• Title/Summary/Keyword: centrifugation

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The Effect of Fertilization on Capacitation in vitro ; Inverment of Epididymal Secretions and Preincubation Time (생쥐 정소상체정자의 전배양시간 및 정소상체추출물의 첨가가 체외수정에 미치는 영향)

  • Kim, J.M.;Suh, B.H.;Lee, J.H.;Chung, K.S.
    • Clinical and Experimental Reproductive Medicine
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    • v.17 no.2
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    • pp.123-128
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    • 1990
  • Capacitation of mouse spermatozoa in vitro is brought about by epididymal secretions released into the m-Tgrode medium at the time of sperm collection. Epididymal mouse sperm suspension achived by centrifugation were preincubated for a total of 120min with aliquants being removed at 5, 30 and 120min. By gently centrifugation and resuspending in fresh medium, the fertilizing rate of unwashed 5-and 30-min suspensions was increased such that 30-min washed samples did not differ significiantly from full capacitated, highly fertile 120-min unwashed samples. When epididymal suspension was added fertilization of cumulus intact oocyte was markedly inhibited, although fertilization of zona free oocytes was unaffected. Washing sperm suspensions preincubated in the absence of $Ca^{2+}$ with the subsequent introduction of exogenous $Ca^{2+}$ resulted in a significant increase in fertilization rates over equivalent unwashed samples.

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Localization of Lipoxygenase in Germinating Soybeans (발아중인 대두콩에서의 Lipoxygenase의 국재(局在))

  • Song, Young-Sun
    • Korean Journal of Food Science and Technology
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    • v.19 no.5
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    • pp.441-445
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    • 1987
  • The subcellular distribution of lipoxygenase in germinating soybean seeds (Glycine max[L.] AmSoy) was investigated by using differential centrifugation and sucrose density gradient fractionation. Most of lipoxygenase -1 and -2/3 activities was present in the supernatant fraction after differential centrifugation of homogenates prepared from three-day-old seedlings; only 1.5% of lipoxygenase activity remained in particulate fractions. The results of a sucrose density gradient fractionation (three-day-old) showed that the lipoxygenase activity coincided with acid phosphatase at the densities of 1.19, 1.23, $1.25g/cm^3$, even though most of lipoxygenase and acid phosphatase activities appeared in supernatant fractions. There was no indication that mitochondria contained any lipoxygenase activity, and it does not appear that glyoxysomes and ER contained any lipoxygenase activity either.

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FORMULATION AND STABILITY TEST OF ANTIAGING CREAM CONTAINING METHANOL FRACTION OIL OF PANGIUM EDULE.REINW. AS A RADICAL SCAVENGER AGENT

  • Djajadisastra, J.;Anwar, E.;Milani, E.
    • Proceedings of the SCSK Conference
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    • 2003.09b
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    • pp.303-306
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    • 2003
  • Indonesia is a tropical country having a temperature range of 25-35$^{\circ}C$ which can affect the skin and causes damages like aging. This aging process is due, at least, to free radical reactions. For this reason, many attempts had been done to find out creams containing natural antioxidant compound which have a potential of free radical scavenger. Kluwek, a fermented form of foot ball fruit or picung (Pangium edule.Reinw), had been proved to contain antioxidant compound in its methanol fraction oil to which antiaging cream was formulated. Stability evaluation was conducted for cream with Kluwek oil compared to base cream, including organoleptic (colour and odour), pH, viscosity, particle size, centrifugation test and flow characteristics either in room temperature (27$^{\circ}C$) or stress condition (4$^{\circ}C$ and 5$0^{\circ}C$) for 8 weeks continuously, and six times cycling test at 4$^{\circ}C$ and 5$0^{\circ}C$ every 24 hours. The results showed that cream with Kluwek oil and base cream were stable at temperature 27 and 4$^{\circ}C$, cycling test and centrifugation test, but not stable at 5$0^{\circ}C$. Free radical evaluation was done by Electron Spin Resonance and the result showed that cream with Kluwek oil had less free radicals compared to base cream.

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Clarification of Mixed Fruit and Vegetable Juices Using Various Clarification Methods (혼합과채주스의 청징 및 품질특성 비교)

  • Sohn, Kyung-Suck;Lee, Jun-Ho
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.35 no.5
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    • pp.629-634
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    • 2006
  • Clarified mixed fruit and vegetable (apple, carrot and orange) juices were prepared using different clarification methods including centrifugation, ultrafiltration (UF), and combined treatment with the blend ratio of 1:1:2, 1:2:1, and 2:1:1 (apple, orange and carrot). Effects of clarification methods on the clarification efficacy as well as other quality parameters were investigated. Clarification was improved with increase in centrifugation speed but was less affected by lowering temperature. Ultrafiltration process was very effective to produce clarified mixed fruit and vegetable juice. Combined treatment did not significantly improve the clarification efficacy since most clarification was already achieved during ultrafiltration process (p>0.05). L*- and b*-values increased while a*-value decreased significantly after clarification regardless of methods in all blend juices (p<0.05). Blend juices with high amount of orange or carrot were better in clarification efficacy and high amount of apple resulted in high turbidity in blend samples.

Electron Microscopical Observation of Transglutaminase-treated Ultra High Temperature Milk Sedimiment (Transglutaminase로 처리한 초고온 살균유 침전물의 전자현미경적 관찰)

  • Moon, Jeong-Han;Hong, Youn-Ho
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.33 no.8
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    • pp.1359-1366
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    • 2004
  • Ultra high temperature treated (UHT) skim milk and colloidal calcium phosphate-free skim milk were treated with microbial transglutaminase (TGase), ultracentrifuged at various rates, lyophilized, and observed for morphological properties with a scanning electron microscope (SEM). UHT skim milk showed small holes of associated micelles at lower centrifugal rates, and became thick and irregular, and fine particles were associated regularly at higher centrifugal rates. When UHT skim milk with TGase was incubated for 1 hour, casein micelles aggregated and broadened as centrifugation rate increased. When UHT skim milk with TGase was incubated for 8 hours, casein micelles were associated irregularly to large aggregates and widened. Colloidal calcium phosphate-free skim milk with TGase incubated for 1 hour and separated by two-step centrifugation showed aggregated lump, while the milk incubated for 8 hours with TGase was associated with broadened, compact, and regular layers as the centrifugation rate increased. Such phenomena were caused by heat treatment, protein crosslinking reaction catalyzed by TGase and conformational changes of casein molecules, and could be dependent on reaction time, temperature and ultracentrifugation rate.

Quality Changes of Orange Juice as Influenced by Clarification Methods (청징방법에 따른 오렌지주스의 품질특성)

  • Sohn, Kyoung-Suck;Seog, En-Ju;Lee, Jun-Ho
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.35 no.3
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    • pp.378-382
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    • 2006
  • Clarified orange juice was prepared using different clarification methods including centrifugation, enzyme treatment, ultrafiltration (UF), and combined treatment(CT). Effect of clarification methods as well as other quality parameters were investigated. Clarification was improved with increase in centrifugation speed and by lowering operating temperature. The optimum condition for centrifugation process was $5^{\circ}C$ and 10,000 rpm. UF and CT processes were very effective to produce clarified orange juice. The optimum condition of UF process was $45^{\circ}C$ and 150 kPa considering flux and turbidity CT did not significantly improve the clarification efficiency since most of the clarification was already achieved during UF process. $L^*$-values increased while $a^*$-values decreased significantly after clarification regardless of methods (p<0.05) Considering color, and recovering rate of vitamin C and soluble solids, UF process was superior than the other methods in producing clarified orange juice.

Efficient isolation of sperm with high DNA integrity and stable chromatin packaging by a combination of density-gradient centrifugation and magnetic-activated cell sorting

  • Chi, Hee-Jun;Kwak, Su-Jin;Kim, Seok-Gi;Kim, Youn-Young;Park, Ji-Young;Yoo, Chang-Seok;Park, Il-Hae;Sun, Hong-Gil;Kim, Jae-Won;Lee, Kyeong-Ho
    • Clinical and Experimental Reproductive Medicine
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    • v.43 no.4
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    • pp.199-206
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    • 2016
  • Objective: This study was carried out to investigate the correlations of the sperm DNA fragmentation index (DFI) with semen parameters and apoptosis, and to investigate the effects of density-gradient centrifugation (DGC) and magnetic-activated cell sorting (MACS) on reducing the proportion of sperm with DNA fragmentation and protamine deficiency. Methods: Semen analysis and a sperm DNA fragmentation assay were performed to assess the correlations between semen parameters and the DFI in 458 semen samples. Sperm with progressive motility or non-apoptosis were isolated by DGC or MACS, respectively, in 29 normozoospermic semen samples. The effects of DGC or MACS alone and of DGC and MACS combined on reducing the amount of sperm in the sample with DNA fragmentation and protamine deficiency were investigated. Results: The sperm DFI showed a significant correlation (r=-0.347, p< 0.001) with sperm motility and morphology (r=-0.114, p< 0.05) but not with other semen parameters. The DFI ($11.5%{\pm}2.0%$) of semen samples was significantly reduced by DGC ($8.1%{\pm}4.1%$) or MACS alone ($7.4%{\pm}3.9%$) (p< 0.05). The DFI was significantly further reduced by a combination of DGC and MACS ($4.1%{\pm}1.3%$, p< 0.05). Moreover, the combination of DGC and MACS ($1.6%{\pm}1.1%$, p< 0.05) significantly reduced the protamine deficiency rate of semen samples compared to DGC ($4.4%{\pm}3.2%$) or MACS alone ($3.4%{\pm}2.2%$). Conclusion: The combination of DGC and MACS may be an effective method to isolate high-quality sperm with progressive motility, non-apoptosis, high DNA integrity, and low protamine deficiency in clinical use.

The Effect of White Water Components on Mechanical Properties of Linerboard (라이너지 공정수의 구성 성분이 종이의 물성에 미치는 영향)

  • 윤혜정;류정용;송봉근;조미선
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.36 no.1
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    • pp.9-15
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    • 2004
  • Micro inorganic solids and dissolved materials contained in the white water of linerboard process was obtained by centrifugation, and their characteristics were analyzed along with their effects on the mechanical properties of linerboard. Micro inorganic materials had little influence on tensile index and ZDT of UKP sheets. They showed rather a positive effect on mechanical properties of KOCC sheets due to adsorbed polymer. Mechanical properties of KOCC sheets decreased remarkably when the concentration of dissolved materials increased especially above 4000 ppm.

Intracellular Localization and Developmental Changes of Purine Catabolic Enzymes during Germination in Cotyledons of Rape Seedlings (발아중 유채자엽 퓨린 분해효소의 활성변화 및 세포내 위치)

  • 권덕기
    • Journal of Plant Biology
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    • v.28 no.3
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    • pp.225-232
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    • 1985
  • Intracellular localization and the developmental changes in activities of uricase and allantoinase during germination were investigated with the cotyledons of rape(Brassica napus L.) seedlings. The development anddisappearance of uricase activity took place independently of light, but allantoinase activity was increased by light. The temporal pattern of uricase activity showed that uricolysis was actively taking place in the cotyledons during their early stages of germination. While uricase can be localized in the microbody fraction isolated from crude organelle extracts of the cotyledons by density gradient centrifugation, most of the allantoinase activity found in the microbody fraction did not appear to be an integral part of the microbody.

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