• Title/Summary/Keyword: Alkaline Pretreatment

검색결과 116건 처리시간 0.02초

Biosynthesis of Xylobiose: A Strategic Way to Enrich the Value of Oil Palm Empty Fruit Bunch Fiber

  • Lakshmi, G. Suvarna;Rajeswari, B. Uma;Prakasham, R.S.
    • Journal of Microbiology and Biotechnology
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    • 제22권8호
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    • pp.1084-1091
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    • 2012
  • Xylooligosaccharides are functional foods mainly produced during the hydrolysis of xylan by physical, chemical, or enzymatic methods. In this study, production of xylobiose was investigated using oil palm empty fruit bunch fiber (OPEFB) as a source material, by chemical and enzymatic methods. Xylanase-specific xylan hydrolysis followed by xylobiose production was observed. Among different xylanases, xylanase from FXY-1 released maximum xylobiose from pretreated OPEFB fiber, and this fungal strain was identified as Aspergillus terreus and subsequently deposited under the accession Number MTCC- 8661. The imperative role of lignin on xylooligosaccharides enzymatic synthesis was exemplified with the notice of xylobiose production only with delignified material. A maximum 262 mg of xylobiose was produced from 1.0 g of pretreated OPEFB fiber using FXY-1 xylanase (6,200 U/ml) at pH 6.0 and $45^{\circ}C$. At optimized environment, the yield of xylobiose was improved to 78.67 g/100 g (based on xylan in the pretreated OPEFB fiber).

Chemopreventive Efficacy of Moringa oleifera Pods Against 7, 12-Dimethylbenz[a]anthracene Induced Hepatic Carcinogenesis in Mice

  • Sharma, Veena;Paliwal, Ritu;Janmeda, Pracheta;Sharma, Shatruhan
    • Asian Pacific Journal of Cancer Prevention
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    • 제13권6호
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    • pp.2563-2569
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    • 2012
  • Oxidative stress is a common mechanism contributing to initiation and progression of hepatic damage in a variety of liver disorders. Hence there is a great demand for the development of agents with potent antioxidant effect. The aim of the present investigation is to evaluate the efficacy of Moringa oleifera as a hepatoprotective and an antioxidant against 7, 12-dimethylbenz[a]anthracene induced hepatocellular damage. Single oral administration of DMBA (15 mg/kg) to mice resulted in significantly (p<0.001) depleted levels of xenobiotic enzymes like, cytochrome P450 and b5. DMBA induced oxidative stress was confirmed by decreased levels of reduced glutathione (GSH) and glutathione-S-transferase (GST) in the liver tissue. The status of hepatic aspartate transaminase (AST), alanine transaminase (ALT), and alkaline phosphatase (ALP) which is indicative of hepatocellular damage were also found to be decreased in DMBA administered mice. Pretreatment with the Moringa oleifera (200 and 400 mg/kg) orally for 14 days significantly reversed the DMBA induced alterations in the liver tissue and offered almost complete protection. The results from the present study indicate that Moringa oleifera exhibits good hepatoprotective and antioxidant potential against DMBA induced hepatocellular damage in mice that might be due to decreased free radical generation.

Hot AC Anodising as a Cr(VI)-free Pre-treatment for Structural Bonding of Aluminium

  • Lapique, Fabrice;Bjorgum, Astrid;Johnsen, Bernt;Walmsley, John
    • 접착 및 계면
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    • 제4권2호
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    • pp.21-29
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    • 2003
  • Hot AC anodising has been evaluated us pre-treatment for aluminium prior to structural adhesive bonding. Phosphoric and sulphuric acid hot AC anodising showed very promising adhesion promoter capabilities with durability comparable with the best standard DC anodising procedures. AC anodising does not required etching prior to anodising and offers u pre-treatment time down to 20 seconds. The interface/interphase between the aluminium substrate and the adhesive was investigated in order to get a better understanding of the involved adhesion mechanisms and to explain the long-tenn properties. The alkaline medium formed at the oxide layer/adhesive interface has been shown to induce a partial dissolution of the oxide layer leading to the formation of metallic ions which diffuse in the adhesive (EPMA measurements). The effect of diffusion of the Al ions on adhesion and joint durability is still uncertain but studies showed that pre-bond moisture affected the joints durability and to some extent the diffusion length. specially for DC anodised samples. So far no direct correlation could be established between the diffusion length d and the joints durability but new trials with better control over the elapsed time between bonding and adhesive curing are expected to help getting a better understanding of the involved mechanisms.

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Environmental Toxic Agents on Genetic Material and Cellular Activity IV. Novobiocin-Mediated Inhibition of DNA Repair Synthesis in Synchronized Chinese Hamster Ovary Cells

  • 엄경일;김춘광;신은주;문용석;이천복
    • 한국환경성돌연변이발암원학회지
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    • 제9권1호
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    • pp.13-22
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    • 1989
  • The effect of novobiocin (NOV), and inhibitor of topoisomerase II, on ethyl methanesulfonate (EMS)-or bleomycin (BLM)-induced DNA repair synthesis was examined during the cell cycle of Chinese hamster ovary (CHO)-K1 cells. Three assays were employed in this study: cell survival, alkaline elution and unscheduled DNA synthesis. EMS was effective at killing CHO cells in G1 phase, wheras BLM preferentially killed cells in G2 and S phases. EMS induced the much more amount of DNA damage in G1 phase, while BLM induced in G2 phase than the other phases. The both of pre- and post-treatment with BOV inhibitied EMS- or BLM-induced DNA repair synthesis in G1 and G2 phases, and pretreatment with NOV inhibited more effectively than the post-treated group. These results suggested that CHO cells exhibited a differential sensitivity to cell lethality and DNA damage in relation to cell cycle according to used chemical agents, and that DNA topoisomerase II participated in an initial stage of DNA repair.

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유기성 폐기물의 산발효 특성 및 알카리 전처리에 관한 연구 (Characteristics of Acid Fermentation and Alkali Pretreatment of Organic Wastes)

  • 박종안;허준무
    • 환경위생공학
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    • 제16권1호
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    • pp.108-116
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    • 2001
  • It is difficult to task to achieve high biological nutrient removal from municipal wastewater because of low organic content. Volatile fatty acids(VFAs) produced from acid fermentation of food wastes can be utilized as external carbon sources for the biological nutrient process. Significant reduction and stabilization of the food wastes can also be obtained from the acid fermentation. The objective of this study is to evaluate characteristics of acid fermentation of the food wastes. Results obtained from the batch experiment of various organic wastes showed that the food wastes had high potential to be used as an external carbon source because of the largest production of the VFAs with low nitrogen and phosphorus content. The fish waste was found to be the next possible organic waste, while the others such as radish cabbage and molasses waste showed high VFAs consumption potential as a results of high nitrogen and phosphorus content. alkaline hydrolysis of the food waste was carried out using NaOH prior to the acid fermentation. As the alkali addition increased, solubilization of the organics as well as TSS reduction increased. However, fraction of soluble COD to total COD became stable after a sharp increase. Alkali addition greater than 0.5g NaOH per g TS resulted in significant increase in pH.

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Two-Phase Chemical Oxidation of Pyrene

  • Choi, Young-Ik
    • 한국환경과학회지
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    • 제16권3호
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    • pp.247-253
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    • 2007
  • Polycyclic aromatic hydrocarbons (PAHs) are a major concern because of their potential mutagenic and carcinogenic risks to human beings. One of these harmful, yet commonly observed PAHs is pyrene. Pyrene is one of the 16 PAHs listed by the United States Environmental Protection Agency as priority pollutants. The purposes of this research are to develop a method of pretreatment for PAH contaminants prior to a typical biological treatment and to demonstrate the biodegradablity of these compounds. Since pyrene is non-polar, hexane was chosen as a solvent to effectively dissolve pyrene. Pyrene solutions were treated with ozone, as it has hish oxidation capacity and electrophilic character. The intermediates and byproducts of pyrene were dissolved in alkaline water at pH 11.4 and neutralized to test for $BOD_5$, COD, and toxicity. These solutions were further ozonated and assessed of biodegradability. The first-order rate constant to was found to be between $0.121day^{-1}$ and $0.081 day^{-1}$, depending on the duration of reozonation. The $BOD_5/COD$ ratio was found to 0.66. The toxicity test showed that after 10 min of reozonation time, the byproducts and intermediates of pyrene were within the lion-toxic range of ${\pm}10%$ inhibition for E-Coli bacteria.

줄풀염색에 의한 모직물의 염색성과 기능성 (Dyeability and Functionality of Wool Fabrics Dyed with Zizania latifolia Turcz. extract)

  • 고은숙;이혜선
    • 한국의류산업학회지
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    • 제21권2호
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    • pp.231-236
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    • 2019
  • This study investigated the proper dyeing conditions, color fastness and functionality of wool fabrics dyed with Zizania latifolia Turcz. We also tried to improve light fastness through treatment with benzophenone ultraviolet absorber. The dyeing of wool fabrics using Zizania latifolia Turcz was good even without pretreatment or mordanting treatment. Optimal wool fabric dyeing conditions were colorant concentration of 200% (o.w.f.), dyeing temperature of $100^{\circ}C$, dyeing time of 80 minutes and a dye bath pH of 3. Color fastness of dyed wool fabrics to washing, rubbing, perspiration and light was 4-5, 5, 4-4-5 (acidic), 4-5 (alkaline) and 2 respectively. The results after treatment with ultraviolet absorber for improving the fastness of daylight were improved to 3-4 grade. The UV protection rate were increased after dyeing and the deodorization of ammonia gas improved to 98%. Bacterial reduction rate (Staphylococcus aureus) of wool fabrics was excellent at 99.9%. All dye fastness (except for light fastness) was excellent; in addition, the functionality of wool fabrics dyed with Zizania latifolia Turcz also improved. The results are expected to be applied to various fields because they indicate excellent results after treatment with ultraviolet absorber for improving the fastness of daylight.

임상보고 가능범위의 실증적 연구 (An Empirical Study of the Clinically Reportable Range in Clinical Chemistry)

  • 장상우;이상곤;최호성;송은영;박용원;이인애
    • 대한임상검사과학회지
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    • 제39권1호
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    • pp.31-36
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    • 2007
  • The purpose of the clinically reportable range (CRR) in clinical chemistry is to estimate linearity in working range. The reportable range includes all results that may be reliably reported, and embraces two types of ranges: the analytical measurement range (AMR) is the range of analyte values that a method can directly measure on the specimen without any dilution, concentration, or other pretreatment not part of the usual assay process. CAP and JCAHO require linearity on analyzers every six months. The clinically reportable range is the range of analyte values that a method can measure, allowing for specimen dilution, concentration, or other pretreatment used to extend the direct analytical measurement range. The AMR cannot exceed the manufacturer's limits. Establishing AMR is easily accomplished with Calibration Verification Assessment and experimental Linearity. For example: The manufacturer states that the limits of the AST on their instrument are 0-1100. The lowest level that could be verified is 2. The upper level is 1241. The verified AMR of the instrument is 2-1241. The lower limit of the range is 2, because that is the lowest level that could be verified by the laboratory. The laboratory could not use the manufacturer's lower limit of 2 because they have not proven that the instrument values below 2 are valid. The upper limit of the range is 1241, because although the lab has shown that the instrument is linear to 1241, the manufacturer does not make that claim. The laboratory needs to demonstrate the accuracy and precision of the analyzer, as well the validation of the patient AMR. Linearity requirements have been eliminated from the CLIA regulations and from the CAP inspection criteria, however, many inspectors continue to feel that linearity studies are a part of good lab practice and should be encouraged. If a lab chooses to continue linearity studies, these studies must fully comply with the calibration/calibration verification requirements of CLIA and/or CAP. The results of lower limit and upper limit of clinically reportable range were total protein (2.1 - 79.9), albumin (1.3 - 39), total bilirubin (0.2 - 106.2), alkaline phosphatase (13 - 6928.2), aspartate aminotransferase (24 - 7446), alanine aminotransferase (13 - 6724.2), gamma glutamyl transpeptidase (16.64 - 9904.2), creatine kinase (15.26 - 4723.8), lactate dehydrogenase (127.66 - 13231.8), creatinine (0.4 - 129.6), blood urea nitrogen (8.67 - 925.8), uric acid (1.6 - 151.2), total cholesterol (48.52 - 3162), triglycerides (36.91 - 3367.8), glucose (31 - 4218), amylase (21 - 6694.2), calcium (3.1 - 118.2), inorganic phosphorus (1.11 - 108), HDL (11.74 - 666), NA (58.3 - 1800), K (1.0 - 69.6), CL (38 - 1230).

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폐기된 해조류를 이용한 납 이온의 흡착 특성 (Adsorption Features of Lead Ion on Waste Undaria pinnatifida)

  • 서명순;김동수
    • 자원리싸이클링
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    • 제13권4호
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    • pp.23-31
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    • 2004
  • 수산물 처리시 폐기물로 발생하는 Undaria pinnatifida 를 $Pb^{2+}$ 가 함유된 폐수의 흡착처리시 흡착제로 활용하는 방안을 검토하였다. 성분분석 결과, Undaria pinnatifida는 주로 탄화수소화합물로 구성되어 있었으며 비표면적이 상당히 높아 흡착제로서의 잠재적 활용도가 큰 것으로 파악되었다. Undaria pinnatifida 입자의 Electrokinetic Potential은 pH 8 부근에서 음의 최대값을 보였으며 전 pH 범위에 걸쳐 음으로 하전되어 양이온의 흡착에 적합한 것으로 검토되었다. $Pb^{2+}$는 실험조건에서 반응개시 수 분 이내에 대부분이 흡착되었으며 평형에 도달하는 시간은 약 30분 정도인 것으로 나타났다. 또한, Undaria pinnatifida 표면에 대한 $Pb^{ 2+}$의 흡착은 Freundlich Isotherm 을 따르는 것으로 관찰되었으며 발열반응의 특성을 확인하였다. 산에 의한 흡착제의 전처리는 흡착능을 향상시켰으나 염기로 전처리할 경우에는 오히려 흡착능이 저하되었다. Undaria pinnatifida 표면에 존재하는 작용기들과 $Pb^{ 2+}$ 와의 Organometallic Complex 형성이 $Pb^{ 2+ }$의 흡착에 주요하게 작용하는 것으로 파악되었으며, 경쟁적 흡착질의 존재, ionic Strength 의 변화, 그리고 착화합물제가 수중에 공존할 경우 $Pb ^{2+}$ /의 흡착성이 상당한 영향을 받는 것으로 관찰되었다.

견의 효소 정련에 관한 연구 (A Study on Enzymatic Degummings of Raw Silk and Silk Fabric)

  • 이용우;송기원;정인모
    • 한국잠사곤충학회지
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    • 제28권1호
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    • pp.66-71
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    • 1986
  • 생사 및 견직물에 대한 효소정련방법을 구명하기 위한 시험 결과 1. 각종 효소정련조건이 정련효율에 비치는 영향에 있어서 정련온도 및 정련용의 산도는 Papain 7$0^{\circ}C$, pH 5-6, Trypsin 4$0^{\circ}C$ pH 8, Alkalase 50-6$0^{\circ}C$, pH 8-9에서 각각 정련효율이 가장 높았다. 2. Alkalase 처리농도가 생사의 정련효율에 미치는 영향에 있어서 처리농도가 0.6-1.0g/l 범위에서 높이면 정련시간을 단축시킬 수 있다. 3. 생사의 Alkalase정련에 있어서 정련전처리(95$^{\circ}C$, 10분 1g/l NaHCO3) 또는 정련후처리(2%, o.w.f. sodium silicate, 8$0^{\circ}C$, 20분)를 행하면 정련효율을 향상시킬 수 있었다. 4. 효소정련견사의 강력(g/d), 신도 및 라우지네스 성적은 비누 정련견사에 비하여 향상되는 경향이었다. 5. Alkalase에 의한 효소정련에 있어서 생견직물의 조련정도가 정련효율에 미치는 영향은 조련연감율이 높을수록 효소정련효율이 높았으며 205 이상에서는 하부다에 및 크\ulcorner데신 모두 완전한 정련이 가능하였다. 6. 조련연감율을 20%로 한 견포에 대하여 3종의 효소정련을 실시한 경우 Papain 및 Trypsin 정련구는 Alkalase 정련구에 비하여 정련효율이 저하되었다. 7. 효소정련견포의 강건도는 크\ulcorner데신의 경우 1.27cm로서 대조인 비누소오다 정련견포 1.53cm에 비하여 17% 저하되었고 Drape 계수는 0.297로서 비누소오다 정련견포의 0.321에 비하여 7% 감소됨으로서 유건한 촉감이 향상되었다.

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