• Title/Summary/Keyword: thermoresistance

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Effects of glycerol and seminal plasma in characteristics of preserved canine spermatozoa (개 정액의 보존시 glycerol 첨가 및 정장제거가 정자의 성상에 미치는 영향)

  • Kim, Kye-seong
    • Korean Journal of Veterinary Research
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    • v.33 no.2
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    • pp.345-350
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    • 1993
  • Multiple ejaculates were collected from four male mongrel dogs. The second fraction and the small volume of third fraction from the ejaculates were divided and treated as follows : control; addition of the egg-yolk Tris extender to the semen at $37^{\circ}C$. group I; Removal of seminal plasma, group II; addition of the glycerolated extender at $4^{\circ}C$, group III Removal of seminal plasma and addition of glycerolated extender at $4^{\circ}C$. The semen cooled to $4^{\circ}C$ was equlibrated for 2hrs and preserved in refrigerator at $4^{\circ}C$. The preserved semen was evaluated for kinetics, morphology, motility and thermoresistance daily for 3 days. 1. The kinectics after preserved days 2 and 3 of group I was significantly higher than that of control(p<0.05). 2. There were no significant difference in abnormal morphology of each group between the periods of storage. 3. The motility after preserved day 1 and days 3 of group I was significantly higher than that of others(p<0.05), and the molity after preserved days 2 of group I and III was signficantly higher than that of others(p<0.05). 4. When the molity of preserved semen was measured during incubation at $37^{\circ}C$, the motility of four groups was declined at similar rates. There was no effect of removal of seminal plasma and glycerol addition on thermoresistance.

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Association of a Single Nucleotide Polymorphism in the 5'-Flanking Region of Porcine HSP70.2 with Backfat Thickness in Duroc Breed

  • Chen, Ming-Yu;Huang, San-Yuan;Lin, En-Chung;Hseu, Tzong-Hsiung;Lee, Wen-Chuan
    • Asian-Australasian Journal of Animal Sciences
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    • v.16 no.1
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    • pp.100-103
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    • 2003
  • Higher environmental temperature affects the economic performance of pigs. Heat shock protein 70 has been shown to play an important role in thermoresistance. The purpose of this study was to assess the effect of a single nucleotide polymorphism in the 5'-flanking region of porcine HSP70.2 on growth performance in Taiwanese Duroc. The genotype of this nt 393 polymorphic site could be verified by digestion with Bsa WI restriction enzyme of a PCR product. Pigs with TT and TC genotypes have thinner backfats than those with CC type (p<0.05). The result suggested that the polymorphic Bsa WI site in the 5'flanking region of porcine HSP70.2 may be used as a marker for the early selection of ultrasonic backfat thickness in Duroc pigs.

Studies on Thermophilic Flat-sour Bacteria in Soymilk: Isolation, Indentification and Determination of Heat Resistance (두유내의 고온성 Flat-sour 변질균의 분리.동정 및 열저항성에 관한 연구)

  • Chung, Je-Bong;Lee, Kyun-Hee;Sohn, Heon-Soo;Kim, Suk-Min
    • Korean Journal of Food Science and Technology
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    • v.20 no.2
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    • pp.218-224
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    • 1988
  • For the optimization of thermal processing conditions in soymilk process, 4 strains of thermoresistant flat-sour bacteria were isolated from soymilk. The isolates were aerobic spore-forming rods, and grew at $-65^{\circ}C$. Based on the morphological and physiological properties, all of the isolated strains were identified as Bacillus stearothermophilus. The heat resistance of spores of 3 isolates and Bacillus stearothermophillus ATCC 12980 as a reference was determined in soymilk(pH 7.0) and pH 7.0 buffer solution. For each of the spores studied, linear regression equations with standard error were presented for the thermal destruction at 110, 115, 121, and $125^{\circ}C$. It was not obvious that the components of soy milk increased the heat resistance of spores. Between the strains studied, variability was noted in the D values at the different temperature, and no one strain was consistently the most heat resistant at all the given temperatures. The average D value for the 4 strains was 77.27, 20.20, 2.76 and 1.39 min at 110, 115, 121 and $125^{\circ}C$, respectively, and the average z value was $8.36^{\circ}C$.

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Combined Effects of Gamma-irradiation and Hyperthermia on the Human Cell Lines for Various Temperatures and Time Sequences (감마선과 온열치료 병용시 세포 치사 능력 증강에 관한 실험적 연구)

  • Koh Kyung Hwan;Cho Chul Koo;Park Woo Yoon;Yoo Seong Yul;Yun Hyong Geun;Shim Jae Won;Lee Mi Jung
    • Radiation Oncology Journal
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    • v.11 no.1
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    • pp.51-58
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    • 1993
  • We tried to establish the theoretical basis of clinical use of combined modality of hyperthermia and radiation therapy. For this purpose, we made an in vitro experiment in order to get the synergistic and/or additive effects on the cell killing of hyperthermia combined with radiation therapy by using the microwave-hyperthermia machine already installed at our department. In our experiment, we use two human cell lines: MKN-45 (adenocarcinoma of stomach) and K-562 (leukemia cell lines). In cases of combined treatments of hyperthermia and gamma-irradiation, the therapeutic effect was the highest in the simultaneous trial. Hyperthermia after gamma irradiation showed slightly higher therapeutic effect than that before irradiation without significant difference, but its effect was the same in the interval of 6 hours between hyperthermia and irradiation. The higher temperature and the longer treatment time were applied, the higher therapeutic effects were observed. We could observe the thermoresistance by time elapse at $43^{\circ}C$. When hyperthermia was done for 30 minutes at the same temperature, thermal enhancement ratio (TER) at DO. 01 (dose required surviving fraction of 0.01) were $2.5{\pm}0.08,\;3.75{\pm}0.18$, and $5.0{\pm}0.15\;at\;436{\circ}C,\;44^{\circ}C,\;and\;45^{\circ}C$ respectively in K-562 leukemia cell lines. Our experimental data showed that more cell killing effect can be obtained in the leukemia cell lines, although they usually are known to be radiosensitive, when treated with combined hyperthermia and radiation therapy. Furthermore, our data show that leukemia cell lines may have various intrinsic radiosensitivity, especially in vitro experiments. The magnitude of cell killing effect, however, will be less than that of MKN-45.

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