• The Bulletin of The Korean Astronomical Society
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• v.35 no.2
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• pp.73.2-73.2
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• 2010

In order to understand internal dynamics of starless cores, molecular line emissions are usually observed. From profiles of the molecular lines, internal motions of starless cores have been deduced using a simple radiative transfer model such as the two-layer model (Myers et al.1996). This brings complexities arising from the chemical evolution. The motivation of this study is to follow the chemical evolution of a starless core that goes through gravitational contraction. For this purpose, we have performed hydrodynamical simulations with a marginally unstable Bonnor-Ebert sphere as an initial condition. We follow the chemical evolution of this core with changing conditions such as the chemical reaction rate at the dust surface and the strength of radiation field that penetrate into the core. At the core center, the molecules suffer from a higher degree of molecular depletion on the dust covered by ice rather than on the bare silicate dust. The stronger radiation field dissociates more molecules at the core envelope. From analysis on the line profile using the two-layer model, we found that the speed of inward motion deduced from the HCN F = 2-1 line adequately traces the true infall speed, when the dust is covered by ice and the core is exposed to the diffuse interstellar radiation field. Under different conditions, the two-layer model significantly underestimate the infall speed.

• The Korean Journal of Physiology and Pharmacology
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• v.5 no.1
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• pp.87-92
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• 2001

Carbon monoxide (CO) binds to soluble guanylate cyclase to lead its activation and elicits smooth muscle relaxation. The vascular tissues have a high capacity to produce CO, since heme oxygenase-2 (HO-2) is constitutively expressed in endothelial and smooth muscle cells, and HO-1 can be greatly up-regulated by oxidative stress. Moreover, the substrate of HO, heme, is readily available for catalysis in vascular tissue. Although the activation of heme oxygenase pathway under various stress conditions may provide a defence mechanism in compromised tissues, the specific role of HO-1-derived CO in the control of aortic contractility still remains to be elucidated. The present study was done to determine the effect of HO-1 induction on the aortic contractility. Thus, the effects of incubation of aortic tissue with S-nitroso-N-acetylpenicillamine (SNAP) for 1 hr on the aortic contractile response to phenylephrine were studied. The preincubation with SNAP resulted in depression of the vasoconstrictor response to phenylephrine. This effect was restored by HO inhibitor or methylene blue but not by NOS inhibitor. The attenuation of vascular reactivity by preincubation with SNAP was also revealed in endothelium-free rings. $AlF4^--evoked$ contraction in control did not differ from that in SNP-treated group. These results suggest that increased production of CO was responsible for the reduction of the contractile response to phenylephrine in aortic ring preincubated with SNAP and this effect of SNAP was independent on endothelium.

• Bulletin of the Korean Chemical Society
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• v.16 no.11
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• pp.1084-1088
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• 1995

A complete solid solution (SrLaAl1-xNixO4) between insulating SrLaAlO4 and metallic SrLaNi(Ⅲ)O4 oxides were prepared under high oxygen pressure (1.5 kbar, 800 ℃). They have tetragonal K2NiF4-type structure in all the solid solution range. Compared with lattice parameters of the same solid solution prepared under normal condition (1 bar, 1200 ℃), large decrease in the c-parameter was induced by high pressure treatment while no noticeable variation of the a-parameter was observed. Although marked changes of structural parameters, magnetic susceptibilities, and electron paramagnetic resonance spectra were consistently occurred before and after x=0.5, overall behaviors were essentially the same with those of solid solution prepared under normal condition. Such a phenomenon is explained by assuming the formation of partially filled narrow σ*x2-y2 band for x>0.5. Lattice contraction along the c-axis by high pressure treatment seems not to broaden this band. Particularly, the continuous absorption characteristic of a high free carrier concentration for x>0.5 and the absence of Ni-O in-plane stretching mode in the infrared absorption spectra supports this picture. However, the conductivities increasing with temperature for all solid solution suggest that some localization character, of probably Anderson type, remains for x>0.5.

• The Bulletin of The Korean Astronomical Society
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• v.46 no.1
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• pp.38.3-38.3
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• 2021

We are developing an optomechanical design of infrared telescope for the CubeSat and Unmanned Aerial Vehicle (UAV) which adapts the Linear Astigmatism Free- Three Mirror System in the confocal off-axis condition. The small entrance pupil (diameter of 40 mm) and the fast telescope (f-number of 1.9) can survey large areas. The telescope structure consists of three mirror modules and a sensor module, which are assembled on the base frame. The mirror structure has duplex layers to minimize a surface deformation and physical size of a mirror mount. All the optomechanical parts and three freeform mirrors are made from the same material, i.e., aluminum 6061-T6. The Coefficient of Thermal Expansion matching single material structure makes the imaging performance to be independent of the thermal expansion. We investigated structural characteristics against external loads through Finite Element Analysis. We confirmed the mirror surface distortion by the gravity and screw tightening, and the overall contraction/expansion following the external temperature environment change (from -30℃ to +30℃).

• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.220-220
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• 2022

Disproportionating Enzyme 1 (DPE1) is an a-1,4-D-glucanotransferase that cleavages the a-1,4-glucosidic bonds and transfers glucosyl groups. In rice endosperm, it participates in starch synthesis by transferring maltooligosyl groups from amylose and amylopectin to amylopectin. Here, we investigated the haplotype variations and evolutionary indices (e.g., genetic diversity and population structure) for the DPE1 gene in 374 rice accessions representing seven subgroups (wild, indica, temperate japonica, tropical japonica, aus, aromatic, and admixture). Variant calling analysis of DPE1 coding regions leads to the identification of six functional haplotypes representing/occupying 8 nonsynonymous SNPs. Nucleotide diversity analysis revealed the highest pi-value in wild group (0.0556) compared to other cultivated groups, of which temperate japonica showed the most reduction of genetic diversity value (0.003). A significant positive Tajima's D value (1.6330) of admixture highlights sudden population contraction under balancing selection, while temperate japonica with the lowest Tajima's D value (-1.3523) showed a selection signature of DPE1 domestication which might be the cause of excess of rare alleles. Moreover, these two subpopulations exhibits a greater differentiation (F_ST=0.0148), indicating a higher genetic diversity. Our findings on functional DPE1 haplotypes will be useful in future breeding programs, and the evolutionary indices can also be applicable in functional studies of the DPE1 gene.

• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.215-215
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• 2022

Starch synthase proteins (SSI, SSII and SSIII) in rice are mainly involved in amylopectin synthesis mediating its chain elongation, and the functional loss of SSII can increase amylose accumulation through decreasing of amylopectin chain proportions. For purposes of identifying functional haplotypes and evolutionary analyses of this gene, SSII-1, we investigated 374 rice accessions belonging to different subgroups of origins. We subsequently performed bioinformatic analyses on their variations through haplotyping, resequencing and structuring based on different classified populations. Haplotyping of cultivated rice accessions using genetic variations within SSII-1 genomic region of chromosome 10 revealed a total of 8 haplotypes, representing 6 functional haplotypes by 4 non-synonymous SNPs of three different exons (1, 4 and 10), which effect on protein structure. Higher nucleotide diversity value was found in wild group (0.0055) compared to any of cultivated subpopulations, of which aus showed the most reduction of diversity value (0.0003). Tajima's D analysis exhibits the most Tajima's D value only in admixture group (0.3600) which appears to be the cause of a sudden population contraction by rare alleles scarcity. A clear separation of some wild accessions from the admixed cultivated subpopulations was observed in PCA and phylogenetic analysis. Similar admixed pattern of population structure was estimated with an increased K values of 2 to 8 where genetic components of almost all cultivated subpopulations were shared with the wild which can also be subsequently estimated by very low F_ST-values by -0.011 (wild-aromatic) and -0.003 (wild-admixture).

• The Korean Journal of Pharmacology
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• v.20 no.1 s.34
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• pp.55-65
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• 1984

Comparative effects of $PGF_{2{\alpha}}$ and ouabain on the isolated rat(Sprague-Dowley) atria were studied. The isolated rat atria were prepared for isometric myography in the isolated organ bath containing Feigen's solution perfused with 95% $O_2$ and 5% $CO_2$, and the pH of the medium was maintained at 7.4. The cumulative concentration-response relationship revealed the positive inotropic effects of both drugs with the higher potency of $PGF_{2{\alpha}}$ and the higher efficacy of ouabain. $PGF_{2{\alpha}}$ showed a positive chronotropic effect, but ouabain showed a tendency of increasing the contraction rate. In low-Ca(1.4 mM) medium, the positive inotropic and chronotropic effect of $PGF_{2{\alpha}}$(by $3{\times}10^{-8}M$) were preponderant $(p<0.05{\sim}p<0.005)$ over those of ouabain(by $3{\times}10^{-3}M$). $Ca^{++}$-addition(cumulative, to 2.8, 4.2, 5.6, and 7.0 mM) into the medium evoked the more sensitive response in the $PGF_{2{\alpha}}$ group than in the ouabain group. In low-K(2.8 mM) medium, the $PGF_{2{\alpha}}a(3{\times}10^{-8}M)$ group and the ouabain$(3{\times}10^{-3}M)$ group showed similar tensions(DT and RT) and contraction rates. And both group showed significantly(p<0.05p<0.01) higher tensions and contraction rates than those of the control group. By the cumulative addition of the $K^+$(to 4.2, 5.6, 7.0 and 8.4 mM), only the DT of the $PGF_{2{\alpha}}$ group was sustained at signifcantly$(p<0.05{\sim}p<0.01)$ higher level than the DT of the control group. The $K^+$-addition inhibited the positive inotropic effect of ouabain significantly (p<0.05). The cumulative addition of lidocaine in high concentrations $(1{\times}10^{-5}\;to\;1{\times}10^{-3}M)$ evoked no significant influence on the intropic activities of $PGF_{2{\alpha}}$ and ouabain, but significant ${\beta}$-blockade with propranolol could not inhibit the positive intropic and chronotropic effect of $PGF_{2{\alpha}}$. In conclusion, it is presumed that $PGF_{2{\alpha}}$ may have some more active mechanism of accelerating the influx of $Ca^{++}$ across the cell membrane of the isolated rat atria as compared with ouabain, and the action site may be located at the cell membrane. As a supposition which needs further investigations, it is presumed that $PGF_{2{\alpha}}$ may have its specific membrane receptors on the atrial muscle or sinus node cells.

• Applied Chemistry for Engineering
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• v.26 no.5
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• pp.598-603
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• 2015

In this study, electrochemical properties of pitch-based activated carbon fibers (ACFs) were investigated by different heat-treatment temperature of the pitch-based ACFs in order to improve the specific capacitance of electric double-layer capacitor (EDLC). The ACFs were prepared by different heat-treatment temperatures of 1050 and $1450^{\circ}C$, after activation with 4 M KOH at $800^{\circ}C$ using stabilized pitch fiber. The specific surface area of prepared ACFs increased from $828m^2/g$ to $987m^2/g$, also the micropore and mesopore volumes of prepared ACFs were increased. These results because pore was produced by desorbing oxygen and hydrogen elements within the ACFs, and pore size was increased by contraction ACFs by heat-treatment process. Because of the porous properties, the specific capacitance was increased from 73 F/g to 119 F/g using cyclic voltammetry with 1 M $H_2SO_4$ at scan rates of 5 mV/s.

• Journal of the Korean Academy of Clinical Electrophysiology
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• v.5 no.2
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• pp.61-72
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• 2007

INTRODUCTION: Local heat and cold application has been frequently used as means of muscle relaxation and blood circulation or reinforcing muscle strength, relaxing muscle tension in clinical situation. In particular, it has been known that long-term heat and cold application for relaxing muscle tension inhibits muscle spasticity or tension. But, it has been rarely reported that what influences of heat and cold application on activation of muscle action potential. Therefore, this study aims to analyze surface temperature and electromyography activities according to the heat and cold application. METHODE: Subjects of this research were 10 normal men and women (5 men, 5 women). Hot pack and cold pack was applied to vastus medialis muscle of thigh and rectus femoris muscle for 20 min. Surface temperature of vastus medialis muscle and rectus femoris muscle was measured, knee joint of subjects was in $45^{\circ}$ flexion, sitting on a chair, maximal isometric contraction was induced, surface electromyography (sEMG) signals were collected and root mean square (RMS) and median frequency (MOF) were analyzed. All measurements were conducted before and immediately after experiment, 10 min., 20 min. and 30 min. after experiment. Data were analyzed with SPSS 12.0 program, comparison of changes in superficial temperature and sEMG signals through repeated measurement was conducted with repeated measures ANOVA and significance level $\alpha$ was 0.05. RESULTS: Changes of surface temperature of vastus medialis muscle according to cold application were radically decreased immediately after application, but it was recovered after 30 min. of application and it showed significant difference (F4. 36=72.216, P<0.001). Surface temperature of rectus femoris also showed radical decrease immediately after application, but it was recovered after 30 min. of application and showed significant difference (F4. 36=88.930, P<0.001). Changes of surface temperature of vastus medialis muscle according to heat application were radically increased immediately after application, but it was recovered after 30 min. of application and it showed significant difference (F4. 36=27.267, P<0.001). Surface temperature of rectus femoris also showed radical decrease immediately after application, but it was recovered after 30 min. of application and showed significant difference (F4. 36=19.774, P<0.001). Changes of sEMG by heat and cold application were no statistical difference. Surface temperature of skeletal muscle after heat and cold application showed significant change for 30 min., but it was found that increase or decrease of surface temperature had not great influence on sEMG activities.

• Journal of radiological science and technology
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• v.30 no.4
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• pp.391-397
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• 2007

Background/Aims : Gallbladder(GB) stone is the most common disease in the biliary system, and the incidence is gradually increasing in Korea. This change may include rapidly proceeding urbanization and changing food factor. We performed this study to investigate related GB stones and contraction of GB as dietary factors. Methods : We investigated 129 subjects(mean age : 47 years). GB stone group is 9 subjects(M: 2, F: 7) in Namyangju-si. Control group without GB stone is 18 subjects(M: 6, F: 12) in Wi-do island. For subjects without GB stone, diabetes mellitus decide 4(M: 2, F: 2) and then each after eat flesh and meat of estimated by experimental group ejection fraction rate(%). Results : Ejection fraction rate of GB were different between meat and fishes intake. When ate the meat in experiment for hypothetical verification, when become ejection fraction rate of meal GB 210 minutes, was the highest and when ate fish, the ejection fraction rate of GB was the highest in meal 120 minutes. Conclusions : After meats intaking the bile inside the GB is stagnant long and the GB stone is formed. We studied the results GB motility may important play a role on GB stone formation.