• BMB Reports
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• v.39 no.3
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• pp.319-328
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• 2006

SecA protein, a cytoplasmic ATPase, plays a central role in the secretion of signal peptide-containing proteins. Here, we examined effects of signal peptide and ATP on the oligomerization, conformational change, and membrane binding of SecA. The wild-type (WT) signal peptide from the ribose-binding protein inhibited ATP binding to soluble SecA and stimulated release of ATP already bound to the protein. The signal peptide enhanced the oligomerization of soluble SecA, while ATP induced dissociation of SecA oligomer. Analysis of SecA unfolding with urea or heat revealed that the WT signal peptide induces an open conformation of soluble SecA, while ATP increased the compactness of SecA. We further obtained evidences that the signal peptide-induced oligomerization and the formation of open structure enhance the membrane binding of SecA, whereas ATP inhibits the interaction of soluble SecA with membranes. On the other hand, the complex of membrane-bound SecA and signal peptide was shown to resume nucleotide-binding activity. From these results, we propose that the translocation components affect the degree of oligomerization of soluble SecA, thereby modulating the membrane binding of SecA in early translocation pathway. A possible sequential interaction of SecA with signal peptide, ATP, and cytoplasmic membrane is discussed.

• Journal of Korean Library and Information Science Society
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• v.10
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• pp.157-191
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• 1983

The purpose of the study is to build a general cost a counting model for university libraries, to clarify the possible areas of its a n.0, pplication by employing job cost accounting and process cost accounting methods. System analysis is performed as to the fields of acquisition, processing (cataloging & classification), and book shelving system. The existing operation processes and time required for each operation of these three systems are analyzed, from which detailed system flowcharts were drawn and job descriptions and the content of job were identified. The results of the study can be summarized as follows: (1) The processing time of one book in each systems: Oriental books. a. Acquisition system. the time required the time required in case of job cost case of job cost accounting after purchasing, 8 min. 21 sec. the time required in case of process cost accounting 15 min. 7 sec. b. Processing system. the time required for non-duplicate, 34 min. 40 sec. the time required for duplicate, 8 min. 49 sec. the time required for purchasing of more than the time required two copies at a time. 4 min. 44 sec. c. Book shelving system. the time required. 1 min. 43 sec. Western books. a. Acquisition system the required in case of job cost accounting, 9 min. 1 sec. the time required in case of process cost accounting. 15 min. 7 sec. b. Processing system. the time required for non-duplicate, 32 min. 58 sec. the time required for duplicate, 9 min. 26 sec. the time required for purchasing of more than two copies at a time. 5 min. 33 sec. c. Book shelving system. the time required. 1 min. 43 sec. (2) Total sum of processing time and processing cost per book. Oriental books (including material cost) the time required. cost. a. non-duplicate, 51 min. 30 sec. 2, 791 won b. duplicate, 25 min. 39 sec. 1, 580 won c. purchasing of more than two copies as a time, 21 min. 34 sec. 1, 368 won Western books(including material cost) a. non-duplicate, 49 min. 48 sec. 3, 189 won b. duplicate, 26 min. 16 sec. 1, 846 won c. purchasing of more than two copies at a time. 22 min. 23 sec. 1, 388 won

• Korean Journal of Agricultural and Forest Meteorology
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• v.5 no.4
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• pp.213-217
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• 2003

Forest fire spread and intensity were modeled as a function of wind and fuel. Spread rate and intensity of forest fire were related to weight and thickness of forest fuel beds and to wind speed. Forest fire spread rate and fire intensity were differentiated according to wind speed. Rapid wind speed causes a faster forest fire spread rate and greater fire intensity than does slow wind speed. Relative burning time of the fire from beginning to end in the model was 161 sec at a wind speed of 0.5 m/sec and 146 sec at 1m/sec on the model. Average forest lire spread rate was 0.014 m/sec at a wind speed of 0.5 m/sec and 0.020 m/sec at 1m/sec. Average fire intensity was 0.183 ㎾/m at a wind speed of 0.5 m/sec, 0.259 ㎾/m at 1m/sec. Fire intensity was greater when forest fire spread rate was rapid.

• Microbiology and Biotechnology Letters
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• v.24 no.4
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• pp.408-414
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• 1996

The SecY is a central component of the protein export machinery that mediate the translocation of secretory proteins across the plasma membrane, and has been known to be rate-limiting factor of secretion in Escherichia coli. In order to study the extracellular protein secretion in Gram-positive microorganism, we have, constructed strains harboring more than one copy of the gene for SecY. Firstly, the gene, for B. subtilis SecY and its promoter region was subcloned into pDH32 and the chimeric vector was inserted into amyE locus by homologous recombination. Secondly, low copy number vector, pCED6, was also used for subcloning the secY gene and for constructing a strain which harbors several copies of secY. The KH1 cell which harbor two copies of secY on the chromosome excreted more extracellular proteins than the wild type PB2. Moreover, the KH2 cells which harbor several copies of secY in pCED6 vector excreted more extracellular proteins than the KH1 cells. Here, we found that the capacity of protein secretion is partly controlled by the number of secY and it is suggested that SecY has also an important role in protein secretion in B. subtilis, a gram positive microorganism, as like in E. coli. This will promote the use of B. subtilis as a host for the expression of useful foreign gene and excretion of precious proteins.

• Advances in Traditional Medicine
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• v.5 no.1
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• pp.69-74
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• 2005

'SecSec' has been used for the purpose of prevention and treatment of throat diseases such as sore throat, cough, bronchial asthma and allergic asthma in Korea. However, its effect in experimental models remains unknown. To investigate the biological effect of SecSec, we examined cytotoxicity and secretion of inflammatory cytokines on human leukemic mast cell line, HMC-1, stimulated with phorbol 12-myristate 13-acetate (PMA) and calcium ionophore A23187. SecSec by itself had no cytotoxicity on HMC-1. When SecSec (1 mg/ml) was added, the secretion of tumor necrosis factor-alpha $(TNF-{\alpha})$, interleukin (IL)-6, and granulocyte macrophage-colony stimulating factor (GM-CSF) was significantly inhibited about 47.20%, 25.55%, and 46.43%, respectively on PMA plus A23187-stimulated HMC-1 cells. But SecSec did not inhibit IL-8 secretion. These findings may help understanding the mechanism of action of this medicine leading to control activated mast cells on allergic inflammatory condition like asthma.

• Journal of radiological science and technology
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• v.31 no.3
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• pp.267-276
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• 2008

The 25 healthy male volunteers aged from 20 to 50years old have been employed in this study. 2D-PC MRA was performed to measure the velocity of the blood flow in the internal carotid artery and internal jugular veins using 3.0T MRI Whole body (signa VH/i GE). ECTRICKS-CEMRA was performed to evaluate the pattern of blood circulation from internal carotid artery to internal jugular vein. Using 2D-PC MRA, the cross-section of the 4th and 5th cervical discs was scanned with 24cm FOV. Then the speed of blood flow was measured for internal carotid artery and internal jugular vein when the subject wears a necktie tightly and no tie. The average of maximum velocity of internal carotid arteries without a necktie was 72.13cm/sec in the right side and 74.96cm/sec in the left side(average 73.54cm/sec in both sides) while the average of maximum velocity of internal jugular veins without a necktie was -34.45cm/sec in the right side and -24.99cm/sec in the left side (-29.72cm/sec in both sides). However, when wearing a necktie tightly, the average of maximum velocity of internal carotid arteries was 61.35cm/sec in the right side and 65.19cm/sec in the left side(average 63.27cm/sec in both sides) while the average of maximum velocity of internal jugular veins was -22.14cm/sec in the right side and -17.93cm/sec in the left side(-20.03cm/sec in both sides). With the necktie tightly knotted, the average blood flow speed of both internal carotid arteries slightly decreased to 86% (63.27/73.54cm/sec) compared to no tie case in which both internal jugularveins significantly went down to 67% (-20.03/-29.72 cm/sec). Thus it is suggested that wearing a necktie affects the circulation of internal jugular veins(33% decrease in blood flow speed) more significantly than that of internal carotid artery(14% decrease in blood flow speed). Without a necktie, ECTRICKS-CEMRA showed natural blood circulation patterns of internal carotid arteries and internal jugular veins without any disturbances or compressions. However, when wearing a necktie tightly, ECTRICKS-CEMRA showed severe compression onto both internal jugular veins in all 25 volunteers. In conclusion, the result of the study showed that the tightly worn necktie instantly presses more internal jugular veins than internal carotid arteries, thereby significantly reducing the blood flow speed and leading to the temporary occlusion. Thus, the defecation or washing the face under the tightly tied necktie situations can cause the unexpected and temporary compression or occlusion of the internal jugular veins, subsequently leading to the occurrences of the stroke due to the secondary intracranial venous hypertension.

• Restorative Dentistry and Endodontics
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• v.24 no.1
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• pp.240-250
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• 1999

The purpose of this study was to evaluate the effect of different etching time on the shear bond strength and adaptibility of composite to enamel and dentin when used one-bottle adhesive Prime & Bond$^{TM}$ 2.0. The proximal and occlusal surfaces of 88 extracted human molars were ground to expose enamel(n=44) and dentin (=44) using diamond wheel saw. Teeth were randomly assigned to four test groups(n=11) and received the following treatments : Control group were conditioned with 36% phosphoric acid for 20 sec. according to the manufacturer's directions. Experimental 10 sec. group, 30 sec. group and 60 sec. group were conditioned with 36% phosphoric acid for 10 sec., 30 sec. and 60 sec., respectively. Teeth were rinsed and dried for 2 sec. Prime & Bond$^{TM}$ 2.0 were applied according to the manufacturer's directions and Spectrum$^{TM}$ TPH composite resins were bonded to enamel and dentin surfaces. All specimens were stored in distilled water for 24 hours. Eighty specimens were sheared in a Universal Testing Machine with a crosshead speed of 5mm/minute. One way ANOVA and LSD test were used for statistical analysis of the data. Failure modes of all specimens after shear bond strength test were examined and listed. Also, representive postfracture modes and eight specimens were examined under scanning electron microscope. The results of this study were as follows: 1. The shear bond strength to enamel was the highest value in 30 sec. group (20.68${\pm}$8.54MPa) and the lowest value in 10 sec. group (14.92${\pm}$6.07MPa), so there was significant difference of shear bond strength between two groups (p<0.05). But there was no significant difference among other groups (p>0.05). With longer etching time to enamel from 10 sec. to 30 sec., higher the shear bond strength was obtained, but the shear bond strength was decreased at 60 sec. etching time. 2. The shear bond strength to dentin was the highest value in control group (13.08${\pm}$6.25MPa) and the lowest value in 60 sec. group (9.47${\pm}$3.35MPa), but there was no significant difference among the all groups (p>0.05). The eching time over 20 sec. decreased the shear bond strength to dentin. 3. In SEM observation, the enamel and resin interfaces were showed close adaptation with no relation to etching time of enamel. And the dentin and resin interfaces were showed close adaptation at 20 sec. and 30 sec. etching time, but showed some gaps at 10 sec. and 60 sec. etching time. Accordingly, these results indicated that a appropriate etching time in Prime & Bond$^{TM}$ 2.0 was required to be 30 sec. in enamel and 20 sec. in dentin for the high shear bond strength and good adaptation between the composite resin and tooth substance.

• Fire Science and Engineering
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• v.17 no.3
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• pp.1-6
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• 2003

In this study, it reviewed about evacuation performance of a specified Office Building. assessment tools is FAST 3.1.7 (Estimation of Flash Over, Estimation of Layer Height Down Flow Time), SIMULEX 32-bit (Estimation of Evacuation Time), JASMINE 3.25d. (Smoke Flow Assessment of a specified time) Result from Fire Scenario # 1, Flash Over is not generated in Compartment. Evacuation Time is estimated 25.2 sec by SIMULEX 32-bit. layer height until this time (25.2 sec) was estimated 2.4 m by FAST 3.1.7. After ignition until this time (25.2 sec), smoke was not release to the a corridor. In consequence, We concluded that people in building are completing the safe evacuation without the damage of smoke. Result from Fire Scenario # 1, Flash Over generated 6 min 33.2 sec in Compartment. Evacuation Time is estimated 1 min 25.5 sec by SIMULEX 32-bit. layer height down flow time is 1 min 40.8 sec by FAST 3.1.7 and 5 min 23 sec by theoretical calculation. Also, total building evacuation time was estimated 2 min 26.6 sec. After ignition until this time (2 min 26.6 sec), smoke released to the a corridor but it amount was few little. Therefore, generated smoke in compartment not effected to the people in buildings.

• Fire Science and Engineering
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• v.26 no.3
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• pp.85-90
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• 2012

The autoignition temperature (AIT) of a material is the lowest temperature at which the material will spontaneously ignite. The AIT is important index for the safe handling of flammable liquids which constitute the solvent mixtures. This study measured the AITs of n-Decane+sec-Butanol system by using ASTM E659 apparatus. The AITs of n-Decane and sec-Butanol which constituted binary system were $212^{\circ}C$ and $447^{\circ}C$, respectively. The experimental AITs of n-Decane+sec-Butanol system were a good agreement with the calculated AITs by the proposed equations with a few A.A.D. (average absolute deviation).

• Proceedings of the KWS Conference
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• 2001.05a
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• pp.114-116
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• 2001

This study deals with friction stir welding of aluminum alloy(A5083). Welding conditions were applied that revolution 2000rpm, friction pressure 25MPa, angle between stir rod section and plate 4$^{\circ}$, projection pin diameter 4mm, traverse speed 0.5mm/sec, 1.0mm/sec, 1.5mm/sec. The experimental results as follows; 1. Welding beads were superior in traverse speed 1.0mm/sec and it were formed plenty of flash in traverse speed 0.5 mm/sec. Welding beads were rough in traverse speed 1.5mm/sec. 2. The maximum tensile strength was 211MPa in traverse speed 1.0mm/sec, in this case the strength was 85% of A5083 base metal tensile strength.