• Transactions on Electrical and Electronic Materials
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• 제12권3호
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• pp.106-109
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• 2011

We investigated the etching characteristics of titanium nitride (TiN) thin film in $BCl_3$/Ar inductively coupled plasma. The etching parameters were the gas mixing ratio, radio frequency (RF) power, direct current (DC)-bias voltages and process pressures. The standard conditions were as follows: total flow rate = 20 sccm, RF power = 500 W, DC-bias voltage = -100 V, substrate temperature = $40^{\circ}C$, and process pressure = 15 mTorr. The maximum etch rate of TiN thin film and the selectivity of TiN to $Al_2O_3$ thin film were 54 nm/min and 0.79. The results of X-ray photoelectron spectroscopy showed no accumulation of etch byproducts from the etched surface of TiN thin film. The TiN film etch was dominated by the chemical etching with assistance by Ar sputtering in reactive ion etching mechanism, based on the experimental results.

• Asian Pacific Journal of Cancer Prevention
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• 제17권12호
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• pp.5185-5188
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• 2016

Objective: Targeted-drug-delivery based lipid nanoparticles has emerged as a new and effective approach in cancer chemotherapy. Here, we investigated the ability of folate-modified nanostructured lipid carriers (NLCs) to enhance letrozol (LTZ) efficacy in MCF-7 breast cancer cells. Methods: New formulations were evaluated regarding to particle size and scanning electron microscope (SEM) features. Anti-proliferative effects of LTZ loaded nanoparticles were examined by MTT assay. To understand molecular mechanisms of apoptosis and cell cycle progression, flow cytometric assays were applied. Results: Optimum size of nanoparticles was obtained in mean average of $98{\pm}7nm$ with a poly dispersity index (PDI) of 0.165. The IC50 value was achieved for LTZ was $2.2{\pm}0.2{\mu}M$. Folate-NLC-LTZ increased the percentage of apoptotic cells from 24.6% to 42.2% compared LTZ alone (p<0.05). Furthermore, LTZ loaded folate targeted NLCs caused marked accumulation of cells in the subG1 phase. Conclusion: Taken together, our results concluded that folate targeted LTZ can be considered as potential delivery system which may overcome limitations of clinical application of LTZ and improve drug efficacy in tumor tissue.

• 한국인지과학회:학술대회논문집
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• 한국인지과학회 2000년도 춘계 학술대회
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• pp.71-75
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• 2000

Conventional atom model must be criticized on the following four points. (1) Natural motions between positive and negative entities are not circular motions but linear going and returning ones, for examples sexual motion, tidal motion, day and night etc. (2) Potential energy generation was neglected when electron changes its orbit from outer one to inner one. The hv is the Kinetic energy of the photo-electron. The total energy difference between orbits comprises kinetic and potential energies. (3) The structure of the space must be taken into consideration because the properties of the electron do not change during the transition form outer orbit to inner one even though it produces photon. (4) Total energy conservation law applies to the energy flow between mind and matter because we daily experiences a interconnection between mind and body. New atomic model (the crystallizing $\pi$-bonding) was proposed in the journal of material processing technology since 1997 for the explanation of the mechanical behaviors in terms of physics. $\prod$-ray physics proved that the electrons can come out from in the nucleus and modern chemistry corresponds to the $\pi$-bonding by the nuclear electrons. The $\pi$-bonding structure of the protons outside the nucleus is that electrons move between protons of the different atoms. The perception step and the characteristic frequency in signal transduction is due to the accumulation of the $\pi$-rays outside fo the proton before their absorption to the nucleus.

• BMB Reports
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• 제43권9호
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• pp.599-603
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• 2010

Troglitazone is an anti-diabetic agent that improves hyperglycemia by reducing peripheral insulin resistance in type II diabetic patients. Troglitazone has been shown to cause growth inhibition of various normal and cancerous cells. However, the molecular mechanism by which troglitazone affects the growth of these cancer cells remains unclear. Here, we report that troglitazone treatment of Hep 3B human hepatocellular carcinoma cells resulted in dose-dependent growth inhibition. Analysis of cell cycle distribution by flow cytometry showed that the number of apoptotic cells was increased in a dose-dependent manner in response to troglitazone treatment. cDNA microarray analysis showed a number of differentially expressed genes in response to troglitazone. Among the upregulated genes, hypoxia-inducible factor 1 (HIF-1)-responsive RTP801 was induced in a dose-dependent manner. We also observed HIF-1 accumulation by immnocytochemistry after troglitazone treatment. These results strongly suggest that RTP801 might be involved in troglitazone-induced apoptosis in Hep 3B cells.

• 한국대기환경학회지
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• 제20권3호
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• pp.345-360
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• 2004

The late sea-breeze and its impacts on ozone distributions were investigated during April to September from 1998 to 2002, in the Busan metropolitan area (including surrounding areas) using the surface ozone concentrations (obtained at 9 monitoring sites), local meteorological variables (obtained near the shore), together with synoptic data. The urban scale ozone concentration was also simulated using the MM5/UAM-V to better understand the role of late sea-breeze in Busan. The results from observation study showed that most of the late sea-breeze occurred when weak offshore synoptic flow (northwesterly) suppressed development of sea - breeze, and the ozone concentration level and frequencies exceeding ozone standard increased with the onset time of sea breeze. We also found that the late sea-breeze clearly induces relatively weak wind speed and high temperature during the daytime As a result it enhances the photochemical ozone accumulation and delays the occurrence time of the averaged maximum ozone concentrations. The results of simulation for high ozone episode (24 August, 2001) by MM5/UAM -V revealed that the late sea-breeze interacted with weak offshore synoptic wind can contribute significantly to high ozone concentration in the coastal urban area. The simulated horizontal and vertical distribution of ozone concentration indicated that ozone can be accumulated over the sea under stagnant condition and return to the land in the late afternoon with the sea breeze, suggesting both the relationship between late sea-breeze and recirculation and the importance of late sea -breeze effects influencing severe ozone pollution in Busan.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2004년도 학술발표회
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• pp.557-562
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• 2004

A surface-piercing barrier model is presented for understanding morphological development in the sheltered region and investigating the main factors causing the severe accumulation. Surface-piercing structures like vertical barriers, surface docks and floating breakwaters are recently favored from the point of view of a marine scenario since they do not in general partition the natural sea. The numerical solutions are compared with experimental data on wave profiles and morphological change rates within a rectangular harbor of a constant depth protected by surface-piercing thin breakwaters as a simplified problem. Our numerical study involves several modules: 1) wave dynamics analyzed by a plane-wave approximation, 2) suspended sediment transport combined with sediment erosion-deposition model, and 3) concurrent morphological changes. Scattering waves are solved by using a plane wave method without inclusion of evanescent modes. Evanescent modes are only considered in predicting the reflection ratio against the vertical barrier and energy losses due to vortex shedding from the lower edge of plate are taken into account. A new relationship to relate the near-bed concentration to the depth-mean concentration is presented by analyzing the vertical structure of concentration. The numerical solutions were also compared with experimental data on morphological changes within a rectangular harbor of constant water depth. Through the numerical experiments, the vortex-induced flow appears to be not ignorable in predicting the morphological changes although the immersion depth of a plate is not deep.

• 설비공학논문집
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• 제7권1호
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• pp.161-170
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• 1995

This study is concerned with the numerical analysis of performance on fin-tube heat exchanger under frosting condition. In this work, tube-by-tube method using LMED is employed. The present results are compared with O'Neal's experimental and numerical results. A standard evaporator model with 2rows-2columns is selected to investigate the effects of the various parameters such as fin pitch, air flow velocity, and humidity. The results show that frost thickness and the amount of frost per unit area decrease as fin-pitch becomes narrower. In the meantime, frost thickness and accumulation rate increase with higher inlet air humidity. It is shown that heat transfer rate increases during 30minutes and then it decreases. Heat transfer rate and the amount of frost increase with air velocity, however frost thickness does not increase over a certain velocity.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2004년도 춘계학술대회 논문집 방전 플라즈마 유기절연재료 초전도 자성체연구회
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• pp.76-81
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• 2004

This paper presents the results of spectral analysis of leakage current waveforms on contaminated insulators under various fog and environment conditions(salt fog, clean fog, rain) The larger the leakage current during 200ms, the higer the power spectrum at 60Hz. For almost equal maximum current during 200ms, however, the spectrum at 60hz and the odd order harmonics increase emphatically when discharges occur continuously for several half-waves. If contaminated insulators suffers from high salt-density fog, the leakage current occurs with high crest value intermittently, results in the low spectrum. Analysis of leakage current data showed that this electrical activity was characterized by transient arcing behavior contaminants are deposited on the insulator surface during salt fog tests. This provides a path for the leakage current to flow along the surface of the insulator. It is important to have an indication of the pollution accumulation in order to evulate the test performance of a particular insulator. If the drop in surface resistivity is severe enough, then the leakage current may escalate into s service interrupting flashover that degrade power quality.

• 상하수도학회지
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• 제13권1호
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• pp.51-60
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• 1999

An intermittently-aerated, intermittently-decanted single-reactor process (KIDEA process : KIST intermittently decanted extended aeration process) was applied for nitrogen removal from wastewater. Synthetic wastewater with chemical oxygen demand (COD): nitrogen (N) ratio of approximately 5.25: 1 was used. The average COD removal efficiency reached above 95%, and under optimal conditions nitrogen removal efficiency also reached above 90%. This process consisted of 72 minute aeration, 48 minute settling and 24 minute effluent decanting with continuous feeding of influent wastewater from the bottom of the reactor, and did not require a separate anoxic mixing-phase. In this process, nitritation ($1^{st}$ step of nitrification) was induced but nitratation($2^{nd}$ step of nitrification) was suppressed. Main factors responsible for the accumulation of nitrite ion in the experimental condition were free ammonium and dissolved oxygen. This condition of nitrite build-up accelerated by continuous feed flow in the bottom of the KIDEA reactor because of high concentration of ammonia nitrogen in the influent. This research provides one of answers to control nitrate build-up.

• 한국식품영양과학회지
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• 제20권2호
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• pp.187-196
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• 1991

Aging is the progressive accumulation of changes with time associated with responsible for the ever-increasing susceptibility to disease and death which accompanies advancing age. Lipid peroxides easily produced in the membrane system by the chain reaction of free radicals which occurred from various environmental factors. The amount of lipid peroxides produced in biological system increased with aging process, and lipid peroxidation damages involved in aging process and pathological disorders. Although lipid peroxides have such deleterious effects on the organisms, there are numerous substances and mechanisms which prevent the reaction of peroxide formation and protect the subject from its toxicity. This review provides an overview of how does lipid peroxidation of unsaturated lipids take place by free radical, and what is the intervention of lipid peroxides in pathogenesis of some human diseases, and also how does food restriction influences the aging process and various pathological disorders. The major focus of this paper is to review the evidence indicating that food restriction retards the aging process, and possible mechanisms of its actions. Therefore, it discussed the effects of age and food restriction on life-span, membrane yield, lipid peroxidation, fatty acid composition and peroxidizability, cholesterol and triglyceride levels, prostaglasndin and thromboxane synthesis, which may be concerned with blood flow, membrane fluidity, homeostasis and glomerular filtration rate in living body.