• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.1478-1479
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• 2007

본 연구는 교류전압 인가시 제조공기(I-Air)의 온도(T)의 변화($+10[^{\circ}C{\sim}-30[^{\circ}C]$)에 따른 절연특성을 구명하였다. 절연특성은 GIS모의 챔버 주입 압력(P)과 비례하는 특성을 보였으나 T가 저하되면서 그 절연특성이 감소하는 경향을 보이지 않고 오히려 증가하는 구간이 일부 존재 하였다. 그리고 챔버내 P의 크기가 클수록 T저하에 따른 P감소율이 더 커졌으며, 절연파괴전압($V_B$)감소폭은 8[atm]에서 가장 큰 변화를 보였으며 4, 6, 2기압 순으로 변화를 보였다.

• Herbal Formula Science
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• v.21 no.1
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• pp.161-176
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• 2013

Objectives : To clarify the anti-arthritic activity of Ostericum koreanum Maxim. (OS) plus Aralia continentalis Kitagawa (AC) in vivo. Methods : All mice were immunized with bovine type II collagen. After a second collagen immunization, mice were treated with OS plus AC once a day for 7 weeks. Oral administration of OS plus AC (200 or 50 mg/kg) significantly suppressed the progression of CIA, which extend is comparable to that of methotrexate (MTX, 0.3 mg/kg), a positive control. The severity of arthritis within the knee joints was evaluated by histological assessment of cartilage destruction and pannus formation. Results : Administration of OS plus AC significantly suppressed the progression of CIA and inhibited the production of TNF-${\alpha}$ and IL-6 in serum. The erosion of cartilage was dramatically reduced in mouse knees after treatment with OS plus AC. In conclusion, our results demonstrates that OS plus AC significantly suppressed the progression of CIA and that this action was characterized by the decreased production of IL-6, IFN-${\gamma}$ and collagen II specific antibody in serum, CD3+CD69+ T cells, MHC class II+/CD11c+ (in DLN), CD11b+Gr-1+ cells (in PBMC), CD11b +Gr-1+ cells, B220+/CD23+ (in paw joint). Conclusions : The the levels of IFN-${\gamma}$ in the culture supernatant of splenocytes stimulated with CD3/CD28 or collagen were dramatically decreased, while those of IL-4 was increased. In the serum of OS and AC-treated mice, the levels of IgM RA factor were decreased.

• Journal of Practical Engineering Education
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• v.13 no.2
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• pp.327-332
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• 2021

Materials used for education include SM20C, Al6061, and acrylic. SM20C materials are used a lot in certification tests and functional competitions as carbon steel, but they are also used in industrial sites. Al6061 is said to be a material that produces a lot of tools because it has lower hardness than carbon steel and is highly flexible. When practical guidance is given to students using acrylic materials, it is a material that causes vibration and tool damage due to excessive cutting. In this process, we examine how impact on the 5-axis equipment 2NC head can affect precision control. The weakest part of a five-axis equipment is the head that controls the AC axis. In the event of precision and cumulative tolerances in this area, the precision of all products is reduced. Thus, a key part of the 2NC head, the spindle housing was carried out using Al7075 T6 (U.S. Alcoasa) material and the entire body using FCD450 (spherical graphite cast iron). In the vibration and cutting process acting on these two materials, the analysis was carried out to determine the value of applying the force as a finite element analysis under extreme conditions. We hope that using these analytical data will help students see and understand the structure of 5-axis machining rather than 5-axis cutting.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.4
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• pp.1471-1477
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• 2015

Background: Adding taxanes to adjuvant antracycline and cyclophosphamide (AC) in combination may provide significant improvement in node-positive and high risk node-negative breast cancer (BC) patients. However, the optimal dose and the role of dose-dense (DD) chemotherapy have yet to be determined. The aim of this study was to compare the efficacy of a DD paclitaxel (P)-AC combination with conventional weekly P-AC or docetaxel D-AC combinations in patients with node-positive breast cancer. Materials and Methods: Newly diagnosed 280 node-positive BC patients diagnosed from 1998 to 2013 in three clinics were retrospectively analyzed. Demographic and medical data were collected from the medical charts. Patients were categorized to 3 groups according to treatment arms: arm A, ddAC-P; arm B, weekly P and AC combination; and arm C; T and AC combination. Adjuvant trastuzumab was added for HER2-positive patients. Kaplan-Meier survival analysis was carried out for disease free survival (DFS) and overall survival (OS). The log-rank test was used to examine the statistical significance of the differences observed between the groups. Two-sided P values <0.05 were considered statistically significant. Results: Of the total of 280 patients, 101 were in arm A, 114 in arm B and 65 in arm C.The median ages were 49, 50 and 46, respectively (p=0.11). Median follow-up was 39 (3-193) months. Stage, lymphovascular and perineural invasion, receptor patern, and menopausal status were similar in the 3 treatment arms, but HER2 positivity was significantly lower in arm A, compared to arms B and C (25.7%, 53.1%, 41.5% in arms A, B and C, respectively; p<0.001). Also grade 3 tumors were significantly less frequent in treatment arm A compared to arm B and C (27.3%, 56.8% and 49.2%, respectively, p=0.01). Afterunivariate and multivariate analysis were performed, 3-year DFS rates were 89%, 81%, and 75%, respectively (p=0.12) and three year OS rates were 96.6%, 89%, and 75% (p=0.62). Conclusions: In this study, no significant difference was found between adjuvant dose dense and conventional taxane treatment regimens.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.8
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• pp.3101-3109
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• 2015

Background: Methylenetetrahydrofolate reductase (MTHFR) is involved in amino acid synthesis and DNA function. Two common polymorphisms are reported, C677T and A1298C, that are implicated in a number of human diseases, including cancer. Objective: The association between MTHFR C677T and A1298C genotype and haplotype frequencies in risk for lung cancer (LC) was investigated in the Jordanian population. Materials and Methods: A total of 98 LC cases were studied for MTHFR C677T and A1298C polymorphisms, compared to 89 controls taken from the general population, employing the PCR-RFLP technique. Results: The frequency of the genotypes of MTHFR C677T among Jordanians was: CC, 59.6%, CT, 33%; and TT, 7.4% among LC cases and 49.4%, 40.2% and 10.3% among controls. No significant association was detected between genetic polymorphism at this site and LC. At MTHFR A12987C, the genotype distribution was AA, 29.5%; AC, 45.3%, and CC 25.3% among LC cases and 36.8%, 50.6% and 12.6% among controls. Carriers of the CC genotype were more likely to have LC (OR=2.5; 95%CI: 1.04-6; p=0.039) as compared to AA carriers. Smokers and males with the CC genotype were 9.9 and 6.7 times more likely to have LC, respectively ($OR_{smokers}=9.9$; 95%CI: 1.2-84.5, p=0.018; $OR_{men}=6.6$; 95%CI: 1.7-26.2, p=0.005). Haplotype analysis of MTHFR polymorphism at the two loci showed differential distribution of the CC haplotype (677C-1298C) between cases and controls. The CC haplotype was associated with an increased risk for lung cancer (OR=1.6; 95% CI: 1.03-2.4, p=0.037). Conclusions: The genetic polymorphism of MTHFR at 1298 and the CC haplotype (risk is apparently lower with the C allele at position 677) may modulate the risk for LC development among the Jordanian population. Risk associated with the 1298C allele is increased in smokers and in males. The results indicate that a critical gene involved in folate metabolism plays a modifying role in lung cancer risk, at least in the Jordanian population.

• Corrosion Science and Technology
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• v.17 no.4
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• pp.166-175
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• 2018

In this study, the electrochemical properties of CP-Ti (commercially pure titanium) and Ti-64 (Ti-6Al-4V) were evaluated and the effect of hydrofluoric acid on corrosion resistance and electrochemical properties was elucidated. Additive manufactured materials were made by DMT (Directed Metal Tooling) method. Samples were heat-treated for 1 hour at $760^{\circ}C$ and then air cooled. Surface morphologies were studied by optical microscope and SEM. Electrochemical properties were evaluated by anodic polarization method and AC-impedance measurement. The oxide film formed on the surface was analyzed using an XPS. The addition of HF led to an increase in the passive current density and critical current density and decreased the polarization resistance regardless of the alloys employed. Based on the composition of the oxide film, the compositional difference observed by the addition of HF was little, regardless of the nature of alloys. The Warburg impedance obtained by AC-impedance measurement indicates the dissolution of the constituents of CP-Ti and Ti-64 through a porous oxide film.

• The Journal of the Petrological Society of Korea
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• v.3 no.3
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• pp.196-219
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• 1994

Granulite complexes in northern (the Nangnim block), eastern (ther Kimchaek zone of the Macheonryong belt) and southern (separate windows among upper Proterozoic structure such as the Wonsan, Nampo and Haeju granulites) parts of the Northern Korea are studied. Multistage deformations, metamorphic and migmatitic events, and granite formations are recognized in these granulite complexes. Mineral thermobarometry and fluid inclusion investigationss are used to establish the P-T evolutionary trends during prograde and retrograde metamorphic events. The peak metamorphism of granulites is characterized by temperature near $800^{\circ}C$ and pressure near 5.5-6 kb. Retrograde evolution includes cooling at constant pressure or with variable pressure ranging up to 7-8 kb. This P-T change corresponds to the transition from high to moderate or low geothermal gradient. The subsequent cooling is ac-companied by significant decompression to 3-4 kb.

• Animal cells and systems
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• v.13 no.4
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• pp.429-437
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• 2009

The control mechanism of gonadotropin-releasing hormone (GnRH) on gonadotropin (GTH) release was studied using cultured pituitary cell or cultured whole pituitary obtained from Testosterone (T) treated and control immature rainbow trout. The release of FSH was not changed by salmon type GnRH (sGnRH), chiken-II type (cGnRH-II), GnRH analogue ([des-$Gly^{10}D-Ala^6$] GnRH ethylamide) and GnRH antagonist ([Ac-3, 4-dehydro-$Pro^1$, D-p-F-$Phe^2$, D-$Trp^{3,6}$] GnRH) in cultured pituitary cells of T-treated and control fish. Indeed, FSH release was not also altered by sGnRH in cultured whole pituitary. All tested drugs had no effect on the release of LH in both culture systems of control fish. The levels of LH, in contrast, such as the pituitary content, basal release and responsiveness to GnRH were increased by T administration in both culture systems. In addition, the release of LH in response to sGnRH or cGnRH-II induced in a dose-dependent manner from cultured pituitary cells of T-treated fish, but which is not significantly different between in both GnRH at the concentration examined. Indeed, LH release was also increased by sGnRH in cultured whole pituitary of T-treated fish. GnRH antagonist suppressed the release of LH by sGnRH ($10^{-8}\;M$) and GnRH analogue ($10^{-8}\;M$) stimulation in a dose-dependent manner from cultured pituitary cells of T-treated fish, and which were totally inhibited by $10^{-7}\;M$ GnRH antagonist. These results indicate that the sensitivity of pituitary cells to GnRH is elevated probably through the T treatment, and that GnRH is involved in the regulation of LH release. GnRH-stimulated LH release is inhibited by GnRH antagonist in a dose-dependent manner. The effects of gonadal steroids on FSH levels are less clear.

• Proceedings of the Korean Society of Toxicology Conference
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• 1998.10a
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• pp.36-36
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• 1998

Tumorigenicity of benzo(a)pyrene (BP) and benzo(a)pyrene diol epoxides ((+)BPDE-1, (-)BPDE-1) was investigated in transgenic TG-AC mice carrying v-Ha-ras oncogene fused to the promoter of the mouse embryonic a-like, z-globin gene. Animals were topically treated twice per week for 25weeks with BPDE (10$\mu$g/mouse) and BP (10, 20, 40$\mu$g/mouse). In addition, animals were treated with BPDE or BP (initiated) followed by TPA (2$\times$2.5$\mu$g/week, for 4 weeks) for promotion study. In the continuous treatment of BPDE or BP, animals treated with 40$\mu$g BP showed $100\%$ tumor response after 20 weeks, $40\%$ of mice for 20$\mu$g BP, and $20\%$ for (+)BPDE-1, but (-)BPDE-1 and 10$\mu$g BP did not show any tumor response. After 25 weeks, most tumors turned out to be carcinomas in animals treated with 40$\mu$g BP. In BPDE or BP/TPA Initiation-promotion study, papilloma response occurred earlier (6 weeks after TPA treatment) than in continuously treated animals with BPDE or BP. RT-PCR assay for transgene expression showed that BP or BPOE was not transgene dependent in its tumorigenicity, but TPA was. Several Cytokine genes(TGF-a, TNF-a) and c-myc gene expressions were monitored in skin tissues during BP carcinogenesis. In early stage of BP treatment, the gene expressions were elevated(c-myc,TGF-a) or unchanged(TNF-a) compared to control, but the levels were gradually decreased during both middle and late stages of cacinogenesis, Gene expression levels of skin papillomas in acetone initiated-TPA promoted animals were close to those of middle stage or between middle and late stages. i-NOS was also highly expressed in carcinoma and papilloma, These data suggest that transgene expressions of TG-AC mice were not dependent on BP carcinogenesis and that TG-AC mice were more sensitive to TPA regardless of types of initiators. In addition, genes(TGF-a, c-myc, TNF-a, i-NOS) were modulated in the skin during BP cacinogenesis or TPA promotion.

• Journal of Magnetics
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• v.10 no.3
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• pp.84-88
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• 2005

Nanoparticles $Ni_{0.7}Zn_{0.3}Fe_2O_4$ is fabricated by a sol-gel method. The magnetic and structural properties of powders were investigated with XRD, SEM, $M\ddot{o}ssbauer$ spectroscopy, and VSM. $Ni_{0.7}Zn_{0.3}Fe_2O_4$ powders annealed at $300^{\circ}C$ have a spinel structure and behaved superparamagnetically. The estimated size of $Ni_{0.7}Zn_{0.3}Fe_2O_4$ nanoparticle is about 11 nm. $Ni_{0.7}Zn_{0.3}Fe_2O_4$ annealed at 400 and $500^{\circ}C$ has a typical spinel structure and is ferrimagnetic in nature. The isomer shifts indicate that the iron ions were ferric at the tetrahedral (A) and the octahedral (B). Blocking temperature $(T_B)\;of\;Ni_{0.7}Zn_{0.3}Fe_2O_4$ nanoparticle is about 260 K. The magnetic anisotropy constant of $Ni_{0.7}Zn_{0.3}Fe_2O_4$ annealed $300^{\circ}C$ were calculated to be $1.7X10^6\;ergs/cm^3$. Also, temperature of the sample increased up to $43^{\circ}C$ within 7 minutes under AC magnetic field of 7 MHz.