• Title/Summary/Keyword: Incubating

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Nitrate uptake of the red tide dinoflagellate Prorocentrum micans measured using a nutrient repletion method: effect of light intensity

  • Lee, Kyung Ha;Jeong, Hae Jin;Kim, Hye Jeong;Lim, An Suk
    • ALGAE
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    • v.32 no.2
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    • pp.139-153
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    • 2017
  • The ability of a red tide species to take up nutrients is a critical factor affecting its red tide dynamics and species competition. Nutrient uptake by red tide species has been conventionally measured by incubating nutrient-depleted cells for a short period at 1 or 2 light intensities. This method may be applicable to certain conditions under which cells remain in oligotrophic water for a long time and high nutrients are suddenly introduced. Thus, a new method should be developed that can be applicable to the conditions under which cells are maintained in eutrophicated waters in healthy conditions and experience light and dark cycles and different light intensities during vertical migration. In this study, a new repletion method reflecting these conditions was developed. The nitrate uptake rates of the red tide dinoflagellate Prorocentrum micans originally maintained in nitrate repletion and depletion conditions as a function of nitrate concentration were measured. With increasing light intensity from 10 to $100{\mu}E\;m^{-2}s^{-1}$, the maximum nitrate uptake rate ($V_{max}$) of P. micans increased from 3.6 to $10.8 pM\;cell^{-1}d^{-1}$ and the half saturation constant ($K_{s-NO3}$) increased from 4.1 to $6.9{\mu}M$. At $20{\mu}E\;m^{-2}s^{-1}$, the $V_{max}$ and $K_{s-NO3}$ of P. micans originally maintained in a nitrate repletion condition were similar to those maintained in a nitrate depletion condition. Thus, differences in cells under nutrient repletion and depletion conditions may not affect $K_{s-NO3}$ and $V_{max}$. Moreover, different light intensities may cause differences in the nitrate uptake of migratory phototrophic dinoflagellates.

pH changes by Streptococcus sobrinus on some commercial drinks (Streptococcus sobrinus에 의한 일부 시판음료의 pH 변화)

  • Youn, Hye-Jeong
    • Journal of Korean society of Dental Hygiene
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    • v.7 no.2
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    • pp.167-176
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    • 2007
  • Objectives: The purpose of this study was to investigate the dental caries activity of some commercial drinks. Methods : Acidity levels were recorded as pH values of original drinks and amount of 50%-sodium hydroxide(NaOH) required to neutralize by titration 50.00ml of the drink(It was called titratable acid). Acidity of the drinks with S. sobrinus was measured at an interval of one hour after incubating ($37^{\circ}C$) the test drinks and control solution which was composed 20.00ml of neutralized drinks as pH 7.0 with 0.2ml of a pooled suspension of S. sobrinus. Results : The drink with the highest pH value was the Cow's milk(pH $6.70{\pm}0.01$), and the most acidic was the Carbonated drink(pH $2.40{\pm}0.02$). The drink with the highest buffer effect was the Fruit juice($139.78{\pm}0.76$), and the lowest was the Glucose solution(control, $4.42{\pm}0.20$). The drinks with S. sobrinus during incubation at $37^{\circ}C$ for 24h were decreased to below critical pH 5.5. Spending times from pH 7.0 to pH 5.5~5.0 were Glucose solution(less than 1h). Carbonated drink(3h), Fruit juice(5h), Cow's milk(8h) and Mixed drink(21h). Conclusions: These results show that some commercial drinks with S. sorbrinus have the possibility of tooth decalcification. Thus, it is suggested that the people who have the low salivary secretion rate and the children who sleep without toothbrushing after drinking need the instruction for diet control and oral health education.

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Preparation and Management of Recipients in Bovine Embryo Transfer (수정란이식에 있어서 수란우의 준비와 관리)

  • 김창근
    • Journal of Embryo Transfer
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    • v.1 no.1
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    • pp.35-49
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    • 1986
  • Recipients are an integral part of embryo transfer and they are expensive to maintain as a good recipient. Recipient management is one of the most important components in a successful embryo transfer program. Management includes selection and subsequent care of the animals. A good recipient is basically on "open" cows or heffers whose reproductive tract is capable of receiving one or two embryos and incubating it to term. Potential recipients should be always be healthy and cycling normally ranging from 18 to 23 days. A thorough veterinary examination is recommended for candidate of recipients and cattle for questionable health should be eliminated from the recipient herd. Age and size of recipients are particularly important considerations when heifers are used, because of most embryos available for transfer are from large dams and sires. Body condition can influence a recipient's production, reproduction and health. Obese and underconditioned cattle should be avoided for use. Transfer of fresh embryos especially requires precise synchronization of donors and recipients. For estrus synchronization, PGF$_2$$\alpha$ is injected twice 10 to 12 days apart and short4erm progestagen treatment is applied to potential recipient cattle by coil into vagina (PRID) or ear implant (Synchro-Mate-B). The highest pregnancy results are achieved in recipients at exact synchrony with donors or 12 to 24 hr earlier than donors. Estrus detection is a major factor in breeding efficiency. High accuracy can be achieved by use of heat mount detection alds or by obserbing cattle for 30-minute peroids 3 times daily. Assay progesterone in milk can be used to discrIminate between pregnant and nonprenant recipients. Rectal palpation on day 35 to 70 after is an accurate and safe method of pregnancy diagnosis. Embryonic mortality in recipients may be associated with factors such as high environmental temperature and nutritional or lactational stress in early lactation period. Achievement of short calving interval requires concentrated management activity during the first 90 days following calving. Acceptable candidate for a recipient should be routinely vaccinated for infectious diseases. Proper nutritional programs according to NRC requirements and body condition scoring system for recipient cattles are vital to the ultimate success of an embryo transfer program.r program.

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Effects of Oxidant, Reductant Treatment and Its Phosphorylation on Qualities and Functional Properties of Defatted Rice Bran Protein Isolates (산화.환원제처리 및 인산화가 분리탈지미강단백의 품질 및 기능적 성질에 미치는 영향)

  • Park, Wan-Kyu;Kim, Seung-Yeol;Lee, Ka-Sun
    • Korean Journal of Food Science and Technology
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    • v.20 no.1
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    • pp.106-111
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    • 1988
  • Comparative effects of oxidant, reductant treatment and its phosphorylation on qualities and functional properties of defatted rice bran protein isolates were investigated. Effects of oxidant and reductant treatment were that essential amino acid content of protein isolates was high and its color, pepsin digestibility were good. The phosphorylated defatted rice bran protein isolated was taken by incubating sodium trimeta phosphate in aqueous solution at pH 10.5 and $35^{\circ}C$ for 3 hours and its protein score was 55. Functional properties such as solubility, whipping activity and foam stability were much improved. But color, pepsin digestibility, bulk density and fat absorption were not affected by phosphorylation.

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Analysis of Outer Membrane Proteins of Yersinia enterocolitica Isolated from Mountainspring Water and Pig

  • Shin, Sung-Jae;Park, Joo-Youn;Park, In-Soo;Shin, Na-Ri;Lee, Deog-Yong;Cho, Young-Wook;Park, Yong-Ha;Yoo, Han-Sang
    • Journal of Microbiology and Biotechnology
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    • v.12 no.4
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    • pp.674-678
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    • 2002
  • Yersinia enterocolitica causes various diseases in humans, including enteritis. The onset of such diseases is closely related with the expression of important virulence factors, particularly outer membrane proteins (OMPs). The expression of OMPs depends on several factors, including temperature, and origin, biotype and serotype of the bacteria. Recently, concerns over food safety have increased along with the demand for the development of sensitive, rapid, and pathogen-specific detection methods. To develop a suitable detection method for Y. enterocolitica isolated from Korean moutainspring water and pig feces, the OMP expression patterns were analyzed phenotypically and immunologically using 12 representative strains from 51 Y. enterocolitica Korean isolates. A 38-kDa OMP was commonly observed in all strains. However, additional OMPs were also observed in different biotypes and serotypes as well as bacterial origins, by incubating Y. enterocolitica at a low temperature. The specificity of the 38-kDa OMP was confirmed by a Western blot analysis with antisera against Y. enterocolitica and Brucella abortus. The results, therefore, indicate that the 38-kDa OMP could be used as a marker for detecting Y. enterocolitica in the environment or for seromonitoring.

The Relaxant Activity of Safranal in Isolated Rat Aortas is Mediated Predominantly via an Endothelium-Independent Mechanism - Vasodilatory mechanism of safranal -

  • Razavi, Bibi Marjan;Amanloo, Mojtaba Alipoor;Imenshahidi, Mohsen;Hosseinzadeh, Hossein
    • Journal of Pharmacopuncture
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    • v.19 no.4
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    • pp.329-335
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    • 2016
  • Objectives: Safranal is a pharmacologically active component of saffron and is responsible for the unique aroma of saffron. The hypotensive effect of safranal has been shown in previous studies. This study evaluates the mechanism for the vasodilatory effects induced by safranal on isolated rat aortas. Methods: To study the vasodilatory effects of safranal (0.2, 0.4 and 0.8 mM), we contracted isolated rat thoracic aorta rings by using $10^{-6}-M$ phenylephrine (PE) or 80-mM KCl. Dimethyl sulfoxide (DMSO) was used as a control. The vasodilatory effect of safranal was also evaluated both on intact and denuded endothelium aortic rings. Furthermore, to study the role of nitric oxide and prostacyclin in the relaxation induced by safranal, we incubated the aortic rings by using L-NAME ($10^{-6}M$) or indomethacin ($10^{-5}M$), each for 20 minutes. Results: Safranal induced relaxation in endothelium-intact aortic rings precontracted by using PE or KCl in a concentration-dependent manner, with a maximum relaxation of more than 100%. The relaxant activity of safranal was not eliminated by incubating the aortic rings with L-NAME ($EC_{50}=0.29$ vs. $EC_{50}=0.43$) or with indomethacin ($EC_{50}=0.29$ vs. $EC_{50}=0.35$), where $EC_{50}$ is the half maximal effective concentration. Also, the vasodilatory activity of safranal was not modified by endothelial removal. Conclusion: This study indicated that relaxant activity of safranal is mediated predominantly through an endothelium-independent mechanism.

Effects of ${\gamma}-Irradiation$ on Meat Proteins (감마선 조사가 육단백질에 미치는 영향)

  • Yook, Hong-Sun;Kim, Mee-Ree;Kim, Jung-Ok;Lim, Seong-Il;Byun, Myung-Woo
    • Korean Journal of Food Science and Technology
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    • v.30 no.2
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    • pp.407-412
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    • 1998
  • The proteins extracted from beef, pork and chicken meats were irradiated with up to 100 kGy at room temperature. The extracted proteins were evaluated on their in vitro digestibility by incubating successively with pepsin and pancreatin conjugate. Amino acid compositions and SDS-PAGE pattern were also analyzedin for these proteins. Gamma irradiation within the applied dose range (up to 100 kGy) produced negligible in in vitro digestibility and amino acid composition. Analysis of gamma-irradiated proteins by SDS-PAGE revealed radiolysis of ovalbumin to proteins or peptides with lower molecular weight. On the other hand, the proteins directly extracted from irradiated meats containing moisture were also evaluated for their in vitro digestibility, amino acid compositions and SDS-PAGE pattern. However, the results obtained from this experiment were similar to those of irradiated proteins after extraction from the meats.

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Liposome/Tat Complex for Facilitating Genistein Uptake into B16 Melanoma Cells

  • Park, Young-Mi;Kang, Myung-Joo;Moon, Ki-Young;Park, Sang-Han;Kang, Mean-Hyung;Choi, Young-Wook
    • Journal of Pharmaceutical Investigation
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    • v.41 no.4
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    • pp.205-210
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    • 2011
  • Genistein (GT), a major isoflavone found in soybeans, has a potent antioxidant effect that protects the skin from UV-induced damages and malignant melanoma. In order to enhance the cellular uptake of GT, liposome/Tat complexes were prepared by an electrostatic interaction of anionic liposome (DMPC/DCP, 9:1 in molar ratio) with Tat peptide (0.02 to 0.08 mole), one of the well-known cell penetrating peptide (CPP). As the amount of Tat increased, the size increased but the zeta potential decreased. In vitro release study with dialysis membrane elicited GT release from liposomal preparations in a controlled manner. The addition of Tat increased GT release, especially for the initial period. In the cellular uptake study by incubating B16 melanoma cells with various liposomal preparations containing GT, B16 melanoma cells demonstrated a time-dependent increase of drug accumulation. Compared to the aqueous GT suspension, intracellular uptake was substantially enhanced by anionic liposomal formulation and further increased by the complex formulation. Therefore, liposome/ Tat complex might be a good candidate for facilitating intracellular drug delivery.

Development of Simple Colorimetric Method for Detecting Contamination of Liquid Spawn of Oyster Mushroom by pH Indicator (pH지시약을 이용한 느타리버섯 액체종균 오염 간이진단법 개발)

  • Jang, Myoung-Jun;Lee, Yun-Hae;Ju, Young-Cheol
    • The Korean Journal of Mycology
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    • v.36 no.1
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    • pp.9-15
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    • 2008
  • For the detection of contaminated liquid spawn, we selected suitable medium, indicator and developed method of diagnosis. The growth of pathogenic bacteria, Pseudomonas sp., and fungi, Trichoderma sp., in YPL media was better than in PDA and NA. In addition, the changes of color and absorbance of media were obviously showed when contaminated liquid spawn by pathogenic bacteria and fungi was incubated on YPL including phenol red for 48 hour at $25^{\circ}C$. The color of YPLP after incubating of infected liquid spawn by Pseudomonas sp. and Trichoderma sp. were changed from orange to red and to scarlet, respectively. Whereas, the color of YPLP after incubation of only Pleurotus ostreatus indicated yellow at liquid spawn. Therefore, it is possible to easily distinguish contaminated liquid spawn by color of change in YPLP.

Native Habitat Survey of Wax Myrtle in Cheju Province and Its Propagation by Seed and Cutting (제주도의 소귀나무 자생지 조사, 실생 및 삽목번식)

  • Ko, Sung-Jun;Kang, Hoon;Ji, Sung-Han;Jang, Jeon-Ik
    • Journal of Bio-Environment Control
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    • v.6 no.3
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    • pp.225-234
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    • 1997
  • This study was carried out to investigate the native distribution of wax myrtle (Myrica rubra) in Cheju Province and its propagation method. Wax myrtle is heavily distributed at 100 to 400m above sea level of Donhong-chun and Hyodon-chun which is bordered by Youngchon-dong of Seogwipo City and Haryeri of Namcheju county. BA, IBA, Kinetin, IAA, and GA3 were applied to promote rooting of cutting but were ineffective in promoting rooting. Treating cuttings with both AgNO,1 which removes rooting inhibitor, tannin and growth regulators such as BA, IBA and Kinetin were also ineffective in promoting rooting. Incubating seeds at 4$0^{\circ}C$ for 30 days resulted in 39% germination. There was distinct difference in leaf shape between seedlings and mature trees.

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