log-normal distribution, were accordingly observed at severely (Biological Monitoring Working Party (BMWP<10), intermediately (BMWP<40) and weakly (BMWP${\geq}50$) polluted sites. The results from a power law and negative exponential distribution were suitably fitted to the field data across the different levels of pollution, according to the Kolmogorov-Smirnov test. The IBMs incorporating natural and toxic survival rates in individuals were useful for presenting community responses to disturbances and could be utilized as an integrative tool to elucidate community establishment processes in benthic macroin-vertebrates in the streams.

• Journal of Microbiology and Biotechnology
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• v.24 no.9
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• pp.1226-1231
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• 2014

The rare actinomycete Pseudonocardia autotrophica was previously shown to produce a solubility-improved toxicity-reduced novel polyene compound named $\underline{N}ystatin$-like $\underline{P}seudonocardia$ $\underline{P}olyene$ (NPP). The low productivity of NPP in P. autotrophica implies that its biosynthetic pathway is tightly regulated. In this study, $wblA_{pau}$ was isolated and identified as a novel negative regulatory gene for NPP production in P. autotrophica, which showed approximately 49% amino acid identity with a global antibiotic down-regulatory gene, wblA, identified from various Streptomycetes species. Although no significant difference in NPP production was observed between P. autotrophica harboring empty vector and the S. coelicolor wblA under its native promoter, approximately 12% less NPP was produced in P. autotrophica expressing the wblA gene under the strong constitutive $ermE^*$ promoter. Furthermore, disruption of the $wblA_{pau}$ gene from P. autotrophica resulted in an approximately 80% increase in NPP productivity. These results strongly suggest that identification and inactivation of the global antibiotic down-regulatory gene wblA ortholog are a critical strategy for improving secondary metabolite overproduction in not only Streptomyces but also non-Streptomyces rare actinomycete species.

• Nutrition Research and Practice
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• v.8 no.2
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• pp.151-157
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• 2014

BACKGROUND/OBJECTIVES: In Asia, various medicinal plants have been used as the primary sources in the health care regimen for thousands of years. In recent decades, various studies have investigated the biological activity and potential medicinal value of the medicinal plants. In this study, 100 methanol extracts from 98 plant species were evaluated for their biological activities. MATERIALS/METHODS: The research properties, including 1,1-diphenyl-2-pic-rylhydrazyl (DPPH) radical scavenging activity, ${\alpha}$-glucosidase and ${\alpha}$-tyrosinase inhibitory effects, anti-inflammatory activity, and anticancer activity were evaluated for the selected extracts. RESULTS: Fifteen of the extracts scavenged more than 90% of the DPPH radical. Among the extracts, approximately 20 extracts showed a strong inhibitory effect on ${\alpha}$-glucosidase, while most had no effect on ${\alpha}$-tyrosinase. In addition, 52% of the extracts showed low toxicity to normal cells, and parts of the extracts exhibited high anti-inflammatory and anticancer activities on the murine macrophage cell (RAW 264.7) and human colon cancer cell (HT-29) lines, respectively. CONCLUSIONS: Our findings may contribute to further nutrition and pharmacological studies. Detailed investigations of the outstanding samples are currently underway.

• Molecular & Cellular Toxicology
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• v.5 no.1
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• pp.93-98
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• 2009

Stephania delavayi Diels. has been used as an immune activator or an anti-inflammatory drug in China. We examined the immune modulation effect and 7-days repeated-dose toxicity to validate its biological safety and efficiency. Mice were repeatedly administrated with 50 mg/kg S. delavayi Diels. daily by I.P for 7 days. S. delavayi Diels. induced B cell activation but had no effect on other immune cells such as T cell, natural killer (NK) cell, and macrophage ($M{\varphi}$). S. delavayi Diels.-treated group exhibited no statistical significance from the control group in physical conditions; body weight, complete blood count (CBC), serum biochemical indexes etc. There was no difference between the control group and S. delavayi Diels.-treated group in gross findings such as histopathological alteration. In conclusion, S. delavayi Diels. is safe above the dose of immune modulation.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.24
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• pp.10745-10748
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• 2015

Background: This analysis was conducted to evaluate the efficacy and safety of irinotecan based chemotherapy for treatment of patients with metastatic breast cancer (MBC) who experienced disease progression after one to three chemotherapy regimens, including at least one anthracycline- or taxane-based. Methods: Clinical studies were identified using a predefined search strategy. Pooled response rates (RR) to treatment were calculated. Results: As irinotecan based regimens, 5 clinical studies which including 217 patients with refractory MBC were considered eligible for inclusion, with irinotecan, cisplatin, capecitabine, or TS-1. Systemic analysis suggested that, in all patients, pooled RR was 48.8% (106/217) with irinotecan based regimens. Thrombocytopenia and leukocytopenia were the main side effects. No grade III or IV renal or liver toxicity was observed. No treatment related deaths occurred. Conclusion: This systemic analysis suggests that irinotecan based regimens are beneficial and safe for treating patients with MBC after other chemotherapy.

• Korean Journal of Materials Research
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• v.32 no.4
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• pp.186-192
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• 2022

Collagen is one of the most widely used biological materials in medical design. Collagen extracted from marine organisms can be a good biomaterial for tissue engineering applications due to its suitable properties. In this study, collagen is extracted from fish skin of Ctenopharyngodon Idella; then, the freeze drying method is used to design a porous scaffold. The scaffolds are modified with the chemical crosslinker N-(3-Dimethylaminopropyl)-N'-ethyl carbodiimide hydrochloride (EDC) to improve some of the overall properties. The extracted collagen samples are evaluated by various analyzes including cytotoxicity test, SDS-PAGE, FTIR, DSC, SEM, biodegradability and cell culture. The results of the SDS-PAGE study demonstrate well the protein patterns of the extracted collagen. The results show that cross-linking of collagen scaffold increases denaturation temperature and degradation time. The results of cytotoxicity show that the modified scaffolds have no toxicity. The cell adhesion study also shows that epithelial cells adhere well to the scaffold. Therefore, this method of chemical modification of collagen scaffold can improve the physical and biological properties. Overall, the modified collagen scaffold can be a promising candidate for tissue engineering applications.

• Korean Journal of Weed Science
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• v.32 no.3
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• pp.195-203
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• 2012

The essential oil was extracted by steam distillation from the aerial part of erect bur-marigold (Bidens tripartita L.), one of the noxious weed in paddy field. The composition of the essential oil was analyzed by gas chromatography-mass spectrometry. The fragrance of the essential oil was green, herbal, oily, spicy. There were 42 constituents in the essential oil：17 hydrocarbons, 6 alcohols, 6 acetates, 5 N-containing compounds, 3 ethers, 3 ketones, 1 lactone and 1 S-containing compound. Major constituents were ${\alpha}$-phellandrene (22.50%), ${\alpha}$-pinene (22.21%), 2,4-dimethyl (2,5-dimethylphenyl) methyl ester benzoic acid (15.11%), limonene (10.66%), ${\beta}$-pinene (35.43%), and ${\beta}$-cubebene (5.27%). The $IC_{50}$ value in MTT assay using HaCaT keratinocyte cell line was 0.018%. However, attachment of patch with 0.1% of the erect bur-marigold essential oil for 24 hr did not show any skin toxicity. Overall results of this study suggest that the essential oil of erect bur-marigold could be used as a source for the development of perfumery industrial products.