• Title/Summary/Keyword: Pst

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Dry etching properties of PST thin films using chlorine-based inductively coupled plasma (Chlorine-based 유도결합 플라즈마를 이용한 PST 박막의 건식 식각 특성)

  • Kim, Gwan-Ha;Kim, Kyoung-Tae;Kim, Dong-Pyo;Lee, Cheol-In;Kim, Chang-Il
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2003.07a
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    • pp.400-403
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    • 2003
  • Etching characteristics of (Pb,Sr)$TiO_3$(PST) thin films were investigated using inductively coupled chlorine based plasma system as functions of gas mixing ratio, RF power and DC bias voltage. It was found that increasing of Ar content in gas mixture lead to sufficient increasing of etch rate and selectivity of PST to Pt. The maximum etch rate of PST film is $562\;{\AA}$/min and the selectivity of PST film to Pt is 0.8 at $Cl_2/(Cl_2+Ar)$ of 20 %. It was proposed that sputter etching is dominant etching mechanism while the contribution of chemical reaction is relatively low due to low volatility of etching products.

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Pancastatin A and B Have Selective Cytotoxicity on Glucose-Deprived PANC-1 Human Pancreatic Cancer Cells

  • Park, Hae-Ryong
    • Journal of Microbiology and Biotechnology
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    • v.30 no.5
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    • pp.733-738
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    • 2020
  • Glucose deprivation and hypoxia frequently occur in solid tumor cells, including pancreatic cancer cells. Glucose deprivation activates the unfolded protein response (UPR) and causes the up-regulation of glucose-regulated protein 78 (GRP78). Induction of GRP78 has been shown to protect cancer cells. Therefore, shutting down of GRP78 expression may be a novel strategy in anticancer drug development. Based on this understanding, a screening system established for anticancer agents that exhibit selective cytotoxicity on pancreatic cancer cells under glucose-deprived conditions. To test this hypothesis, the new compounds isolated, pancastatin A (PST-A) and B (PST-B), from Ponciri Fructus. PST-A and B were identified as glabretal triterpenoid moieties by electrospray ionization mass spectrometry and nuclear magnetic resonance spectroscopic methods. PST-A and B suppressed the accumulation of the UPR hallmark gene, GRP78, during glucose deprivation. Furthermore, PST-A and B showed selective cytotoxicity on PANC-1 pancreatic cancer cells under glucose deprivation. Interestingly, PST-A and B had no effect on these cells under normal growth conditions. Our results suggest that PST-A and B act as novel therapeutic agents to induce selective cell death in glucose-deprived pancreatic cancer cells.

Design and Implementation of Efficient PA Technology for Mobile PST (모바일 PST를 위한 효율적 PA 기법 설계 및 구현)

  • Shim, Jae-Sung;Park, Seok-Cheon
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.18 no.12
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    • pp.3049-3054
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    • 2014
  • PST stands for the Premium Sales Tool for Product Consulting is customized product catalog system. In other words, the product classification categories of content for consulting and sales to customers by providing useful information for the maximization of an overall system. These problems with mobility and flexibility of updating the solution to integrate mobile with mobile devices, but high-performance high-resolutions era content data continuously, but still it is difficult to handle. In this paper, to solve this problem, depending on the user's gesture by allowing periodic allocation and release of a problem for load generation enhanced by improving the PST system has been designed and implemented. Implementation was a result of the test the performance of the system, that PA system that has been provided by the traditional DA system show the allocation and the average 78% of the rate of decrease the load is released in the frequency of page, CPU utilization was reduced an average 72% I was confirmed.

A Multimedia Presentation Model Based On PST (PST를 기반으로 하는 멀티미디어 프리젠테이션 모델)

  • Choi, Hae-Gill;Choi, Sook-Young;Yoo, Kwan-Jong
    • The Transactions of the Korea Information Processing Society
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    • v.5 no.12
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    • pp.3063-3076
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    • 1998
  • To facilitate presentations of various media and transfer their implicit meaning efficiently, needed are effective development techniques for representing and manipulation temporal and spatial informations between multimedia data. Especially, these emporal and spatial informationsl are so deeply related with each other that it is required to have the integrated mehod for their representation. This paper suggests the Presentation Synchronization Trdd(PST) which represents their temporal and spatial informationsl and the efficient presentation model as traversing this PST. In this model, without knowing the specific user's interface or any script languages, the user can write the presentation scenario only based on allen's tecporal specification. This model has a characteristic of allowing user's inputs that may dynamically modify the presentation sequence in presentation time. As through the renmining steps of consistency checking for their relations. PST generation, and PST traversing step, this model provides users with simple and effective presentation of multimedial data by having them be presented auton\matically.

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Polystyrene-b-poly(oligo(ethylene oxide) Monomethyl Ether Methacrylate)-b-polystyrene Triblock Copolymers as Potential Carriers for Hydrophobic Drugs

  • You, Qianqian;Chang, Haibo;Guo, Qipeng;Zhang, Yudong;Zhang, Puyu
    • Bulletin of the Korean Chemical Society
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    • v.34 no.2
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    • pp.558-564
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    • 2013
  • A simple and effective method is introduced to synthesize a series of polystyrene-b-poly(oligo(ethylene oxide) monomethyl ether methacrylate)-b-polystyrene (PSt-b-POEOMA-b-PSt) triblock copolymers. The structures of PSt-b-POEOMA-b-PSt copolymers were characterized by Fourier-transform infrared spectroscopy (FTIR) and nuclear magnetic resonance ($^1H$ NMR) spectroscopy. The molecular weight and molecular weight distribution of the copolymer were measured by gel permeation chromatography (GPC). Furthermore, the self-assembling and drug-loaded behaviours of three different ratios of PSt-b-POEOMA-b-PSt were studied. These copolymers could readily self-assemble into micelles in aqueous solution. The vitamin E-loaded copolymer micelles were produced by the dialysis method. The micelle size and core-shell structure of the block copolymer micelles and the drug-loaded micelles were confirmed by dynamic light scattering (DLS) and transmission electron microscopy (TEM). The thermal properties of the copolymer micelles before and after drug-loaded were investigated by different scanning calorimetry (DSC). The results show that the micelle size is slightly increased with increasing the content of hydrophobic segments and the micelles are still core-shell spherical structures after drug-loaded. Moreover, the glass transition temperature (Tg) of polystyrene is reduced after the drug loaded. The drug loading content (DLC) of the copolymer micelles is 70%-80% by ultraviolet (UV) photolithography analysis. These properties indicate the micelles self-assembled from PSt-b-POEOMA-b-PSt copolymers would have potential as carriers for the encapsulation of hydrophobic drugs.

Effects of Grafting Cultivation on the Growth and Yield of Paprika in Highlands (고랭지 착색단고추의 접목재배 효과)

  • Lee, Jong-Nam;Lee, Eung-Ho;Kim, Jeom-Sun;Kim, Won-Bae;Ryu, Seung-Yeol;Yong, Yeong-Rok
    • Journal of Bio-Environment Control
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    • v.13 no.1
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    • pp.33-38
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    • 2004
  • This experiment was conducted to screen the suitable rootstocks for the soil cultivation of paprika (Capsicum annuum L.) in highland. Sixteen kinds of rootstocks were grafted to the red colored 'Spirit' scion for the resistances to diseases like fruit lot (Phytophthora capsici) and bacterial wilt (Ralstonia solanacearum). Four varieties among the rootstocks, 'Tantandaemok', 'Skurt-S', 'AC 2258', and 'PST 8301' were selected for the high resistance to fruit rot of paprika. However non-grafted control plants were totally dead at five days after inoculation. Furthermore, seven varieties including 'Yeokgang', ;Tantandaemok', 'TE412', 'MC 4', 'PST VK', and 'PST NV' were selected for the high resistance to bacterial wilt. The grafting with pest resistant rootstocks could enhance the rhizophere environment through root fresh weight increase. High yielding rootstocks for paprica 'Spirit' were PST 8301, MC 4, and Wanggeun.

Tendency Analysis of Indoor Natural Ventilation by PST(Particle Streak Tracking) System (PST(Particle Streak Tracking)시스템을 통한 실내자연환기 경향분석)

  • Lee, Keon-Ho;Kim, Hyeon-Soo;Jang, Dae-Hee;Son, Young-Joo
    • KIEAE Journal
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    • v.7 no.6
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    • pp.9-15
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    • 2007
  • Ventilation of buildings provide occupants with comfort and plays a very informant role in supplying indoor ventilation requirement. Also, natural ventilation is more comfortable than forced ventilation taking account of mental comfort. Especially factors, airflow velocity and direction etc., should be reflected in establishment of comfortable indoor environment because indoor airflow can directly affect comfort of occupants. However, a device which enables indoor air movement to be analyzed has not existed until now. Hence, it has mostly depended on simulation results of fluid analysis but the results often differ far from reality. PST(Particle-Streak-Tracking) System, an alternative to improve this problem, is currently applied to natural ventilation in building, air conditioning, and airflow analysis in the inside of a plane etc. This study closely examine the property and strength and weakness of PST that is first introduced into KICT and then evaluate applicable possibility.

Etching characteristics of PST thin film and ion energy distribution using inductively coupled plasma (유도결합 플라즈마를 이용한 PST 박막의 식각 특성 및 이온 에너지 분포)

  • Kim, Gwan-Ha;Kim, Kyoung-Tae;Kim, Chang-Il
    • Proceedings of the KIEE Conference
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    • 2004.11a
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    • pp.98-100
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    • 2004
  • In this study, PST thin films were etched with inductively coupled $Cl_2/(Cl_2+Ar)$ plasmas. The etch characteristics of PST thin films as a function of $Cl_2/(Cl_2+Ar)$ gasmixtures were analyzed by using quadrupole mass spectrometer (QMS). Systematic studies were carried out as a function of the etching parameters, including the RF power and the working pressure. The maximum PST film etch rate is 56.2 nm/min, because a small addition of $Cl_2$ to the $Cl_2$/Ar mixture increased the chemical effect. It was proposed that sputter etching is the dominant etching mechanism while the contribution of chemical reaction is relatively low due to low volatility of etching products.

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The Pst 1 Polymorphism of the Human Apolipoprotein AI Gene in Korean Elite Athletes

  • Kang, Byung-Yong;Kim, Hyun-Hee;Lee, Kang-Oh
    • Animal cells and systems
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    • v.7 no.1
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    • pp.69-73
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    • 2003
  • Serum lipid and lipoprotein levels are influenced by genetic factors, and exorcise increases the concentrations of cardio-protective parameters such as high-density lipoprotein cholesterol (HDL-cholesterol) and apolipoproteinAI (apoAI) in human serum. In the present study, we tested the effect of adaptation to endurance exercise on the association of a genetic polymorphism (Pst 1 RFLP) in the apoAI gene with these biochemical parameters. The genotype and allele frequencies for the Pst 1 RFLP were not significantly different between the elite athletes and sedentary controls (P>0.05). There were also no significant associations between the Pst 1 RFLP of the apoAI gene and the biochemical parameters in elite athletic group. Thus, our results suggest that the Pst 1 RFLP of the apoAI gene was not significantly associated with the serum apoAI and HDL-cholesterol concentrations as well as athletic performance in Koreans.

Activation of Defense Responses in Chinese Cabbage by a Nonhost Pathogen, Pseudomonas syringae pv. tomato

  • Park, Yong-Soon;Jeon, Myeong-Hoon;Lee, Sung-Hee;Moon, Jee-Sook;Cha, Jae-Soon;Kim, Hak-Yong;Cho, Tae-Ju
    • BMB Reports
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    • v.38 no.6
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    • pp.748-754
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    • 2005
  • Pseudomonas syringae pv. tomato (Pst) causes a bacterial speck disease in tomato and Arabidopsis. In Chinese cabbage, in which host-pathogen interactions are not well understood, Pst does not cause disease but rather elicits a hypersensitive response. Pst induces localized cell death and $H_2O_2$ accumulation, a typical hypersensitive response, in infiltrated cabbage leaves. Pre-inoculation with Pst was found to induce resistance to Erwinia carotovora subsp. carotovora, a pathogen that causes soft rot disease in Chinese cabbage. An examination of the expression profiles of 12 previously identified Pst-inducible genes revealed that the majority of these genes were activated by salicylic acid or BTH; however, expressions of the genes encoding PR4 and a class IV chitinase were induced by ethephon, an ethylene-releasing compound, but not by salicylic acid, BTH, or methyl jasmonate. This implies that Pst activates both salicylate-dependent and salicylate-independent defense responses in Chinese cabbage.