• The Korean Journal of Zoology
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• v.6 no.2
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• pp.11-15
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• 1963

A total of 220 adult male mice (18-20g) of the S.M. strain were divided into ten experimental and control groups. The total-body X-ray irradiation doses used were 50 r, 100r, 200r, 400r, 600r, 800r, 1,000r, 1,200r, 1,400r, and1,600r. The respiratory arrest (mortality) caused by each irradiation doses were observed for 30 days. Relationships between irradiation doses and survival time and percentage of response were examined. From this experiment, a formula was obtained to express the relationship among three factors, which may be presented as follows : {{{{{{{{P= { 10} over { SQRT { 2 pi } } INT _{ - INF }^{ p'} e-{(p'-50)^2 } over {200 }dp···(a) p'=100 LEFT { t^0.3- LEFT ( { { 16.9965} over {D-60 } } RIGHT ) ^{ { 1} over {2.5 } } } / LEFT { LEFT ( { 26372.43} over {D-81.86 } RIGHT ) ^{ { 1} over {2.5 } } -( { { 16.9965} over {D-60 } } RIGHT ) ^{ { 1} over {2.5 } } ···(b) p= { (D-60) t^0.75-16.9965} over {0.2186 t^0.75 +263.55434 }····(c) }} {{{{P= { 10} over { SQRT { 2 pi } } INT _{ - INF }^{ p'} e-{(p'-50)^2 } over {200 }dp···(a) p'=100 LEFT { t^0.3- LEFT ( { { 16.9965} over {D-60 } } RIGHT ) ^{ { 1} over {2.5 } } } / LEFT { LEFT ( { 26372.43} over {D-81.86 } RIGHT ) ^{ { 1} over {2.5 } } -( { { 16.9965} over {D-60 } } RIGHT ) ^{ { 1} over {2.5 } } ···(b) p= { (D-60) t^0.75-16.9965} over {0.2186 t^0.75 +263.55434 }····(c)

• Journal of dental hygiene science
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• v.18 no.5
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• pp.305-311
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• 2018

The purpose of this study was to identify the effect of providing toothbrushing by professionals as part of oral hygiene education for the elderly. We randomly visited 12 centers in the metropolitan city and analyzed the data of 114 participants among 310 early registrants aged >65 years, who participated in the study at all 3 time points. The subjects were categorized into an experimental group (odd-numbered visits) and a control group (even-numbered visits). Oral hygiene practices were provided for both experimental and control groups, but professional toothbrushing was performed in a different manner in the experimental group. Differences in plaque index (PI) according to the subjects' general characteristics and oral health status were assessed using the t-test, and the effect of PI difference between the experimental and control groups was assessed by repeated measure two-way analysis of variance. A stepwise multiple regression analysis was used to analyze factors affecting the PI. At baseline, the mean overall PI was 61.82. In both experimental and control groups, the PI significantly reduced from the baseline (p<0.01). At 5 weeks, the experimental group showed a decrease of 27.16 points from the baseline, and the 10-week PI was similar to the 5-week PI. The control group showed a decrease of 14.87 points from the baseline, and the PI increased by 5.74 points at 10 weeks. PI-related factors were gender and self-xerostomia. The PI was lower in the female group and the group with self- xerostomia (p<0.01). It is important to select an appropriate method to educate elderly subjects on proper removal of dental plaque and to habituate correct behavior, which requires inclusion of a direct toothbrushing intervention by a specialist.

• BMB Reports
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• v.34 no.2
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• pp.109-113
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• 2001

The Serratia marcescens metalloprotease inhibitor (SmaPI) is a proteinase inhibitor toward Serratia marcescens metalloprotease (SMP). The three-dimensional structure of SmaPI was calculated by computer modeling using the structure complex between SMP and the Erwinia chrysanthemi inhibitor as a template. Based on this model structure, the substitution of the amino acid residues, Ala4, Leu-5, Pro-6, and Thr-7, were located at the hinge region of the N-terminal segment by site-directed mutagenesis. Although the A4R and T7A mutant SmaPIs showed a nearly full inhibitory activity, the inhibitory activity of SmaPI decreased significantly when the Leu-5 was converted to Ala, Gly, Ile, or Val. Surprisingly, the L5I and L5V mutant SmaPIs showed less inhibitory activities than the L5A mutant. From these results, we suggested that the orientations and positions of respective aliphatic groups in the side-chain of position 5 mainly affected the inhibitory activity of SmaPI. The overall side-chain hydrophobicity was only slightly affected. The side-chain of the Leu-5 residue contributed approximately 0.79 kcal/mol out of 8.44 kcal/mol to the binding of SmaPI with SMP The inhibitory activities of P6A and F6G were also severely decreased. The Pro-6 may have a critical role in maintaining the strict conformation of the N-terminal portion that may be important in the inhibitory activity of SmaPI. In conclusion, Leu-5 and Pro-6 have crucial roles in the inhibitory function of SmaPI toward SMP.

• Journal of Environmental Health Sciences
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• v.38 no.5
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• pp.380-385
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• 2012

Background: Manganese (Mn) has been found to increase the signal intensity of the globus pallidus (GP) on T1-weighted magnetic resonance images (MRI). We performed this study in order to determine the features of liver disease that correlate with pallidal signal intensities. Methods: We assessed blood Mn levels and pallidal signals in T1-weighted MRI in 49 patients with liver cirrhosis and 23 healthy controls. Results: Increased signal intensity in the GP was observed in 30 of 49 (61.2%) patients with liver cirrhosis, with the pallidal index (PI) in patients with Child-Pugh classes B and C differing significantly from the PI in controls. Multiple linear regression analysis showed that blood Mn concentrations and Child-Pugh scores in cirrhotics were significantly associated with increased PI after controlling for other confounders (p<0.05 each). Conclusions: Pallidal signals on T1-weighted MRI are mainly observed in advanced liver cirrhosis. The present study suggests that advanced liver cirrhosis may be a human model for manganism.

• Journal of Electrical Engineering and Technology
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• v.12 no.5
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• pp.1821-1834
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• 2017

Medium voltage control applications due to obtain better output voltage and reduced electro-magnetic interference multi level inverter is used. In closed loop control with inverter, the PI controller does not operate satisfactorily when the operating point changes. This paper presents the performance of Co-Efficient diagram PI controller based indirect vector controlled induction motor drive fed from three-level inverter under different operating conditions (dynamic and steady state). The proposed Co-Efficient diagram PI controller based three level inverter significantly reduces the torque ripple compared to that of conventional PI controller. The performance of the indirect vector controlled induction motor drive has been simulated at different operating conditions. For three-level inverter control, a simplified space vector modulation technique is implemented, which reduces the coordinate transformations complications in the algorithms. The performance parameters, torque ripple contents and THD of induction motor drive with three-level inverter is compared under different operating conditions using CDM-PI and conventional PI controllers.

• Journal of Periodontal and Implant Science
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• v.50 no.5
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• pp.340-354
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• 2020

Purpose: This pilot study was conducted to evaluate the cleaning efficacy of an angled implant brush for home oral hygiene of full-arch fixed-implant prostheses. Methods: Forty-one patients treated with a full-arch implant rehabilitation in the maxilla or mandible (164 implants) for at least 4 months were enrolled. The screw-retained fixed prostheses were removed and baseline (T0) parameters were recorded, including plaque index (PI), probing depth (PD), and bleeding on probing (BOP). All patients completed a 5-item questionnaire on hygiene maintenance and received an implant brush for home hygiene. After 1 month (T1) PI, PD, and BOP were recorded again and patients completed a 7-item questionnaire to evaluate their satisfaction with the implant brush. One-way repeated-measures analysis of variance was conducted to evaluate the significance of changes in PI, PD, and BOP. A P value <0.05 was considered to indicate statistical significance. Results: A statistically significant reduction of BOP (0.62±0.6 at T0 vs. 0.5±0.5 at T1; P=0.032) was found, while no statistically significant changes in PD (1.74±0.5 mm at T0 vs. 1.77±0.5 mm at T1; P=0.050) or PI (1.9±0.7 at T0 vs. 1.7±0.7 at T1; P=0.280) occurred. According to the 7-item questionnaire, patients reported no difficulty in using the angled brush (63.4%) and deemed it highly (46.3%) or very highly (4.8%) effective in improving their home oral hygiene. Conclusions: Within the limits of the present pilot study, the patients experienced a reduction of BOP 1 month after being instructed to use the angled implant brush. The angled implant brush appeared to be a well-accepted device for home-care hygiene of full-arch fixed-implant rehabilitations.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.11 no.6
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• pp.486-492
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• 1998

The amorphous Co-based magnetic films have a large saturation flux density, a low coercive force, and a zero magnetostriction constant. Therefore, they have been studied for application to magnetic recoding heads and micro magnetic devices. However, it was found that the magnetic anisotropy was changed for each film fabrication processes. In this study, we investigated how to control the anisotropy of sputtered amorphous $Co_{89}Nb{8.5}Zr{2.5}$ films. After deposition, the rotational field annealing ant the uniaxial field annealing were performed under the magnetic field of 1.5 kOe. the annealing was done at the temperature range from 400 to $600^{\circ}C$ for one hour. As-deposited amorphous $Co_{89}Nb{8.5}Zr{2.5}$ thin film had saturation magnetization ($4\piM_5$) of 0.8 T, coercive force($_IH_C$) of 1.5 Oe, and anisotropy field($H_k$) of 11 Oe. The amorphous $Co_{89}Nb{8.5}Zr{2.5}$ thin films annealed by rotational field annealing at $500^{\circ}C$ for one hour was found to be isotropy, and $4\piM_5$ of 0.9 T was obtained from these films, Also, the magnetic anisotropy of as-deposited films could be controlled by uniaxial field annealing at $400^{\circ}C$ for one hour. Anisotropy field($H_k$) of 17 Oe and $4\piM_5$ of 1.0 T were obtained by this method.

• Journal of IKEEE
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• v.27 no.4
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• pp.567-572
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• 2023

In this paper, the breakdown voltage of Pi-LDMOS (Partial isolation lateral double diffused metal oxide semiconductor) was analyzed by simulation. Breakdown voltage variation is investigated under various settings of Parial buied oxide(P-BOX) parameters(length, thickness, location) and their mechanism is specified. In addition, the change in on-resistance in the breakdown voltage and trade-off relationship was analyzed according to the change in the P-BOX parameter, and the Figure-of-merit(FOM) was calculated and compared. In proposed structure, Lbox=5 ㎛, tbox=2 ㎛, and Lbc=2 ㎛ showed the highest breakdown voltage of 138V, and Lbox=5 ㎛, tbox=1.6 ㎛, and Lbc=2 ㎛ showed the highest FOM. Compared to conventional LDMOS, the breakdown voltage is 123% and FOM is 3.89 times improved. Therefore, Pi-LDMOS has a high breakdown voltage and FOM, which can contribute to the improvement of the stable operating range of the Power IC.

• Polymer(Korea)
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• v.37 no.5
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• pp.618-624
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• 2013

Hydroquinone bis(trimellitic anhydride) (HQ-TA) was synthesized from trimellitic anhydride chloride and hydroquinone. Poly(amic acid)s (PAAs) were synthesized by reacting a HQ-TA with six different diamines, which were cyclized to yield polyimides (PIs) containing ester linkages by chemical- and thermal-imidization methods. The various PIs were synthesized from structurally different aromatic diamines. The glass transition temperatures ($T_g$) were in the range of 167-$215^{\circ}C$, and the decomposition temperatures (${T_D}^i$) were in the range of $364-451^{\circ}C$. The maximum improvements in coefficient of thermal expansion (CTE) and barrier to oxygen permeation were observed in PIs using TFB (3.23 $ppm/^{\circ}C$) and 4,4-ODA (< $10^{-2}cc/m^2/day$), respectively. The PI films possessed a transmittance of 65-89% at 500 nm and had a yellowish color with a yellow index (YI) of 3.01-69.52.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1994.04a
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• pp.186-186
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• 1994

Many agonists have been known to activate the hydrolysis of membrane phospholipids through the bindings with corresponding receptors on the various cells. Diacylglycerol and inositol 1,4,5-trisphosphate(IP3) generated by the action of phosphoinositide-specific phospholipase C (PI-PLC) are well known second messengers for the activation of protein kinase C and the mobilization of Ca2+ in many cells. Three types of PI-PLC isozyme (${\alpha}$,${\gamma}$, and $\delta$) and several subtrpes for each type have been identified from mammalian sources by purification of enzymes and cloning of their cDNAs. Each type PI-PLC isozyme is coupled to different receptors and mediators, for example, ${\beta}$-types are coupled to the seven-transmembrane-receptors via Gq family of G-proteins and ${\beta}$-types directly to the receptor tyrosine kinases. Specific modulators for the signaling pathway through each type of PI-PLC should be very useful as potential potential candidates for lend substances in developing novel drugs. To establish the sensitive and convenient screening systems for searching modulators on PI-PLC mediated signaling, two kinds of approaches have been tried. (1) Establishment of in vitro assay condition for each type of PI-PLC isozyme: Overexpression by using vaccinia virus and purification of each isozyme was carried out for the preparation of large amounts of enaymes. Optimum and sensitive assay condition for the measurements of PI-ELC activities were established. (2) Development of the cell lines in which each type of PI-PLC is permanently overexpressed: A fibroblast cell line (3T3${\gamma}$1-7) in which PI-PLC-${\gamma}$1 was overexpressed by using pZip-neo expression vector was developed and used for the measurement of PDGF-induced IP3 formation. The responses for IP3 formed in 3T3${\gamma}$1-7 cells by the treatment of PDGF is 8 times more sensitive than those in control cells. 3T3${\gamma}$l-7 cell is useful for the screening of the inhibitors on the PDGF-induced cellular responses from large number of samples in a small volume(50 ${\mu}$l) and short time(5-15 min). Using these systems, we screened hundreds of herb-extracts for the inhibition of PDGF-induced IP3 formation and selected several extracts that showed the inhibition as the candidates for isolation and characterization of active substances. The determination of the acting point of selected extracts or fractions in the PDGF signaling pathway has been analyzing.