• Molecules and Cells
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• v.21 no.3
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• pp.356-359
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• 2006

The transcription factor E2F1 coordinates cell cycle progression and induces apoptosis in response to DNA damage stress. Aside from DNA damage, the role of E2F1 in the endoplasmic reticulum (ER) stress signaling pathways is unclear. We found that $E2F1^{-/-}$ murine embryonic fibroblasts (MEFs) are resistant to apoptosis triggered by the ER stress inducer thapsigargin. In addition, E2F1 deficiency results in enhanced phosphorylation of eukaryotic translation initiation factor $2{\alpha}$ ($elF2{\alpha}$). These results therefore indicate that E2F1 deficiency increases phosphorylation of $elF2{\alpha}$ in response to ER stress triggered by thapsigargin, and suggest that the reduction in ER stress-induced apoptosis in E2F1-deficient cells is related to the high level of $elF2{\alpha}$ phosphorylation.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.02a
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• pp.54-54
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• 2011

The demand for low-friction, wear and corrosion resistant components, which operate under severe conditions, has directed attentions to advanced surface engineering technologies. The Filtered Vacuum Arc Cathode Deposition (FVACD) process has demonstrated atomically smooth surface at relatively high deposition rates over large surface areas. Preparation of Ti-Si-C-N nanocomposite coatings on (100) Si and stainless steel substrates with tetramethylsilane (TMS) gas pressures to optimize the film preparation conditions. Ti-S-C-N coatings were characterized using X-ray diffraction, X-ray photoelectron spectroscopy, transmission electron microscopy, nanoindentation, Rockwell C indentation and ball-on-disk wear tests. The XRD results have confirmed phase formation information of TiSiCN coatings, which shows mixing of TiN and TiC structure, corresponding to (111), (200) and (220) planes of TiCN. The chemical composition of the film was investigated by XPS core level spectra. The binding energy of the elements present in the films was estimated using XPS measurements and it shows present of elemental information corresponding to Ti2p, N1s, Si 2p and C1. Film hardness and elastic modulus were measured with a nano-indenter, and film hardness reached 40 GPa. Tribological behaviors of the films were evaluated using a ball-on-disk tribometer, and the films demonstrated properties of low-friction and good wear resistance.

• Wind and Structures
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• v.17 no.4
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• pp.419-433
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• 2013

This paper investigates the vertical profiles of horizontal mean wind speed and direction based on the synchronized measurements from a Doppler radar profiler and an anemometer during 16 tropical cyclones at a coastal site in Hong Kong. The speed profiles with both open sea and hilly exposures were found to follow the log-law below a height of 500 m. Above this height, there was an additional wind speed shear in the profile for hilly upwind terrain. The fitting parameters with both the power-law and the log-law varied with wind strength. The direction profiles were also sensitive to local terrain setups and surrounding topographic features. For a uniform open sea terrain, wind direction veered logarithmically with height from the surface level up to the free atmospheric altitude of about 1200 m. The accumulated veering angle within the whole boundary layer was observed to be $30^{\circ}$. Mean wind direction under other terrain conditions also increased logarithmically with height above 500 m with a trend of rougher exposures corresponding to lager veering angles. A number of empirical parameters for engineering applications were presented, including the speed adjustment factors, power exponents of speed profiles, and veering angle, etc. The objective of this study aims to provide useful information on boundary layer wind characteristics for wind-resistant design of high-rise structures in coastal areas.

• Nuclear Engineering and Technology
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• v.54 no.8
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• pp.2999-3005
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• 2022

The new experimental setup has been built at the 11b channel of the IBR-2 research reactor at FLNP, JINR, to study the elemental composition of samples by registration of prompt gamma emission during thermal neutron capture. The setup consists of a curved mirror neutron guide and a radiation-resistant HPGe high-purity germanium detector. The detector is surrounded by lead shielding to suppress the natural background gamma level. The sample is placed in a vacuum channel and surrounded by a LiF shield to suppress the gamma background generated by scattered neutrons. This work presents characteristics of the experimental setup. An example of hydrogen concentration determining in a diamond powder made by detonation synthesis is given and on its basis, the sensitivity of the setup is calculated being ~4 ㎍.

• Journal of the Earthquake Engineering Society of Korea
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• v.27 no.2
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• pp.91-99
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• 2023

Structural vibration induced by earthquake hazards is one of the most significant concerns in structure performance-based design. Structural hazards evoked from seismic events must be properly identified to make buildings resilient enough to withstand extreme earthquake loadings. To investigate the effects of combined earthquake-resistant systems, shear walls and five types of dampers are incorporated in nineteen structural models by altering their arrangements. All the building models were developed as per ACI 318-14 and ASCE 7-16. Seismic fragility curves were developed from the incremental dynamic analyses (IDA) performed by using seven sets of ground motions, and eventually, by following FEMA P695 provisions, the collapse margin ratio (CMR) was computed from the collapse curves. It is evident from the results that the seismic performance of the proposed combined shear wall-damper system is significantly better than the models equipped with shear walls only. The scrutinized dual seismic resisting system is expected to be applied practically to ensure a multi-level shield for tall structures in high seismic risk zones.

• Korean journal of applied entomology
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• v.63 no.1
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• pp.33-42
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• 2024

The green peach aphid, Myzus persicae is a representative agricultural insect pest that is polyphagous and causes serious damage to tobacco, potatoes, peppers, cabbage, and peaches. In this study, we analyzed the level of development of insecticide resistance to λ-cyhalothrin, imidacloprid, and flupyradifurone and the point mutations (R81T, L1014F, M918L) in 12 field populations of M. persicae. In addition, the expression level of CYP6CY3, a cytochrome P450 gene, was analyzed through qRT-PCR. As a result, λ-cyhalothrin showed high resistance ratio (RR) of > 200 in all 12 populations. Imidacloprid and flupyradifurone showed high RR of >200 in YS, UR, HY, and WJ populations. The R81T was detected in approximately 50%, L1014F in approximately 33.3%, and M918L in 100% of the 12 populations. Additionally, the expression level of subunit CYP6CY3 was highest in imidacloprid-resistant population (YS). These results suggest that M918L point mutation can be used as λ-cyhalothrin-resistance molecular diagnostic and R81T point mutation and the high expression of CYP6CY3 can be used as imidacloprid-resistance molecular diagnostic markers.

• Child Health Nursing Research
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• v.22 no.4
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• pp.379-389
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• 2016

Purpose: A longitudinal study was conducted to explore flora colonization and oral glucose high-risk newborns during the first 7 days after birth. Methods: Oral secretions of hospitalized newborns were obtained for microbial cultures and glucose test at days 1-7 after birth. Results: Among the total 112 newborns, 40% were girls and 73% were premature. Mean gestational age was $34.4{\pm}3.2$ weeks and weight was $2,266{\pm}697.5$ grams. The most common flora included Streptococcus (28.2%), Methicillin-resistant Staphylococcus aureus (MRSA, 10.9%), Staphylococcus (6.0%) and Coagulase-Negative Staphylococcus (CNS, 4.0%). The average oral glucose level was $29.2{\pm}23.0mg/dL{\sim}58.2{\pm}39.5mg/dL$. Newborns with higher oral glucose than serum (crude odds ratio [ORc] =1.75; 95% confidence interval [CI] =1.03-2.97), phototherapy (ORc=3.30; 95% CI=2.29-4.76) and prone position (ORc= 2.04; 95% CI=1.13-3.69) were more likely to be colonized. Having oral tubes (ORc=0.42; 95% CI=0.29-0.59), parental nutrition (ORc=0.21; 95% CI=0.13-0.32) and antibiotics (ORc=0.51; 95% CI=0.36-0.73) had protective effects. For oral glucose statistical significances existed on time effect among newborns with Streptococcus (F=9.78, p=.024), MRSA (F=7.60, p=.037) or CNS (F=11.15, p=.019) and interaction between time and colonization among newborns with all of four flora (F=2.73, p=.029) or colonization with only Staphylococcus (F=2.91, p=.034). Conclusion: High-risk newborns develop flora colonization at an early period of life. Their clinical features were associated with types and time of oral flora colonization. They need close monitoring and multifaceted intervention to improve oral environment and infection control.

• Journal of Korean Society of Steel Construction
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• v.17 no.5 s.78
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• pp.569-580
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• 2005

The postbeam joint connection of the existing steel structure moment flexible frame system did not produce sufficient seismic resistance during the earthquakes in Northridge and Kobe, and it sustained brittle fracturing on the joint connection. This study was performed to execute the high-tensile bolt share connection of H-beams web and the full-scale experiment as a parameter of the existing reinforcement of H-flange rib, by making the shape of the existing joint connection. This experiment was performed to determine the extent of the decrease of the number of high-tensile bolts and how to improve workability of the two-phase shear connection of web beam. In addition, this study was performed to enhance the seismic resistant capacity through the enforcement of rib plates. As a result of the experiment of two-phase shear connection of H-beam web and of joint connection to be reinforced by rib plates, the results of this study showed that the initial stiffness, energy-dissipation capacity, and rotational capacity of plasticity was higher than the existing joint connection. As to the rate of increasing the strength and deformation capacity, there were differences between the tension side and compression side because of the position of shear tap. However, as a whole, they have shown excellent seismic resistant capacity. Also, all the test subjects exceeded 4% (rate of delamination), about 0.029 rad (total plastic capacity), and about 130% (maximum strength of joint connection) of fully plastic moment for the original section. Accordingly, this study was considered as it would be available in the design more than the intermediate-level of moment flexible frame.

• Korean Journal of Breeding Science
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• v.40 no.3
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• pp.344-347
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• 2008

"Nunbora" is a new japonica rice cultivar developed from a cross between Iksan433 resistant to bacterial blight and Miyadamamochi, a waxy line. at Honam Agricultural Research Institute, NICS, RDA, in 2006. This cultivar is a short grain shape and about 118 days of growth duration from transplanting "Nunbora" to harvesting under Korean climatic conditions. The milled rice are snow white and glutinuous. This cultivar shows high resistant reactions to the bacterial blight pathogen race $K_1{\sim}K_3$ and blast respectively. The milled rice yield of "Nunbora" is about 5.34 MT/ha under the standard fertilizer level of the ordinary transplanting cultivation. "Nunbora" would be adaptable for in the middle plain, north middle-mountin plain and Honam plain, and Youngnam plain areas of Korea.

• Biomedical Science Letters
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• v.1 no.1
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• pp.55-72
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• 1995

Forty gentamicin-resistant isolates of Enterococcus faecalis were selected from various clinical materials, determined their antimicrobial susceptibility, and studied there R-plasmid characteristics and polypeptide patterns. All of the isolates were susceptible to vancomycin. The MICs($\mu$/ml) of antimicrobial agents to the isolates were as follows; the MIC of gentamicin was 128 and $\geq$2040, ampicillin 1 and 1, chlorarmphenicol 2 and 8, erythromycin 32 and 256, and vancomycin 1 and 2. E. faecalis HL-1 strain had 8 plasmid DNA elements, HL-2 and HL-3 strains had 6, HL-4 had 7, HL-5 had 4, and HL-6 had 5. The 51.7 Kb of gentamicin resistance plasmid DNA was conjugally transferred from two strains of E. faecalis HL-1 and HL-6 to S. aureus SK 982. The plasmid transfer frequency between S. aureus SK 982 and E. faecalis HL-1 or E. faecalis HL-6 was 6.3$\times10^{-4} and 3.7$\times10^{-5}$, respectively. Plasmid curing ratio after the treatment of ethidium bromide(10$\mu$/ml) to E. faecalis tarnsconjugants R-1 and R-6 were about 51% and 67%, respectively. The tetracycline gene was located in 2.15 Kb plasmid of E. faecalis HL-1, but it was not found in the E. faecalis HL-6 by Southern blot analyses. The antigenic components of E. faecalis HL-1, HL-6, R-1 and R-6 strains were analyzed by SDS-PAGE and immunoblotting. The E. faecalis strains had 7 to 16 polypeptide bands, however their major proteins were 97.8 and 26.8 Kd. At the Immunoblotting, 97.8, 95.8, 74.8, 63.5, 33.7 and 26.8 Kd polypeptides of the strains showed major antigenic activities with patient's sera infected intra-abdominally with an E. faecalis strain.