검색결과

검색조건
좁혀보기
검색필터
결과 내 재검색

간행물

    분야

      발행연도

      -

        검색결과 46

        21.
        2012.06 구독 인증기관·개인회원 무료
        In mammal, oocytes are arrested at the metaphase Ⅱ until fertilization. However, unfertilized oocytes that remain in the oviduct or under in vitro culture, which is called "oocyte aging". Asynchrony negatively affects fertilization, pre- and post-implantation embryo development. Caffeine is known to phosphodiesterase inhibitor that rescues oocyte aging in several species. Nevertheless, the effect of caffeine was not clear in bovine aging oocytes. In this study investigated the cytoskeleton distribution in aged oocytes and the embryo development ability of aged oocytes from treated with or without caffeine during maturation. The cumulus and oocyte complexes (COCs) were cultured in 10% FBSTCM199 for up to 22h at 38.5℃ in 5% CO₂. For oocyte aging study, the COCs were cultured in 10% FBS-TCM199 supplemented with or without 10 mM caffeine for 40hs. And then oocytes underwent in vitro fertilization using highly motile sperm recovered from frozen and than thawed bull semen. As a result normal cytoskeleton percentage of caffeine treatment group more than the aging group (67.57%±4.11 VS 44.61%±6.40) and no significantly different compared to control group. Aged oocytes derived from addition of caffeine to the in vitro maturation medium significantly increased the percentage of 2- cell that developed to the blastocyst stage compared to the aging group. Blastocysts derived from caffeine treatment group significantly increased the total cell number compare aging (90.44%±10.18 VS 67.88%±7.72). Apoptotic fragmenting of genomic DNA was measured in individual embryos using the TUNEL assay. Blastocyst derived from caffeine treatment group significantly decereased the apoptotic index compared to blastocyst derived from aging group. In conclusion, we inferred that the caffeine treatment during oocytes aging periode can improved the develpmental rate and quaility in bovine embryos developing in vitro.
        22.
        2011.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this study, 160 tea tree (Camellia sinensis L.) lines were classified by caffeine content using colorimetric methods. Among them, caffeine-rich lines (HR-78, HR-137, HR-82 and HR-123) and poor lines (HP-85, HP-88, HP-19, and HP-131) were selected. To know the difference in morphological and genetic characters between caffeine-rich and poor lines, we used leaf/shoot growth and RAPD methods. Cluster pattern of morphological characters (leaf width, leaf length, leaf area and shoot length) showed that shoot length was longer in caffein-rich lines than in -poor lines. In genetic analysis, amplified DNA bands having various sizes were detected in RAPD analysis where 30 random primers were used. However, the discriminated primer set that distinguish caffein-rich tree line from -poor lines was not found. These results can be used as the basic data to determine the morphological and genetic differences among caffein-rich and -poor lines
        4,000원
        24.
        2008.12 구독 인증기관 무료, 개인회원 유료
        The objective of this study was to examine the effect of caffeine and sodium bicarbonate in a fertilization medium on the fertilizability of boar spermatozoa that were frozen in straws. Boar spermatozoa were extended with Beltsville F5 extender and frozen in 0.25‐ml straws. In vitro matured porcine oocytes were fertilized in vitro (IVF) with frozen‐thawed boar spermatozoa for 6 h in a modified tris‐buffered medium (mTBM) or in its modified medium by substituting the tris with 25 mM sodium bicarbonate (modified bicarbonate‐buffered medium; mBBM). Some of inseminated oocytes were fixed and stained for examination of sperm penetration. IVF embryos were cultured in a North Carolina State University‐23 medium for embryo development. The percentage of live sperm was 47±4% and morphological abnormality of acrosome was found in 14±3% of spermatozoa. Optimal sperm concentration for IVF was 0.75~1.0×106 sperms/ml when mTBM containing 5 mM caffeine was used as the fertilization medium. Sperm penetration was significantly (p<0.05) stimulated by increasing caffeine concentration in the IVF medium. In addition, mBBM significantly (p<0.05) increased sperm penetration (92%) compared to mTBM (65%). More (p<0.05) blastocysts (22% vs. 32%) developed from the oocytes that were fertilized in mBBM containing 1 mM caffeine than from those fertilized in mTBM with 5 mM caffeine. Our results indicate that boar spermatozoa can be frozen successfully in straws with holding their normal fertilizability and that caffeine and sodium bicarbonate stimulates sperm penetration in vitro.
        4,000원
        25.
        2008.12 구독 인증기관 무료, 개인회원 유료
        The techniques of IVM, IVF and IVC of canine oocytes may provide useful information for gamete salvage programs and the conservation of endangered canidae. This investigation has been made to determine the efficiency of in vitro maturation (IVM) as a basic experiment to study the development of canine oocytes after in vitro fertilization (IVF). The rate of oocytes developing to the MII stage was higher in the hormone treated group (10 IU/ml hCG+eCG, 14.7%, p<0.05) than in the control group (0 IU/ml hCG+eCG, 10.0%). The monospermy and pronuclear rates of canine oocytes were investigated after caffeine treatment on IVF. Canine oocytes were fertilized in the Fert‐TALP medium supplemented with 0, 10, 20 or 30 mM caffeine (Fert I, Fert II, Fert III or Fert IV, respectively). The highest pronuclear formation rate was obtained in the Fert I for 24 h IVF (6.7%, 6/89). Therefore, it is believed that unlike in other mammals, caffeine in canine IVF does not increase the efficiency of fertilization rate, and is not an important factor.
        4,000원
        29.
        2005.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Radioprotection is of practical importance for the normal tissues of tumor patients subject to radiotherapy, people with planned or accidental exposure to radiation, and the public and radiation workers. Since oxygen enhances radiation - induced biologica
        4,000원
        31.
        2002.09 KCI 등재 구독 인증기관·개인회원 무료
        Snails and slugs are members of the mollusk phylum. They are similar in biology and structure, except slugs lack the snail's external spiral shell. Snails and slugs feed on a variety of living plants, decaying plant matter, fruit, and flowers. They are among the most bothersome creatures on horticultural crops such as Chinese cabbage, cabbage, lettuce, ginseng, lily, and orchid (Kim et al., 1990; Kim, 1992; Sorensen, 1994). Several species of
        32.
        2001.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was performed to survey and evaluate the contents of caffeine in commercial palatability foods by HPLC. The contents of caffeine in commercial palatability foods were 9.0-49.2 mg in black tea, 35.9-141.4 mg in coffee, 12.4-48.0 mg in green tea, 7.1-16.5 mg in brown rice green tea, 22.8 mg in cocoa tea, 10.3-25.0 mg in cola and 10.0-48.2 mg in ice bar(coffee) respectively. The contents of caffeine extracted from black tea, coffee(roasted beans) and green tea were rapidly increased for five minutes from the extraction initiation, and were not nearly changed after ten minutes. Moreover, the caffeine contents were increased until 100℃ of extraction temperature.
        4,000원
        35.
        1999.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        To make up the medium for quantitative selection of capacitated-sperm through sucrose layer, the effects of BSA, caffeine, heparin and progesterone on sperm swim-up migration and movement were examined. And the results obtained were as follows; 1. BSA of 4mg/ml in bMSS stimulated sperm migration and movement, and attracted capacitated-sperm. 2. Caffeine of 5mM in bMSS containing 4mg/ml BSA stimulated sperm movement and attracted capacitated-sperm. 3. Heparin of 20/ml in bMAA containing both 4mg/ml BSA and 5mM caffeine stimulated movement and capacitation of sperm. 4. Progesterone of 50/ml in bMSS containing all 4mg/ml BSA, 5mM caffeine and 20/ml heparin (BCHP-MSS) attracted capacitated-sperm. 5. Effect of BCHP-MSS on sperm on sperm attraction was not different from effect of 10% follicular fluid solution (FF-MSS) on sperm swim-up separation. In conclusion, bMSS with 4mg/ml BSA, 5mM caffeine, 20/ml heparin and 50/ml progesterone(BCHP-MSS) was a optimal condition for selection of capacitated-sperm through sucrose layer.
        4,000원
        36.
        1996.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 수정능획득유기물질로 알려진 카페인 헤파린을 병행처리하여 한우 정자의 첨체 반응율과 생존율을 알아보고 수정능획득과정 중에 단백질의 변화상을 전기영동방법으로 조사하였다. 동결융해후 정자의 생존율은 90%이상이었으나 전배양처리후 0.5시간에 70%로 감소하고 2시간 이후에는 35%로 감소하였다. 정자의 첨체반응율은 동결융해후 정상정자가 85.7%였으나 전배양시간에 따라 53.4%에서 14.3%로 감소하였다. 동결융해후 첨체가 소실된 생존정자는 9.
        4,000원
        38.
        1992.11 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Effects of caffeine, heparin and caffeine-heparin treatments for in vitro capacitation of Korean Native Cattle sperm on acrosorne reaction and viability were studied using the methods of Wells-Awa and Dual stain. The results were summerized as follows: 1. The acrosome reaction of sperm when treated with caffeine after 0 to 4 hrs of preincubation were 11.0~75.7% for Wells-Awa stain, and 14.3~75.55% for Dual stain. True acrosome reaction of sperm for Dual stain was 3.0~29.2%. The viability of sperm was 62. 2~27.2%. 2. The acrosome reaction of sperm when treated with heparin after 0 to 4 hrs of preincubation were 17.0~81.2% for Wells-Awa, and 14.3~75.5% for Dual Stain. True acrosome reaction of sperm for Dual stain was 1.5~26.6%. The viability of sperm was 58.6~35. 8%. 3. The acrosome reaction of sperm when treated with caffeine-heparin after 0 to 4 hrs of preincubation were 13.0~83.2% for Wells Awa, and 11.0~78.5% for Dual stain. True acrosome reaction of for Dual stain was 5.1~26.3%. The viability of sperm was 60.5~30.1%.
        4,000원
        40.
        2018.12 KCI 등재 서비스 종료(열람 제한)
        During the past few decades, significant increase in the consumption of coffee has led to rapid increase in the production of coffee waste in South Korea. Spent coffee waste is often treated as a general waste and is directly disposed without the necessary treatment. Spent Coffee Grounds (SCGs) can release several organic contaminants, including caffeine. In this study, leaching tests were conducted for SCGs and oxidative degradation of caffeine were also conducted. The tested SCGs contained approximately 4.4 mg caffeine per gram of coffee waste. Results from the leaching tests show that approximately 90% of the caffeine can be extracted at each step during sequential extraction. Advanced oxidation methods for the degradation of caffeine, such as UV/H2O2, photo-Fenton reaction, and UV/O3, were tested. UV radiation has a limited effect on the degradation of caffeine. In particular, UV-A and UV-B radiations present in sunlight cause marginal degradation, thereby indicating that natural degradation of caffeine is minimal. However, O3 can cause rapid degradation of caffeine, and the values of pseudo-first order rate constants were found to be ranging from 0.817min-1 to 1.506 min-1 when the ozone generation rate was 37.1 g/m3. Additionally, the degradation rate of caffeine is dependent on the wavelength of irradiation.
        1 2 3