Titanium dioxide (), which is one of the most basic materials in our daily life, plays a key role for environment purification. We synthesized nanoparticles by the hydrolysis reactions of titanium tetraisopropoxide using as a peptizing agent or as a chelating agent in the sol-gel method. The powder consisted of a rod shape or a spherical shape according to the concentration and kind of acid. The physical properties of nanoparticles were investigated with X-ray diffraction, SEM, BET analysis, and UV-Vis spectrophotometer.

The effects of doping on the crystal structure, ferroelectric, and piezoelectric properties of (K,Na) (KNN) ceramics have been investigated. was found to be effective in enhancing the densification and grain growth during sintering. X-ray diffraction analysis indicated that Mn ions substituted B-site Nb ions up to 2 mol%, however, further doping induced unwanted secondary phases. In comparison with undoped KNN ceramics, the well developed microstructure and the substitution to B-sites in 2 mol% Mn-doped KNN ceramics resulted in significant improvements in both piezoelectric coupling coefficient and electromechanical quality factor.

Rice black-streaked dwarf virus (RBSDV), a member of the genus Fijivirus within the family Reoviridae, is the causative agent of maize rough dwarf and rice black-streaked dwarf diseases, both of which can lead to severe yield losses in east Asia. Although molecular approaches such as RT-PCR have potential for detection and diagnosis of this virus infections, their impact on high throughput certification is still limited. Therefore, the development of an antibody-based assay for rapid and effective diagnosis of RBSDV is preferable. In this study, we collected RBSDV from rice with rough dwarf disease and its complete nucleotide sequences of 10 genomic segments encoding 12 non-overlapping ORFs were determined. Among 12 ORFs, ORF1, 2 and 12 showed high level of similarities with the RdRp, major core protein and major outer shell protein, respectively. These ORFs were expressed as polyhedrin fusion protein or full-length soluble protein using baculovirus expression system for the preparation of specific antibody against RBSDV, which could be useful for the detection and diagnosis of this virus.

Mamestra brassicae nucleopolyhedrovirus-K1 (MabrNPV-K1) was isolated from naturally infected Mamestra brassicae (Lepidoptera: Noctuidae) larvae in Korea. Restriction endonuclease fragment analysis using EcoRI, PstI, and BamHI estimated that the total genome size of MabrNPV-K1 is about 150 Kb. The full genome sequences of MabrNPV-K1 were determined, analyzed and compared to those of other baculoviruses. The MabrNPV-K1 genome consisted of 152,471 bp and had an overall G + C contents of 39.90 %. Computer-assisted analysis predicted 159 open reading frames (ORFs) of 150 nucleotides or greater that showed minimal overlap. The gene content and arrangement in MabrNPV-K1 were most similar to those of Mamestra configurata nucleopolyhedrovirus-B (MacoNPV-B), including three polh, p10 and lef-8 gene homologues. The MabrNPV-K1 genome contains four homologous repeat regions (hr1,hr2,hr3,hr4) that account for 3.1% of the genome. The genomic positions of MabrNPV-K1 regions hr1– hr4 are conserved with the genomic positions of MacoNPV-B hr1–hr4. This indicates that the position of MabrNPV–K1 hrs is conserved with regard to both the upstream and downstream genes. Given that hrs share higher similarity within a virus strain than any hrs between species, this evidence further indicates that hrs play a fundamental role in viral life cycle and replication process appears to be tightly linked to functional conservation. The dot plot analysis, percent identity of the gene homologues and a phylogenetic analysis suggested that MabrNPV-K1 is a Group II NPV that is closely related to MacoNPV but with a distinct genomic organization.

We isolated two baculoviruses, Spodoptera litura granulovirus (SlGV) and S. litura nucleopolyhedrovirus (SlNPV) in the dead larvae of S. litura. The granule of SlGV were ovoidal shape with an approximate measure of 240-340 nm×140-180 nm, and each granule contained one single rod-shape virion with a mean size of 180-200 nm×20-40 nm. Whereas, the polyhedra of SlNPV were irregular in shape with a approximate diameter of 1.0-1.5 ㎛, and numerous virions comprised of the multinucleocapsid were contained in each polyhedra. The major component of occlusion bodies produced by SlGV and SlNPV were about 29 and 30 kDa, respectively. When the phylogenic relationship between these viruses were analyzed using the nucleotide sequences of granulin gene from SlGV and polyhedrin gene from SlNPV, they were not closely related to each other. We also found that the two viruses showed similar insecticidal activity against 2nd instar larvae of Spodotera litura in terms of dose-response, but SlGV showed much longer LT50 than that of SlNPV. The two baculoviruses might be cooperatively be applied as biological control agent for the control of S. litura

The Classical Swine Fever Virus (CSFV) is a member of the Pestivirus genus of the Flaviviridae. The polyprotein composed of eight nonstructural and four structural proteins (nucleocapsid protein C and three envelope glycoprotein E0, E1 and E2). E2, the most immunogenic of the CSFV glycoproteins, induces a protective immune response in swine. The objective of this study was to enhance production of E2 protein by fusion with partial polyhedrin of nucleopolyhedrovirus in insect cells. We generated various E2 form by fusion with different combinations of the partial polyhedrin and deletion of the C-terminal transmembrane region (TMR). Expression of the E2 protein was identified by SDS-PAGE and Western blot analysis using anti-CSFV E2 monoclonal antibodies. The fusion expression of an E2 protein with the partial polyhedrin markedly increased expression levels. Also, expression of E2 proteinlacking TMR region was higher than that of intact E2 protein. As a result, the fusion expression of E2 protein lacking the C-terminal TMR with partial polyhedrin was significantly increased in insect cells. These suggest that the fusion of target foreign protein with partial polyhedrin could enhance significantly the production of target protein.

Autographa californica nucleopolyhedrovirus (AcMNPV) has a large doublestrand DNA genome of approximately 134 kbp and harbors 156 open reading frames (ORFs). To elucidate DNA replication cascade of AcMNPV, we developed a novel baculovirus genome that can be maintained in Escherichia coli as a plasmid and can infect susceptible lepidopteran insect cells. This genome, named bAc-MK, contains a mini-F replicon and a kanamycin resistance marker. Using a convenient Tn7 transposon-based system, pPCS-S, 55 single ORF-truncated mutants were generated by random insertion into bAc-MK genome. These single ORF-truncated mutants were independently transfected into Sf9 cells, 16 of them were found affecting viral replication since they defected in producing polyhedra. Furthermore, to verify the pathogenicity of the single ORF-truncated mutants, the remaining 39 mutants were subjected to bioassay to Spodoptera exigua 3rd instar larvae. Among them, ac9-, ac49-, ac103- and ac105-knockout mutants showed higher mortality compared to that of bAc-MK. These results suggested that these ORFs could be related to pathogenicity of AcMNPV.

The Bacillus thuringiensis strain K4 was isolated from fallen leaves, sampled in a forest region of the city of Mungyeong, Korea. The flagellated vegetative cells of B. thuringiensis strain K4 were agglutinated with the H3 reference antiserum and further, agglutinated with 3b and 3d monospecific antisera but non-reactive for 3c and 3e factor sera. These results create a new serogroup with flagellar antigenic structure of 3a3b3d, designated serovar mogi. The strain K4 showed high activity against dipteran larvae, Anopheles sinensis and Culex pipiens pallens while no lepidopteran toxicity. It produced a single ovoidal-shaped parasporal crystal whose SDS-PAGE protein profile consisted of several bands ranging from 75 to 30 kDa. Through the protein identification by nano-LC-ESI-IT MS analysis, the putative peptides of Cry19Ba, Cry40ORF2, Cry27Aa and Cry20Aa were detected. In contrast to the plasmid profile of B. thuringiensis H3 serotype strains, the strain K4 contained only a large plasmid (~100 kb) and we cloned partial cry27Aa, cry19Ba and cry40ORF2 genes from it by thermal asymmetric interlaced PCR. Sequencing analysis showed 87%, 88% and 88% homologous with known cry27Aa, cry19Ba and cry40ORF2 genes, respectively. The new type strain, B. thuringiensis subsp. mogi (H3a3b3d) will be a good resource for new mosquitocidal cry genes.

In agricultural fields, the entomopathogenic fungal species have been investigated for their potential as the biological control agents due to their role of natural enemies for insects. To address the requirements of a potential South Korea based biocontrol effort using entomopathogenic fungi, we investigated the occurrence of various entomopathogenic fungi in 1080 soil samples representing from various area and locations in South Korea. Entomopathogenic fungi were isolated from soils using semiselective medium SDA-D50 contained saboraund dextrose agar, 50 ug/ml dodine, 100 ug/ml chloramphenicol and 50 ug/ml streptomycin. The isolated putative fungi were identified by the determination of internal transcribed spacer (ITS) region sequences of the nuclear ribosomal analysis. As a result, entomopathogenic fungi were found to occur in 30.8% of the soil samples studied. The most abundant species were Beauveria bassiana (Bals.) Vuill. and Metarhizium anisopliae (Metschn.) Sorok. Isolates of B. brongniartii, Cordyceps sp., Lecanicillium sp., Isaria sp. and Tolypocladium cylindrosporum were also found. The occurrence of entomopathogenic fungi was analyzed by the area and soil types. These positive entomopathogenic fungi may have potential against variety pests in agriculture and forest

In a previous study, aggregation pheromone trap added with refrigerated eggs of Riptortus pedestris (Fabricius) (Hemiptera: Alydidae) in a netted pouch was found to enhance parasitism by its egg parasitoid Ooencyrtus nezarae Ishii (Hymenoptera: Encyrtidae) in soybean fields. However, the eggs released in the netted pouch would not be well exploited by the egg parasitoid due to reduced encounter of the eggs and elevated inter- or intraspecific competition among the parasitoids in clumped condition of released eggs inside the pouch. To solve this problem, new trap was developed with twelve separate cells for egg placement. Efficiency of this new trap was evaluated in a soybean field in Songcheon, Andong. Newly developed trap and formerly designed trap each with 180 refrigerated eggs were placed at a distance of 15-20m in the field. The released eggs were collected every week, and the experiment was replicated for three weeks. In addition, comparison was carried out by placing eggs in different density in the cell (120 in total per trap) for three weeks. Parasitism in newly developed trap (32-35%) was higher than that in the former trap (16-20%). Parasitism in the trap where eggs were released in six cells was the highest, followed by three cells, one cell, and eggs released in the pouch. From these findings, newly developed traps is better than previous design in enhancing the parasitism in soybean fields.

본 연구는 1997년부터 WTO 가입을 추진 중인 아제르바이잔 농업현황과 농업정책 동향을 살펴보고, 이를 바탕으로 WTO 가입 협상전략 및 향후 지속적인 농업농촌 발전을 위한 대응전략을 탐구한다. 주요 연구결과는 아래와 같다. 아제르바이잔에서 농업은 전체 GDP의 5.7%, 고용인구의 38%를 차지하고 있으며, 석유와 건설부문에 이어 제 3위의 매우 중요한 산업분야이다. 아제르바이잔의 농업은 경제성장, 산업다변화, 빈곤경감, 고용창출에 큰 기여를 해오고 있다. 즉 농업분야는 경제적 측면뿐만 아니라 국가 정치 및 사회 안정차원에서도 매우 중요하다. 하지만 WTO 가입은 향후 아제르바이잔 농업에 기회요인이자 동시에 큰 도전으로 다가설 것으로 보인다. 따라서 WTO 가입협상에서 보다 유리한 조건을 확보하기 위한 협상전략과 함께 WTO 가입 이후 농업의 지속적 성장을 위한 효과적 발전전략을 마련하는 것이 무엇보다 중요한 시점이다. WTO 가입협상 관련하여 무엇보다 중요한 것은 개도국 지위의 확보이며, 이를 통해 농가소득과 농업성장에 중요한 위치를 차지하는 민감품목에 대한 점진적이고 신축적인 시장개방이 되도록 시장접근, 국내보조 분야에서 효과적인 가입협상 전략을 마련해야 한다. 또한 아제르바이잔은 WTO 가입이후에 대비하여 밀을 비롯한 기초식량의 생산성 증대, 고부가가치 생산 및 수출의 확대, 농촌지역의 활력유지를 위한 구체적인 실천방안을 종합적으로 마련해야 할 것이다.

Nano sized SiC particles (270 nm) are easily agglomerated in nickel sulfamate electrolytic bath during a composite electrodeposition process. The agglomeration of nano particles in composite coatings can significantly reduce the mechanical properties of the composite coatings. In this study, Ni-SiC nano composite coatings were fabricated using a conventional electrodeposition process with the aid of ultrasound. Nano particles were found to be distributed homogeneously with reduced agglomeration in the ultrasonicated samples. Substantial improvements in mechanical properties were observed in the composite coatings prepared in presence of ultrasound over those without ultrasound. Ni-SiC composite coatings were prepared with variable ultrasonic frequencies ranging from 24 kHz to 78 kHz and ultrasonic powers up to 300 watts. The ultrasonic frequency of 38 kHz with ultrasonic power of 200 watt was revealed to be the best ultrasonic conditions for homogeneous dispersion of nano SiC particles with improved mechanical properties in the composite coatings. The microstructures, phase compositions, and mechanical properties of the composite coatings were observed and evaluated using SEM, XRD, Vickers microhardness, and wear test. The Vickers microhardness of composite coatings under ultrasonic condition was significantly improved as compared to the coatings without ultrasound. The friction coefficient of the composite coating prepared with an ultrasonic condition was also smaller than the pure nickel coatings. A synergistic combination of superior wear resistance and improved microhardness was found in the Ni-SiC composite coatings prepared with ultrasonic conditions.

Human gingival fibroblasts (hGFs) were reported to play an important role in inflammatory reactions to lipopolysaccharide (LPS) from P.gingivalis in the periodontal connective tissue. Although the biostimulatory effects of hyperbaric oxygen therapy, such as anti-inflammatory activity, have been reported, the pathological mechanism is not completely understood. This study examined the changes in the inflammatory cytokine profiles, which are produced after exposure to hyperbaric oxygen in P.gingivalis LPS-treated human gingival fibroblasts, and subsequently to examine the mitogen activated protein kinase (MAPK) pathway involved in cytokine production. Gingival fibroblasts with or without P.gingivalis LPS were exposed to hyperbaric oxygen, and the cytokine profiles in the supernatant were observed using a human inflammation antibody array. The expression of cyclooxyginase-2 (COX-2) protein, phosphorylation of extracellular signal-regulated kinase (ERK1/2), p38, and c-Jun-N-terminal kinase (JNK) MAPK by western blot analysis, and the amount of prostaglandin E2 (PGE2) in the supernatant by an enzyme-linked immunoassay were determined. COX-2 protein expression and PGE2productionwereincreasedsignificantlyintheP. gingivalis LPS-treated group, and were decreased by treating P. gingivalis LPS with hyperbaric oxygen. Treatment of P. gingivalis LPS in the gingival fibroblasts led an increase in the amount of pro-inflammatory-related cytokines interleukin-6 (IL-6) and IL-8 released, whereas hyperbaric oxygen inhibits the irrelease. Ananalysis of the MAPK signal transduction showed that hyperbaric oxygen induced a significant decrease in the level of P38 phosphorylation regardless of the presence or absence of LPS. In addition, hyperbaric oxygen promoted JNK phosphorylation, significantly in the presence of LPS. Hyperbaric oxygen can inhibit pro-inflammatory cytokines and mediate the MAPK signal pathway, and appears to be useful as an anti-inflammatory tool.

The discovery of antibiotics has helped to save the lives of an uncountable number of people. Antibiotics have been grouped in different classes based on their origin, structure, and mechanism of action. An intrinsic and acquired mechanism of antimicrobial resistance has been identified in many bacterial strains that are of high clinical importance. This has seriously jeopardized the use of antibiotics and has also caused the spread of microbes that are resistant to effective first-choice, or “first-line” drugs. Thus, sensible use of antibiotics and the search for effective alternative measures are of high importance in order to minimize the effect due to existing and emerging antimicrobial resistant microbes.

The porcine reproductive and respiratory syndrome virus (PRRSV) has three major structural proteins which designated as GP4, GP5, and M. They have been considered very important to arouse the humoral and cellular immune responses against PRRSV infection and proposed to be the excellent candidate proteins in the design of PRRS bioengineering vaccine. However, the PRRSV structural proteins are produced in low levels in the infected cells because it forms insoluble protein and possesses several transmembrane regions. To overcome this problem, we fused the GP4, GP5, and M with SUMO (Small ubiquitin-related modifier), and expressed the fused gene in Bm5 cells and silkworm larvae. Expression of the proteins were analyzed by 12% SDS-PAGE and western blotting using 6xHis tag and porcine anti-PRRSV antibodies. In results, SUMO fused proteins were expressed at a high level in Bm5 cells. The levels of protein using the silkworm larvae is higher than that using Bm5 cells. The fused protein was purified by Ni-NTA affinity chromatography. This study demonstrated that SUMO, when fused with PRRSV structural proteins, was able to promote its soluble expression. This may be a better method to produce PRRSV structural proteins for vaccine development.

In agricultural fields, the entomopathogenic fungal species have been investigated for their potential as the biological control agents due to their role of natural enemies for insects. To address the requirements of a potential South Korea based biocontrol effort using entomopathogenic fungi, we investigated the occurrence of various entomopathogenic fungi in 1080 soil samples representing from various area and locations in South Korea. Entomopathogenic fungi were isolated from soils using semiselective medium SDA-D50 contained saboraund dextrose agar, 50 ug/ml dodine, 100 ug/ml chloramphenicol and 50 ug/ml streptomycin. The isolated putative fungi were identified by the determination of internal transcribed spacer (ITS) region sequences of the nuclear ribosomal analysis. As a result, entomopathogenic fungi were found to occur in 30.8% of the soil samples studied. The most abundant species were Beauveria bassiana (Bals.) Vuill. and Metarhizium anisopliae (Metschn.) Sorok. Isolates of B. brongniartii, Cordyceps sp., Lecanicillium sp., Isaria sp. and Tolypocladium cylindrosporum were also found. The occurrence of entomopathogenic fungi was analyzed by the area and soil types. These positive entomopathogenic fungi may have potential against variety pests in agriculture and forest

Entomopathogenic fungi are widely available as biological control agents for controlling insect pests in agriculture and forestry. The fungal culture broth contains various pathogenesis-related components such as blastospores, mycelium and insecticidal enzymes such as chitinase, Pr1- and Pr2-proteases, which have been reported to play an important role in penetrating insect cuticles. In this study, we tried to evaluate the utility of culture broth from Beauveria bassiana SFB-205 to control lepidopteran pests. High level of insecticidal activity correspond to over 90% of mortality were observed when the culture broth of B. bassiana SFB-205 was inoculated to the Spodoptera litura larvae together with the B. thuringiensis K1. The freeze-dried culture broth showed synergistic effects in insecticidal activity against larvae of S. exigua and S. litura when treated with corresponding baculoviruses, SeNPV and SlNPV. Active ingredient of the B. bassiana SFB-205 culture broth was identified to chitinase, which have truncated form by insertional mutation compared to previously reported chitinases.

Bacillus thuringiensis 1-3 (Bt 1-3) which was isolated from a Korean soil sample showed high insecticidal activity against Aedes aegypti as well as Plutella xylostella. The isolate was determined to belong to ssp. aizawai (H7) type by an H antiserum agglutination test and produced bipyramidal-shaped crystal proteins with a molecular weight of 130 kDa. PCR analysis with cry gene specific primers showed that Bt 1-3 contained cry1Aa, cry1Ab, cry1C, cry1D and cry2A gene, differing from spp. aizawai (reference strain) which contains cry1Aa, cry1Ab, cry1C and cry1D. We modified the plasmid capture system (PCS) to clone plasmid from Bt 1-3 through in vitro transposition. Fifty-three clones were acquired and their sizes were approximately 10 kb. Based on the sequence analysis, they were classified according to similarities with four known Bt plasmids, pGI3, pBMB175, pGI1 and pGI2, respectively. One of pGI3-like clones, named as pBt1-3, was fully sequenced and its 20 putative open reading frames (ORFs), Rep-protein, double-strand origin of replication (dso), single-strand origin of replication (sso), have been identified. The structure of pBt1-3 showed high similarity with pGI3 which is one of rolling-circle replication (RCR) group VI family.