이가 양이온이 토끼 위 유문동 근세포의 외향성 포타슘 전류에 미치는 영향

임인자,조성일,방효원,엄대용,이상돈 중앙대학교 의과대학 의과학연구소 1994 中央醫大誌 Vol.19 No.3

Using the whole-cell mode patch-clamp techniques at 20~23℃, membrane currents were recorded from single smooth muscle cells enzymatically isolated from the rabbit gastric antrum. Outward currents were activated with a threshold around-30 mV and carried by K^+, which showed apparent outward rectification. The outward current was potentiated by high (4 mM) calcium, but reduced by EGTA and cadmium in bath solution. The outward current was potentiated by caffeine above -10 mV by test pulses, however, not changed below -10 mV. External TEA(2~4 mM) inhibited the outward current in a concentration-dependent manner. The outward current was slightly increased by 4-AP(5 mM) above -10 mV by test pulse but decreased below -10 mV in normal Tyrode solution. In the presence of 10 mM TEA to block outward K^+ current, the residual outward current was further blocked by 4-AP on the whole voltage range of test pulses. Outward K^+ current could be divided into two components : (1)a Ca^2+- and voltage-dependent oscillatory current. It was blocked by TEA of low concentration and slightly increased by 4-AP. Delayed rectifier K^+ current was Ca^2+-independent, but voltage-dependent and it was insensitive to TEA(2~4 mM) and could be blocked by 4-AP in the presence of TEA(10 mM) to block Ca^2+ -activated K^+ current. When Mg^2+ was applied extracellularly or into intrapipette solution, outward K^+ currents were decreased in a dose-dependent manner and the degree of block was increased with depolarization. Ca^2+ -activated K^+ current was potentiated by elevation of extracellular calcium but this potentiation had bell-shaped concentration dependency. External barium, which was known to block the K^+ currents, potentiated Ca^2+ -activated K^+ current in normal Tyrode solution. But is blocked the residual outward current in the presence of 10 mM TEA to block Ca^2+ -activated K^+ current. The above results suggested that magnesium might have blocked outward K^+ current by inhibiting the Ca^2+ -activated K^+ current and the calcium-induced calcium release. And calcium increased the Ca2+ -activated K^+ current up to 2~4 mM and then decreased it probably by the calcium channel inactivation in higher concentration. Barium might have been a charge carrier for Ca^2+ -activated K^+ current and blocked only the delayed rectifier K^+ current.

Sheath Heater 모듈 실링용 B₂O₃-ZnO-Bi₂O₃계 유리소재 및 첨가제에 따른 물성 변화

최진삼,신동우,배원태,Choi, Jinsam,Shin, Dong Woo,Bae, Won Tae 한국세라믹학회 2013 한국세라믹학회지 Vol.50 No.1

We investigated the thermal and electrical properties of the $B_2O_3-ZnO-Bi_2O_3$ glass system as a sealing material in sheath heater modules. A composition with over 90 wt% $Bi_2O_3$ in the $B_2O_3-ZnO-Bi_2O_3$ system was glassified by controlling the cooling rate. The glass transition temperature and thermal expansion coefficient in bismate glass could be controlled by the minor ingredients of ZnO, $SiO_2$, $BaO_2$, and $K_2O$. The $B_2O_3-ZnO-Bi_2O_3$ glass system bonded well to metal, and bismate glass insulating properties were comparable to those of bismate glass $B_2O_3-ZnO-PbO$ glass system in a sheath heater module.

가스 질화침탄처리한 탄소강의 화합물층 성장 및 부식특성에 미치는 CO2함량의 영향

김영희 ( Y. H. Kim ),김석동 ( S. D. Kim ),윤희재 ( H. J. Yoon ) 한국열처리공학회 2002 熱處理工學會誌 Vol.15 No.5

N/A This study has been performed to investigate the effect of CO_2 content on the growth characteristics of the compound layer, porous layer and corrosion characteristics of carbon steels after gaseous nitrocarburizing in 70%NH_3-CO_2-N_2 at 580℃ for 2.5 hrs. The results obtained from the experiment were the thickness of the compound and porous layers increased with increasing CO_2 contents. At the same fixed gas composition the thickness of the compound and porous layer increased with increasing carbon content of the specimens. X-ray diffraction analysis showed that compound layer was mainly consisted of ε-Fe_2-3(N,C) and γ`-Fe_4N as the increased with CO_2 contents in atmosphere, compound layer was chiefly consisted of ε-Fe_2-3(N,C) phase. With increasing CO_2 content and total flow rate in gaseous nitrocarburizing, the amount of ε-Fe_2-3(N,C) phase in the compound layer was increased. The current density of passivity decreased with increasing CO_2 content due to the development of porous layer at the out most surface of ε-Fe_2-3(N,C).

SPI-4.2 프로토콜을 사용한 PHY-LINK 계층간의 데이터 전송 성능평가

박노식,손승일,최익성,이범철 한국정보통신학회 2004 한국정보통신학회논문지 Vol.8 No.3

시스템 패킷 인터페이스 4레벨 2단계(System Packet Interface Leve14 Phase 2)는 10Gbps 이더넷 응용 뿐만아니라, OC-192 대역폭의 ATM 및 POS를 통한 패킷 또는 셀 전송을 위한 물리계층과 링크계층 소자간의 인터페이스이다. 본 논문에서는 시스템 패킷 인터페이스 4레벨 2단계(SPI-4.2)에 대한 연구와 C언어를 이용한 인터페이스 모듈의 성능평가를 실시하였다. SPI-4.2 인터페이스 모들은 512워드의 FIFO를 사용할 경우 랜덤 유니폼 트래픽에서는 97%까지, 버스트 길이 32를 갖는 버스트 트래픽에서는 94% 까지의 offered load에 대해 적응이 가능하다. 그리고 14 바이트 미만의 작은 크기 패킷을 대규모로 수신할 경우, 오버헤드로 인한 성능 저하가 발생한다는 것을 확인하였다. SPI-4.2 인터페이스 모듈은 기가비트/테라비트 라우터, 광학 크로스바 스위치 및 SONET/SDH 기반의 전송 시스템에서 라인카드로 사용할 경우 적합할 것으로 사료된다. System Packet Interface Level 4 Phase(SPI-4.2) is an interface for packet and cell transfer between a physical layer(PHY) device and a link layer device, for aggregate bandwidths of OC-192 ATM and Packet Over Sonet/SDH(POS), as well as 10Gbps Ethernet applications. In this paper, we performs the research for SPI-4.2. Also we analyze the performance of SPI-4.2 interface module after modeling using C programming language. This paper shows that SPI-4.2 interface module with 512-word FIFO depth is able to be adapted for the offered loads to 97% in random uniform traffic and 94% in bursty traffic with bursty length 32. SPI-4.2 interface module can experience an performance degradation due to heavy overhead when it massively receives small size packets less than 14-byte. SPI-4.2 interface module is suited for line cards in gigabit/terabit routers, and optical cross-connect switches, and SONET/SDH-based transmission systems.

Nrf2-mediated Induction of Phase 2 Detoxifying Enzymes by Curled Dock (Rumex crispus L.) Seed Extract

Hyo Jung Kim,정채림,박인실,서화진,권오운,김정상 한국식품과학회 2013 Food Science and Biotechnology Vol.22 No.3

Curled dock (Rumex crispus L.) is known to have several health benefits including antioxidant, antifungal,and anti-inflammatory effects. The potential to induce phase 2 detoxifying enzymes of butanol extract of curled dock (BECD) seeds was investigated. BECD increased the activity of NAD(P)H:quinone oxidoreductase and expression of phase 2 detoxifying enzymes such as heme oxygenase 1, γ-glutamylcysteine synthetase, NAD(P)H:quinone oxidoreductase,and glutathione reductase, in both hepa1c1c7 and its mutant BPRc1 cells. The translocation of transcription factor nuclear factor-erythroid 2 p45-related factor 2 (Nrf2) and binding to antioxidant response element (ARE) in the promoter region of phase 2 detoxifying/antioxidant enzymes were promoted by BECD in HepG2-C8 cells. Furthermore,BECD enhanced phosphorylation of Akt in hepatoma cell lines while Nrf2 activation induced by BECD was suppressed by an inhibitor of Akt. This result suggests that BECD induces phase 2 detoxifying enzymes through the Akt/Nrf2/ARE signaling pathway. BECD merits further study to be developed as detoxification agent.

P2P와 저작권 보호

박현경(Park Hyun-Kyung) 부산대학교 법학연구소 2002 법학연구 Vol.43 No.1

In cyber-space, Copyright Law faced unexpected problems caused by new techNoogies. As the current system of copyright was established without considering new techNoogies, it cannot settle the problems only with the current system. P2P file-sharing techNoogy is one of the representative examples involving the relationships between copyright and techNoogies. P2P techNoogy allows users to search, copy, transfer files that are stored on other’s hard drives to own the files in common. It helps to realize free distribution of information in cyber-space through the information decentralized system. At the same time, it makes users easily to infringe copyright of works and also makes difficult to protect copyright owner. P2P techNoogy can be developed in enormous area in near the future, for examples, it can provide the environment which enables limited community to share it’s files directly, combining with other techNoogies, it can be used in e-business, like shopping mall or internet auction. Besides it makes a contribution to realize sharing of information between netizens. In the contrary, it has some dark sides. P2P service provides the environment which enables it’s users to transfer the files which are protected by the copyright without any permission. Moreover, through the development of circumventive techNoogies, it disturbs the current system of copyright. In the case of Napster, as the central server existed and it could control the users through the server, copyright owner can insist the responsibility of the service provider. But in the cases of Gnutella or Freenet, they don’t have any central server and information transfers are autonomous and anonymous. So copyright owner cannot find the target to ask the responsibility. There can be several questions. 1. Current system of copyright law can be maintained under the P2P techNoogies? The current copyright law which makes most of users around the world the offenders must be examined in view of digitalized network to enhance the effect of copyright law. 2. The files-transfer between users under the P2p system can be considered as fair use so that they can be exempted from the charge of infringement of copyright? Under the constitution, copyright has been protected from other’s infringements giving the exclusive rights to copyright-holder. It is natural that this rule is applied equally to cyber-space and users have to accept the concepts of copyright under the constitution. However, there are some differences to exercise copyright law in cyber-space. 3. P2P service can be exempted from the responsibility of supporter because of it’s circumventive techNoogy? Under current system, it needs to discuss in case by case. Most service providers adopting hybrid P2P techNoogy cannot escape the responsibility of infringement of copyright as a supporters. But in the case of pure P2P service, there are not any legal, techNoogical resolutions. Moreover this area will be expanded with the development of circumventive techNoogies. Finally, the discussion of the infringement of copyright causing by P2P service should not be limited in legal, techNoogica1 aspects. The legal system of copyright has to provide the reasonable standards of copyright in cyber-space, and copyright holders have to make their own protective methods. The most important thing to protect copyright is the change of market. The established market must try to be suited to new system of market in cyber-space. "Make the content easier and cheaper to buy than to steal" gives us one of the resolutions in cyber-space market to protect both the sharing of information and the guarantee of copyright.

Competitive Adsorption of CO₂ and H₂O Molecules on the BaO (100) Surface: A First-Principle Study

Kwon, Soon-Chul,Lee, Wang-Ro,Lee, Han-Na,Kim, J-Hoon,Lee, Han-Lim Korean Chemical Society 2011 Bulletin of the Korean Chemical Society Vol.32 No.3

$CO_2$ adsorption on mineral sorbents has a potential to sequester $CO_2$. This study used a density functional theory (DFT) study of $CO_2$ adsorption on barium oxide (BaO) in the presence of $H_2O$ to determine the role of $H_2O$ on the $CO_2$ adsorption properties on the ($2{\times}2$; $11.05\;{\AA}{\times}11.05\;{\AA}$) BaO (100) surface because BaO shows a high reactivity for $CO_2$ adsorption and the gas mixture of power plants generally contains $CO_2$ and $H_2O$. We investigated the adsorption properties (e.g., adsorption energies and geometries) of a single $CO_2$ molecule, a single $H_2O$ molecule on the surface to achieve molecular structures and molecular reaction mechanisms. In order to evaluate the coordinative effect of $H_2O$ molecules, this study also carried out the adsorption of a pair of $H_2O$ molecules, which was strongly bounded to neighboring (-1.91 eV) oxygen sites and distant sites (-1.86 eV), and two molecules ($CO_2$ and $H_2O$), which were also firmly bounded to neighboring sites (-2.32 eV) and distant sites (-2.23 eV). The quantum mechanical calculations show that $H_2O$ molecule does not influence on the chemisorption of $CO_2$ on the BaO surface, producing a stable carbonate due to the strong interaction between the $CO_2$ molecule and the BaO surface, resulting from the high charge transfer (-0.76 e).

Inhibition of oxidative stress induced‑cytotoxicity by coptisine in V79‑4 Chinese hamster lung fibroblasts through the induction of Nrf‑2 mediated HO‑1 expression

Hyeon‑Gyun Jo,Cheol Park,이혜숙,Gi‑Young Kim,Young‑Sam Keum,Jin Won Hyun,Taeg Kyu Kwon,Yung Hyun Choi,Su Hyun Hong 한국유전학회 2021 Genes & Genomics Vol.43 No.1

Background Coptisine is a natural alkaloid compound and is known to have multiple benefcial efects including antioxidant activity. However, whether it can protect lung fbroblasts from oxidative damage has not been studied yet. Objectives To investigate the potential inhibitory efect of coptisine against oxidative stress in V79-4 lung fbroblast cells. Methods V79-4 cells were treated with H2O2 (1 mM) in the presence or absence of coptisine (50 µg/ml), N-acetyl cysteine (NAC, 10 mM) or zinc protoporphyrin IX (ZnPP, 10 µM) for the indicated times. The alleviating efects of coptisine on cytotoxicity, cell cycle arrest, apoptosis, reactive oxygen species (ROS) production, DNA damage, mitochondrial dynamics, and inhibition of ATP production against H2O2 were investigated. Western blot analysis was used to analyze the expression levels of specifc proteins. Results Coptisine inhibited H2O2-induced cytotoxicity and DNA damage by blocking abnormal ROS generation. H2O2 treatment caused cell cycle arrest at the G2/M phase accompanied by increased expression of cyclin-dependent kinase (Cdk) inhibitor p21WAF1/CIP1 and decreased expression of cyclin B1 and cyclin A. However, these efects were attenuated in the presence of coptisine or NAC. Coptisine also prevented apoptosis by decreasing the rate of Bax/Bcl-2 expression in H2O2-stimulated cells and suppressing the loss of mitochondrial membrane potential and the cytosolic release of cytochrome c. In addition, the activation of nuclear factor-erythroid-2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1) was markedly promoted by coptisine in the presence of H2O2. However, zinc protoporphyrin IX, a potent inhibitor of HO-1, attenuated the ROS scavenging and anti-apoptotic efects of coptisine. Conclusions Based on current data, we suggest that coptisine can be used as a potential treatment for oxidative stress-related lung disease.

생물학적 자극 통제 수단으로 활용하기 위한 돼지 페로몬성 냄새 물질의 탐색 : Ligand Based Approach에 의한 돼지 페로몬성 Tetrahydrofuran-2-yl 계 화합물의 예측

성민규,조윤기,박창식,성낙도 한국동물생명공학회(구 한국동물번식학회) 2008 Reproductive & developmental biology Vol.32 No.3

돼지 페르몬성 냄새 물질을 탐색하기 위하여 tetrahydrofuran-2-yl 계 화합물들과 관측된 결합 친화력상수(Obs.p[Od]50) 사이의 정량적인 구조-활성관계(QSAR)로부터 4개 형태의 모델(2D-QSAR, HQSR, CoMFA 및 CoMSIA)들이 유도되었다. Ligand based approache로부터 최적화된 CoMFA 모델(예측성; r2cv.(q2)=0.886 및 상관성 r2RCV 0.984)이 가장 좋은 모델이었다. CoMFA 모델로부터 돼지 페르몬성 냄새 물질로 예측된 N1-allyl-N2 -(tetrahydrofuran-2-yl)methyl) oxalamide (P1), 2- (4-trimethylammoniummethylcyclohexyloxy)tetrahydrofurane (P5) 및 2- (3-trimethylammonium-methylcyclohexyloxy)tetrahydrofurane (P6) 분자들은 비교적 높은 결합 친화력 상수값(Pred.p[Od]50) =8~10)과 몇 가지 독성에 대하여 낮은 독성간을 나타내었다. To search a new porcine pheromonal odorant, the models of four type (2D-QSAR, HQSAR, CoMFA & CoMSlA) were derived from quantitative structure-activity relationship (QSAR) between tetrahydrofuran-2-yl family compounds and their observed binding affinity constants (Obs.p[Od]50). The optimized CoMFA model (predictability; r2cv.(q2)=0.886 & correlation coefficient r2RCV =0.984) from ligand based approaches was confirmed as the best model among them. The N1-allyl-N2 -(tetrahydrofuran-2-yl)methyl)oxalamide (P1), 2-(4-trimethylammoniummethylcyclohexyloxy)tetrahydrofurane (P5) and 2-(3-trimethylammoniummethylcyclohexyloxy)tetrahydrofurane (P6) molecules predicted as porcine pheromonal odorant by the CoMFA model were showed relatively high binding affinity constant values (Pred.p[Od]50) =8~10) and very lower toxicity values against some sorts of toxicity.

EZH2-Mediated microRNA-139-5p Regulates Epithelial-Mesenchymal Transition and Lymph Node Metastasis of Pancreatic Cancer

Ma, Jin,Zhang, Jun,Weng, Yuan-Chi,Wang, Jian-Cheng Korean Society for Molecular and Cellular Biology 2018 Molecules and cells Vol.41 No.9

Pancreatic cancer (PC) is one of the most aggressive cancers presenting with high rates of invasion and metastasis, and unfavorable prognoses. The current study aims to investigate whether EZH2/miR-139-5p axis affects epithelial-mesenchymal transition (EMT) and lymph node metastasis (LNM) in PC, and the mechanism how EZH2 regulates miR-139-5p. Human PC and adjacent normal tissues were collected to determine expression of EZH2 and miR-139-5p, and their relationship with clinicopathological features of PC. Human PC cell line was selected, and treated with miR-139-5p mimics/inhibitors, EZH2 vector or shEZH2 in order to validate the regulation of EZH2-mediated miR-139-5p in PC cells. Dual-luciferase report gene assay and chromatin immunoprecipitation assay were employed to identify the relationship between miR-139-5p and EZH2. RT-qPCR and Western blot analysis were conducted to determine the expression of miR-139-5p, EZH2 and EMT-related markers and ZEB1/2. Tumor formation ability and in vitro cell activity were also analyzed. Highly-expressed EZH2 and poorly-expressed miR-139-5p were detected in PC tissues, and miR-139-5p and EZH2 expressions were associated with patients at Stage III/IV, with LNM and highly-differentiated tumors. EZH2 suppressed the expression of miR-139-5p through up-regulating Histone 3 Lysine 27 Trimethylation (H3K27me3). EMT, cell proliferation, migration and invasion were impeded, and tumor formation and LNM were reduced in PC cells transfected with miR-139-5p mimics and shEZH2. MiR-139-5p transcription is inhibited by EZH2 through up-regulating H3K27me3, thereby down-regulation of EZH2 and up-regulation of miR-139-5p impede EMT and LNM in PC. In addition, the EZH2/miR-139-5p axis presents as a promising therapeutic strategy for the treatment of PC.