• 제목/요약/키워드: pH-gradient

검색결과 312건 처리시간 0.032초

혈액과 조직의 $CO_2$완충능 및 세포막을 통한 $H^+$농도 경사 ($CO_2$ Buffering and Hydrogen Ion Concentration Gradient across Cell Membrane in Acute Acid-Base Disturbances in Dogs)

  • 황상익;박영배;민병구;김우겸
    • The Korean Journal of Physiology
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    • 제17권2호
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    • pp.119-124
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    • 1983
  • The in vivo and in vitro buffer capacities of true plasma and tissue buffer capaciies were compared on dogs. Intracellular pH was determined on skeletal muscle by a modification of the method of Schloerb and Grantham using $C^{14}$ DMO. The in vivo curve for plasma or extracellular fluid has a much lower slope than the in vitro curve. The in vivo slope of skeletal muscle in the dog is approximately 20 sl. The slope for skeletal muscle in vivo falls between the in vitro and in vivo slopes of true plasma. It appears that intracellular hydrogen ion varies linearly with extracellular hydrogen ion when $CO_2$ tension is changed. Both hydrogen ion gradient and Hi/He ratio vary in skeletal muscle, with an increase in $CO_2$ tension. Infusion of 0.3N HCl gave two distinct patterns, the $H_i-H_e$ gradient decreased; and it would appear that very little hydrogen ion as such penetrated to the inside of the cells during the time of observation. Although lactic acid presumably enters the cell and the same of larger load was given as was used for hydrochloric acid, only very mild intracellular acidosis resulted, ostensibly due to metabolism of this substrate. Gluconic acid produced a more severe acidosis, both intracellularly and extracellularly, but with both of these acids the hydrogen ion gradient decreased and the $H_i/H_e$ ratio also decreased. The experiments on the dogs with hemorrhagic shock the hydrogen ion increase producing the acidosis originates inside the cells. Even so, the hydrogen ion gradient increased only very slightly in the acute experiments. This may suggest that even over short intervals of time skeletal muscle cells have a capacity to pump out hydrogen ions at a rate which maintains approximately the normal $H_i/H_e$ gradient when the source of the hydrogen ion is in the interior of the cell.

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Saccharomyces 종의 등전점 전기영동에 의한 단백질 분획상 차이에 관한 연구 (Studies on the Differentiation of Protein Patterns from Saccharomyces species by Isoelectric Focusing in Polyacrylamide Gels)

  • 김종진;한면수;최상규
    • 미생물학회지
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    • 제29권3호
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    • pp.179-183
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    • 1991
  • The whole proteins from 10 different Saccharomyces species were separated by isoelectric focusing, which was carried out in pH gradient polyacrylamide gels with the carrier ampholytes of various pH ranges. About 25 protein bands were found in the gel using pH 3.0-10.0 carrier ampholytes. In gel using pH 4.0-7.0 carrier ampholytes, the protein band of pI 6.3 was found in Sacch. cerevisiae NCYC 478, ATCC 26787, Sacch. rosei and Sacch. uvarum, but it was absent in Sacch. cerevisiae ATCC 24903, ATCC 42949, ATCC 36029, Sacch. steineri var hara, Sacch. bayanus, and Sacch. diastaticus.

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Lp ESTIMATES FOR SCHRÖDINGER TYPE OPERATORS ON THE HEISENBERG GROUP

  • Yu, Liu
    • 대한수학회지
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    • 제47권2호
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    • pp.425-443
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    • 2010
  • We investigate the Schr$\ddot{o}$dinger type operator $H_2\;=\;(-\Delta_{\mathbb{H}^n})^2+V^2$ on the Heisenberg group $\mathbb{H}^n$, where $\Delta_{\mathbb{H}^n}$ is the sublaplacian and the nonnegative potential V belongs to the reverse H$\ddot{o}$lder class $B_q$ for $q\geq\frac{Q}{2}$, where Q is the homogeneous dimension of $\mathbb{H}^n$. We shall establish the estimates of the fundamental solution for the operator $H_2$ and obtain the $L^p$ estimates for the operator $\nabla^4_{\mathbb{H}^n}H^{-1}_2$, where $\nabla_{\mathbb{H}^n}$ is the gradient operator on $\mathbb{H}^n$.

보리품종 구분에 적합한 전기영동법과 효소 (Appropriate Electrophoresis Techniques and Isozymes to Identification of Barley Cultivars)

  • 손응룡;이용세;윤경은;하용웅
    • 한국작물학회지
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    • 제30권4호
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    • pp.405-411
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    • 1985
  • 본 실험은 보리품종의 구분에 가장 적합한 전기영동법과 효소를 구명하고자 6개 보리품종(알찬보리, 수원 216호, 조풍보리, 사천 6호, 향맥, 히노데하다가)의 종실 단백질을 7.5% polyacrylamide slab gel, 2-30% polyacrylamide porosity gradient tube gel, isoelectricfocusing(pH 4-9)과 starch gel을 사용 전기영동 후 protein band pattern과 esterase, acid phosphatase, malate dehydrogenase, glutamate dehydrogenase 및 leucine aminopeptidase의 동위효소 pattern을 관찰하였던 결과는 다음과 같았다. 1. 7.5% polyacrylamide slab gel에서 단백질 pattern과 2-30% polyacrylamide porosity gradient tube gel에서의 단백질과 esterase의 band pattern이 품종간 뚜렷한 차이를 보여 보리품종구분에 가장 적합하였다. 2. Acid phosphatase, malate dehydrogenase, glutamate dehydrogenase 및 leucine aminopeptidase 등의 동위효소 pattern은 모든 실험한 품종이 동일한 형태를 보여 품종구분에 이용하기에는 적합하지 않았다.

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Cadmium Inhibition of Renal Endosomal Acidification

  • Kim, Moo-Seong;Kim, Kyoung-Ryong;Ahn, Do-Whan;Park, Yang-Saeng
    • The Korean Journal of Physiology and Pharmacology
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    • 제4권1호
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    • pp.63-72
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    • 2000
  • Chronic exposure to cadmium (Cd) results in an inhibition of protein endocytosis in the renal proximal tubule, leading to proteinuria. In order to gain insight into the mechanism by which Cd impairs the protein endocytosis, we investigated the effect of Cd on the acidification of renal cortical endocytotic vesicles (endosomes). The endosomal acidification was assessed by measuring the pH gradient-dependent fluorescence change, using acridine orange or FITC-dextran as a probe. In renal endosomes isolated from Cd-intoxicated rats, the $V_{max}$ of ATP-driven fluorescence quenching ($H^+-ATPase$ dependent intravesicular acidification) was significantly attenuated with no substantial changes in the apparent $K_m,$ indicating that the capacity of acidification was reduced. When endosomes from normal animals were directly exposed to free Cd in vitro, the $V_{max}$ was slightly reduced, whereas the $K_m$ was markedly increased, implying that the biochemical property of the $H^+-ATPase$ was altered by Cd. In endosomes exposed to free Cd in vitro, the rate of dissipation of the transmembrane pH gradient after $H^+-ATPase$ inhibition appeared to be significantly faster compared to that in normal endosomes, indicating that the $H^+-conductance$ of the membrane was increased by Cd. These results suggest that in long-term Cd-exposed animals, free Cd ions liberated in the proximal tubular cytoplasm by lysosomal degradation of cadmium-metallothionein complex (CdMT) may impair endosomal acidification 1) by reducing the $H^+-ATPase$ density in the endosomal membrane, 2) by suppressing the intrinsic $H^+-ATPase$ activity, and 3) possibly by increasing the membrane conductance to $H^+$ ion. Such effects of Cd could be responsible for the alterations of proximal tubular endocytotic activities, protein reabsorption and various transporter distributions observed in Cd-exposed cells and animals.

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Effect of Disodium Fumarate on In vitro Rumen Fermentation of Different Substrates and Rumen Bacterial Communities as Revealed by Denaturing Gradient Gel Electrophoresis Analysis of 16S Ribosomal DNA

  • Mao, S.Y.;Zhang, G.;Zhu, W.Y.
    • Asian-Australasian Journal of Animal Sciences
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    • 제20권4호
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    • pp.543-549
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    • 2007
  • Two experiments were conducted to investigate the effects of disodium fumarate on the in vitro rumen fermentation profiles of different substrates and microbial communities. In experiment 1, nine diets (high-forage diet (forage:concentrate, e.g. F:C = 7:3, DM basis), medium-forage diet (F:C = 5:5, DM basis), low-forage diet(F:C = 1:9, DM basis), cracked corn, cracked wheat, soluble starch, tall elata (Festuca elata), perennial ryegrass and rice straw) were fermented in vitro by rumen microorganisms from local goats. The results showed that during 24 h incubations, for all substrates, disodium fumarate increased (p<0.05) the gas production, and tended to increase (p<0.10) the acetate, propionate and total VFA concentration and decrease the ratio of acetate to propionate, whereas no treatment effect was observed for the lactate concentration. The apparent DM loss for tall elata, perennial ryegrass and rice straw increased (p<0.05) with the addition of disodium fumarate. With the exception of tall elata, perennial ryegrass and rice straw, disodium fumarate addition increased the final pH (p<0.05) for all substrates. In experiment 2, three substrates (a high-forage diet, a medium-forage diet and a high concentrate diet) were fermented by mixed rumen microbes in vitro. A polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) technique was applied to compare microbial DNA fingerprints between substrates at the end of 24 h incubation. The results showed that when Festuca elata was used as substrate, the control and disodium fumarate treatments had similar DGGE profiles, with their similarities higher than 96%. As the ratio of concentrate increased, however, the similarities in DGGE profiles decreased between the control and disodium fumarate treatment. Overall, these results suggest that disodium fumarate is effective in increasing the pH and gas production for the diets differing in forage: concentrate ratio, grain cereals and soluble starch, and in increasing dry matter loss for the forages (tall elata, perennial ryegrass and rice straw) in vitro, whereas its effect on changes of ruminal microbial community may largely depend on the general nature of the substrate.

불포화 자연토의 동전기 시스템에 따른 정화 특성 (The Remediation Characteristics of Natural Soil according to ElectroKinetic Remediation Systems under Unsaturated Conditions)

  • 김병일;김기년;한상재;김수삼
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2004년도 춘계학술발표회
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    • pp.873-881
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    • 2004
  • A serious of EK remediation tests on contaminated soil are performed under unsaturated conditions and analyzed for electrical potential, water content, pH and so on. The results indicated that electrical potential and pH distributions in the sample are dependent on the amount and inward/outward flow of hydrogen ion. Specially, for the closed system the water content is largely decreased with the flow of hydrogen. The maximum electrical conductivity is measured at the catholyte of CEM(Sealing) test and directly related to the remedial efficiency. Although pHs in the region near to the anode are similarly developed, the different concentration of lead is measured with the electrical gradient contrary to the lead concentration dependent on pH within the sample.

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Optimization of in vitro fertilization technique for oocytes of indigenous zebu cows

  • Rahman, Mohammad Moshiur;Rahman, Md. Masudur;Juyena, Nasrin Sultana;Bhuiyan, Mohammad Musharraf Uddin
    • 한국동물생명공학회지
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    • 제35권2호
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    • pp.142-148
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    • 2020
  • The research work was undertaken to determine an effective fertilization medium, sperm separation method and sperm capacitating agent for optimum in vitro fertilization (IVF) rates of indigenous zebu cow oocytes. In experiment 1, tissue culture medium (TCM 199), Tyrode's albumin lactate pyruvate (TALP) and Brackett and Oliphant (BO) medium were used as basic medium for IVF of oocytes of indigenous zebu cows. In experiment 2, three sperm separation methods namely centrifugation, swim up and percoll gradient methods were used for separation of motile and viable spermatozoa for IVF. In experiment 3, for capacitation of spermatozoa, IVF medium supplemented with the heparin, mixture of penicillamine, hypotaurine and epinephrine (PHE) or the combination of heparin with PHE were used for fertilization. In vitro culture (IVC) of presumptive zygotes was done in modified synthetic oviduct fluid (mSOF) medium using standard procedure 24 h after sperm-oocytes co-culture. The cleavage rate was determined to evaluate the efficacy of fertilization medium, sperm separation method and sperm capacitating agent 24 h after IVC. The cleavage rate was higher in oocytes fertilized in TALP (63.3%) than in TCM 199 (47.5%) (p < 0.05). The cleavage rate was higher in oocytes fertilized by spermatozoa separated by percoll gradient method (62.3%) than by centrifugation (51.6%) (p < 0.05). The cleavage rate of oocytes was higher when insemination was done with spermatozoa capacitated in TALP supplemented with heparin and PHE (61.3%) compared to control (40.9%) (p < 0.05). In conclusions, TALP based medium and percoll gradient sperm separation followed by capacitation with combination of heparin and PHE are suitable for IVF of indigenous zebu cow oocytes in Bangladesh.

Clostridium acetobutylicum의 내산성 기작

  • 김병홍
    • 미생물과산업
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    • 제11권1호
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    • pp.3-7
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    • 1985
  • 미생물은 고등생물과 그들이 생육하는 환경을 조절할 수 있는 능력이 제한되어 있다. 환경 변화에 따라 자신을 적응시킬 수 있는 능력이 있어야 끊임없이 변하는 환경에서 살아 남을 수 있고 다른 미생물과의 경재에서 이길 수 있다. 온도, 삼투압, 영양물질의 온도, 수소 ion농도는 자연계에서 짧은 시간에 넓은 폭으로 변하며 미생물에서 energy 대사의 중심이 되는 proton motive force를 이루는 proton gradient (.DELTA.pH)의 크기를 결정한는 중요한 환경인자이다.

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인산염 이온 형태에 의한 pH 변량 모형 (pH Variance Model Depending on Phosphate Ion Form)

  • 소재우;소순일;남상용
    • 원예과학기술지
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    • 제33권6호
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    • pp.854-859
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    • 2015
  • 본 시험은 배양액 내 pH 변화에 따른 이온과 EC의 모형을 구명하고자 수행하였다. 배양액 내 $HPO_4{^{-2}}$$H_2PO_4{^-}$의 변량에 따른 pH가 변하는데, pH 4.0-5.0은 EC의 변량이 상승하고, pH 5.0-7.0은 EC의 변량이 완만하고, pH 7.0-8.0은 다시 상승하였다. 배양액 내 다량원소의 변량을 보면, pH가 상승할수록 K, Ca, N, P의 이온 농도도 증가하는데, 특히 K과 P의 변량이 크게 나타났다. 반면 Mg와 S의 변량은 일정하게 유지되었다. 배양액의 IBM(ion balance model)에 따른 분석에서, EC의 변량은 크게 변하지 않고, 이온의 균형점이 a분면에서 d분면으로 이동하면 pH가 상승하면서 음이온 보다 양이온이 증가하는 것으로 나타났다. 또한 pH 변량이 높을수록 EC 중앙선으로부터 멀어져 배양액의 이온 불균형이 증가되었다. $HPO_4{^{-2}}$$H_2PO_4{^-}$의 변량에 대한 K와 Ca의 당량비 보정은 pH가 증가할수록 K는 감소하지만 Ca는 증가하였고, EC 변량의 영향보다 큰 것으로 나타났다. K와 Ca의 당량비 보정에 따른 pH 변량은 0.97의 이차 다항식 상관모형을 나타냈다. 본 연구를 통해 인산염의 구배에 따른 pH, 이온, EC의 변량에 대하여 pH 변량 모형이 구명되었다.