• 제목/요약/키워드: ionophore

검색결과 308건 처리시간 0.021초

소 초기배의 체외수정에 관한 연구 (Studies on the In vitro Culture of Early Bovine Embryos)

  • 황우석;권오경;조충호
    • 한국임상수의학회지
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    • 제7권2호
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    • pp.517-519
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    • 1990
  • 소 난소로부터 난자를 채취하여 체외성숙과 체외수정을 실시하였다. 난의 성숙배양을 위한 배양액은 소 태아혈청을 첨가한 TCM 199으로 $CO_2$배양기에서 24시간 배양하였다. 체외수정에는 동결융해정액을 사용하였으며 Caffeine과 Ca Ionophore 처리후 매정에 공하였다. 배양난자중 40%가 Metaphase II까지 성숙하였다. 성숙율에 대한 소 태아혈청의 농도변화와 HEPES 첨가여부의 효과는 없었다. 체외수정율과 분할율의 성적은 각각 23.1%와 14.4%였다.

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Effects of Panax ginseng, zearalenol, and estradiol on sperm function

  • Gray, Sandra L.;Lackey, Brett R.;Boone, William R.
    • Journal of Ginseng Research
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    • 제40권3호
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    • pp.251-259
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    • 2016
  • Background: Estrogen signaling pathways are modulated by exogenous factors. Panax ginseng exerts multiple activities in biological systems and is classified as an adaptogen. Zearalenol is a potent mycoestrogen that may be present in herbs and crops arising from contamination or endophytic association. The goal of this study was to investigate the impact of P. ginseng, zearalenol and estradiol in tests on spermatozoal function. Methods: The affinity of these compounds for estrogen receptor (ER)-alpha and beta ($ER{\alpha}$ and $ER{\beta}$)-was assessed in receptor binding assays. Functional tests on boar spermatozoa motility, movement and kinematic parameters were conducted using a computer-assisted sperm analyzer. Tests for capacitation, acrosome reaction (AR), and chromatin decondensation in spermatozoa were performed using microscopic analysis. Results: Zearalenol-but not estradiol ($E_2$)- or ginseng-treated spermatozoa-decreased the percentage of overall, progressive, and rapid motile cells. Zearalenol also decreased spontaneous AR and increased chromatin decondensation. Ginseng decreased chromatin decondensation in response to calcium ionophore and decreased AR in response to progesterone ($P_4$) and ionophore. Conclusion: Zearalenol has adverse effects on sperm motility and function by targeting multiple signaling cascades, including $P_4$, $E_2$, and calcium pathways. Ginseng protects against chromatin damage and thus may be beneficial to reproductive fitness.

Synthesis of Azo-functionalized Calix[4]arenes and Its Application to Chloride-selective Electrode as Ionophores

  • Lee, Hyo-Kyoung;Yeo, Hee-Kyoung;Park, Duck-Hee;Jeon, Seung-Won
    • Bulletin of the Korean Chemical Society
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    • 제24권12호
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    • pp.1737-1741
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    • 2003
  • Azo-functionalized calix[4]arenes as ionophores for chloride-selective electrode, 5,11,17,23-Tetra-tert-butyl-25,27-bis[(N,N-dimethyl-aniline-azo-phenylthioureido)ethyl]oxy-26,28-dihydroxycalix[4]arene (4a) and 5,11,17,23-Tetra-tert-butyl-25,27-bis[(N,N-dimethyl-aniline-azo-phenylthioureido)ethyl]oxy-26,28-dimethoxycalix[4]arene (4b) were synthesized. The PVC membrane electrode based on azo-functionalized calix[4]arene 4a with o-NPOE exhibits a linear stable response over a wide concentration range ($1.5{\times}10^{-4}-1.0{\times}10^{-1}$) with a slope of -52.0 mV/decade and a detection limit of log[$Cl^-$] = -4.02. This ionophore-based membrane exhibited improved selectivity for chloride anion compared with classical Hofmeister series.

An Amperometric Proton Selective Sensor with an Elliptic Microhole Liquid/Gel Interface for Vitamin-C Quantification

  • Faisal, Shaikh Nayeem;Hossain, Md. Mokarrom;Lee, Hye-Jin
    • Journal of Electrochemical Science and Technology
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    • 제1권2호
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    • pp.121-126
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    • 2010
  • An amperometric ascorbic acid selective sensor utilizing the transfer reaction of proton liberated from the dissociation of ascorbic acid in aqueous solution across an elliptic micro-hole water/organic gel interface is demonstrated. This redox inactive sensing platform offers an alternative way for the detection of ascorbic acid to avoid a fouling effect which is one of the major concerns in redox based sensing systems. The detection principle is simply measuring the current change with respect to the assisted transfer of protons by a proton selective ionophore (e.g., ETH 1778) across the micro-hole interface between the water and the polyvinylchloride-2-nitrophenyloctylether gel phase. The assisted transfer reaction of protons generated from ascorbic acid across the polarized micro-hole interface was first characterized using cyclic voltammetry. An improved sensitivity for the quantitative analysis of ascorbic acid was achieved using differential pulse stripping voltammetry with a linear response ranging from 1 to $100\;{\mu}M$ concentrations of ascorbic acid. As a demonstration, the developed sensor was applied for analyzing the content of vitamin-C in different types of commercial pharmaceutical tablets and syrups, and a satisfactory recovery from these samples were also obtained.

A Novel Iron(III) Selective Membrane Electrode Containing a Tripodal Polycatacholamine as Sensor

  • Bera, Rati Kanta;Sahoo, Suban K;Baral, Minati;Kanungo, B.K.
    • Bulletin of the Korean Chemical Society
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    • 제32권10호
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    • pp.3592-3596
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    • 2011
  • A novel poly(vinylchloride)-based membrane sensor using $N^1$,$N^3$,$N^5$-tris(2-(2,3-dihydroxybenzylamino)-ethyl)cyclohexane-1,3,5-tricarboxamide (CYCOENCAT, L) as ionophore has been prepared and explored as $Fe^{3+}$ selective electrode. The membrane electrode composed of ionophore, poly(vinylchloride) and o-nitropheyloctyl ether in the optimum ratio 4:33:63 gave excellent potentiometric response characteristics, and displayed a linear log[$Fe^{3+}$] versus EMF response over a wide concentration range of $1.0{\times}10^{-5}-1.0{\times}10^{-1}$ M with super nernstian slope of 28.0 mV/decade and the detection limit of $8.0{\times}10^{-6}$ M. The proposed ion selective electrode showed fast response time (< 15 s), wide pH range (3.0-7.0), high non-aqueous tolerance (up to 20%) and adequate long life time (120 days). It also exhibited very good selectivity for $Fe^{3+}$ relative to a wide variety of alkali, alkaline earth, transition and heavy metal ions. Further, the analytical applicability of the sensor was tested as an indicator electrode in the potentiometric titration of $Fe^{3+}$ with EDTA.

캘릭스 [4]크라운 유도체를 이온선택성 물질로 사용한 세슘이온 선택성 막전극 (Cesium Ion-Selective Electrode Based on Upper-rim Calix[4]crown Ionophore)

  • 남궁미옥;임혜재;백경수;윤영자
    • 분석과학
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    • 제13권4호
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    • pp.428-432
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    • 2000
  • 새로운 캘릭스[4]크라운 화합물을 이온 선택성 물질로 사용하고 지지체로 PVC(polyvinyl chloride), 가소제로 DOS(dioctyl sebacate)를 사용하여 이온선택성 막전극을 제작 하였다. 제작한 막전극을 지시전극으로 사용하여 알칼리, 알칼리토금속 이온에 대하여 각각의 감응전위를 측정한 결과, pH7.20 Tris buffer에서 $10^{-5}-10^{-1}M$ 농도의 변화에 따른 $Cs^+$이온의 감응전위가 이론적인 Nernst식 기울기에 가까운 52.3 mV/decade로 직선성이 잘 성립하는 감응전위를 나타내었다. $Cs^+$이온 농도변화에 따른 막의 감응시간은 $t_{90%}$=10sec이었고, 막의 사용기간은 2개월 정도이다.

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Electroanalytical Determination of Copper(II) Ions Using a Polymer Membrane Sensor

  • Oguz Ozbek;Meliha Burcu Gurdere;Caglar Berkel;Omer Isildak
    • Journal of Electrochemical Science and Technology
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    • 제14권1호
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    • pp.66-74
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    • 2023
  • In this study, a new potentiometric sensor selective to copper(II) ions was developed and characterized. The developed sensor has a polymeric membrane and contains 4.0% electroactive material (ionophore), 33.0% poly(vinyl chloride) (PVC), 63.0% bis(2-ethylhexyl)sebacate (BEHS) and 1.0% potassium tetrakis(p-chlorophenyl)borate (KTpClPB). This novel copper(II)-selective sensor exhibits a Nernstian response over a wide concentration range from 1.0×10-6 to 1.0×10-1 mol L-1 with a slope of 29.6 (±1.2) mV decade-1, and a lower detection limit of 8.75×10-7 mol L-1. The sensor, which was produced economically by synthesizing the ionophore in the laboratory, has a good selectivity and repeatability, fast response time and stable potentiometric behaviour. The potential response of the sensor remains unaffected of pH in the range of 5.0-10.0. Based on the analytical applications of the sensor, we showed that it can be used as an indicator electrode in the quantification of Cu2+ ions by potentiometric titration against EDTA, and can also be successfully utilized for the determination of copper(II) ions in different real samples.

체외수정시술시 예후 인자로서 정자 첨체반응 유발검사의 유용성 (A Stimulated Acrosome Reaction Test as a Prognostic Factor in In Vitro Fertilization)

  • 김정훈;채희동;강은희;추형식;전용필;강병문;장윤석;목정은
    • Clinical and Experimental Reproductive Medicine
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    • 제25권3호
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    • pp.251-260
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    • 1998
  • It is well known that the clinical test for responsibility of accurate fertilization capacity in male partners is very important to diagnose and treat the infertility. However, it has been reported that the traditional semen analysis cannot accurately predict fertilization and pregnancy potential. The present study was performed to evaluate the acrosomal reaction to ionophore challenge (ARIC) test as a prognostic indicator for fertilization of sperm and oocyte in an in vitro fertilization and embryo transfer (IVF-ET) program. From March 1996 to Februry 1997, 30 couples undergoing IVF program were allocated to this study group. All female partners in the study group were 35 years old or less and their serum level of basal follicle stimulating hormone (FSH) and estradiol $(E_2)$ were normal. All the male partners have normal parameters of semen analysis. The ARIC tests were performed on the day of ovum pick up and in vitro insemination in all the male partners. The controlled ovarian hyperstimulation (COH) using luteal long protocol of gonadotropin releasing hormone (GnRH) agonist was used in all couples for IVF-ET. The acrosomal reaction with $10{\mu}l$ of 10% DMSO was induced spontaneously in $10.1{\pm}9.8%$, and acrosomal reaction with calcium ionophore A 23187 was induced in $27.4{\pm}18.1%$, and the ARIC value was $17.4{\pm}16.2%$. There were no significant correlation between the ARIC value and the fertilization rate ($r^2$=0.044, p=0.268). There were also no significant correlation between the ARIC value and the percentage of the grade I, II embryos ($r^2$=0.046, p=0.261). On the basis of above results, it was suggested that ARIC test might not be a useful prognostic indicator for fertilization in IVF-ET in male partners with normal parameters of conventional semen analysis. We guessed that IVF-ET could be performed to the patients primarily without universal appilcation of ARIC test to all male partenrs, and if fertilization failure occurs, the micro assisted fertilization (MAF) such as intracytoplsmic sperm injection (ICSI) might be used as an alternative mode of treatment with acceptable success rate.

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해마추상체 신경세포에서 칼슘에 의한 신경섬유 성장억제에 대한 칼파인 억제제의 영향 (Effect of Calpain Inhibitors on $Ca^{2+}-Induced$ Suppression of Neurite Outgrowth in Isolated Hippocampal Pyramidal Neurons)

  • 송동근
    • 대한약리학회지
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    • 제29권2호
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    • pp.165-174
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    • 1993
  • 칼슘이온은 신경섬유 성장의 중요한 조절인자이나 그 정확한 작용기전은 불명확하다. 세포골격 단백은 in vivo 및 in vitro에서 칼슘의존성 단백분해효소(칼파인)에 의해 신속히 분해되므로, 칼슘이온에 의한 신경섬유의 퇴행에 있어서 칼파인의 관련성을 추구하기위하여, 배양된 해마신경세포에서 칼슘이온 ionophore인 A23187에 의한 신경섬유의 성장억제가 칼파인의 억제제인 EST 및 MDL 28170에 의해 차단되는지를 조사하였다. A23187은 100nM의 농도에서 축삭에는 영향이 없이 수상돌기의 퇴행을 유발하였으나, 300 nM의 농도에서는 축삭의 성장을 억제하였다. EST(5 혹은 20 uM) 및 MDL 28170(20 uM)은 100 nM A23187의 수상돌기에 대한 작용과 300 nM A23187의 축삭에 대한 작용을 효과적으로 차단하였다. EST는 A23187에의한 세포내 칼슘이온의 증가를 차단하지 못하였다. 이상의 결과는 해마추상체세포에서 칼슘에 의한 신경섬유의 퇴행이 칼파인에 의해 매개됨을 시사한다.

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시호 Saponin의 혈소판 활성화 작용에 관한 연구 (Studies on Platelet Activation of Saikosaponin Isolated From Bupleuri Radix)

  • 박영현;송민주;김남수
    • 한국식품위생안전성학회지
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    • 제13권4호
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    • pp.355-359
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    • 1998
  • 식물중에서 배당체 일종인 saponins을 다량 함유한 시호(Bupleurum falcatum)로부터 생체 조절 기능을 갖는 유효성분을 분리하여 혈소판 활성화 작용을 통하여 뇌심혈관계 질환 연구에 이용하고자 시호 용매 분획물에서 분리 및 동정한 Saikosapini을 thronbin, collagen, arachidonic acid 등의 효능제(agonist)와 세포의 $Ca^{2+}$ 의존성을 비교연구하였다. 시호 용매추출물 중에 acetone 추출물이 혈소판 응집작용이 강하며, 그 유효성분을 분리 및 동정한 saikosaponin a와 d는 C16 위치에 각각 ${\alpha}와\;{\beta}$형의 OH기를 갖는 이성체로, saikosapnin d가 a보다 강한 응집작용을 갖는 구조활성관계를 나타내고 있다. 각 효능제에 따라서 혈소판 활성화에 대한 세포의 $Ca^{2+}$ 의존성은 thrombin > colagen $\geq$ PAF>PMA> arachidonic acid $\geq$ Ionophore A23187순으로 나타났다. 시호 추출물 및 saikosaponin의 혈소판 활성화 작용은 기존 효능제와 다른 세포의 $Ca^{2+}$의존성을 나타내는 것으로 사료된다.

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