• Asian Pacific Journal of Cancer Prevention
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• 제17권5호
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• pp.2453-2457
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• 2016

Background: Dysregulation of HSP90 gene expression is known to take place in breast cancer. Here we used D,L-lactic-co-glycolic acid-polyethylene glycol-17-dimethylaminoethylamino-17-demethoxy geldanamycin (PLGA-PEG-17DMAG) complexes and free 17-DMAG to inhibit the expression of HSP90 gene in the T47D breast cancer cell line. The purpose was to determine whether nanoencapsulating 17DMAG improves the anti-cancer effects as compared to free 17DMAG. Materials and Methods: The T47D breast cancer cell line was grown in RPMI 1640 supplemented with 10% FBS. Encapsulation of 17DMAG was conducted through a double emulsion method and properties of copolymers were characterized by Fourier transform infrared spectroscopy and H nuclear magnetic resonance spectroscopy. Assessment of drug cytotoxicity was by MTT assay. After treatment of T47D cells with a given amount of drug, RNA was extracted and cDNA was synthesized. In order to assess HSP90 gene expression, real-time PCR was performed. Results: Taking into account drug load, IC50 was significant decreased in nanocapsulated 17DMAG in comparison with free 17DMAG. This finding was associated with decrease of HSP90 gene expression. Conclusions: PLGA-PEG-17DMAG complexes can be more effective than free 17DMAG in down-regulating of HSP90 expression, at the saesm time exerting more potent cytotoxic effects. Therefore, PLGA-PEG could be a superior carrier for this type of hydrophobic agent.

• 조명전기설비학회논문지
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• 제13권3호
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• pp.7-13
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• 1999

본 논문에서는 70[W] 메탈해라이드등을 위한 저전력 고주파 점등방식의 전자식 안정기가 연구되었다. 입력전원은 220[V]의 교류전압이 사용되며 전력처리시스템에 의하여 고주파의 교류전압으로 변환된다. 음향적 공명현상에 의한 등의 물리적 파손을 방징하기 위하여 제안된 안정기는 등에 22[kHz]의 교류전압을 공급한다. 이는 시동시간이나 소비전력감소와 같은 유용한 결과를 나타낸다. 실험결과, 등의 관전압과 관전류는 각각 피크치 155[V]와 0.6[A]이었다. 등의 전광속은 입력전력 82[W]에 대하여 5300[lm]이었으며 발광효율은 64.63[lm/w]를 나타내었다. 평균 완전점등시간과 재점등시간은 각각 3.9분과 4.5분을 나타냈었다.

• Parasites, Hosts and Diseases
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• 제22권1호
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• pp.127-134
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• 1984

As a series of studies to clarify clonorchicidal substances in body surface mucus of some freshwater fishes, the substance in the epidermal mucus of Cyprinus carpio was isolated by silica gel column and thin layer chromatography and analysed for its chemical nature. Wormicidal trial was done in vitro, and the results obtained are summarized as follows: The mucus was extracted by ethyl ether and separated into 4 fractions by column chromatography using benzene as solvent. The second fraction with yellowish red colour among them showed the strongest clonorchicidal effect. The yellowish red fraction obtained by column chromatography was then fractionated into 6 spots by thin layer chromatography with petrol/ etherjchloroform (30/70, v/v), and the Rf. 0.714 spot among the 6 spots showed the strongest effect. The Rf. 0.714 spot was further fractionated into 6 spots by thin layer chromatography with benzene/acetone (90/10, vlv), and the Rf. 0.800 spot among the later 6 spots revealed the strongest effect. The Rf. 0.800 spot was chromatographed on column with benzene and 2 fractions were obtained. The second fraction of light brown colour represented the final purified fraction. By these Purification Procedures, clonorchicidal substance was Purified 15-fold with 0.035 yield from the mucus of C. carpio, and 10mg of the final fraction killed the cercaria in 26 min, the metacercaria in 115 min, and the adult in 443 min. Infra red and nuclear magnetic resonance spectrometric analysis of the purified substance revealed that the substance belongs to an ethyl ester of unsaturated fatty acid with 2 double bonds, 15 methylene groups and 1 methyl group.

• Journal of Chest Surgery
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• 제47권6호
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• pp.510-516
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• 2014

Background: Acute cerebral infarction is a major risk factor for postoperative neurologic complications in cardiac surgery. However, the outcomes associated with acute silent cerebral infarction (ASCI) have not been not well established. Few studies have reported the postoperative outcomes of these patients in light of preoperative Diffusion-weighted magnetic resonance imaging (DWI). We studied the postoperative neurologic outcomes of patients with preoperative ASCI detected by DWI. Methods: We retrospectively studied 32 patients with preoperative ASCI detected by DWI. None of the patients had preoperative neurologic symptoms. The mean age at operation was $68.8{\pm}9.5$ years. Five patients had previous histories of stroke. Four patients had been diagnosed with infective endocarditis. Single cerebral infarct lesions were detected in 16 patients, double lesions in 13, and multiple lesions (>5) in three. The median size of the infarct lesions was 4 mm (range, 2 to 25 mm). The operations of three of the 32 patients were delayed pending follow-up DWI studies. Results: There were two in-hospital mortalities. Neurologic complications also occurred in two patients. One patient developed extensive cerebral infarction unrelated to preoperative infarct lesions. One patient showed sustained delirium over one week but recovered completely without any neurologic deficits. In two patients, postoperative DWI confirmed that no significant changes had occurred in the lesions. Conclusion: Patients with preoperative ASCI showed excellent postoperative neurologic outcomes. Preoperative ASCI was not a risk factor for postoperative neurologic deterioration.

• 대한화학회지
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• 제19권4호
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• pp.233-239
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• 1975

세개의 二重結合에 衣하여 conjugate된 비대칭화합물 cis-2-bitenedialdioxime의 두 oxime group의 configuration을 溶媒, 溫度 및 濃度의 影響에 대한 NMR 硏究로서 決定하였다. 溶液狀態에서의 이 化合物은 $-35^{circ}$∼$-95^{\circ}C$의 溫度條件下에서는 항상 "syn-syn" configuration으로 存在함을 알았다. 또한 이 化合物의 oxime group과 溶媒사이의 水素結合의 相對的强度와 溫度 및 濃度에 의 피리딘의 考察하고 몇가지 水素結合의 모델을 提示하였다. 特히 피리딘溶媒 속에서는 水素結合은 한 영향을 窒素가 갖고 있는 非共有電子雙에 衣해서 일어나지 않고, oxime 의 hydroxyl proton과 피리딘의 $\pi$軌道函數 사이에 形成되는 $\pi$-착물의 結果임을 알았다.

• 한국철도학회논문집
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• 제9권6호
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• pp.761-765
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• 2006

At present, harmonic currents cause serious problems in power conversion system using the semiconductor switching device. Also some of the conversion system provokes harmonic currents against to the main power supply system and causes hindrances for the system. Main power impedance of the traditional LC passive filter method, influences on the filter characteristics and amplifies the harmonics when resonance phenomenon is occurred. And the traditional existing 2 level inverter systems show the limit in capacity of voltage and current in case of occurring sudden load change. So, to solve this problem active filter which uses cascaded H-bridge multi level inverter has been designed and ex-filter system circuits were totally investigated. With multi level active filtering system not only the size of filter but also the size of filter for transformer can be reduced by half and so as to the weight, while the capacity of inverter can be double sized and wave forms can be compensated exactly and precisely. Also by the benefit of the increase in rating capacity, the various currents owing to the load fluctuation can be dealt more steadily. In order to simulate the wave form of harmonics based on the measured data on the AC 25kV high speed Domestic Commercial railway, it was simulated with PSCAD/EMTDC and PSIM. Based on the results of this demonstration, the power supply system and inverter system would be more stable and also promoting its efficiency.

• 한국전자파학회논문지
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• 제14권8호
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• pp.855-862
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• 2003

본 논문에서 제안하는 안테나는 기존 내장형 안테나의 일종인 PIFA의 단점으로 협대역 문제를 해결하기 위하여, 복사 소자와 접지면 사이에 단락판을 위치시키는 변형된 안테나 형태인 PIFA(Planar Inverted-FAntenna) 구조를 제안하였다. 또한 보다 넓은 대역폭을 가지도록 방사 패치에 톱니모양의 perturbation을 주었다. 제안된 방식으로 단말기에 내장형으로 사용하기 위하여 안테나의 높이(h=0.015λ)를 최소한으로 하여 원하는 대역폭(5.2 %)을 얻었다. slim형으로 하기 위해 안테나의 특성을 급전위치(Yf, Zf), 단락 스트립(Short plate)의 위치 (Zs), 폭 (Ws), perturbation폭(w), 길이(d), 단락 스트립 높이(h), 유전율 변화($\varepsilon$$_{r}$)가 안테나에 어떤 변화를 미치는지를 조사하였다. 또한 기존 PIFA 안테나와의 대역을 비교하고, 제안된 패턴을 H, E plane으로 나타내었다. 논문의 객관성을 입증하기 위하여 FIM(Finite Integration Method) 방식에 기반인 MWS(Microwave Studio) 소프트웨어를 이용하여 Simulation 하였으며, 각각의 구조 파라미터 변화에 따른 안테나 특성을 분석하였다. 그리고 실제 제작한 안테나의 실험결과와 비교하여 증명한 결과, 제안된 방식의 PIFA 안테나 실용화가 가능성을 확인하였다..

• 한국광학회지
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• 제20권4호
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• pp.249-254
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• 2009

본 연구에서는 파라핀이 코팅된 Rb원자 증기 셀을 이용하여 $^{87}Rb$ $D_1$전이선의 Hanle스펙트럼과 비선형 광자기 효과 신호를 조사하였다. 파라핀 코팅 증기 셀의 효과에 의한 좁은 스펙트럼 폭을 가진 영역과 순수 증기 셀에서 얻을 수 있는 넓은 스펙트럼폭을 가진 이중구조의 Hanle 스펙트럼을 관측할 수 있었다. 스펙트럼에 나타난 이중구조에서 좁은 선폭 영역의 선폭은 1 kHz로 측정되었고, 스펙트럼 크기는 전체 스펙트럼에 대해서 10%로 측정되었다. 또한, Hanle 스펙트럼에 대응되는 이중 미분형태의 비선형 광자기 신호를 관측하였으며, 기울기가 급격하게 변하는 비선형 광자기 신호의 기울기는 레이저의 출력이 $200{\mu}W$일 때 대략 10 mV/${\mu}T$였다.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2012년도 춘계학술발표대회
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• pp.110.1-110.1
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• 2012

Recently, advances in ZnO based oxide semiconductor materials have accelerated the development of thin-film transistors (TFTs), which are the building blocks for active matrix flat-panel displays including liquid crystal displays (LCD) and organic light-emitting diodes (OLED). However, the electrical performances of oxide semiconductors are significantly affected by interactions with the ambient atmosphere. Jeong et al. reported that the channel of the IGZO-TFT is very sensitive to water vapor adsorption. Thus, water vapor passivation layers are necessary for long-term current stability in the operation of the oxide-based TFTs. In the present work, $Al_2O_3$ and $TiO_2$ thin films were deposited on poly ether sulfon (PES) and $SnO_x$-based TFTs by electron cyclotron resonance atomic layer deposition (ECR-ALD). And enhancing the WVTR (water vapor transmission rate) characteristics, barrier layer structure was modified to $Al_2O_3/TiO_2$ layered structure. For example, $Al_2O_3$, $TiO_2$ single layer, $Al_2O_3/TiO_2$ double layer and $Al_2O_3/TiO_2/Al_2O_3/TiO_2$ multilayer were studied for enhancement of water vapor barrier properties. After thin film water vapor barrier deposited on PES substrate and $SnO_x$-based TFT, thin film permeation characteristics were three orders of magnitude smaller than that without water vapor barrier layer of PES substrate, stability of $SnO_x$-based TFT devices were significantly improved. Therefore, the results indicate that $Al_2O_3/TiO_2$ water vapor barrier layers are highly proper for use as a passivation layer in $SnO_x$-based TFT devices.

• 한국전산구조공학회논문집
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• 제15권4호
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• pp.693-702
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• 2002

본 연구에서는 고속철도 열차와 교량구조물의 상호작용에 의한 동적응답을 보다 정밀하게 분석하기 위해 3차원의 주행차량모형을 적용한 20량편성정밀 열차모형과 경부고속철도의 주교량 형식인 2경간 연속 PSC 박스거더교(2@40m)를 대강으로 3차원의 뼈대요소를 사용한 교량모형을 이용하여 철도교의 동적거동 해석 프로그램을 개발하였으며, 열차의 주행시험 결과와의 비교를 통해 개발된 프로그램의 타당성을 검증하였다. 또한 보다 효율적인 열차모형을 제시하기 위해 다양한 편성모형 및 하중모형의 조합에 따른 분석결과에 의하면 가장 무거운 KTX의 동력차를 대상으로 주행차량모형을 적용하고 나머지 차량들은 주행하중모형을 적용한 혼합모형이 효율적인 것으로 판단되었으며, 경부고속철도와 같이 복선구조의 교량인 경우에는 열차의 교행에 의해 증폭될 수 있는 교량의 동적응답 특성에 대한 체계적인 검토가 필요한 것으로 나타났다