• Asian Pacific Journal of Cancer Prevention
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• 제15권4호
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• pp.1745-1749
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• 2014

Background: Platycodin D (PD), a triterpenoid saponin isolated from the Chinese medicinal herb Platycodonis radix, possesses anti-cancer effects in several cancer cell lines. The aim of this study was to evaluate its anticancer activities in hepatocellular carcinoma cells. Materials and Methods: MTT and colony formation assays were performed to evaluate cell proliferation, along with flow cytometry and Western blotting for apoptosis. Cell adhesion was tested by observing cellular morphology under a microscope, while the transwell assay was employed to investigate the cell migration and invasion. Results: PD concentration-dependently inhibited cell proliferation in both HepG2 and Hep3B cells, and significantly suppressed colony formation and induced apoptosis in HepG2 cells. The protein levels of cleaved poly ADP-ribose polymerase (PARP) and Bax were up-regulated while that of survivin was down-regulated after treatment with PD. Moreover, PD not only obviously suppressed the adhesion of HepG2 cells to Matrigel, but also remarkably depressed their migration and invasion induced by 12-O-tetradecanoylphorbol 13-acetate (TPA). Conclusions: PD presents anti-cancer potential in hepatocellular carcinoma cells via inducing apoptosis, and inhibiting cell adhesion, migration and invasion, indicating promising features as a lead compound for anti-cancer agent development.

• 한국임상약학회지
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• 제24권3호
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• pp.206-212
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• 2014

Objectives: This was to evaluate the current usage of three erythropoietin stimulating agents (ESA) and their efficacy for management of anemia in peritoneal dialysis (PD) patients with chronic kidney disease. Methods: It was a retrospective comparative study through review of electronic medical records of chronic kidney disease patients undergoing PD at a tertiary teaching hospital from January 1998 to June 2013. Results: Average administration frequency was 1.66 times/week in EPO group, 0.75 times/week in DA group, and 0.19 times/week in MPG-EPO group. At the first 4 weeks, there were significant differences in mean hemoglobin levels between EPO and DA groups ($9.25{\pm}1.28g/dL$, $10.02{\pm}0.95g/dL$ each, p = 0.018) and also in hemoglobin response rates (10.0%, 45.2% each, p = 0.008), but since after 4 week, there had been no significant differences. There also showed no significant differences in achievement of hemoglobin target between the two groups. When converted to MPG-EPO in EPO/DA groups, there showed a slight increase in hemoglobin levels of both groups. MPG-EPO was the highest compared with two other drugs by the average cost based on the average weekly dose. Conclusion: EPO, DA, and MPG-EPO showed similar effects in treatment of anemia of PD patients based on hemoglobin target range (11.0~12.0 g/dL) which NFK-K/DOQI guidelines suggest. Though the average cost of MPG-EPO was higher than the other two drugs, the number of PD patients using MPG-EPO has increased and it is thought that long half-life and low administration frequency of MPG-EPO have improved the compliance of PD patients who have to self-administrate.

• Annals of Clinical Neurophysiology
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• 제11권1호
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• pp.9-15
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• 2009

Background: To investigate the differences of locomotor dynamics between Parkinson's disease (PD) patients with tremor dominant symptom and patients with postural instability dominant symptom. Methods: 66 subjects with PD were classified into two subgroups, tremor-dominant group and postural instability and gait disorder group by Unified Parkinson's disease rating scale (UPDRS). The spatial, temporal and electrodynamic gait parameters were recorded automatically using computerized 3-D motion analysis system with electrogoniometer. Results: There was no significant difference in cadence, pelvic tilt range, hip flexion range, knee flexion range and ankle dorsiflexion range. Postural instability and gait disorder group showed decreased gait velocity, short stride length, decreased range of motion in pelvic obliquity, pelvic rotation and ankle plantar flexion. Conclusions: There was meaningful difference in locomotor dynamics between Parkinson's disease(PD) patients with tremor dominant symptom and patients with postural instability dominant symptom.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1997년도 하계학술대회 논문집 C
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• pp.1222-1225
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• 1997

A gaseous oxygen detector has been developed in a configuration of Pd-$SnO_x$-$Si_3N_4$-$SiO_2$-Si-Al with highly resistive $SnO_x$ layer as the oxygen adsorptive element. In this paper, we present the characteristics of the device in response to oxygen adsoption/desorption under applied d.c. bias. Experimental results showed that the oxygen adsorptive response by the device was reduced significantly under a positive gate bias, for all experimental regions of $O_2$ partial pressure. On the other hand, the application of a negative gate bias increased the device's adsorptive response of oxgyen. A device model concerning this electroadsorption/desorption behavior of the device is provided.

• Journal of Magnetics
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• 제5권3호
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• pp.76-80
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• 2000

Soft x-ray standing waves produced by a multilayer interference substrate add depth-sensitivity to magnetic circular dichroism to resolve changes in Co magnetism across a 10${\AA}$ distance from the Co center to the Co-Pd interface of a Pd/Co/Pd trilayer having in-plane magnetization. Large enhancements of in-plane orbital and spin magnetic moments, as well as the number of d holes, are strongly localized in a thin interface layer. These results provide new insight into the phenomenon of magnetic anisotropy at buried interfaces, and suggest a broad applicability of such standing wave measurements to interface magnetism studies.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 하계학술대회 논문집 C
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• pp.1843-1844
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• 2003

154 kV급 가스절연개폐장치(GIS)용dp 장착할 수 있는 내장형 극초단파 (UHF) 부분방전(PD) 센서의 고주파 특성을 전산모사 하였다. UHF PD 센서는 일종의 광대역 안테나이므로 3차원 전자기장 해석도구를 활용하여 주파수 또는 시간 영역에서 고주파특성을 해석하였다. 센서의 구조를 결정하는 센서장착용 구멍과 센서의 크기를 변수로 조절하면서 내장형 UHF PD 센서의 특성을 해석 하였다. 센서가 장착되는 구멍의 크기와 센서의 구조변화에 따라 반사손실이 변화하였으며 GIS의 전파 mode의 영향을 받는다.

• 한국철도학회논문집
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• 제12권2호
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• pp.249-253
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• 2009

본 논문에서는 부분방전 측정에 의한 하이브리드 차량용 견인전동기의 절연평가에 대하여 기술하였다. 부분방전법은 효과적인 비파괴시험으로 저압용 전기전자기기의 절연성능평가에 사용되어 왔다. 부분방전 측정시스템은 결합회로망, 저잡음 증폭회로 및 주변 전자회로로 구성되며, 주변 잡음의 영향을 최소화하기 위하여 차폐함내에 설치하였다. 교정실험으로부터 부분방전 측정시스템의 주파수 대역은 $1[MHz]{\sim}30[MHz]$ (-3[dB]), 감도는 19[mV/pC]로 평가되었다. 기사용 전동기와 신품 전동기에서 방전개시전압(DIV)과 겉보기 전하량(q)을 측정한 결과, 기사용 전동기의 방전개시전압은 $1,100[V_{rms}]$, 겉보기 전하량은 105[pC], 신품 전동기에서의 방전개시전압은 $1,400[V_{rms}]$, 겉보기 전하량은 84[pC]이었다. 방전개시전압과 전하량을 비교함으로써 견인전동기의 절연상태를 평가할 수 있었다.

• 대한화학회지
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• 제66권6호
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• pp.442-450
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• 2022

생리학적 활성을 보일 것으로 기대되는 다양한 pyrrolopyrimidine 유도체를 O-arylation과 Suzuki 짝지움 반응을 통해 합성하였다. 금속 촉매 Cu를 사용하고 마이크로파 조사 조건에서O-arylation을 성공적으로 진행하여 pyrrolo[3,2-d]pyrimidine의 4번 위치에 phenol기를 도입할 수 있었다. 또한, 금속촉매 Pd를 사용하는 Suzuki짝지움 반응도 마이크로파를 사용하여 pyrrolo[3,2-d]pyrimidine의 4번 위치에 aryl 기를 도입할 수 있었다. 유도체의 다양화를 위한 반응 조건으로 마이크로파를 사용함으로써 긴 반응 시간과 열전달 효율성 문제를 가지고 있는 전통적인 열 반응의 단점을 획기적으로 극복할 수 있었다. 본 연구 결과는 신약개발 연구에 중요한 역할을 할 것으로 기대되는 pyrrolo[3,2-d]pyrimidine 유도체를 다양화하는데 사용할 수 있다.

• 한국전자파학회논문지
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• 제17권10호
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• pp.959-966
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• 2006

본 논문은 다이플렉서를 이용하여 디지털 셀룰라 대역($f_o$=880 MHz)과 IMT-2000 대역($f_o$=2,140 MHz) 기지국에서 동시에 사용 가능한 이중 대역 전치 왜곡 선형 전력 증폭기(Predistortion Linear Power Amplifier: PD LPA)의 설계 방법을 제시하였다. 입 출력단에 사용된 다이플렉서는 결함 접지 구조(Defected Ground Structure: DGS)를 이용한 저역 통과 여파기와 높은 Q값을 갖는 캐패시터와 마이크로 스트립 스터브를 이용한 고역 통과 여파기로 이루어져 있다. 입출력 반사 계수 특성을 좋게 하기 위하여 3 dB 하이브리드 결합기를 이용한 반사형 타입의 전치 왜곡 선형화기를 설계하였다. IS-95 CDMA IFA 신호와 WCDMA IFA 신호를 이용하여 각 대역에서 제작된 이중 대역 전치 왜곡 선형 전력 증폭기의 인접 채널 누설비(Adjacent Channel Leakage Ratio: ACLR) 개선 정도를 측정한 결과 880 MHz 대역에서 약 10 dB, 2,140 MHz 대역에서 약 9.36 dB 개선되었다.

• Imaging Science in Dentistry
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• 제53권2호
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• pp.127-135
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• 2023

Purpose: This study assessed the intensity of artifacts produced by 2 metal posts, 2 cements, and different exposure parameters using 2 cone-beam computed tomography (CBCT) units. Materials and Methods: The sample was composed of 20 single-rooted premolars, divided into 4 groups: Ni-Cr/zinc phosphate, Ni-Cr/resin cement, Ag-Pd/zinc phosphate, and Ag-Pd/resin cement. Samples were scanned before and after post insertion and cementation using a CS9000 3D scanner with 4 exposure parameters (85/90 kV and 6.3/10 mA) and an i-CAT scanner with 120 kV and 5 mA. The presence of artifacts was assessed subjectively by 2 observers and objectively by a trained observer using ImageJ software. The Mann-Whitney, Wilcoxon, weighted kappa, and chi-square tests were used to assess data at a 95% confidence level(α<0.05). Results: In the subjective analyses, AgPd presented more hypodense and hyperdense lines than NiCr (P<0.05), and more hypodense halos were found using i-CAT (P<0.05) than using CS9000 3D. More hypodense halos, hypodense lines, and hyperdense lines were observed at 10 mA than at 6.3 mA (P<0.05). More hypodense halos were observed at 85 kV than at 90 kV (P<0.05). CS9000 3D presented more hypodense and hyperdense lines than i-CAT (P<0.05). In the objective analyses, AgPd presented higher percentages of hyperdense and hypodense artifacts than NiCr (P<0.05). Zinc phosphate cement presented higher hyperdense artifact percentages on CS9000 3D scans(P<0.05). CS9000 3D presented higher artifact percentages than i-CAT(P<0.05). Conclusion: High-atomic-number alloys, higher tube current, and lower tube voltage may increase the artifacts present in CBCT images.