• Journal of Life Science
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• 제25권8호
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• pp.889-895
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• 2015

Endothelial dysfunction is an initial step in atherosclerosis. B vitamins (B6, B12, and folate) are important contributing factors to vascular homeostasis. Deficiencies in these B vitamins induce cardiovascular diseases by altering vascular homeostasis. Folate plays important roles in nitric oxide homeostasis in the endothelium. To determine the dose-dependent effect of dietary folate on atherosclerosis, we studied aortic relaxation and hepatic C-reactive protein (CRP) levels in C57BL/6 mice. In this study, a total of 54 male C57BL/6, 8-wk old mice were split into 2 dietary groups (control and Western style diet). Each diet group was divided into 3 subgroups according to dietary folate dosage (0.2, 2, and 8 mg/kg). After 18 months, the relaxation response seen in aortic rings from mice fed 0.2 or 2 mg folate/kg in both diet groups. However, the aortic relaxation response was not seen and no differences were observed in mice fed 8mg folate/kg in either diet group (p<0.05). Hepatic CRP levels at all folate dosages (0.2, 2, 8 mg folate/kg) were higher in the groups fed a Western style diet than in mice fed a control diet (p=0.035). CRP levels were lower in mice fed 0.2 mg folate/kg than in mice fed 2 or 8 mg folate/kg in both diet groups (p<0.05). These results indicate that in C57BL/6 mice 0.2 mg folate/kg may be enough to prevent atherosclerosis by inducing the relaxation responses of the aorta and by reducing levels of hepatic CRP, regardless of dietary style.

• Journal of the Korean earth science society
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• 제32권7호
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• pp.761-769
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• 2011

Daily minimum temperature and freezing data of the Seoul weather station ($37^{\circ}$34'N, $126^{\circ}$57'E, Songwol-dong Jongno-gu Seoul, hereinafter Songwol) and freezing data of the Han River station ($37^{\circ}$30'N, $126^{\circ}$57'E, hereinafter Han River) were used to study the long-term variation of the freezing climate for Seoul, Korea, for the period of 100 years from 1907 to 2006. 'Freezing' of Songwol is defined that the water in outdoor fields is frozen, and 'freezing' of the Han River located 6 km away from Songwol is defined as the region 100 meters upstream of the second and fourth piers in the south end of the Han River Bridge is fully frozen. The mean first freezing date for Songwol was October 28, and one for Han River was December 28; these showed a late tendency, with the rate of 0.78 days $decade^{-1}$ and 3.47 days $decade^{-1}$, respectively. The mean annual freezing days was 159.06 days for Songwol and 50.33 days for Han River; each showed a $decade^{-1}$shorter tendency, with rates of 2.01 days $decade^{-1}$ and 5.24 days $decade^{-1}$, respectively. All the seven no-freezing years (1960, 1971, 1972, 1978, 1988, 1991, and 2006) for Han River came after 1950. The mean daily minimum temperatures of the first freezing dates for Songwol and Han River were $0.55^{\circ}C$ and $-12.22^{\circ}C$. The first freezing occurred after 6.43 days for Songwol and after 8.94 days for Han River with daily minimum temperature below $0^{\circ}C$. The annual minimum temperatures of Songwol and Han River exhibited positive correlations with the first freezing date and negative correlations with freezing days. The result shows that the freezing climate change is relevant to temperature change and is a part of overall climate change. By conducting additional studies with various methods and wider region, we will be able to monitor the freezing climate.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• 제31권3호
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• pp.83-94
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• 2013

The purpose of this study is to offer basic data about prototype conservation of the Orijangnim, natural monument No. 404. For this study, March to August 2010, was a literature surveys and field research, and based on this, the Delphi survey of local residents and experts meeting were diagnosed with forest back ground, spatial extent, in the form of forests, flora and vegetation of the surrounding area, so examined closely the original form. Range of the Orijangnim was presumed from Jacheon middle school entrance($N36^{\circ}05^{\prime}59.9^{{\prime}{\prime}}/E128^{\circ}54^{\prime}32.9^{{\prime}{\prime}}$) to Odong of Hwabukmyeon village entrance($N36^{\circ}05^{\prime}31.0^{{\prime}{\prime}}/E128^{\circ}54^{\prime}32.5^{{\prime}{\prime}}$). The Orijangnim in the original form of the existing forest surrounding the village along gohyeon river going back a long S-shaped about 2km is considered. The investigated vascular plants consist of total 198 taxa : 2 forms, 20 varieties, 179 species, 152 Genera, 72 Families. Most of the 60 kinds of large land plants lots of whole plants accounted for 33.3%. A main vegetation of the Orijangnim have been distributed 473 objects of 21 species, and evergreen conifers is 19% to 92 objects, on the other hand, deciduous broadleaf tree is 79% to 373 objects, so the Orijangnim can be maxed forest that deciduous broadleaf tree is dominant. When consider the composition purpose of forest, environment of location, tree size, surrounding flora and vegetation, because an original vegetation of Orijangnim is suggested Zelkova serrata, Salix glandulosa, Celtis sinensis Pers., Quercus variabilis, Quercus acutissima , Sophora japonica L., Cornus walteri Wanger. we must restore around such species of tree. Cedrus deodara (Roxb.) Loudon, Chaenomeles sinensis, Prunus yedoensis Matsum., Ginkgo biloba , Pinus thunbergii Parl., Populus tomentiglandulosa T. Lee is considered to have been planted in the last.

• Journal of the Korean Crystal Growth and Crystal Technology
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• 제23권6호
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• pp.283-290
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• 2013

A stoichiometric mixture of evaporating materials for $MgGa_2Se_4$ single crystal thin films was prepared from horizontal electric furnace. To obtain the single crystal thin films, $MgGa_2Se_4$ mixed crystal was deposited on thoroughly etched semi-insulating GaAs(100) substrate by the Hot Wall Epitaxy (HWE) system. The source and substrate temperatures were $610^{\circ}C$ and $400^{\circ}C$, respectively. The crystalline structure of the single crystal thin films was investigated by double crystal X-ray diffraction (DCXD). The temperature dependence of the energy band gap of the $MgGa_2Se_4$ obtained from the absorption spectra was well described by the Varshni's relation, $E_g(T)=2.34 eV-(8.81{\times}10^{-4}eV/K)T^2/(T+251K)$. The crystal field and the spin-orbit splitting energies for the valence band of the $MgGa_2Se_4$ have been estimated to be 190.6 meV and 118.8 meV, respectively, by means of the photocurrent spectra and the Hopfield quasicubic model. These results indicate that the splitting of the ${\Delta}so$ definitely exists in the ${\Gamma}_5$ states of the valence band of the $MgGa_2Se_4$/GaAs epilayer. The three photocurrent peaks observed at 10 K are ascribed to the $A_{1^-}$, $B_{1^-}$exciton for n = 1 and $C_{27}-exciton$ peaks for n = 27.

• Current Research on Agriculture and Life Sciences
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• 제11권
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• pp.43-54
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• 1993

This experiment was conducted at Andong county cropping season to investigate rice response and consequent changes in the physiological activities and agronomic characters of rice as affected by growth regulator treatments, and to determine how low temperature controls some plant growth mechanisms. Plant growth regulators, particularly ABA, applied to 15 DAT regardless of concentration, gave higher tar plant height and tiller number after 10days of low temperature treatment than did the untreated plant. However, the differences in plant height and tiller number among treatments diminished to plant growth. Chlorophyll content seemed to be enhanced by growth regulators under low temperature condition. The 10-day treatment of low temperature decreased chlorophyll content by more than 17% compared with the untreated control. The oxidizing activity of roots decreased sharply to 52.2a after 10 days in low temperature condition. On the other hand, ABA at concentration of $10^{-4}M$, highly attains oxiding activity of roots. Generally, plant growth regulators applied at 15 DAT under low temperature reduced grain yield more than did the untreated control which can be attributed to decreased yield components. When growth regulators were applied to booting stage, the tiller number did not show significant difference, whereas the significant difference in culm length at harvest was observed in all treatment as a result of different concentration of growth regulators. The growth regulators generally exhibited a significant effect on yield component except on panicle length. Grain yield of low temperature treated plot at booting stage was significantly influenced by application of growth regulators. This was due to decreased number of spikelet and low filled spikelet percentage. However, TIBA treatment at booting stage showed no significant differences in grain yield.

• The korean journal of orthodontics
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• 제34권3호
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• pp.253-260
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• 2004

Frictional force between the orthodontic bracket and arch wire during sliding tooth movement is related to many factors, such as the size, shape and material of both the bracket and wire, ligation method and the angle formed between the bracket and wire. There have been clear conclusions drawn in regard to most of these factors, but as to the effect of bracket width on frictional force there are only conflicting studies. This study was designed to investigate the effect of bracket width on the amount of frictional forces generated during clinically simulated tooth movement. Three different widths of brackets $(0.018{\times}0.025'\;standard)$ narrow (2.40mm), medium (3.00mm) and wide (4.25mm) were used in tandem with $0.016{\times}0.022'$ stainless steel wire. Three bracket-arch wire combinations were drawn on for 4 minutes on a testing apparatus with a head speed of 0.5mm/min and tested 7 times each. To reproduce biological conditions, dentoalveolar models were designed with indirect technique using a material with similar elastic properties as periodontal ligament (PDL). In addition, to minimize the effect of ligation force, elastomer was used with added resin, which was attached to the bracket to make up for the discrepancies of bracket width. The results were as follows: 1. Maximum frictional force for each bracket-arch wire combination was: Narrow (2.40mm): $68.09\pm4.69gmf$ Medium (3.00mm): $72.75\pm4.98 gmf$ Wide (4.25mm): $72.59\pm4.54gmf$ 2. Frictional force was increased with more displacement of wire through the bracket slot. 3. The ANOVA psot-hoc test showed that the bracker width had no significant effect on frictional force when tested under clinically simulated conditions(p>0.05).

• The korean journal of orthodontics
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• 제37권3호
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• pp.171-181
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• 2007

Objective: The present study was aimed at an analytical formulation of the micro-implant related torque as a function of implant size, i.e. the diameter and length, screw size, and the bony resistance at the implant to bone interface. Methods: The resistance at the implant to cancellous bone interface $(S_{can})$ was assumed to be in the range of 1.0-2.5 MPa. Micro-implant model of Absoanchor (Dentos Inc. Daegu, Korea) was used in the course of the analysis. Results: The results showed that the torque was a strong function of diameter, length, and the screw height. As the diameter increased and as the screw size decreased, the torque index decreased. However the strength index was a different function of the implant and bone factors. The whole Absoanchor implant models were within the safe region when the resistance at the implant/cancellous bone $(=S_{can})$ was 1.0 or less. Conclusion: For bone with $S_{can}$ of 1.5 MPa, the cervical diameter should be greater than 1.5 mm if micro-implant models of 12 mm long are to be placed. For $S_{can}$ of 2.0 MPa, micro-implant models of larger cervical diameter than 1.5 mm were found to be safe only if the endosseous length was less than 8 mm.

• Journal of the Korean Crystal Growth and Crystal Technology
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• 제18권5호
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• pp.217-224
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• 2008

A stoichiometric mixture of evaporating materials for $ZnIn_2Se_4$ single crystal thin films was prepared from horizontal electric furnace. To obtain the single crystal thin films, $ZnIn_2Se_4$ mixed crystal was deposited on thoroughly etched semi-insulating GaAs(100) substrate by the Hot Wall Epitaxy (HWE) system. The source and substrate temperatures were $630^{\circ}C$ and $400^{\circ}C$, respectively. The crystalline structure of the single crystal thin films was investigated by the photoluminescence and double crystal X-ray diffraction (DCXD). The carrier density and mobility of $ZnIn_2Se_4$ single crystal thin films measured from Hall effect by van der Pauw method are $9.41\times10^{16}cm^{-3}$ and $292cm^2/v{\cdot}s$ at 293 K, respectively. The temperature dependence of the energy band gap of the $ZnIn_2Se_4$ obtained from the absorption spectra was well described by the Varshni's relation, $E_g(T)=1.8622eV-(5.23\times10^{-4}eV/K)T^2/(T+775.5K)$. The crystal field and the spin-orbit splitting energies for the valence band of the $ZnIn_2Se_4$ have been estimated to be 182.7 meV and 42.6 meV, respectively, by means of the photocurrent spectra and the Hopfield quasicubic model. These results indicate that the splitting of the ${\Delta}so$ definitely exists in the ${\Gamma}_5$ states of the valence band of the $ZnIn_2Se_4/GaAs$ epilayer. The three photo current peaks observed at 10 K are ascribed to the $A_{1}-$, $B_{1}-exciton$ for n = 1 and $C_{27}-exciton$ peaks for n = 27.

• Journal of Life Science
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• 제30권1호
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• pp.45-57
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• 2020

The prenatal period in livestock animals is crucial for meat production because net increase in the number of muscle fibers is finished before birth. However, there is no study on the growth and development mechanism of muscles in Hanwoo during this period. Therefore, to find candidate genes involved in muscle growth and development during this period in Hanwoo, mRNA expression data of longissimus in Hanwoo at 6 and 9 months post-conceptional age (MPA) were analyzed. We independently identified differentially expressed genes (DEGs) using DESeq2 and edgeR which are R software packages, and considered the overlaps of the results as final-DEGs to use in downstream analysis. The DEGs were classified into several modules using WGCNA then the modules' functions were analyzed to identify modules which involved in myogenesis and adipogenesis. Finally, the hub genes which had the highest WGCNA module membership among the top 10% genes of the STRING network maximal clique centrality were identified. 913(6 MPA specific DEGs) and 233(9 MPA specific DEGs) DEGs were figured out, and these were classified into five and two modules, respectively. Two of the identified modules'(one was in 6, and another was in 9 MPA specific modules) functions was found to be related to myogenesis and adipogenesis. One of the hub genes belonging to the 6 MPA specific module was axin1 (AXIN1) which is known as an inhibitor of Wnt signaling pathway, another was succinate-CoA ligase ADP-forming beta subunit (SUCLA2) which is known as a crucial component of citrate cycle.

• Korean Journal of Agricultural and Forest Meteorology
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• 제19권3호
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• pp.153-163
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• 2017

The objective of this study is to enhance the model's speed of estimating weather variables (e.g., minimum/maximum temperature, sunshine hour, PRISM (Parameter-elevation Regression on Independent Slopes Model) based precipitation), which are applied to the Agrometeorological Early Warning System (http://www.agmet.kr). The current process of weather estimation is operated on high-performance multi-core CPUs that have 8 physical cores and 16 logical threads. Nonetheless, the server is not even dedicated to the handling of a single county, indicating that very high overhead is involved in calculating the 10 counties of the Seomjin River Basin. In order to reduce such overhead, several cache and parallelization techniques were used to measure the performance and to check the applicability. Results are as follows: (1) for simple calculations such as Growing Degree Days accumulation, the time required for Input and Output (I/O) is significantly greater than that for calculation, suggesting the need of a technique which reduces disk I/O bottlenecks; (2) when there are many I/O, it is advantageous to distribute them on several servers. However, each server must have a cache for input data so that it does not compete for the same resource; and (3) GPU-based parallel processing method is most suitable for models such as PRISM with large computation loads.