• 제목/요약/키워드: bicarbonate

검색결과 459건 처리시간 0.029초

막걸리 중 ochratoxin A 분석의 개선 (Revision of the Analysis of Makgeolli for Ochratoxin A)

  • 박제원
    • 한국식품과학회지
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    • 제38권1호
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    • pp.140-142
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    • 2006
  • 이전의 연구 결과에 나타난 바 있는 막걸리 중 ochratoxin A의 낮은 회수율(<50%)은 시료 내 본 곰팡이독소의 추출 혹은 전처리 과정의 개선이 필요함을 지적하였다. 본 연구에서 막걸리 시료의 균질화에 이용되던 추출 용액을 PBS 용액 대신 3% sodium bicarbonate 용액으로 채택할 경우, 80% 이상의 첨가된 ochratoxin A가 회수되어 그 검출이 용이해졌다. 한편 개선된 해당 분석법의 막걸리 시료에 대한 적용 가능성을 알아보기 위하여 국내 시판 중인 살균막걸리 30점을 대상으로 분석한 결과 밀 막걸리 2점에서 ochratoxin A가 검출되었고(0.8, 2.1 ppb), 그 결과를 다시 HPLC-ESI-MS로 확정하였다. 본 연구를 통해 수행된 개선된 시료 전처리 방법(3% sodium bicarbonate)과 병행된 IAC 및 HPLC-FD 분석법은 막걸리를 대상으로 한 ochratoxin A의 오염 조사에 유효한 분석법임이 확인되었다.

휴대용 정삼투 담수화 장치의 설계 및 평가에 관한 연구 (Design and Evaluation of Portable Forward Osmosis Desalination Device)

  • 박철우;강호;정동호;차재철;김대중
    • 대한기계학회논문집B
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    • 제37권3호
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    • pp.301-305
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    • 2013
  • 식수의 보급이 원활하지 않은 경우를 대비하여 저에너지, 자급형 휴대용 담수화 장치를 설계하고 실험하여 그 활용 가능성을 제시하였다. 장비 구성이 단순한 정삼투 현상을 이용하여 휴대용 담수화 장치를 설계하였으며 중탄산암모늄을 이용하여 적은 에너지원을 이용한 담수화가 가능하도록 하였다. 여러 농도의 중탄산암모늄 수용액과 염화나트륨 수용액을 각기 사용하여 휴대용 담수화 장치의 담수화 성능을 조절할 수 있음을 확인하였다. 염 제거 실험을 통하여 음용 가능한 물을 확보하였고 온도를 증가시킴에 따라 그 시간을 단축시킬 수 있음을 확인하였다.

Chemical Characterization of Neutral Extracts Prepared by Treating Pinus radiata Bark with Sodium Bicarbonate

  • MUN, Ji Sun;KIM, Hwan Chul;MUN, Sung Phil
    • Journal of the Korean Wood Science and Technology
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    • 제48권6호
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    • pp.878-887
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    • 2020
  • A neutral extract (NE), that is soluble in cold water and has excellent antioxidant activity, from Pinus radiata pine bark was prepared by sodium bicarbonate treatment, and its chemical characteristics were investigated. NE was prepared by treating P. radiata bark with 0.8% NaHCO3 aqueous solution with a 5 : 1 liquor-to-bark ratio at boiling temperature for 1 h, resulting in 44% yield and final pH of 6.66. The yield of NE was 11% higher than that of the hot water extract (HWE) due to the increase in the solubility of polyphenols, the main component in the bark, by NaHCO3 treatment. NE was characterized through FT-IR, NMR, and MALDI TOF MS analyses. The results indicated that NE is mostly composed of proanthocyanidins (PAs) consisting of procyanidin (PC) units. The acetylated neutral extract (Ac-NE) had weight average molecular weight (${\bar{M}}w$) of 5,300 Da. The Ac-NE had wide molecular weight distribution and its polydispersity (${\bar{M}}w/{\bar{M}}n$) was 6 times higher than that of pure PA. The antioxidant activity of NE was determined by 2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging assay and showed that NE had comparable antioxidant activity with pure PA.

Effects of Selected Environmental Conditions on Biomass and Geosmin Production by Streptomyces halstedii

  • Schrader, Kevin K.;Blevins, Willard T.
    • Journal of Microbiology
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    • 제37권3호
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    • pp.159-167
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    • 1999
  • The effects of bicarbonate concentration, atmospheric carbon dioxide level, and reduced atmospheric oxygen on biomass and geosmin production and geosmin/biomass (G/B) values for Streptomyces halstedii, a producer of the off-flavor compound geosmin, were determined. In addition, a study was performed to determined possible synergistic relationships between a cyanobacterium, Oscillatoria tenuis UTEX #1566, and S. halstedii in the enhancement of actinomycete growth and/or geosmin production. These studies took into consideration those conditions that can occur during cyanobacterial bloom die-offs. Increasing bicarbonate concentration caused slight decreases in geosmin production and G/B for S. halstedii. Increasing atmospheric oxygen promoted geosmin production and G/B while lower oxygen levels resulted in a decrease in geosmin production and G/B by S. halstedii. Biomass production by S. halstedii was adversely affected by reduced oxygen levels while changes in bicarbonate concentration and atmospheric carbon dioxdie levels had little effect on biomass production. Sonicated cells of O. tenuis UTEX #1566 promoted biomass production by S. halstedii, and O. tenuis culture (cells and extracellular metabolites) and culture supernatnat (extracellular metabolites) each promoted geosmin and G/B yields for S. halstedii. In certain aquatic systems, environmental conditions resulting from cyanobacterial blooms and subsequent bloom die-offs could favor actinomycete growth and off-flavor compound by certain actinomycetes.

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급성백혈병 환자를 대상으로 구강함수제별 구내염 및 구강안위감에 대한 무작위대조시험연구 (Randomized Controlled Trial for Preventing Stomatitis and Discomfort among Acute Leukemic Patients)

  • 송지은;소향숙;주덕;김은정
    • 종양간호연구
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    • 제11권1호
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    • pp.33-40
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    • 2011
  • Purpose: This study compared the effect of two oral care agents on preventing stomatitis and discomfort for acute leukemic patients. Methods: A total of forty patients was enrolled and randomly assigned to sodium bicarbonate or chlorhexidine group. WHO oral toxicity scale was used for measuring stomatitis and Beck's subjective oral discomfort scale for evaluating oral comfort. Data was collected from August 2009 to February 2010. The data was analyzed using Chi-square test, Fisher's exact test, and Mann-Whitney test. Results: Data analyzed was thirty five one. The incidence of stomatitis was 47.4%, 68.8% in sodium bicarbonate and chlohexidine group respectively. The onset of stomatitis was about the 10th and 9th day after chemotherapy initiation, and the duration was 8.0 and 8.67 day respectively. The severity of stomatitis was highest on the 21st day after chemotherapy initiation. There were no statistical differences in the status of stomatitis and the levels of oral comfort during treatment periods. Conclusion: Nurses should routinely assess oral cavity and encourage patients to do oral care actively from second to third week after chemotherapy initiation. Also sodium bicarbonate agent can be recommended to for preventing stomatitis.

Winter flounder, Pleuronectes americanus에 대한 염산리도카인-중탄산나트륨의 마취효과 (Anaesthetic Effect of Lidocaine Hydrochloride-Sodium Bicarbonate on the Winter Flounder, Pleuronectes americanus)

  • 박인석;허준욱;송영채;임재현
    • Ocean and Polar Research
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    • 제26권3호
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    • pp.475-480
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    • 2004
  • Recently, less toxic and more effective anaesthetics are essential for marine fishes. Lidocaine belongs to a group of anaesthetics which are used as local anaesthetic in human medicine. This chemical was tested fer winter flounder, Pleunnectes americanus. Anaesthetic effect of lidocaine hydrochloride-sodium bicarbonate mixture (lidocaine $HCl/NaHCO_3$) was tested for the winter flounder at five different temperature regimes: $3^{\circ}C,\;7^{\circ}C,\;11^{\circ}C,\;15^{\circ}C\;and\;19^{\circ}C$ Anaesthetic dose and temperature-dependent relationship in exposure and recovery time were observed for the winter flounder of $17.2{\pm}0.1cm$ mean total length. Based on the results, anaesthetic lidocaine $HCl/NaHCO_3$ showed rapid exposure time and rapid recovery time for winter flounder. The results indicate that lidocaine $HCl/NaHCO_3$ can be used as suitable anaesthetic for this species.

Cu,Zn-Superoxide Dismutase Is an Intracellular Catalyst for the H2O2-dependent Oxidation of Dichlorodihydrofluorescein

  • Kim, Young-Mi;Lim, Jung-Mi;Kim, Byung-Chul;Han, Sanghwa
    • Molecules and Cells
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    • 제21권1호
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    • pp.161-165
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    • 2006
  • Dichlorodihydrofluorescein ($DCFH_2$) is a widely used probe for intracellular $H_2O_2$. However, $H_2O_2$ can oxidize $DCFH_2$ only in the presence of a catalyst, whose identity in cells has not been clearly defined. We compared the peroxidase activity of Cu,Zn-superoxide dismutase (CuZnSOD), cytochrome c, horseradish peroxidase (HRP), $Cu^{2+}$, and $Fe^{3+}$ under various conditions to identify an intracellular catalyst. Enormous increase by bicarbonate in the rate of $DCFH_2$ oxidation distinguished CuZnSOD from cytochrome c and HRP. Cyanide inhibited the reaction catalyzed by CuZnSOD but accelerated that by $Cu^{2+}$ and $Fe^{3+}$. Oxidation of $DCFH_2$ by $H_2O_2$ in the presence of a cell lysate was also enhanced by bicarbonate and inhibited by cyanide. Confocal microscopy of $H_2O_2$-treated cells showed enhanced DCF fluorescence in the presence of bicarbonate and attenuated fluorescence for the cells pre-incubated with KCN. Moreover, DCF fluorescence was intensified in CuZnSOD-transfected HaCaT and RAW 264.7 cells. We propose that CuZnSOD is a potential intracellular catalyst for the $H_2O_2$-dependent oxidation of $DCFH_2$.

Effect of KHCO3 Concentration Using CuO Nanowire for Electrochemical CO2 Reduction Reaction

  • Kanase, Rohini Subhash;Kang, Soon Hyung
    • 마이크로전자및패키징학회지
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    • 제27권4호
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    • pp.11-17
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    • 2020
  • Copper has been proved to be the best catalyst for electrochemical CO2 reduction reaction, however, for optimal efficiency and selectivity, its performance requires improvements. Electrochemical CO2 reduction reaction (RR) using CuO nanowire electrode was performed with different concentrations of KHCO3 electrolyte (0.1 M, 0.5 M, and 1 M). Cu(OH)2 was formed on Cu foil, followed by thermal-treatment at 200℃ under the air atmosphere for 2 hrs to transform it to the crystalline phase of CuO. We evaluated the effects of different KHCO3 electrolyte concentrations on electrochemical CO2 reduction reaction (RR) using the CuO nanowire electrode. At a constant current (5mA), low concentrated bicarbonate exhibited a more negative potential -0.77 V vs. Reversible Hydrogen Electrode (RHE) (briefly abbreviated as VRHE), while the negative potential reduced to -0.33 VRHE in the high concentration of bicarbonate solution. Production of H2 and CH4 increased with an increased concentration of electrolyte (KHCO3). CH4 production efficiency was high at low negative potential whereas HCOOH was not influenced by bicarbonate concentration. Our study provides insights into efficient, economically viable, and sustainable methods of mitigating the harmful environmental effects of CO2 emission.

Geochemical evaluation of groundwater quality of Peshawar Basin, Pakistan

  • Akhter, Gulraiz;Mand, Bilal A.;Shah, Munir H.
    • Advances in environmental research
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    • 제10권1호
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    • pp.43-57
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    • 2021
  • Evaluation of groundwater quality is vital due to its diverse use for several purposes. In the present study, groundwater quality and suitability from the Peshawar basin, Pakistan, were evaluated for drinking and irrigation purposes. The water samples were analysed for major cations (Ca, Mg, Na and K) and anions (chloride, bicarbonate and sulphate) along with other physicochemical parameters (pH, electrical conductivity, total dissolved solids, and total hardness). About 95% of the water samples were found to be within the WHO, US-EPA and Pak-EPA permissible levels for drinking purposes. Seventy percent (70%) of the water samples belonged to the hard water category. Irrigation water quality parameters, such as, chloride, residual sodium bicarbonate, sodium adsorption ratio, percent sodium, magnesium adsorption ratio, Kelly's ration and permeability index were evaluated which demonstrated that the groundwater was highly to moderately suitable for irrigation. A correlation study was conducted to find out the mutual associations among the variables. Piper diagram indicated the overall chemical nature of the study area was calcium-magnesium bicarbonate type. Cluster analysis revealed mutual apportionment of various parameters in the groundwater of the Peshawar basin, Pakistan.

Effect of bicarbonate and progesterone on plasma membrane integrity, acrosome reaction and proportion of fatty acids in boar sperm

  • Park, Choon-Keun;Lee, Sang-Hee
    • 한국동물생명공학회지
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    • 제37권3호
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    • pp.202-208
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    • 2022
  • This study investigated the influence of sodium bicarbonate (NaHCO3) and progesterone on acrosome reaction and proportion of polyunsaturated fatty acid (PUFA) composition boar sperm. The sperm were diluted with semen extender and incubated with NaHCO3 and progesterone at 38℃, 5% CO2 for 6 h. Plasma membrane integrity and acrosome reaction were analyzed using SYBR14/propidium iodide (PI) and FITC-PNA/PI doubling staining method, and proportion of PUFA was analyzed using gas chromatography. In results, Plasma membrane integrity was significantly decreased in 50 mM NaHCO3 group and acrosome reaction was significantly increased by over the 100 mM NaHCO3 group compared to control group (p < 0.05). In addition, progesterone significantly increased decreased plasma membrane integrity at 100 mM progesterone and acrosome reaction at over the 5.0 µM progesterone (p < 0.05), but there was no difference among the 5.0 to 100 µM groups. PUFAs were significantly decreased in 100 mM NaHCO3 and 50 µM progesterone treatments compared to control group. In summary NaHCO3 and progesterone induce acrosome reaction and reduce PUFA composition in boar sperm, therefore, the results maybe help to understand basically knowledge for the acrosome reaction and PUFA composition in boar sperm.