한국에서의 Human T-Cell Leukemia Virus Type-1(HTLV-1)에 대한 혈청학적 및 역학에 관한 연구

이영열,이성열,김은실,이홍복,김병국,이문호,박선양,김노경,서철원,규경채,최강원,조한익,고월청,야마구찌이찌세이 대한내과학회 1986 대한내과학회지 Vol.31 No.2

Type-C retrovirus, human T-cell leukemia virus type-l(HTLV-1), has been shown to be associated etiologically with adult T-cell leukemia, which is an endemic disease in southwestern parts of Japan. We examined the seroepidemiological characteristics of antibody to adult T-cell leukemia virus associated antigen (anti-ATLA-antibody) by the indirect immunofluorescent assay and ELISA from the healthy individuals and various diseased patients in the Republic of Korea, a country adjacent to Japan in which HTLV-1 is endemic. The results were as follows. 24 out of 9,603 individuals(0.25%) were seropiositive. The positve rate was 0.17% in males and 0.36% in females, the sex difference was female predominent relatively. HTLV-1 carriers were found 16 individuals in Seoul, 5 in Kyonggi area, 1 in Chungnam and Jonbuk, respectively, but found only 1 individual in Busan city and Jaejoo area close to southwestern parts of Japan. Positive rate to anti-ATLA-antibody seemed to be high in older age, especially at the 50s(0. 4Yo). In conclusion the prevalence rate of anti-ATLA- antibody seemed to be very low in the Republic of Korea adjacent to Japan in which HTLV-1 is endemic and no patient with adult T-cell leukemia has been found as yet. Also we noted that the Republic of Korea is not an endemic area to HTLV-1.

Genetic Variability in Korean Original and Japanese Naturalized Tea Plants Detected by Flower Pistil Morphology , RFLP of PAL Gene , and RAPD Markers

Yamaguchi,S .,S . Matsumoto,J . I . Tanaka,Y . Yamaguchi,D . I . Shin,Y . G . Park 한국임학회 1996 한국임학회 학술발표논문집 Vol.1996 No.-

Effects of local structural damage in a steel truss bridge on internal dynamic coupling and modal damping

Yamaguchi, Hiroki,Matsumoto, Yasunao,Yoshioka, Tsutomu Techno-Press 2015 Smart Structures and Systems, An International Jou Vol.15 No.3

Structural health monitoring of steel truss bridge based on changes in modal properties was investigated in this study. Vibration measurements with five sensors were conducted at an existing Warren truss bridge with partial fractures in diagonal members before and after an emergency repair work. Modal properties identified by the Eigensystem Realization Algorithm showed evidences of increases in modal damping due to the damage in diagonal member. In order to understand the dynamic behavior of the bridge and possible mechanism of those increases in modal damping, theoretical modal analysis was conducted with three dimensional frame models. It was found that vibrations of the main truss could be coupled internally with local vibrations of diagonal members and the degree of coupling could change with structural changes in diagonal members. Additional vibration measurements with fifteen sensors were then conducted so as to understand the consistency of those theoretical findings with the actual dynamic behavior. Modal properties experimentally identified showed that the damping change caused by the damage in diagonal member described above could have occurred in a diagonal-coupled mode. The results in this study imply that damages in diagonal members could be detected from changes in modal damping of diagonal-coupled modes.

Genetic mapping of the compatibility between a lily isolate of Cucumber mosaic virus and a satellite RNA

Yamaguchi, Naoya,Seshimo, Yuko,Yoshimoto, Eri,Ahn, Hong Il,Ryu, Ki Hyun,Choi, Jang Kyung,Masuta, Chikara Microbiology Society 2005 The Journal of general virology Vol.86 No.8

<P>Five isolates of Cucumber mosaic virus (CMV) from Lilium sp. (lily), which were isolated from specimens in Japan, Korea and Taiwan, were unable to support satellite RNA (satRNA) accumulation. In order to map the CMV sequences that are involved in satRNA support, HL-CMV (Japanese lily isolate), Y-CMV (ordinary strain) and Y-satellite RNA (Y-sat) were used as the source material. The pseudorecombinants between Y-CMV and HL-CMV revealed that RNA1 was essential for satRNA replication in lily. The results of chimeric constructs and various mutations showed that two amino acid residues (at positions 876 and 891) in the 1a protein were the determinants for the inability of HL-CMV to support a satRNA. Specifically, Thr at position 876 had a more pronounced effect than Met at position 891. Specific changes in RNA sequence were also detected in the 3' terminus of Y-sat and these particular alterations allowed it to be supported by HL-CMV. It is believed that, through evolution, the adaptation of CMV to lily resulted in the introduction of amino acid changes in the 1a protein, changes that coincidentally affected the ability of lily CMV to support satRNAs.</P>

A Study on the Fundamental Surge Frequencies in Multi-Stage Axial Flow Compressor Systems

Yamaguchi, Nobuyuki Korean Society for Fluid machinery 2014 International journal of fluid machinery and syste Vol.7 No.4

Surge phenomena in multi-stage axial flow compressors were studied with attention to the frequency behaviors. A new parameter "volume-modified reduced surge frequency" was introduced, which took into consideration the essential surge process, i.e., emptying and filling of the working gas in the delivery plenum. The behaviors of the relative surge frequencies at the stall stagnation boundaries, compared with the corresponding duct resonance frequencies, have demonstrated the existence of two types of surges; i.e., a near-resonant surge and a subharmonic surge. The former, which has fundamentally a near-resonance frequency, occurs predominantly at the stall stagnation boundary for the short -and-fat plenum delivery flow-path and the long-and-narrow delivery duct flow-path, and possibly in the intermediate conditions. The latter, which has a subharmonic frequency of the fundamental near-resonant one and occurs mainly in the intermediate zone, is considered to be caused by the reduced frequency restricted to a limited range. In relation with those dimensionless frequencies at the stall stagnation boundary, the surge frequency behaviors in more general situations away from the boundaries could be estimated, though very roughly.

Analytical Study on Stall Stagnation Boundaries in Axial-Flow Compressor and Duct Systems

Yamaguchi, Nobuyuki Korean Society for Fluid machinery 2013 International journal of fluid machinery and syste Vol.6 No.2

Stall stagnations in the system of axial-flow compressors and ducts occur in transition from deep surge conditions to decayed or converged stall conditions. The present study is concerned with the boundaries between the deep surges and the stagnation stalls on the basis of analytical results by a code on surge transients analysis and simulation. The fundamental acoustical-geometrical stagnation boundaries were made clear from examinations of the results on a variety of duct configurations coupled with a nine-stage compressor and a single stage fan. The boundary was found to be formed by three parts, i.e., B- and A-boundaries, and an intermediate zone. The B-boundary occurs for the suction-duct having a length of about a quarter of the wave-length of the first resonance in the case of very short and fat plenum-type delivery duct. On the other hand, the A-boundary occurs for the long and narrow duct-type delivery flow-path having a length about a fifth of the wavelength and relatively small sectional area in the case of short and narrow suction ducts. In addition to this, the reduced surge-cycle frequencies with respect to the duct lengths are observed to have respective limiting values at the stagnation boundaries. The reduced frequency for the B-boundary is related with a limiting value of the Greitzer's B parameter. The tendency and the characteristic features of the related flow behaviors in the neighborhood of the boundaries were also made clearer.

A Study on the Deep-Surge Frequencies in Various Conditions of Axial Flow Compressors and Flow-paths

Yamaguchi, Nobuyuki Korean Society for Fluid machinery 2017 International journal of fluid machinery and syste Vol.10 No.4

Frequencies of deep surges and their behaviors in axial flow compressors were surveyed numerically. Relative surge frequencies, normalized by the basic acoustical resonance frequencies, are seen to tend to lower together with increases in the stalling pressure ratios, i.e. increases in the number of stages and the compressor tip speed, and also together with increases in the flow-path sectional area ratios. However, it appears difficult to express simply the general behaviors of the relative frequencies affected by the various factors. In order to know the essential behaviors, a modified reduced surge frequency is proposed, which is a dimensionless number comparing the mass flow filling and emptying the plenum volume in surge and the mass flow provided by the compressor. The modified reduced surge frequencies are found to have or approach a definite and nearly constant value in conditions of deep surges. The parameter suggests the fundamental mechanism of deep surges and could be used to determine approximate frequencies of deep-surges in various conditions of compressors and flow-paths.

Dental Implant Surgical Navigation System by Retinal Imaging Display

Yamaguchi S,Yamanishi Y,Ono S,Yatani H,Imazato S 대한치과재료학회 2011 대한치과기재학회 학술대회 Vol.2011 No.5

Analysis of Abutment Fracture on a Single Standing Implant

Yamaguchi Y,Shiota M,Ahn K,Nagao H,Kasugai S 대한치과재료학회 2011 대한치과기재학회 학술대회 Vol.2011 No.5

A Study on the Fundamental Cause of Stall Stagnation Phenomena in Surges in Compressor Systems

Yamaguchi, Nobuyuki Korean Society for Fluid machinery 2017 International journal of fluid machinery and syste Vol.10 No.2

Although the stall stagnation phenomena have often been experienced in site and also analytically in numerical experiments in surges in systems of compressors and flow paths, the fundamental causes have not been identified yet. In order to clarify the situations, behaviours of infinitesimal disturbance waves superposed on a main flow were studied in a simplified one-dimensional flow model. A ratio of the amplifying rate of the system instability to the characteristic slope of the compressor element was surveyed as the instability enhancement factor. Numerical calculations have shown the following tendency of the factor. In the situation where both the sectional area ratio and the length ratio of the delivery flow-path to the suction duct are sufficiently large, the enhancement factors are greater in magnitude, which means occurrence of ordinary deep surges. However, in the situation where the area ratio and/or the length ratio is relatively smaller, the enhancement factor tends to lessen significantly, which situation tends to suppress deep surges for the same value of the characteristic slope. It could result in the stall stagnation condition. In the domain of area ratio vs. length ratio of the delivery duct to the suction duct, contour-lines of the enhancement factor behave qualitatively similar to those of the stall stagnation boundaries of a fan analytically obtained, suggesting that a certain range of the enhancement factor values could specify the stagnation occurrence. The significant decreases in the factors are observed to accompany appearances of phase lags and travelling waves in the wave motions, which macroscopically suggests breaking down of the complete surge actions of filling and emptying of the air in the delivery duct. The strength of the action is deeply related with acoustic interferences and is evaluated in terms of the volume-modified reduced resonance frequency proposed by the author. These observations have shown the fundamental cause and the sequence of the stall stagnation in principle.