• Mycobiology
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• 제37권4호
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• pp.267-271
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• 2009

A fungal strain producing a high level of cellulase was selected from 320 fungal isolates and identified as Aspergillus sp. This strain was further improved for cellulase production by sequential treatments by two repeated rounds of $\gamma$-irradiation of $Co^{60}$, ultraviolet treatment and four repeated rounds of treatment with N-methyl-N'-nitro-N-nitrosoguanidine. The best mutant strain, Aspergillus sp. XTG-4, was selected after screening and the activities of carboxymethyl cellulase, filter paper cellulase and $\beta$-glucosidase of the cellulase were improved by 2.03-, 3.20-, and 1.80-fold, respectively, when compared to the wild type strain. After being subcultured 19 times, the enzyme production of the mutant Aspergillus sp. XTG-4s was stable.

• Toxicological Research
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• 제12권1호
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• pp.101-111
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• 1996

The local irritation studies of DA-3285, recombinant human erytropoietin(rHu-EPO), were carried out in rabbits after the following treatment; single application into the conjunctival sac of the eye, single subcutaneous injection, 7-day repeated subcutaneous injection and 8-day repeated infusion into the ear vein. Also, the local irritancy of DA-3285 leaked around vein was studied in mice by single perivascular injection. The results obtained were as follows. In the result of ocular irritation test, DA-3285 could be considered as a non-irritating material. In single and 7-day repeated subcutaneous irritation test, the irritancy of DA-3285 was not so much different from that of saline. The vascular irritancy of DA3285 by 8-day repeated infusion was negligible and similar to that of saline. And the irritancy of DA3285 by perivascular injection was comparable to that of saline. These results indicate that DA-3285 has no irritating activity when injected through subcutaneous or intravenous route for clinical practice as 3.5% solution.

• 대한치과기공학회지
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• 제4권1호
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• pp.5-7
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• 1982

This study was performed to examine the effect of repeated firing on porcelain color stability. Sixty sepcimens of generally uniform size and shape(9.7 12mm)were prepared using the manufactorer's specifications and among them 50 specimens that showed no defect after firing procedure were selected. All samples, abraded with sandpaper disc, ultrasonically cleaned, and air fired to amedium glaze were devided into 10 groups according to the number of repeated firing and, upon completion, mounted on a 13 by 16cm board. 30 persons(five dentists, ten dental techanicians, and fiftheen students) were asked to compare the samples for variations, in hue, chroma and value under natural and artificial light. The results were as follows:(1) There were no color change detected in the first four firings.(2) Slight color change were noticed in subsequent firings(ie: greater decreases in value with slight increases In chroam)(3) However, the hue remained constant in all 10 groups after repeated firings.

• Structural Engineering and Mechanics
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• 제37권1호
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• pp.1-15
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• 2011

The response of concrete to transient dynamic loading has received extensive attention for both civil and military applications. Accordingly, thoroughly understanding the response and failure modes of concrete subjected to impact or explosive loading is vital to the protection provided by fortifications. Reactive powder concrete (RPC), as developed by Richard and Cheyrezy (1995) in recent years, is a unique mixture that is cured such that it has an ultra-high compressive strength. In this work, the concrete cylinders with different steel fiber volume fractions were subjected to repeated impact loading by a split Hopkinson Pressure Bar (SHPB) device. Experimental results indicate that the ability of repeated impact resistance of ultra-high-strength concrete was markedly superior to that of other specimens. Additionally, the rate of damage was decelerated and the energy absorption of ultra-high-strength concrete improved as the steel fiber volume fraction increased.

• Earthquakes and Structures
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• 제3권3_4호
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• pp.231-248
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• 2012

In this study, a systematic investigation is carried out on the seismic behaviour of plane moment resisting steel frames (MRF) to repeated strong ground motions. Such a sequence of earthquakes results in a significant damage accumulation in a structure because any rehabilitation action between any two successive seismic motions cannot be practically materialised due to lack of time. In this work, thirty-six MRF which have been designed for seismic and vertical loads according to European codes are first subjected to five real seismic sequences which are recorded at the same station, in the same direction and in a short period of time, up to three days. Furthermore, the examined frames are also subjected to sixty artificial seismic sequences. This investigation shows that the sequences of ground motions have a significant effect on the response and, hence, on the design of MRF. Additionally, it is concluded that ductility demands, behaviour factor and seismic damage of the repeated ground motions can be satisfactorily estimated using appropriate combinations of the corresponding demands of single ground motions.

• 대한설비공학회지:설비저널
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• 제17권4호
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• pp.473-488
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• 1988

This paper is concerned with the prediction of two dimensional turbulent flows in the parallel plate with the repeated cylindrical blockages. The purpose of this paper is to find the effect of the eccentricity and the pitch of the repeated cylindrical blockages on the flow field, heat transfer coefficients and friction factors. A special technique is developed for the solution of the fully developed turbulent recirculating flow, in which the flow field varies periodically. A non-othogonal coordinate transformation is employed to solve the momentum and the energy equations. The results show that the pitch ratio or the eccentricity of the repeated blockages become smaller, or the Reynolds number of the flow larger, friction factors and heat transfer coefficients increase.

• 대한응급의학회지
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• 제29권5호
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• pp.551-556
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• 2018

Cases of repeated acute gastric dilatations after binge eating in one patient are rarely reported. We report here a case of repeated acute gastric dilatations in a 22-year-old woman with bulimia nervosa. Her repeated acute gastric dilatations seem to have been related to superior mesenteric artery syndrome. On her last visit due to acute gastric dilatation, she underwent emergency gastric decompression surgery because of abdominal compartment syndrome; however, she eventually died because of ischemia reperfusion injury. Emergency physicians should be aware of the need to manage acute gastric dilatation in patients with eating disorder and should pay attention to the signs and distinctive clinical features of abdominal compartment syndrome.

• Restorative Dentistry and Endodontics
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• 제40권1호
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• pp.91-95
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• 2015

• 한국의류학회지
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• 제20권6호
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• pp.975-982
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• 1996

This study was conducted to examine the fatigue phenomenon of mechanical properites in denim fabrics for slacks during repeated shear and tensile deformation by analysing the change in the basic dynamic properties of fabrics on the basic of experiments to obtain the basic data necessary to measure their fatigue. In addition, this study was carried out by allowing these denim fabrics at market to go through the repeated deformation under such different loads as 500 gf/cm2 and 1000 gf/cm2 by using a simulated fatigue tester, by calculating both dynamic properties and hand value (HV) of these fabrics with KES-F system and then by obtaining the THV through these calculated properties. The results are as follows: 1 The fatigue phenomenon of dynamic properties was remarkably shown by the repeated shear and tensile deformation, while the increase of hysterical plastic substances was also remarkable in these shearing and bending properties. 2. The elasticity values of tensile, bending and compression properties, such as, B and G were reduced: whereas RT and RC values increased. It was shown, then, that those fabrics lost their elasticity and became flexible and soft with the increase of fatigue. 3. The fatigue phenomenon of hand value also showed that those fabrics became soft in relation with the change of all dynamic properties, and that their performance was also change to flexible hand value. 4. TRhe degree of fatigue was also shown by the loads given to the repeated deformation. It was shown that the fatigue was higher for the tensile load of 1000 gf/cm3 than did the standard load of 500 gf/cm3 It is necessary, therefore, to consider the load in accordance with their usage when examining the fatigue phenomenon with respect to the dynamic properties of clothing materials. 5. The loads were nearly not influenced by the change in the general hand value tended to show a little of increase with the increase of fatigue, Based on those results, it seems that the fatigue phenomonon is related to the loads given to the repeated deformation.

• Journal of Periodontal and Implant Science
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• 제37권3호
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• pp.535-542
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• 2007

Background : Repeated dis/re-connection of implant abutment caused bone loss around implant fixtures due to the new formation of biologic width of the mucosal-implant barrier. The aim of this clinical study was to evaluate whether the repeated dis/re-connection of implant abutment cause bone loss clinically and the effect of cleansing methods on a bone loss during the early healing period. Methods : A total 50 implants were installed in 20 patients and repeated dis/re-connection of abutment was performed at the time of surgery and once per week for 12 weeks. 0.9% normal saline solution as group1 and 0.1% chlorhexidine solution as group 2 was used to clean abutments. All patients had radiographs taken at the placement of implant and 4, 8, and 12 weeks postoperatively. The data for bone loss around implant were analyzed. Results: The marginal bone loss at 12 weeks were $1.28{\pm}0.51mm$, $1,32{\pm}0,57mm$ in the mesial and distal sides in group1, $1.94{\pm}0.75mm$, $1.81{\pm}0.84mm$ in group 2, respectively. In view of marginal bone loss, there was not a significant statistical difference between groups. Conclusions : Repeated dis/re-connection of implant abutment may not cause marginal bone loss around implant fixture although limited samples and short-term observation period. In spite of more bone loss in group 2, there was no statistical significant difference between groups. In context of those results, the clinical significance of the repeated dis/re-connection of implant abutment and the cleansing method of abutments is debatable when it comes to marginal bone loss during early healing period.