검색결과

검색조건
좁혀보기
검색필터
결과 내 재검색

간행물

    분야

      발행연도

      -

        검색결과 77

        21.
        2011.10 구독 인증기관·개인회원 무료
        Bacterial contamination reduces the semen quality, semen preservation, and cause of disease spread as well. Sperm fertility is essential factor of reproductive performance in swine. Sperm fertility is affected by semen quality such as sperm motility, abnormality, morphology, and rate of bacterial contamination. This study was conducted to determine the relationship between elapsed time after semen preservation on the changes of bacteria and semen quality. Semen was diluted with BTS extender without antibiotic for 7 days and sperm parameter and fertility were measured. Sperm motility was measured by CASA and total bacteria number was counted after 22 24 hr incubation from counting agar plate in which sperm dilute to 10 106 in 0.9% saline solution and inoculate to agar. Acrosomal integrity was measured by Chlortetracycline (CTC) staining. CTC patterns were uniform fluorescence over the whole head (pattern A), characteristic of uncapacitated acrosome-intact spermatozoa; fluorescence-free band in the post-acrosomal region (pattern B), characteristic of capacitated acrosome-intact spermatozoa; and almost no fluorescence over the whole head except for a thin band in the equatorial segment (pattern C), characteristic of acrosome reacted spermatozoa. Total number of bacteria was significantly increased (p<0.0001) 3 days after preservation. Sperm motility, viability, and morphological abnormality on elapsed time after preservation were lower from 5 (77.24±6.47, p<0.001) and 7 days (77.24±6.47, p< 0.001) after preservation compared to 1 (15.71±7.18) and 3 days(18.39±7.22) after preservation, respectively. Sperm viability was significantly lower (53.25±35.03, p<0.0001) at 7 days after preservation. Mohological abnormality of sperm was lower (p<0.001) at 1 (15.71±7.18) and 3 (18.39±7.22) days compared to (5 21.84±7.91) and 7 (22.59± 9.93) days after preservation. Acrosomal integrity and capacitation rate (pattern A) were significantly lower (p<0.001) from 5 days after preservation.
        33.
        2007.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The quantification of ammonia concentrations has received a lot of scientific attention. Numerous devices for the quantification of NH3 in the ambient air have been developed to provide more technical possibilities for research in abating NH3 emission from various source processes. For the proper quantification of NH3, a number of sampling methods have been discussed by grouping them into different categories based on the principle of functioning. In general, active samplers employ pumps to draw air in, while passive samplers are exposed to air over a certain period of time to obtain integrated signature of NH3. In case of the former, impingers and absorption flasks can be employed simultaneously with suitable absorbents to capture NH3 passing through them. The methods of analysis include both in-situ and laboratory determination. In the laboratory, colorimetric or ion chromatographic methods are generally used for its quantification. In the field, a number of real time analyzers have been proven to be useful. These real time analyzers can be grouped according to their principle of operation. These analyzers may use the principle of spectroscopy (e.g. DOAS), photoacousticics (e.g. photoacoustic monitor) or Chemiluminescence (NOx analyzer). The automated annular denuder sampling system with on-line analyzer is also suitable for continuous monitoring of ammonia in air.
        4,500원
        37.
        2006.04 구독 인증기관·개인회원 무료
        The corrosion performance of a powder metallurgical aluminum alloy in aeronautical environments was studied for both as sintered and heat treated states. Sintered samples were obtained by uniaxial pressing of an Al-Cu-Mg prealloyed powder followed by liquid phase sintering. The heat treatments applied were T4 and T6. Corrosion behaviour was assessed by means of potentiodynamic polarization. Results for the equivalent commercial wrought counterpart, AA2024-T3, are also presented for comparison. Similar corrosion performance was observed for both as sintered and AA2024-T3 samples, while corrosion resistance of the PM materials was improved by the heat treatment, especially in the T4 state.
        38.
        2005.06 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        The Cosmic Evolution Survey (COSMOS) is a Hubble Space Telescope (HST) treasury project. The COSMOS aims to perform a 2 square degree imaging survey of an equatorial field in I(F814W) band, using the Advanced Camera for Surveys (ACS). Such a wide field survey, combined with ground-based photometric and spectroscopic data, is essential to understand the interplay between large scale structure, evolution and formation of galaxies and dark matter. In 2004, we have obtained high-quality, broad band images of the COSMOS field (B, V, r', i', and z') using Suprime-Cam on the Subaru Telescope, and we have started our new optical multi-band program, COSMOS-21 in 2005. Here, we present a brief summary of the current status of the COSMOS project together with contributions from the Subaru Telescope. Our future Subaru program, COSMOS-21, is also discussed briefly.
        3,000원
        39.
        2005.06 구독 인증기관 무료, 개인회원 유료
        This study were examined whether plasminogen activators (PAs) are produced by porcine fresh or frozen-thawed cumulus-oocytes complexes (COCs) and cumulus cell free-oocytes. In fresh or frozen-thawed COCs and oocytes for 0 hour cultured, no activity of PAs was detected. However, at 24 hours of culture urokinase-type plasminogen activator (uPA) was detected in COCs and denuded oocytes. In the frozen-thawed COCs and cumulus cell free-oocytes cultured for 24 hours, no PAs were observed. After COCs were cultured for 48 hours, tissue-type plasminogen activator (tPA) and tPA-PAI were observed in COCs only. In the frozen-thawed COCs and cumulus cell free-oocytes cultured for 48 hours, no PAs were observed. These results suggest that uPA, tPA and tPA-PAI are produced by porcine COCs, but only uPA by oocytes during maturation for 24 hours. Only tPA, and tPA-PAI are produced by COCs cultured for 48 hours, and no PAs are produced by denuded-oocytes cultured for 48 hours. In all of the frozen-thawed groups, no PAs are observed by COCs and denuded-oocytes.
        4,000원
        1 2 3 4