• Title, Summary, Keyword: redox index

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Extraction and quantification of phenolic compounds from Prunus armeniaca seed and their role in biotransformation of xenobiotic compounds

  • Bibi, Ismat;Sultan, Aneela;Kamal, Shagufta;Nouren, Shazia;Safa, Yusra;Jalani, Kashif;Sultan, Misbah;Atta, Sadia;Rehman, Fariha
    • The Korean Journal of Chemical Engineering
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    • v.34 no.2
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    • pp.392-399
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    • 2017
  • The current research project has been devoted to isolating new low cost and eco-friendly phenolic compounds from fruit seeds, peels and vegetables to reduce the atmospheric pollution. Natural phenolic compounds were extracted from different fruit seeds and agriculture waste: P. armeniaca, P. persica, P. domestica and Triticum aesativum. The total phenolic content was quantified, and the maximum value (1 mL extract having $1,933{\mu}g$) was found in P. armeniaca seed extract. Phytochemical screening showed that P. armeniaca seeds contain higher amount of alkaloid, tannins, saponins and flavonoid. P. armeniaca seeds enhanced the biotransformation of reactive yellow dye up to 69.89% with maximum laccase (322.45 IU/mL) production. Biodegradation of reactive yellow was only 23.34% without natural redox mediator at sixth day of incubation. Use of P. armeniaca seed stimulators resulted in maximum laccase activity (894.4 IU/mL) with 99.5% rate of removal. UV-Vis, HPLC & FTIR analysis confirmed the transformation of parent dye into various new products. Phytotoxicity study indicated 0% germination index of Avena sativa seeds with reactive yellow, whereas 83% germination index having 100% seed germination while 83% root elongation with treated sample. Thus, the study revealed that the natural phenolic compounds could serve as high potential redox mediators for enhanced laccase-mediated decolorization of reactive yellow dye.

Insect Cell Cultures for Recombinant Protein Production (재조합 단백질 생산을 위한 곤충세포의 배양)

  • 박영민;정용주양재명정인식
    • KSBB Journal
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    • v.4 no.3
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    • pp.266-270
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    • 1989
  • Insect cell cultures were performed in laboratory-scale vessels. The batch growth of insect cells was affected by such parameters as serum content, other nutrients, seeding density, and mechanical agitation. Lactate and ammonium were not likely to be environmental factors that inhibited cell growth at the concentrations observed at the end of batch cultures. In addition, redox potential was found to be a useful index in monitoring low-level dissolved oxygen during the cultivation of insect cells. Recombinant protein production by cells infected with a genetically-modified baculovirus was also demons treated. The maximum beta-galactosidase synthesis of 2800 units per reactor volume was achieved at the dilution rate of $0.006hr^{-1}$.

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Synthesis of Poly(ethylene oxide-b-acrylonitrile) Block Copolymers with Higher Polyacrylonitrile Content Using Controlled Radical Polymerization Techniques (조절 라디칼 중합법을 이용한 PAN 함량이 많은 PEO-b-PAN 블록 공중합체의 합성)

  • Kim, Tae-Young;Kwark, Young-Je
    • Textile Science and Engineering
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    • v.52 no.1
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    • pp.20-25
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    • 2015
  • Poly(ethylene oxide-b-acrylonitrile) (PEO-b-PAN) block copolymers were prepared as precursors to mesoporous carbons. Redox-initiated radical polymerization and controlled radical polymerization techniques, such as reversible addition-fragmentation chain transfer (RAFT) and activators regenerated by electron transfer atom-transfer radical polymerization (ARGET ATRP), were successfully applied to prepare PEO-b-PAN block copolymers with high PAN content. Radical polymerization of acrylonitrile (AN) using ceric ion as redox initiator gave block copolymers with PEO:PAN ratio of up to 1:38.4, but their high molecular weight and polydispersity index (PDI) indicated that the structure was not controlled. Therefore, in order to achieve better control on the structure of the PAN block, controlled radical polymerization techniques were used. Poly(ethylene oxide) with trithiocarbonate (PEO-CTA) and bromide (PEO-Br) end groups were synthesized as polymeric chain transfer agent for the RAFT process and as initiator for the ATRP process, respectively. The RAFT process of AN using PEO-CTA gave block copolymers with PAN block length 0.53-3.58 times that of the PEO block. Moreover, ARGET ATRP allowed to prepare block copolymers with a very high molecular weight of 72,000, while maintaining a PDI value as low as 1.20.

Prognostic Significance of Altered Blood and Tissue Glutathione Levels in Head and Neck Squamous Cell Carcinoma Cases

  • Khan, Sami Ullah;Mahjabeen, Ishrat;Malik, Faraz Arshad;Kayani, Mahmood Akhtar
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.18
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    • pp.7603-7609
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    • 2014
  • Glutathione is a thiol compound that plays an important role in the antioxidant defense system of the cell and its deficiency leads to an increased susceptibility to oxidative stress and, thus, progression of many disease states including head and neck cancer. In the present study, alterations of glutathione levels were investigated in study cohort of 500 samples (cohort 1 containing 200 head and neck cancer blood samples along with 200 healthy controls and cohort II with 50 head and neck squamous cell carcinoma tissue samples along with 50 control tissues) by high performance liquid chromatography. The results indicated that mean blood glutathione levels were significantly reduced in head and neck cancer patients (p<0.001) compared to respective controls. In contrast, the levels of glutathione total (p<0.05) and glutathione reduced (p<0.05) were significantly elevated in head and neck squamous cell carcinoma tissues compared to the adjacent cancer-free control tissues. In addition to this, pearson correlation performed to correlate different tissue glutathione levels (GSH) with clinical/pathological parameters demonstrated a significant negative correlation between pT-stage and GSH level ($r=-0.263^{**}$; p<0.01), C-stage and GSH level ($r=-0.335^{**}$; p<0.01), grade and GSH ($r=-0.329^{**}$; p<0.01) and grade versus redox index ($r=-0.213^{**}$; p<0.01) in HNSCC tissues. Our study suggests that dysregulation of glutathione levels in head and neck cancer has the potential to predict metastasis, and may serve as a prognostic marker.

Mobility of Transition Metals by Change of Redox Condition in Dump Tailings from the Dukum Mine, Korea (덕음광산 광미의 산화${\cdot}$환원 조건에 따른 전이원소의 이동성)

  • 문용희;문희수;박영석;문지원;송윤구;이종천
    • Economic and Environmental Geology
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    • v.36 no.4
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    • pp.285-293
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    • 2003
  • Tailings of Dukum mine in the vadose and saturated zone were investigated to reveal the mobility of metal elements and the condition of mineralogical solubility according to redox environments throughout the geochemical analysis, thermodynamic modelling, and mineralogical study for solid-samples and water samples(vadose zone; distilled water: tailings=5 : 1 reacted, saturated zone; pore-water extracted). In the vadose zone, sulfide oxidation has generated low-pH(2.72∼6.91) condition and high concentration levels of S $O_4$$^{2-}$(561∼1430mg/L) and other metals(Zn : 0.12∼l57 mg/L, Pb : 0.06∼0.83 mg/L, Cd : 0.06∼l.35 mg/L). Jarosite$(KFe_3(SO_4)_2(OH)_6)$ and gypsum$(CaSO_4{\cdot}2H_2O$) were identified on XRD patterns and thermodynamics modelling. In the saturated zone, concentration of metal ions decreased because pH values were neutral(7.25∼8.10). But Fe and Mn susceptible to redox potential increased by low-pe values(7.40∼3.40) as the depth increased. Rhodochrosite$(MnCO_3)$ identified by XRD and thermodynamics modelling suggested that $Mn^{4+}$ or $Mn^{3+}$ was reduced to $Mn^{2+}$. Along pH conditions, concentrations of dissolved metal ions has been most abundant in vadose zone throughout borehole samples. It was observed that pH had more effect on metal solubilities than redox potential. How-ever, the release of co-precipitated heavy metals following the dissolution of Fe-Mn oxyhydroxides could be the mechanism by which reduced condition affected heavy metal solubility considering the decrease of pe as depth increased in tile saturated zone.

Potential Study for the Sedimentary Exhalative Pb-Zn Mineralization in Dyusembay Area, Kazakhstan (카자흐스탄 듀셈바이지역의 퇴적분기형 연-아연 광화작용에 대한 잠재력 연구)

  • No, Sang-gun;Lee, Seung-han;Park, Ki-woong;Jeong, Hyeon-guk;Yun, Ji-seong;Kim, Sun-ok;Park, Maeng-eon
    • Economic and Environmental Geology
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    • v.51 no.3
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    • pp.213-222
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    • 2018
  • Metasediment-hosted Pb-Zn mineralized zone has been found in Dyusembay of Kazakhstan. Its petrological properties, metal index, alteration index and redox-sensitivity are compared with those of SEDEX type deposit. Mineralization is developed along foliation of host rock (graphitic phyllite) and controlled by folds and faults; major ore minerals including pyrite, pyrrhotite, sphalerite, and galena are disseminated or interlayered with fine-grained quartz. The margin of the mineralized zone is metamorphosed accompanying sericite and chlorite. Hydrothermal brecciation and Pb-Zn mineralization formed in quartz-calcite stockworks are confirmed at the around of Maytyubin granitoid intrusions. The mineralization is classified into three types according to those of occurrence, paragenesis, chemical composition and isotopic characteristics. Type 1 whose fine-grained pyrite, pyrrhotite and sphalerite are formed in parallel yet discontinuous to well-developed foliations of the host rock; its geochemistry is similar to those of the earlier stage in SEDEX-type mineralization. In case of type 2, the ore minerals of which are concentrated being parallel to a foliation by regional metamorphism, and most of them associated with quartz and muscovite (${\pm}$ biotite) paragenetically. Type 3 is formed in the hydrothermal breccia zone whose ore minerals are controlled by foliation and breccia and developed in quartz ${\pm}$ calcite veins having a form such as stratification, stockwork or veinlets. Host rocks in the mineralized zone indicate homogeneous metamorphic grade and there is no specific alteration zonation. Also, all types (type 1, type 2, and type 3) represent similar REEs patterns, it can be interpreted that these are originated from a same source. Sulphides occurred in mineralized zone indicate a limited range of sulphur isotope values (type 2, ${\delta}^{34}S=-13.3{\sim}-11.7$‰; type 3, ${\delta}^{34}S=-13.9{\sim}-8.2$‰), and a result of geothermometry presents different temperature ranges: type 2($251{\pm}38^{\circ}C{\sim}277{\pm}40^{\circ}C$); type 3($360{\pm}2^{\circ}C$ to $537{\pm}29^{\circ}C$). It is estimated to be due to the effect of metamorphism and Maytyubin granitoid intrusions, respectively. In addition, ternary chart of thorium, scandium, and zircon for discrimination of tectonic setting and redox sensitivity using V/Mo values indicate that hydrothermal sediments put on reduction environment after precipitation, before being affected by metamorphism and intrusion activity. Geochemical data are plotted on a distal trend of SEDEX-type with discrimination plot using SEDEX index. As a result, petrological-geochemical properties demonstrate that Dyusembay Pb-Zn mineralized zone is comparable to distal-type of SEDEX deposit.

Opto-Electrochemical Sensing Device Based on Long-Period Grating Coated with Boron-Doped Diamond Thin Film

  • Bogdanowicz, Robert;Sobaszek, Michał;Ficek, Mateusz;Gnyba, Marcin;Ryl, Jacek;Siuzdak, Katarzyna;Bock, Wojtek J.;Smietana, Mateusz
    • Journal of the Optical Society of Korea
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    • v.19 no.6
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    • pp.705-710
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    • 2015
  • The fabrication process of thin boron-doped nanocrystalline diamond (B-NCD) microelectrodes on fused silica single mode optical fiber cladding has been investigated. The B-NCD films were deposited on the fibers using Microwave Plasma Assisted Chemical Vapor Deposition (MW PA CVD) at glass substrate temperature of 475 ℃. We have obtained homogenous, continuous and polycrystalline surface morphology with high sp3 content in B-NCD films and mean grain size in the range of 100-250 nm. The films deposited on the glass reference samples exhibit high refractive index (n=2.05 at λ=550 nm) and low extinction coefficient. Furthermore, cyclic voltammograms (CV) were recorded to determine the electrochemical window and reaction reversibility at the B-NCD fiber-based electrode. CV measurements in aqueous media consisting of 5 mM K3[Fe(CN)6] in 0.5 M Na2SO4 demonstrated a width of the electrochemical window up to 1.03 V and relatively fast kinetics expressed by a redox peak splitting below 500 mV. Moreover, thanks to high-n B-NCD overlay, the coated fibers can be also used for enhancing the sensitivity of long-period gratings (LPGs) induced in the fiber. The LPG is capable of measuring variations in refractive index of the surrounding liquid by tracing the shift in resonance appearing in the transmitted spectrum. Possible combined CV and LPG-based measurements are discussed in this work.

Evaluation of the Systemic Oxidative Stress Status during Major Orthopedic Surgery in Dogs: A Clinical Study (개에서 정형외과 수술에 따른 전신 산화스트레스 상태의 평가)

  • Lee, Jae Yeon;Won, Heung Seok;Hwang, Hag Kyun;Jeong, Seong Mok;Kim, Myung Cheol
    • Journal of Veterinary Clinics
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    • v.30 no.1
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    • pp.1-4
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    • 2013
  • The present study evaluated the systemic oxidative stress status during major orthopedic surgery in dogs. Sixteen dogs presented with various orthopedic diseases involving fractures or luxation of limbs. All patients underwent orthopedic surgery for treatment of fractures or luxation of limbs. A significant increase in the plasma total oxidant status (TOS) and oxidative stress index (OSI) levels in dogs after surgery was observed. Plasma total antioxidant status (TAS) levels were significantly decreased in dogs after surgery. The results of this study suggested that association or relationship in serum between TOS or TAS levels and redox imbalance were caused by surgical trauma in orthopedic disease conditions.

A Study on the Antimicrobial Activity of Microcystis aeruginosa by Redox Reaction of Cu-Zn Alloy Metal Fiber (구리-아연 합금사의 산화-환원 반응을 통한 Microcystis aeruginosa의 사멸 특성에 관한 연구)

  • Song, Ju-Yeong;Kim, Hee-Seon;Lee, Sang-Ho;Kim, Jong-Hwa;Park, Keun-Ho
    • Journal of the Korean Applied Science and Technology
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    • v.25 no.2
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    • pp.168-174
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    • 2008
  • This study is focused on the antimicrobial activity of cyanobacteria Microcystis aeruginosa by the reduction and oxidation reaction of copper and zinc alloy metal fiber filter. Cu/Zn ion is easily makes radicals with molecular hydroperoxide. Especially, hydroperoxide radical shows strong toxicity to the strains. Plasma membrane causes conformational change when hydroperoxide radical binds to plasma membrane. Elution of copper ion from copper and zinc alloy metal fiber is detected in the cyanobacteria solution as 0.5 ppm, and that of zinc ion is 0 ppm respectively. Zinc ion is figured to form a hydroxide in the cyanobacteria solution and precipitated to form a sludge. The concentration of chlorophyll-a in the cyanobacteria solution was proved to be the index of antimicrobial level of Microcystis aeruginosa.

A Study on Bioremediation of Fish Farm Sediment Using CaO2 by Enhancement of Indigenous Microbial Activity (어류양식장 저질개선을 위한 과산화칼슘 투입에 의한 생태 환경변화 관찰)

  • Cho, Daechul;Bae, Hwan-Jin;Kwon, Sung-Hyun
    • Journal of Environmental Science International
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    • v.21 no.10
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    • pp.1187-1193
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    • 2012
  • The aim of this research is to enhance the bottom environment of Geoje fish farm that has been severely contaminated. Treatment of microbial agent and/or calcium oxide significantly changed that environment: in ignition loss, either treatment (25% or 21%) showed better than mixed treatment (13.2%). In COD, the oxygen releasing agent or mixed treatment reduced the index by more than 20%. In T-P and T-N, the effects of $CaO_2$ on them were overwhelming (50% or more) meanwhile that of the microbial agent on them was less than 20%. Also, $CaO_2$ influenced on the microbial flora: Desulfobvibrio thermophilus, a sulfate reducing bacterium decreased in number, considering the increase of pH and rise of redox potential. In contrast, Pseudomonas sp., Pseudoalteromonas sp., Pseudomonas aeruginosa were remarkably dominant over other species with mixed treatment as a PCA analysis confirmed it.