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Physical and Chemical Evaluations of Refregerated Flatfish Treated with Organic Acids (유기산으로 처리한 냉장 광어의 이화학적 평가)

  • 김광현;김창렬
    • The Korean Journal of Food And Nutrition
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    • v.11 no.3
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    • pp.334-339
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    • 1998
  • Flatfish strips were treated with 0.5%(v/v) acetic acid(AA), 0.5%(v/v) lactic acid(LA), or 0.5%(v/w) citric acid(CA) for 5 min. All strips were individually placed in Whirl-Pak sample bags and stored at 4 or 10$^{\circ}C$. pH, TBA, color, and sensory quality of strips were evaluated after 0, 3, 6, 9, and 12 days of storage time. The pH of samples treated with AA for 5 min ranged from 5.39 to 6.64 for 12 days at 4$^{\circ}C$, which had a significantly (P<0.05) lower level compared to the controls during storage time. Acid treatments had a significantly (P<0.05) higher levels of TBA values compared to the controls for 12 days at 4$^{\circ}C$. All acid treatments had lower Hunter a and b color scores compared to the controls. Acid treatments were liked less by sensory panels than the fresh control due to acidic odor and flesh discoloration.

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pH-mediated Regulation of Pacemaker Activity in Cultured Interstitial Cells of Cajal

  • Kim, Byung-Joo;Lee, Jae-Hwa;So, In-Suk;Kim, Ki-Whan
    • The Korean Journal of Physiology and Pharmacology
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    • v.10 no.1
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    • pp.7-11
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    • 2006
  • Interstitial cells of Cajal (ICCs) are pacemakers in gastrointestinal tracts, regulating rhythmicity by activating nonselective cation channels (NSCCs). In the present study, we investigated the general characteristics and pH-mediated regulation of pacemaker activity in cultured interstitial cells of Cajal. Under voltage clamp mode and at the holding potential of -60 mV, the I-V relationships and difference current showed that there was no reversal potential and voltage-independent inward current. Also, when the holding potentials were changed from +20 mV to -80 mV with intervals of 20 mV, there was little difference in inward current. In pacemaker activity, the resting membrane potential (RMP) was depolarized (In pH 5.5, $23{\pm}1.5$ mV depolarized) and the amplitude was decreased by a decrease of the extracellular pH. However, in case of increase of extracellular pH, the RMP was slightly hyperpolarized and the amplitude was decreased a little. The melastatin type transient receptor potential (TRPM) channel 7 has been suggested to be required for intestinal pacemaking activity. TRPM7 produced large outward currents and small inward currents by voltage ramps, ranging from +100 to -100 mV from a holding potential of -60 mV. The inward current of TRPM7 was dramatically increased by a decrease in the extracellular pH. At pH 4.0, the average inward current amplitude measured at -100 mV was increased by about 7 fold, compared with the current amplitude at pH 7.4. Changes in the outward current (measured at +100 mV) were much smaller than those of the inward current. These results indicate that the resting membrane potential of pacemaking activity might be depolarized by external acidic pH through TRPM7 that is required for intestinal pacemaking activity.

Dual Regulation of R-Type CaV2.3 Channels by M1 Muscarinic Receptors

  • Jeong, Jin-Young;Kweon, Hae-Jin;Suh, Byung-Chang
    • Molecules and Cells
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    • v.39 no.4
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    • pp.322-329
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    • 2016
  • Voltage-gated $Ca^{2+}$ ($Ca_V$) channels are dynamically modulated by Gprotein-coupled receptors (GPCR). The $M_1$ muscarinic receptor stimulation is known to enhance $Ca_V2.3$ channel gating through the activation of protein kinase C (PKC). Here, we found that $M_1$ receptors also inhibit $Ca_V2.3$ currents when the channels are fully activated by PKC. In whole-cell configuration, the application of phorbol 12-myristate 13-acetate (PMA), a PKC activator, potentiated $Ca_V2.3$ currents by ~two-fold. After the PMA-induced potentiation, stimulation of $M_1$ receptors decreased the $Ca_V2.3$ currents by $52{\pm}8%$. We examined whether the depletion of phosphatidylinositol 4,5-bisphosphate ($PI(4,5)P_2$) is responsible for the muscarinic suppression of $Ca_V2.3$ currents by using two methods: the Danio rerio voltage-sensing phosphatase (Dr-VSP) system and the rapamycin-induced translocatable pseudojanin (PJ) system. First, dephosphorylation of $PI(4,5)P_2$ to phosphatidylinositol 4-phosphate (PI(4)P) by Dr-VSP significantly suppressed $Ca_V2.3$ currents, by $53{\pm}3%$. Next, dephosphorylation of both PI(4)P and $PI(4,5)P_2$ to PI by PJ translocation further decreased the current by up to $66{\pm}3%$. The results suggest that $Ca_V2.3$ currents are modulated by the $M_1$ receptor in a dual mode-that is, potentiation through the activation of PKC and suppression by the depletion of membrane $PI(4,5)P_2$. Our results also suggest that there is rapid turnover between PI(4)P and $PI(4,5)P_2$ in the plasma membrane.

Electro-chemical properties of $Li_{2}O=P_{2}O_{5}-V_{2}O_{5}$ Glass-ceramics for Cathode Materials (정극재료용 $Li_{2}O=P_{2}O_{5}-V_{2}O_{5}$ 계 결정화 유리의 전기화학적 특성)

  • 손명모;이헌수;구할본;김윤선
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2000.11a
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    • pp.295-298
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    • 2000
  • Vanadate glasses in the Li$_2$O-P$_2$O$_{5}$-V$_2$O$_{5}$ system containing 10~20mo1% glass former, P$_2$O$_{5}$ were prepared by melting the batch in pt. crucible followed by quenching on the copper plate. We found that Li$_2$O-P$_2$O$_{5}$-V$_2$O$_{5}$ g1ass-ceramics obtained from crystallization of glass showed significantly higher capacity and longer cycle life than Li$_2$O-P$_2$O$_{5}$-V$_2$O$_{5}$ g1ass. In the present paper, we describe electro-chemical properties during crystallization process and find the best crystallization condition of Li$_2$O-P$_2$O$_{5}$-V$_2$O$_{5}$ g1ass as cathod material. Li$_2$O-P$_2$O$_{5}$-V$_2$O$_{5}$ glass-ceramics shows superior rechargeable capacity of 220 mAh/g in the cycling between 2.0 and 3.9V. between 2.0 and 3.9V.

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Structure and physical properties of Earth Crust material in the Middle of Korean Peninsula(2) : Comparison between elastic Velocity and point-load of core specimen of sedimentary rocks. (한반도 중부권 지각물질의 구조와 물성연구(2) : 퇴적암류 코아시료의 탄성파 속도와 점재하 강도 비교)

  • 송무영;황인선
    • The Journal of Engineering Geology
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    • v.3 no.1
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    • pp.21-37
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    • 1993
  • In order to investigate the correlation of sedimentary rock properties. specific gravity, porosity, water content, sonic wave velodty, and point4oad strength index of core samples of limestones, sandstones and shales were measured. The relationships between density and velocity show $V_p=16300d-38719.3,{\;}V_s1896.4d-29225.1$ of regression equation for sandstones and $Vp=4085d-10264.8,{\;}V_s=3519d-7841.3$ for shales and <$Vp=4085d^2-20747d+303,{\;}V_s=3899d^2-21442d+318$ for limestones. Seismic wave velocity of shales which have high density is lower than that of sandstones, and this seems to be an effect of bedding in shale. P-wave velocity and S-wave velocity of limestones, sandstones and shales show the linear relationships as a whole. The regression equations are respectively calculated V_s=0.26V_p+1041.6m/sec,{\;}V_s=0.43V_p+424.2m/sec,{\;}and{\;}Vs=0.51V_p+261.9m/sec$ and the correlation coefficients of the velocity show r= 0.86 in sandstones, r= 0.75 in limestones and r=0.86 in shales. According to the point4oad strength test for limestones, point4ord strength anisotropy was not so dear even though the specimens show generally the banded structure. Variations of dip angle of bedding whihin the range $30^{\circ}-60^{\circ}$ does not have much influence upon the diametral strength index and axial strength index. From the result of point load test, P-wave velocity increases with point4ord strength index but the regression equations are $V_p=98.5lI{s_d}+4082.1m/sec,{\;}V_p=106.41{s_a}+3954m/sec$ and their correlation coefficient is low.

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Kinetics and Mechanism of Mutant O-acetylserine Sulfhydrylase-A (C43S) from Salmonella typhimurium LT-2

  • Yoon, Moon-Young
    • BMB Reports
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    • v.29 no.3
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    • pp.210-214
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    • 1996
  • The pH dependence of the kinetic parameters of mutant O-acetylserine sulfhydrylase (OASS) from Salmonella typhimurium LT-2 has been determined in order to obtain information on the chemical mechanism. The initial velocity pattern obtained by varying the concentrations of OAS at several fixed concentrations of TNB, shows an intersection on the left of the ordinate at pH 7.0, indicating that the kinetic mechanism is a sequential mechanism in which substrate inhibition by OAS is observed while the wild type enzyme showed a ping pong mechanism. The values of $V/E_t$, $V/K_{OAS}E_{t}$ and $V/K_{TNB}E_{t}$ decreased by about 68%, 14% and 16% as compared with the wild type enzyme. The $V/K_{OAS}E_{t}$ is a pK of 6.5 on the acid side of the pH profile, and the $V/K_{TNB}$ is pH independent. As compared with the wild type enzyme, the pKs in the V/K profiles are shifted, reflecting that binding of the cofactor in free E:OAS is less asymmetric.

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CYCLIC CODES OVER THE RING 𝔽p[u, v, w]/〈u2, v2, w2, uv - vu, vw - wv, uw - wu〉

  • Kewat, Pramod Kumar;Kushwaha, Sarika
    • Bulletin of the Korean Mathematical Society
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    • v.55 no.1
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    • pp.115-137
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    • 2018
  • Let $R_{u{^2},v^2,w^2,p}$ be a finite non chain ring ${\mathbb{F}}_p[u,v,w]{\langle}u^2,\;v^2,\;w^2,\;uv-vu,\;vw-wv,\;uw-wu{\rangle}$, where p is a prime number. This ring is a part of family of Frobenius rings. In this paper, we explore the structures of cyclic codes over the ring $R_{u{^2},v^2,w^2,p}$ of arbitrary length. We obtain a unique set of generators for these codes and also characterize free cyclic codes. We show that Gray images of cyclic codes are 8-quasicyclic binary linear codes of length 8n over ${\mathbb{F}}_p$. We also determine the rank and the Hamming distance for these codes. At last, we have given some examples.

국제양돈수의학회(I.P.V.S.) -수의업무 세계화의 길이 보인다.-

  • 강영배
    • Journal of the korean veterinary medical association
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    • v.32 no.8
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    • pp.535-539
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    • 1996
  • 국제양돈수의학회(International Pig Veterinary Society ; I.P.V.S) 제14차 총회 및 학술대회가 1996년 7월 7일부터 11일까지 이태리 중북부의 대학도시 볼로냐(Bologna, Italy)에서 개최되었다. I.P.V.S.는 1969년에 영국의 캠브리지 (Cambridge, United Kingdom)에서 창립된 이래 1996년 현재 53개 회원국 1,700 여명의 회원을 확보하고 있으며, 세계 각국의 양돈과 수의학에 관심을 가지고 있는 학자, 생산자 그리고 관련업계 인사들의 학술$\cdot$기술 정보교류와 협력을 목적으로 매 2년마다 세계 주요도시를 순회 하면서 개최되고 있다. 앞으로 2년후(1998년도)에는 I.P.V.S.의 탄생국인 영국의 버밍햄(Birmingham, United Kingdom)에서 제 15차 총회 및 학술대회를 개최할 예정이며 2000년대에는 시드니 올림픽과 때를 맞추어 호주의 멜보른(Melboume, Australia)에서 제16차 총회를 개최하기로 결정되어 있다. 금년(1996년도) I.P.V.S 총회에는 우리나라에서 30개 기관/업체로부터 50여명이 참여한 바 있으며 총 27편 (구두 9편, 포스터 18편)의 학술논문을 발표하는 등 눈부신 활약을 보인 바 있다. 금년도 I.P.V.S. 총회의 특징은 돼지의 전염성 질병중 근래에 우리나라에서도 문제시 되고 있는 '돼지 생식기 호흡기 중후군 (Porcine Reproductive and Respiratory Syndrome ; PRRS)'이 세계적인 관심의 대상이었으며, 이태리 양돈병리축산학회 (Societa Italiana di Patologia ed Allevamento dei Suini ; S.I.P.A.S) 주관으로 '돼지 적리 (Swine Dysentery)'에 관한 Satellite Symposium이 개최되었다는 점이다. WTO 이래 어려워지고만 있는 우리나라 축산업 분야중 그래도 비젼이 보이는 양돈산업과 관련하여, I.P.V.S.를 통하여 우리나라 수의업무의 세계화의 길을 찾아보고자, 1 국제양돈수의학회(I.P.V.S)의 역사 (양돈과 수의업무 전문가의 새로운 만남의 장), 2 I.P.V.S.에의 참여(제13차 방콕대회), 3 한국 수의사의 활약(제14차 볼로냐대회), 4 세계화의 길(제15차 버밍햄대회, 제16차 멜보른대회), 5 국내양돈의 문제와 우리가 해야할 일(수의업무 세계화의 길을 찾자)등의 순으로 적어보고자 한다.

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Effect on the Growth of Pllioblastus pygmaed and Soil Characteristics as Affected by Difference of Soil Thickness and Soil Mixture Ratio in the Shallow-Extensive Green Roof Module System (저관리 옥상녹화 모듈에서 토심, 배합비의 차이가 토양의 특성 및 흰줄무늬사사의 생육에 미치는 영향)

  • Park, Je-Hea;Ju, Jin-Hee;Yoon, Yong-Han
    • Journal of Environmental Science International
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    • v.19 no.7
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    • pp.871-877
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    • 2010
  • The objectives of this study were to compare growth of Pllioblastus pygmaed and soil characteristics as affected by difference of soil thickness and mixture ratio in shallow-extensive green roof module system, and to identify the level of soil thickness and mixture as suitable growing condition to achieve the desired plants in green roof. Different soil thickness levels were achieved under 15cm and 25cm of shallow-extensive green roof module system that was made by woody materials for $500{\times}500{\times}300mm$. Soil mixture ratio were three types for perlit: peatmoss: leafmold=6:2:2(v/v/v, $P_6P_2L_2$), perlit: peatmoss: leafmold=5:3:2(v/v/v, $P_5P_3L_2$) and perlit: peatmoss: leafmold=4:4:2(v/v/v, $P_4P_4L_2$). On June 2006, Pllioblastus pygmaed were planted directly in a green roof module system in rows. All treatment were arranged in a randomized complete block design with three replication. The results are summarized below. In term of soil characteristics, Soil acidity and electric conductivity was measured in pH 6.0~6.6 and 0.12dS/m~0.19dS/m, respectively. Organic matter and exchangeable cations desorption fell in the order: $P_4P_4L_2$ > $P_5P_3L_2$ > $P_6P_2L_2$. $P_6P_2L_2$ had higher levels of the total solid phase and liquid phase, and $P_4P_4L_2$ had gas phase for three phases of soil in the 15cm and 25cm soil thickness. Although Pllioblastus pygmaed was possibled soil thickness 15cm, there was a trend towards increased soil thickness with increased leaf length, number of leaves and chlorophyll contents in 25cm. The growth response of Pllioblastus pygmaed had fine and sustain condition in order to $P_6P_2L_2$ = $P_5P_3L_2$ > $P_4P_4L_2$. However, The results of this study suggested that plants grown under $P_4P_4L_2$ appear a higher density ground covering than plants grown under $P_6P_2L_2$. Collectively, our data emphasize that soil thickness for growth of Pllioblastus pygmaed were greater than soil mixture ratio in shallow-extensive green roof module system.

The Effect of Environmental Factor on the Survival of Marine Vibrio vulnificus (해양 Vibrio vulnificus의 생존에 미치는 환경적 요인의 영향)

  • 이봉헌;박흥재
    • Journal of Environmental Science International
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    • v.5 no.2
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    • pp.179-185
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    • 1996
  • This study was conducted to investigate the effects of environmental factors such as temperature, salinity, pH, and UV light on-the survival of life-threatening Vibrio vulnificus. In the temperature range of 15 to $25^{\circ}C$, the numbers of V. vulnificus incieased during the 6-day incubation, but outside this range, the survival of V. vulnificus was poor. Incubation between 1 and $10^{\circ}C$ showed that V. vulnifcts survived poorly below $10^{\circ}C$. At sal:nities between 5 and 25ppt, the numbers of V. vulnificus increased or remained unchanged for 6-day. At salinities above this range, the numbers of V. vulnificus decreased. The optimal pH range was 6.5 to 8.0 and outside this range, the survival ratio of V. vulnificus was small. At 15-and $25^{\circ}C$, UV radiation was bactericidal for cultures of V, vulnificus. The counts of V. vulnificus were reduced approximately 10, 000-fold after 2h of UV light treatment at both temperatures. Above results mowed 1ha't environmental factors were effective on the survival of V. vulniucus in the environment.

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