• Journal of the Institute of Electronics Engineers of Korea TC
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• v.38 no.7
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• pp.22-27
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• 2001

In this paper, the complex permittivity of various dielectrics such as powder(sugar and flour) and solid(teflon and acrvl) are measured by using an open ended coaxial-line probe, which is self designed and manufactured, The probe is connected to a vector network analyzer(VNA) through a coaxial cable, The end of the cable is corrected by using an OSL(open, short, and load) calibration kit, The phase difference, which is produced by inserting the probe at the end of the line. is compensated by using the numerically calculated reflection coefficient of distilled water, The complex permittivity is reconstructed by inserting the measured reflection coefficient, which is produced at the interface between the probe and measuring material, into ,an virtual conical cable conversion model. Over a wide frequency range from 30 MHz to 3 GHz, the measured complex permittivitis of various powder and solid using the our method are compared with the results, which are measured by using an transmission-line method of the Korea Research Institute of Standards and Science(KRISS).

• Tuberculosis and Respiratory Diseases
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• v.44 no.3
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• pp.534-546
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• 1997

Background : The p53 and retinoblastoma(Rb) tumor suppressor genes are associated with the pathogenesis of several types of human cancer. Substantial proportion of the primary lung cancers or cell lines have been reported to have the p53 and/or the Rb gene mutations. But, so far there is no report on the analysis of the Rb gene polymorphism as one of the genetic susceptibility marker. This study was undertaken to establish the gene frequencies of the polymorphic genotypes of the p53 and Rb genes in Koreans to evaluate the possible involvement of these genotypes as a risk factor of lung cancer. Methods : In this study 145 controls without previous and present tumor history and 128 lung cancer patients were subjected to analysis. The two intragenic polymorphisms of the p53 gene(exon 4/ AccII, intron 6/MspI) and one intron 17/XbaI polymorphism of the Rb gene were analysed by the method of polymersae chain reaction- restriction fragment length polymorphisms(PCR-RFLPs). The genotype of the intron 3/16 bp repeat polymorphism of p53 was determined by PCR and direct gel electrophoresis. Results : There were no significant differences in the genotype distributions of the p53 gene between lung cancer patients and controls. But heterozygotes(Arg/Pro) of the exon 4/AccII polymorphisms were slightly over-represented than controls, especially in the Kreyberg type I cancer, which was known to be associated with smoking. The intron 3/16 bp duplication and the intron 6/MspI polymorphisms were in complete linkage disequilibrium. About 95% of the individuals were homozygotes of the common alleles both in the 16 duplication and MspI polymorphisms, and no differences were deteced in the genotype distributions between lung cancer patients and controls. Overall genotype distributions of the Rb gene polymorphisms between lung cancer patients and controls were not significantly different However, the genotype distributions in the Kreyberg type I cancer were significantly different from those of controls(p = 0.0297) or adenocarcinomas(p = 0.0008). It was noticeable that 73.4% of the patients with adenocarcinomas were heterozygotes(r1/r2) whereas 39.2% of the Kreyberg type I cancer were heterozygous at this polymorphisms. In the lung cancer patients, significant differences were also noted between the high dose smokers and low dose smokers including non-smokers(p = 0.0258). The relative risk to Kreyberg type I cancer was significantly reduced in the individuals with the genotype of r1/r2(odds ratio = 0.46, 95% C.I. = 0.25-0.86, p = 0.0124). The combined genotype distribution of the exon 4 AccII of the p53 and the intron 17 Rb gene polymorphisms in Kreyberg type I cancers were significantly different from dose of controls or adenocarcinomas. The highest odds ratio were observed in the individuals with the genotypes of Arg/Pro and r2/r2(odds ratio = 1.97,95% C.I. = 0.84-4.59) and lowest one was in the patients with Arg/Arg, r1/r2 genotype(odds ratio = 0.54, 95% C.I. = 0.25-1.14). Conclusion : The p53 and the Rb gene polymorphisms modulate the risk of smoking induced lung cancer development in Koeans. However, the exact mechanism of risk modulation by these polymorphism remains to be determined. For more discrete clarification of associations between specific genotypes and lung cancer risk, the evaluations of these polymorphisms in other ethnics and more number of patients will be needed.

• Journal of Applied Biological Chemistry
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• v.61 no.1
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• pp.83-91
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• 2018

Advances in bacterial and fungal genome mining uncover a plethora of cryptic secondary metabolite biosynthetic gene clusters. Guided by the genome information, targeted transcriptional derepression could be employed to determine the product of a cryptic gene cluster and to explore its biological role. Monascus spp. are food grade filamentous fungi popular in eastern Asia and several genome data belong to them are now available. We achieved transcription activation of a cryptic fungal polyketide synthase-nonribosomal peptide synthase gene Mpfus1 in Monascus purpureus ${\Delta}MpPKS5$ by inserting Aspergillus gpdA promoter at the upstream of Mpfus1 through double crossover gene replacement. The gene cluster with Mpfus1 show a high similarity to those for the biosynthesis of conjugated polyene derivatives with 2-pyrrolidone ring and the mycotoxin fusarin is the representative member of this group. The ${\Delta}MpPKS5$ is incapable of producing azaphilone pigment, providing an excellent background to identify chromogenic and UV-absorbing compounds. Activation of Mpfus1 resulted in a yellow hue on mycelia and its methanol extract exhibit a maximum absorption at 365 nm. HPLC analysis of the organic extracts indicated the presence of a variety of yellow compounds in the extract. This implies that the product of MpFus1 is metabolically or chemically unstable. LC-MS analysis guided us to predict the MpFus1 product and to propose that the Mpfus1-containing gene cluster encode the biosynthesis of a desmethyl analogue of fusarin. This study showcases the genome mining in Monascus and the possibility to unveil new biological activities embedded in it.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.9A
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• pp.754-762
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• 2003

The coupled and propagated property of the composite side-polished fiber and infinite planar waveguide with conductor cladding (PWGCC) is presented by using the 3-D finite difference beam propagating method (FD-BPM) in according to the variety of refractive indexes between the fiber and the infinite planar waveguide. It is also introduced for the technique to be applied at and consisted of the analysis domain of 3-D FD-BPM for the coupling between the side-polished fiber and PWG. It is also compared the properties of coupling between the side-polished fiber and PWGCC with them of the general symmetric and asymmetric PWG without perfect conductor (PEC), which has been investigated by many researcher.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.26 no.11B
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• pp.1600-1606
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• 2001

Resonant frequency in rectangular microstrip patch antenna on anisotropic substrates with airgap and superstrate are analyzed. Dyadic Green function is derived for selected anisotropic material by constitutive relation. From these results, integral equations of electric fields are formulated using Fourier transform in space region. The electric field integral equations are discretized into the matrix form by applying Galerkin\`s moment method. Sinusoidal functions are selected as basis functions because they resemble in the actual standing wave on the patch. To verify the validity of numerical result, we compare our result with existing one and get a good agreement between them. From the numerical results, the resonant frequency in the variation of air gap, patch length and anisotropy ratio are presented and analysed.

• Journal of the Korean Vacuum Society
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• v.17 no.2
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• pp.122-129
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• 2008

Ferroelectric properties of the PMT-PT were also studied from the temperature dependence of hysteresis loops using a method slightly modified from Sawyer-Tower's. Dielectric, pyroelectric and piezoelectric properties of the ceramics in the system PMT-PT were investigated. The resulted densities of the PMT-PT ceramics system were greater than 97 % of the theoretical value. As observed SEM micrograph of the fracture surfaces of the PMT-PT ceramics system, the average grain sizes were increased about 3-5 ${\mu}m$ to 6-8 ${\mu}m$ with increasing sintering temperature. The specimens with PT<0.30 for PMT-PT solid solution system exhibited the dielectric and pyroelectric properties of a typical relaxor ferroelectrics. The composition with the maximum dielectric constant exhibits relatively superior pyroelectric and piezoelectric properties.

• Korean Journal of Microbiology
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• v.54 no.1
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• pp.74-76
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• 2018

Recently, Fusobacterium nucleatum subsp. vincentii was reclassified as Fusobacterium vincentii based on the average nucleotide identity and genome-to-genome distance analyses. F. vincentii is a Gram-negative, anaerobic, and filament-shaped bacterium. F. vincentii is a member of normal flora of human oral cavity and plays a role in periodontal diseases. F. vincentii KCOM 2931 was isolated from a periodontitis lesion. Here, we present the complete genome sequence of F. vincentii KCOM 2931.

• Korean Journal of Microbiology
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• v.54 no.1
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• pp.71-73
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• 2018

Recently, Fusobacterium nucleatum subsp. polymorphum was reclassified as Fusobacterium polymorphum based on the average nucleotide identity and genome-to-genome distance analyses. F. polymorphum is a Gram-negative, anaerobic, and filament-shaped bacterium. F. polymorphum is a part of normal flora of oral cavity and causative agent of periodontal diseases. F. polymorphum KCOM 1001 (= ChDC F119) was isolated from a human subgingival plaque of gingivitis lesion. Here, we present the complete genome sequence of F. polymorphum KCOM 1001.

• Korean Journal of Microbiology
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• v.54 no.3
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• pp.293-294
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• 2018

Yangia sp. TSBP01, isolated from tidal flat sediment contaminated by the oil spill, is known to convert indole to indigo via an intermediate called indoxyl. Our analysis revealed that Yangia sp. TSBP01 contained the genome of 5,165,974 bp (G + C content: 66.5%) being composed of two chromosomes and five plasmids. This strain had genes encoding several oxygenases such as indole oxygenase directly involved in the conversion of indole to indoxyl.

• Korean Journal of Microbiology
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• v.53 no.4
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• pp.323-325
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• 2017

Pectobacterium carotovorum subsp. actinidiae KKH3 is an Enterobacteriaceae bacterial pathogen that infects kiwi plants, causing canker-like symptoms that pose a threat to the kiwifruit industry. Because the strain was originally isolated from woody plants and possesses numerous plant cell wall-degrading enzymes, this draft genome report provides insight into possible bioconversion applications, as well as a better understanding of this important plant pathogen.