• The Korean Journal of Pesticide Science
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• v.2 no.2
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• pp.75-82
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• 1998

This study was conducted to find out the biochemical or metabolic resistance mechanism of brown planthopper (BPH) to carbofuran. Differences between resistant ($LD_{50};\;20.3{\mu}g/g$) and susceptible strains($LD_{50};\;0.3{\mu}g/g$) were shown. The amounts of carbofuran metabolite, benzofuranol, and the origin, not developed by Thin Layer Chromatography, were much more in the susceptible strain. But the mother compound, carbofuran, was much more in the resistant strain. The tendencies of metabolism one and three hours after treatment were similar in both strains except for the amounts of metabolites described above. From the study, it is supposed that hydrolytic enzyme, esterase, changes its role from cleaving the esteric bond of carbofuran to making conjugates with carbofuran. This seems to be the main resistance mechanism of BPH to carbofuran. Oxidase and transferase may play little or no role in resistance mechanism. Oxidative and transferring enzymes gave no effects on the metabolism of carbofuran in the resistant strain compared with the susceptible strain.

• Journal of Adhesion and Interface
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• v.5 no.1
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• pp.3-11
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• 2004

In this work, the cure behaviors of the DGEBA/PMR-15 blends initiated by N-benzylpyrazinium hexafluoroantimonate (BPH) as a cationic latent catalyst were performed in DSC and DMA analyses. And, the thermal stabilities were carried out by TGA analysis and their mechanical interfacial properties of blends were measured in the context of critical stress intensity factor ($K_{IC}$). As a result, the curing activation energy ($E_a$) determined from Ozawa's equation in DSC and the relaxation activation energy ($E_r$) from DMA were increased with increasing PMA-15 content. Also, the thermal stabilities obtained from the integral procedural decomposition temperature (IPDT) and the glass transition temperature ($T_g$) were highly improved with increasing the PMR-15 content, which were probably due to the high heat resistance. And, the $K_{IC}$ showed a similar behavior with $E_a$, which was attributed to the improving of the interfacial adhesion or hydrogen bondings between intermolecular chains.

• Journal of Sensor Science and Technology
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• v.15 no.2
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• pp.139-147
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• 2006

Lower urinary tract symptoms (LUTS) affect self-assessed quality of life. The prevalence of LUTS is commonly high in the elderly. The purpose of urodynamic investigation is to obtain information on the function of the urinary system. One of the most frequently used measurement procedures in urodynamics is filling and voiding cystometry. But in this system transurethral catheter is used and it makes patients uncomfortable. The aim of this study is to implement the system that could evaluate noninvasively the function of urinary tract. A new system has been developed to analyze urine flow rate and vesical pressure during voiding. These signals were recorded simultaneously and transmitted to a PC. For system evaluation, a model for the lower urinary system of men was constructed. From the evaluation of the model, vesical pressure was correlated with the occlusion degree. In a pilot study with five male subjects, maximum of standard deviation was 1.26, error rate was 3.49 and coefficient of variation was 3.48.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.6
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• pp.3499-3502
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• 2013

MicroRNAs (miRNAs) are a class of endogenously expressed small, non-coding, single-stranded RNAs that negatively regulate gene expression, mainly by binding to 3'- untranslated regions (3'UTR) of their target messenger RNAs (mRNAs), which cause blocks of translation and/or mRNA cleavage. Recently, miRNAprofiling studies demonstrated the microRNA-497 (miR-497) level to be down-regulated in all prostate carcinomas compared with BPH samples. The purpose of this study was to investigate the potential role of miR-497 in human prostate cancer. Proliferation, cell cycle and apoptosis assays were conducted to explore the potential function of miR-497 in human prostate cancer cells. Results showed that miR-497 suppressed cellular growth and initiated G0/G1 phase arrest of LNCaP and PC-3 cells. We also observed that miR-497 increased the percentage of apoptotic cells by increasing caspase-3/7 activity. Taken together, our results demonstrated that miR-497 can inhibit growth and induce apoptosis by caspase-3 activation in prostate cancer cells, which suggest its use as a potential therapeutic target in the future.

• Microbiology and Biotechnology Letters
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• v.22 no.1
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• pp.37-44
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• 1994

The homology among the genes coding for degradation of bipheny(BP) and 4-chlorobiphenyl(4CB) was comparatively analyzed by Southern hybridization in several BP/4CB degrading bacterial strains. As the hybridization results of their genomic DNAs with pcbABCD as the DNA probe, the group of Pseudomonas sp. DJ-12. P08 and P27 strain was separated by the group of P20 and P1242 strains. The P. pseudoalcaligenes KF707 showed the hybidization signal which was homologous to the group of DJ-12, but they had different restriction endonuclease sites. The pcbAB genes in pCUl recombinant plasmid from Pseudomonas sp. DJ-12 appeared to be homologous to pchAB genes in pKTF20 cloned from P. pseudoalcaligenes KF707, but the C genes in both strains were not homologous. The bphABC in pKTF20 showed the signals homologous to the cbp ACB in pAW6194 cloned from P. putida OU83, but homologous signal was not found botween the pcbABCD genes in pCUl and the cbpADCB genes in pAW6194 recombbinant plasmid.

• Korean Journal of Organic Agriculture
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• v.26 no.3
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• pp.489-500
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• 2018

Rural Development Administration (RDA) is promoting the AFACI IPM (Asian Food & Agricultural Cooperation Initiative program). AFACI consist of 12 countries including Bangladesh, Cambodia, Thailand, Vietnam and so on. The main goal of the AFACI IPM project is 'Establishment of an international cooperative network for the best management of migratory rice planthoppers and setting data-base of pests occurrence information. As a result of the suvey, Planthoppers were increasing all the way from tillering stage to ripe stage and do not appear to be peak of one or two like korea case. In detail, 1,673 of BPH (Nilaparvata lugens) occurred in survey site of Svay Reang, Cambodia, followed by 1.237 at Dobila, Bangladesh. In the case of White backed planthopper (Sogatella furcifera), 1,163 of WBPH occurred in survey site of Dobila, Bangladesh and 849 WBPH were collected at Hamkuria, Bangladesh. It is expected to verify the occurrence and movement patterns of hoppers among member countries in the future.

• Molecules and Cells
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• v.28 no.2
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• pp.131-137
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• 2009

Plant defensins are small (5-10 kDa) basic peptides thought to be an important component of the defense pathway against fungal and/or bacterial pathogens. To understand the role of plant defensins in protecting plants against the brown planthopper, a type of insect herbivore, we isolated the Brassica rapa Defensin 1 (BrD1) gene and introduced it into rice (Oryza sativa L.) to produce stable transgenic plants. The BrD1 protein is homologous to other plant defensins and contains both an N-terminal endoplasmic reticulum signal sequence and a defensin domain, which are highly conserved in all plant defensins. Based on a phylogenetic analysis of the defensin domain of various plant defensins, we established that BrD1 belongs to a distinct subgroup of plant defensins. Relative to the wild type, transgenic rices expressing BrD1 exhibit strong resistance to brown planthopper nymphs and female adults. These results suggest that BrD1 exhibits insecticidal activity, and might be useful for developing cereal crop plants resistant to sap-sucking insects, such as the brown planthopper.

• Plant Breeding and Biotechnology
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• v.7 no.3
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• pp.272-286
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• 2019

Developing elite hybrid rice varieties is one important objective of rice breeding programs. Several genes related to male sterilities, restores, and pollinators have been identified through map-based gene cloning within natural variations of rice. These identified genes are good targets for introducing genetic traits in molecular breeding. This study was conducted to breed elite hybrid lines with major genes related to hybrid traits and disease/insect resistance in 240 genetic resources and F₁ hybrid combinations of rice. Molecular markers were reset for three major hybrid genes (S5, Rf3, Rf4) and thirteen disease/insect resistant genes (rice bacterial blight resistance genes Xa3, Xa4, xa5, Xa7, xa13, Xa21; blast resistance genes Pita, Pib, Pi5, Pii; brown planthopper resistant genes Bph18(t) and tungro virus resistance gene tsv1). Genotypes were then analyzed using molecular marker-assisted selection (MAS). Biological assay was then performed at the Red River Delta region in Vietnam using eleven F₁ hybrid combinations and two control vatieties. Results showed that nine F₁ hybrid combinations were highly resistant to rice bacterial blight and blast. Finally, eight F₁ hybrid rice varieties with resistance to disease/insect were selected from eleven F₁ hybrid combinations. Their characteristics such as agricultural traits and yields were then investigated. These F₁ hybrid rice varieties developed with major genes related to hybrid traits and disease/insect resistant genes could be useful for hybrid breeding programs to achieve high yield with biotic and abiotic resistance.

• Journal of Microbiology and Biotechnology
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• v.12 no.5
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• pp.729-734
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• 2002

Radiorespirometric analysis revealed that Pseudomonas sp. strain KKI isolated from a soil contaminated with petroleum hydrocarbons was able to catabolize polycyclic aromatic hydrocarbons such as phenanthrene and naphthalene. The rate and extent of phenanthrene mineralization was markedly enhanced when the cells were pregrown on either naphthalene or phenanthrene, compared to the cells grown on universal carbon sources (i.e., TSA medium). Deduced amino acid sequence of the Rieske-type iron-sulfur center of a putative phenanthrene dioxygenase (PhnAl) obtained from the strain KKI shared significant homology with DxnAl (dioxin dioxygenase) from Spingomonas sp. RW1, BphA1b (biphenyl dioxygenase) from Spingomonas aromaticivorans F199, and PhnAc (phenanthrene diokygenase) from Burkholderia sp. RP007 or Alcaligenes faecalis AFK2. Northern hybridization using the dioxygenase gene fragment cloned from KKI showed that the expression of the putative phn dioxygenase gene reached the highest level in cells grown in the minimal medium containing phenanthrene and $KNO_3$, and the expression of the phn gene was repressed in cells grown with glucose. In addition to the metabolic change, phospholipid ester-linked fatty acids (PLFA) analysis revealed that the total cellular fatty acid composition of KKI was significantly changed in response to phenanthrene. Fatty acids such as 14:0, 16:0 3OH, 17:0 cyclo, 18:1$\omega$7c, 19:0 cyclo increased in phenanthrene-exposed cells, while fatty acids such as 10:0 3OH, 12:0, 12:0 2OH, 12:0 3OH, 16:1$\omega$7c, 15:0 iso 2OH, 16:0, 18:1$\omega$6c, 18:0 decreased.

• Korean Journal of Agricultural Science
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• v.8 no.1
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• pp.18-28
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• 1981

The purpose of this study was to establish the intergrated control of rice insect pests. Specific objectives were to reveal the diversity of natural enemies in rice field environment, to obtain basic informations of their population dynamics, and to screen the selective insecticides for the conservation of natural enemies. The results of the study were as follows. 1. In numbers of species and in numbers of each species of parasitic Hymenoptera of rice insect pests were more diverse and abundant in rice paddy leeves and banks than paddy fields. Braconid Mymarid and pteromalid were predominated in the field and their population was high during early August to mid September. 2. Of the predatory spiders, Pirata subpiraticus was the largest in number and amounted to 72% of the total, Gnatonarium dentatum, Pachygnatha clerki and Clubiona japonicola were the next. It was also found that P. subpiraticus had three generations in a year. 3. Hence the activities of the predatory spider species and parasitic Hymenoptera were high in early to mid August and September, it would be better promising to avoid chemical applications at this time of periods as possible. 4. The relative toxicity of several insecticides which have been used for the control of brown plant hopper (BPH) showed that P. subpiraticus was 1.1-73.1 times higher than BPH and G. dentatum to P. subpiraticus was 1.1-73.1 times, respectively. 5. Three conventional insecticides, Padan, Diazinon and Carbofuran were screened for toxicity to predatory spider species. The insecticides deffered in their toxicity to the predators. However, Padan was appeared to be the least toxic to the predators.