• Bulletin of the Korean Chemical Society
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• v.35 no.5
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• pp.1294-1298
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• 2014

Non-small cell lung cancer (NSCLC) is the most common type of lung cancer representing 85% of lung cancer patients. Despite several EGFR-targeted drugs have been developed in the treatment of NSCLC, the clinical efficacy of these EGFR-targeted therapies is being challenged by the occurrence of drug resistance. In this regard, Hsp90 represents great promise as a therapeutic target of cancerous diseases due to its role in modulating and stabilizing numerous oncogenic proteins. Accordingly, inhibition of single Hsp90 protein simultaneously disables multiple signaling networks so as to overcome drug resistance in cancer. In this study, we synthesized a series of 11 butein analogues and evaluated their biological activities against gefitinibresistant NSCLC cells (H1975). Our study indicated that analogue 1h inhibited the proliferation of H1975 cells, down-regulated the expression of Hsp90 client proteins, including EGFR, Met, Her2, Akt and Cdk4, and upregulated the expression of Hsp70. The result suggested that compound 1h disrupted Hsp90 chaperoning function and could serve a potential lead compound to overcome the drug resistance in cancer chemotherapy.

• 한국생물공학회:학술대회논문집
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• 2003.10a
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• pp.384-387
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• 2003

We measured the inlet concentration of odorous gases from the food-waste composting facility for 90 days. In consequence of this survey, we ascertained that the gaseous concentration was detected $10{\sim}100ppm$ in operating time, but $0{\sim}10ppm$ in a shutdown of the facility. The initial removal efficiency of this biofilter was roughly represented 80%, however, 90% before and after twenty days. We have thought that this biofilter accomplished the treatment of those odorous gases effectively, because the pressure-drop was not exceeded a value of $20mmH_2O$ after 90 days.

• Advanced Composite Materials
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• v.18 no.1
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• pp.43-59
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• 2009

The current study assessed the effect of a bolt hole on tensile fatigue properties of CFRP laminates. Two specimens, i.e. $[(0/90)_3]S$, $[(0/45/90/-45)_2]_S$, were analyzed using a finite element method and were experimentally tested for cases, both with and without a hole, whose diameter corresponded to 0.12 times the specimen width. Delamination positions predicted by a 3-dimensional static finite element analysis were matched well to those observed by an ultrasonic imaging system in the middle of fatigue test. A hole whose diameter corresponds to 0.12 times the specimen width caused the fatigue strength to decrease by 9% and 11% under 5 Hz loading frequency, and by 22% and 25% under 10 Hz loading frequency for $[(0/90)_3]_S$ and $[(0/45/90/-45)_2]_S$, respectively. Because the decrease in sectional area due to the hole was normalized in calculation of the tensile strength, a stress concentration around the hole is believed to induce the strength degradation of fatigue specimens. From the finite element analyses, the stress concentration factor around a hole was expected as 8.8 and 9.5 for $[(0/90)_3]_S$ and $[(0/45/90/-45)_2]_S$, respectively.

• Microbiology and Biotechnology Letters
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• v.21 no.4
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• pp.366-372
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• 1993

The aim of this study was to find out the rapid fermentation of soy sauce from koji hydrolyzate using column type reactor packed with immobilized yeast cells. Each immobilized cell of Zygosaccharomyces rouxii BH-90 and Candida versatilis BH-91 in the packed column type reactor produced 2.8% ethyl alcohol and 18mg/l 4-ethylguaiacol over 96 hours under the optimal condition. Continuous fermentation was performed by immobilized Z. rouxii BH-90 packed in column type reactor. Immobilized Z. rouxii BH-90 produced 2.30~2.85% ethyl alcohol during 30 days, and decreased gradually from 40 days to 80 days. Also C. versatilis BH-91 produced 4-ethylguaiacol at the constant rate of 16~18mg/l and decreased gradually after 40 days. Final product of soy sauce contained 2.8% ethyl alcohol and 18mg/l 4-ethylguaiacol. However, amino acid compositions of final products were consisted of predominantly glutamic acid, leucine, arginine, aspartic acid, lysine and valine, which were more than 50% of total amino acid.

• Composites Research
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• v.12 no.4
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• pp.8-16
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• 1999

In this study, when the applied directions of tensile loading is changed fatigue damage of quasi-isotropic composite laminates was discussed. Low cycle fatigue tests of $[0/-60/+60]_s$ laminates and $[+30/-30/90]_s$ laminates were carried out. Material systems used were AS4/Epoxy and AS4/PEEK. The fatigue damage of $[+30/-30/90]_s$ laminates differed from that of $[0/-60/+60]_s$ laminates. The position of delamination generated at AS4/Epoxy and AS4/PEEK $[+30/-30/90]_s$ laminates appeared differently according to the kind of matrix. Critical values of strain energy release rate were obtained by using the strain measured at the initiation of delamination. The experimental results agreed well with the results obtained by the proposed method for determining strain energy release rate.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2007.06a
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• pp.91-94
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• 2007

In this paper, the six-port phase correlator using $90^{\circ}$ hybrid branch-line coupler and three-arm branch $90^{\circ}$ hybrid coupler were designed. The performances for two six-port phase correlators were analyzed by using ADS2003A tool. Three-arm six-port phase collerator provides more wide dynamic frequency range than that of six-port using the conventional hybrid coupler in range of circa five times. Six-port phase correlators were fabricated to evaluate the performance of two six-port phase correlators. The measured performances for two six-port phase correlators show the good accordance with the simulation data.

• The Korean Journal of Applied Statistics
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• v.21 no.5
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• pp.867-873
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• 2008

It is a convention to use 5% significance level when a statistical test is employed for clinical data. But when a confidence interval is used for testing equivalence, 90% confidence interval has often been used. When $1-{\alpha}$ confidence interval is used for hypothesis testing, its significance level is often ${\alpha}$. So it makes a confusion that the significance level is 10% if 90% confidence interval is employed for testing equivalence. In this paper I will clarify this issue by reviewing relevant papers and conducting simulation studies. I hope that it will be beneficial to statisticians in pharmaceutical companies, CROs, university hospitals.

• Journal of Oral Medicine and Pain
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• v.20 no.2
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• pp.335-345
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• 1995

Emotional state of dental outpatients was studied by means of symptom checklist-90- revision, 229 male and 290 female dental outpatients were subjected at the private local clinic in Pusna, during the period from 1994 to 1995. T-scores from SCL-90-R were analyzed psychologically by means of 90 questionnaires through Korean manual of SCL-90-R. The obntained results were as follows : 1. Mean value of T-scores on 9 basic scales of SCL-90-R in all the dental outpatients was within normal range. 2. T-scores in male were significantly higher than that in female, and there was a significant difference by age group in female. 3. There were higher levels of T-scores in groups of high academic carrier, salaryman, public servant, and unmarried person. 4. T-score of patients with periodontal pain was the highest in all subject groups. 5. While T-score of patients with K01(embedded and impated teeth) was the highest, that of K02(dental caries) was the lowest. 6. T-score in acute group was higher than that in chronic group. 7. T-score of patients treated in field of oral surgery or oral medicine was higher than those of other fields of dental treatments.

• Journal of the Korean Society of Food Science and Nutrition
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• v.30 no.1
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• pp.6-13
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• 2001

The study was conducted to investigate the effect of the browning inhibitors such as PVPP(polyvinylpoly-pyrrolidone), A.A.(ascorbic acid) on nonezymatic browning factors [free sugar, total amino acid, organic acid, A.A., HMF (hydroxymethylfurfural)] and enzymatic browning factors [PRO (polyphenoloxidase) activity, polyphenol compounds] in concentrated apple juice during 90 days storage. Considering color value (L value, $\Delta$E), absorbance at 420 nm, concentrated apple juice during 90 days storage. Considering color the effect of browning inhibition. According to the storage period, the changes of nonenzymatic factors in concentrated apple juice added with browning inhibitors were similar to those in control (concentrated apple juice without browning inhibitors), which were the decreased of sucrose(0.24~0.35% at 90 days), the slight increase of glucose and fructose, the decrease of total amino acid (530.4~573.1 mg/10g at 90 days), same value of A.A. at 90 days (38.5~78.6 mg/100g), and the increase of HMF (27.8~30.6 mg/100g at 90 days). On the contrary, enzymatic browning factors were significantly inhibited in concentrated apple juice added with PVPP, judging from the slow increase of PRO activity and the significant decrease of initial value in polyphenol compounds (especially chlorogenic acid). These results suggest that PVPP plays an important role as enzymatic browning inhibitor, that is, a scavenger of polyphenol compounds by adsorption in concentrated apple juice.

• Composites Research
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• v.14 no.3
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• pp.10-17
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• 2001

A reseach was peformed to develop composite pressure vessels in conjunction with design, fabrication, and test. Fiber pattern and angels were decided by CADFIL software and they were [$liner/15^{\circ}/15^{\circ}/90^{\circ}/18^{\circ}/90^{\circ}/21^{\circ}/21^{\circ}/90^{\circ}$]. Fabrication of bottles were done by 5-axis filament winding machine. During fabrication fiber optic sensors were embedded to measure the strain at points when internal pressure was applied by water pump. Conventional strain gage instrumentation showed the stable test results. The test results were compared to finite element analysis results and they were close each other in strain values. One can see the successful design and fabrication of single boss composite vessels.