• Journal of Life Science
• /
• v.20 no.8
• /
• pp.1254-1260
• /
• 2010

Microorganisms near the plant rhizosphere usually inhabit the surface or the inside of the plant roots and have a direct effect on plant growth by secreting plant growth promoters or antagonistic materials which protect the root zone system from various pathogens. This study was carried out to identify and isolate the antagonistic materials after isolation of microorganisms showing high antagonistic activities, in hopes of contributing to the development of sustainable agriculture and the preservation of agricultural environments. A number of antagonistic bacteria were isolated from paddy soil. Among isolates, RRj 228 showed plant growth promotion and antagonistic activity. RRj 228 was identified as Pseudomonas sp. according to the results of physiological properties and genetic methods. On the basis of the results of anti-fungal spectrum against several pathogens by RRj 228, the antagonistic effect of the isolate against Botrytis cinerea, Pythium ultimum, Phytopthola capsici, and Rhizoctonia solani, especially against red-pepper anthracnose caused by Colletotrichum acutatum, was remarkable. The experiment evaluating the biological control effect by RRj 228 revealed that the $ED_{50}$ value by the RRj 228 culture against C. acutatum, R. solani and P. ultimum were 0.14 mg/ml, 0.16 mg/ml and 0.29 mg/ml, respectively. An antagonistic substance was isolated and purified by several chromatographies from the RRj 228 culture. The $^1H$ and $^{13}C$ assignment of the antagonistic substance was achieved from two-dimensional $^1H-^1H$ COSY, HMQC, and HMBC. Finally, the antagonistic substance was identified as Phenazine-1-carboxylic acid ($C_{13}H_8N_2O_2$, M.W.=224).

• Journal of the Korea Concrete Institute
• /
• v.21 no.1
• /
• pp.85-92
• /
• 2009

A concrete is considered unfriendly-environmental material because it uses cement which emits much $CO_2$ during producing process. However, a concrete absorbs $CO_2$ through carbonation process during service life. In this paper how much concrete absorbs $CO_2$ through carbonation was calculated using 1) concentration of carbonatable substances in concrete, 2) carbonated volume of concrete, 3) molecular weight of $CO_2$ based on references and the method was proposed. $CO_2$ emission from producing $1m^3$ concrete was calculated based on $CO_2$ emission datum of materials used in concrete. From using these methods that calculate $CO_2$ emission and absorption of concrete, assessment of $CO_2$ emission-absorption against a real apartment was conducted by subtracting absorption $CO_2$ according to service life from $CO_2$ emission in the process of making concrete. As a result, a ratio of absorption over emission of $CO_2$ through concrete carbonation according to service life 40, 60, 80 years was assessed about 3.65, 4.47, 5.18%. An objective of this study is to propose how to calculate emission - absorption of $CO_2$ from producing and using concrete. Although the result value, emission - absorption of $CO_2$, is 5.18% very low when the service life of an apartment is 80years, the value can be improved by reducing emission from using blended cement such as blast furnace slag or increasing replacement ratio of cement and increasing carbonated volume of concrete from expanding service life of a building. This study may be useful when $CO_2$ emission - absorption of concrete is evaluated in the further study.

• Journal of Life Science
• /
• v.20 no.8
• /
• pp.1193-1200
• /
• 2010

The cDNA cloning and developmental profiles of the mRNA for A. pernyi arylphorin was determined. The complete A. pernyi arylphorin cDNA sequence comprised 2,234 bp (without the poly $A^+$ tail), including an open reading frame of 2,112 bp beginning with a methionine ATG at bp34. The A. pernyi arylphorin contained 704 amino acids which are highly enriched in aromatic amino acids, phenylalanine and tyrosine. The calculated molecular mass of the A. pernyi arylphorin from the ORF was 83,439 Da. The deduced amino acid sequence of A. pernyi arylphorin showed 78, 71, 62 and 64% identity with those of H. cecropia, M. sexta $\alpha$ subunit, M. sexta $\beta$ subunit and B. mori storage protein. In Northern blot analysis, the A. pernyi arylphorin mRNA only in the fat body of the 5th instar larvae was responsible for gene expression of the protein, and the synthetic activity of the mRNA was detected strongly in the early larvae, but not in the middle or late-stage larvae. In addition, a very weak signal in mRNA activity was detected in pupal stages, but this was considered to be inactive mRNA after reviewing the results of the labeling experiment of this protein.

• The Korean Journal of Malacology
• /
• v.25 no.2
• /
• pp.153-160
• /
• 2009

Pisidium (Neopisidium) coreanum is a freshwater snail and lives in spring water near mountain areas. Interestingly, this snail has been traditionally regarded as medicinal food, and thus has been used as folk remedies for healing broken bones. Recently, alpha classification on Pisidium (Neopisidium) coreanum through redescription has been conducted. However, not much attention has been made in beta classification. In this study, we performed the beta classification based on metallothionein (MT) genes found from various organisms. To this end, the complete cDNA sequences were obtained from the Expressed Sequence Tag (EST) sequencing project of Pisidium (Neopisidium) coreanum. The coding region (315 bp) encoded an amino acid sequence of 105 residues. The combined results from BLAST analyses, multiple sequence alignment and molecular phylogenetic study of Pc-MT gene indicate that Pisidium (Neopisidium) coreanum has similarity to freshwater bivalve such as Dreissena polymorpha (zebra mussel), Unio tumidus (swollen river mussel) and Crassostrea ariakensis (suminoe oyster).

• Korean Journal of Plant Resources
• /
• v.31 no.5
• /
• pp.466-477
• /
• 2018

In this study, the anti-inflammatory activities of the extracts of different parts of Hovenia dulcis such as leaves, stems, and roots were investigated. Among them, the roots extract (RE) showed the most potent suppressive effect against pro-inflammatory mediators in LPS-stimulated mouse macrophage cells. RE induced dose-dependent reduction of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) and concomitantly reduced the production of NO and $PGE_2$. Additionally, pre-treatment with RE significantly suppressed the production of inflammatory cytokines, such as tumor necrosis $factor-{\alpha}$ ($TNF-{\alpha}$), interleukin $(IL)-1{\beta}$, and IL-6, as well as mRNA levels. Moreover, phosphorylation of mitogen-activated protein kinases (MAPKs) and nuclear translocation of nuclear factor-kappa B (NF-kB) were also strongly attenuated by RE in RAW264.7 cell. Furthermore, RE induced HO-1 expression through nuclear translocation of nuclear factor E2-related factor 2 (Nrf2) and increase HO-1 activity in RAW264.7 macrophages. Therefore, these results indicate that RE strongly inhibits LPS-induced inflammatory responses by blocking NF-kB activation, inhibiting MAPKs phosphorylation, and enhancing HO-1 expression in macrophages, suggesting that RE of H. dulicis and a major component, 27-O-protocatechuoylbetulinic acid could be applied as a valuable natural anti-inflammatory material.

• Korean Journal of Ecology and Environment
• /
• v.33 no.4 s.92
• /
• pp.366-373
• /
• 2000

Toxin production and low digestibility of cyanobacteria are known to cause low exploitability of cyanobacteria by zooplankton. In this study, we compared relative tolerance and compatibility of zooplankton taxa in eight eutrophic lakes, exposed to frequent cyanobacterial blooms, uring the summer season of 1999. Microcystis, Anabaena, Oscillatoria and Phormidium were common cyanobacteria in all lakes. with relatively lower $NO_3-N$ concentration (<0.2 mgN/l) and TN/TP ratio (<20), compared with other lakes where colonial cyanobacteria dominated. Rotifers were dominant zooplankton in most lakes, and among them, Keratella, Polyarthra and Hexathra were common. The laboratory feeding experiment showed that relative copepods that greatly decreased (90%) after 4 day when cyanobacteria were used as the food source of zooplankton, while rotifers gradually increased with the change of dominant taxa from Keratella through Pompholyx to Monostyla. These results suggest that rotifers may be capable of coexisting with cyanobacteria by exploiting them for the food source.

• Applied Microscopy
• /
• v.34 no.3
• /
• pp.171-178
• /
• 2004

Metallothionein (MT) is a family of ubiquitous, low molecular weight (6-7 kDa), cysteine-rich protein with a high affinity to metal ions and has no aromatic amino acids and histidine. Some of the known functions of MT include detoxification of heavy metals and alkylating agents and neutralization of free radicals. Also, this protein may affect a number of cellular processes including gene expression, apoptosis, proliferation and differentiation. But, its actual functions are still not clear. The present study was undertaken to examine immunocytochemically the localization of MT in developing rat liver. On the day 11 of gestation, the fetal rat liver has already been formed and contained numerous oval cells with high nuclear cytoplasmic ratio, which were the progenitors of hepatic parenchymal cells, but no reaction products of MT were detected at this time. And then, positive reactions against MT started to appear predominantly in the parenchymal cells of liver from the 13th day after gestation. Reaction products, immunogold particles or brown coloration, were localized at both the nucleus and the cytoplasm of the parenchymal cells, except mitochondria. The intensity of this reaction gradually increased, and exhibited the strongest at birth. The intensity of MT staining and immunogold labelling diminished with growth, and by the 15th day after birth weak positive reaction was observed in the cells. In brief, positive reactions for MT were observed in the oval cells and the parenchymal cells during fetal stage, meanwhile they were present only in the parenchymal cells after birth. The present results suggest that MT possibly involves parechymal cell proliferation and differentiation through the storage or the supply of various metal ions in the developing rat liver.

• Journal of Preventive Medicine and Public Health
• /
• v.21 no.2 s.24
• /
• pp.224-237
• /
• 1988

To determine the causes of and related factors to childhood injuries, the emergency room records and inpatient medical records were reviewed for 4,849 injured children out of 15,790 pediatric patients(<15 years old) who visited the emergency rooms of 3 university hospitals and 2 general hospitals in Taegu from 1 January to 31 December 1987. Out of total injured children, 54.675 were 3-8 years old and the male to female ratio of the total injured children was about 2:1. The leading causes of injury were falls and slips (29.1%) and traffic accident(28.2%). The frequency of injury was higher in May-October than the rest of months and 51.6% of the injuries occurred between 15 and 20 o'clock. Falls and slips took place most frequently at the stairway(25.7%). The most common interpersonal violence was inflicted injuries(85.6%) and there were 11 child rapes. Dog bites accounted for 67.6% of all biting injuries and it occured 2.9 times more in male than in female. CO intoxication was the most common cause of poisoning (45.3%) and scalding accounted for 85.2% of all burns. Common places of drownings were river (32.2%), swimming pool (22.6%) and construction site(19.3%). To prevent childhood injuries, it is recommended to eliminate the hazardous environmental factors, to provide safe playgrounds, to educate the children for safety from kindergarten and the general public through mass communication, to establish a strict safety standard for houses, public buildings and facilities, and playgrounds.

• Journal of the Korean Wood Science and Technology
• /
• v.38 no.3
• /
• pp.213-222
• /
• 2010

In this study, chemical compositions - holocellulose, lignin and monomeric sugars - were characterized with two poplar wood cell walls, one of which was grown at normal condition (CPW) and the other was genetically modified by antisence suppression of CCoAOMT gene expression (ACPW). Milled wood lignins were isolated from CPW and ACPW and subjected to methoxyl group, DFRC, Py-GC/MS, GPC, $^{13}C$-NMR analysis, respectively. There were few differences in holocellulose contents in both cell walls, which were determined to 81.6% in CPW and to 82.3% in ACPW. However, lignin contents in ACPW was clearly decreased by the suppression of CCoAOMT gene expression. In CPW 21.7% of lignin contents was determined, while lignin contents in ACPW was lowered to 18.3%. The relative poor solubility of ACPW in alkali solution could be attributed to the reduction of lignin content. The glucose contents of CPW and ACPW were measured to 511.0 mg/g and 584.8 mg/g and xylose contents 217.8 mg/g and 187.5 mg/g, respectively, indicating that suppression of CCoAOMT gene expression could be also influenced to the formation of monomeric sugar compositions. In depth investigation for milled wood lignin (MWL) isolated from both samples revealed that the methoxyl contents at ACPW was decreased by 7% in comparison to that of CPW, which were indirectly evidenced by $^{13}C$-NMR spectra and Py-GC/MS. According to the data from Py-GC/MS S/G ratios of lignin in CPW and ACPW were determined to 0.59 and 0.44, respectively. As conclusive remark, the biosynthesis of syringyl unit could be further influenced by antisense suppression of CCoAOMT during phenylpropanoid pathway in the plant cell wall rather than that of guaiacyl unit.

• Journal of Biomedical Engineering Research
• /
• v.23 no.2
• /
• pp.147-153
• /
• 2002

The purpose of this study was to evacuate the effect of different types of Poly(lactic-co-glycolic acid) (PLGA) scaffolds on the formation of human auricular and septal cartilages. All of the scaffolds were formed in a tubular shape for potential application for artificial trachea or esophagus with either 110,000 g/mol PLGA. 220,000 g/mol PLGA. or a combination of both. In order to maintain the tubular shape in vivo, two methods were used. One method was inserting polyethylene tube at the center of scaffolds made of 110,000 g/mol PLGA. The other method involved combination of the two different molecular weight PLGA's. The inner surface of tubular shaped scaffold made with 110,000 g/mol PLGA was coated with 220,000 9/mol PLGA to give more mechanical rigidity. Elastic cartilage was taken from the ear of a patient aged under 20 nears old and hyaline cartilage was taken from the nasal septum. The chondrocytes were then isolated. After second passage, the chondrocytes were seeded on the PLGA scaffolds followed by in vitro culture for one week. The cells-PLGA scaffold complex were implanted subcutaneously on the back of nude mice for 8 weeks. The tissue engineered cartilages were separated from nude mice and examined histologically after staining with the Hematoxylin Eosin. The morphology of the scaffolds were examined by scanning electron microscopy. The pores were well formed and uniformly distributed in the various PLGA scaffolds. After 8 weeks in vivo culture, cartilage was well formed with 110,000 g/mol PLGA. however lumen had collapsed. In contrast. a minimal amount of neocartilage was formed with 220,000 g/mol PLGA, while the architecture of scaffold and lumen were well preserved. Elastic cartilage formed more neocartilage than hyaline. Hyaline and elastic neocartilage were well formed on 110,000 g/mol PLGA with the polyethylene tube, exhibiting mature chondrocytes and preservation of the tubular shape. It was found that 110,000 g/mol PLGA was more appropriate for cartilage formation but higher molecular weight polymer was necessary to maintain the three dimensional shape of the scaffold.