Sample records for peroxidase display enhanced

  1. Self-Assembled Complexes of Horseradish Peroxidase with Magnetic Nanoparticles Showing Enhanced Peroxidase Activity

    KAUST Repository

    Corgié , Sté phane C.; Kahawong, Patarawan; Duan, Xiaonan; Bowser, Daniel; Edward, Joseph B.; Walker, Larry P.; Giannelis, Emmanuel P.


    Bio-nanocatalysts (BNCs) consisting of horseradish peroxidase (HRP) self-assembled with magnetic nanoparticles (MNPs) enhance enzymatic activity due to the faster turnover and lower inhibition of the enzyme. The size and magnetization of the MNPs

  2. Self-Assembled Complexes of Horseradish Peroxidase with Magnetic Nanoparticles Showing Enhanced Peroxidase Activity

    KAUST Repository

    Corgié, Stéphane C.


    Bio-nanocatalysts (BNCs) consisting of horseradish peroxidase (HRP) self-assembled with magnetic nanoparticles (MNPs) enhance enzymatic activity due to the faster turnover and lower inhibition of the enzyme. The size and magnetization of the MNPs affect the formation of the BNCs, and ultimately control the activity of the bound enzymes. Smaller MNPs form small clusters with a low affinity for the HRP. While the turnover for the bound fraction is drastically increased, there is no difference in the H 2O 2 inhibitory concentration. Larger MNPs with a higher magnetization aggregate in larger clusters and have a higher affinity for the enzyme and a lower substrate inhibition. All of the BNCs are more active than the free enzyme or the MNPs (BNCs > HRP ≤laquo; MNPs). Since the BNCs show surprising resilience in various reaction conditions, they may pave the way towards new hybrid biocatalysts with increased activities and unique catalytic properties for magnetosensitive enzymatic reactions. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Ascorbate peroxidase gene from Brassica napus enhances salt and ...

    African Journals Online (AJOL)

    Moreover, under the drought stress, BnAPX transgenic seeds displayed higher germination rate and the seedlings showed reduced wither and apoptosis phenomena. Therefore, our studies revealed that BnAPX was able to enhance the environmental tolerance of Arabidopsis to salt and drought stresses. In addition ...

  4. Biotechnological advances towards an enhanced peroxidase production in Pichia pastoris. (United States)

    Krainer, Florian W; Gerstmann, Michaela A; Darnhofer, Barbara; Birner-Gruenberger, Ruth; Glieder, Anton


    Horseradish peroxidase (HRP) is a high-demand enzyme for applications in diagnostics, bioremediation, biocatalysis and medicine. Current HRP preparations are isolated from horseradish roots as mixtures of biochemically diverse isoenzymes. Thus, there is a strong need for a recombinant production process enabling a steady supply with enzyme preparations of consistent high quality. However, most current recombinant production systems are limited at titers in the low mg/L range. In this study, we used the well-known yeast Pichia pastoris as host for recombinant HRP production. To enhance recombinant enzyme titers we systematically evaluated engineering approaches on the secretion process, coproduction of helper proteins, and compared expression from the strong methanol-inducible PAOX1 promoter, the strong constitutive PGAP promoter, and a novel bidirectional promoter PHTX1. Ultimately, coproduction of HRP and active Hac1 under PHTX1 control yielded a recombinant HRP titer of 132mg/L after 56h of cultivation in a methanol-independent and easy-to-do bioreactor cultivation process. With regard to the many versatile applications for HRP, the establishment of a microbial host system suitable for efficient recombinant HRP production was highly overdue. The novel HRP production platform in P. pastoris presented in this study sets a new benchmark for this medically relevant enzyme. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

  5. Peroxidase-Mimicking Nanozyme with Enhanced Activity and High Stability Based on Metal-Support Interactions. (United States)

    Li, Zhihao; Yang, Xiangdong; Yang, Yanbing; Tan, Yaning; He, Yue; Liu, Meng; Liu, Xinwen; Yuan, Quan


    Peroxidase-mimicking nanozymes offer unique advantages in terms of high stability and low cost over natural peroxidase for applications in bioanalysis, biomedicine, and the treatment of pollution. However, the design of high-efficiency peroxidase-mimicking nanozymes remains a great challenge. In this study, we adopted a structural-design approach through hybridization of cube-CeO 2 and Pt nanoparticles to create a new peroxidase-mimicking nanozyme with high efficiency and excellent stability. Relative to pure cube-CeO 2 and Pt nanoparticles, the as-hybridized Pt/cube-CeO 2 nanocomposites display much improved activities because of the strong metal-support interaction. Meanwhile, the nanocomposites also maintain high catalytic activity after long-term storage and multiple recycling. Based on their excellent properties, Pt/cube-CeO 2 nanocomposites were used to construct high-performance colorimetric biosensors for the sensitive detection of metabolites, including H 2 O 2 and glucose. Our findings highlight opportunities for the development of high-efficiency peroxidase-mimicking nanozymes with potential applications such as diagnostics, biomedicine, and the treatment of pollution. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Ascorbate peroxidase gene from Brassica napus enhances salt and ...

    African Journals Online (AJOL)



    Dec 12, 2011 ... enhances salt and drought tolerances in Arabidopsis ... Laboratory of Hydraulics and Mountain River Engineering, Sichuan University, Chengdu, .... CCTTCGCAAGACCCTTCCTC-3′) and the reverse primer annealed.

  7. Ultra-high-throughput screening of an in vitro-synthesized horseradish peroxidase displayed on microbeads using cell sorter.

    Directory of Open Access Journals (Sweden)

    Bo Zhu

    Full Text Available The C1a isoenzyme of horseradish peroxidase (HRP is an industrially important heme-containing enzyme that utilizes hydrogen peroxide to oxidize a wide variety of inorganic and organic compounds for practical applications, including synthesis of fine chemicals, medical diagnostics, and bioremediation. To develop a ultra-high-throughput screening system for HRP, we successfully produced active HRP in an Escherichia coli cell-free protein synthesis system, by adding disulfide bond isomerase DsbC and optimizing the concentrations of hemin and calcium ions and the temperature. The biosynthesized HRP was fused with a single-chain Cro (scCro DNA-binding tag at its N-terminal and C-terminal sites. The addition of the scCro-tag at both ends increased the solubility of the protein. Next, HRP and its fusion proteins were successfully synthesized in a water droplet emulsion by using hexadecane as the oil phase and SunSoft No. 818SK as the surfactant. HRP fusion proteins were displayed on microbeads attached with double-stranded DNA (containing the scCro binding sequence via scCro-DNA interactions. The activities of the immobilized HRP fusion proteins were detected with a tyramide-based fluorogenic assay using flow cytometry. Moreover, a model microbead library containing wild type hrp (WT and inactive mutant (MUT genes was screened using fluorescence-activated cell-sorting, thus efficiently enriching the WT gene from the 1:100 (WT:MUT library. The technique described here could serve as a novel platform for the ultra-high-throughput discovery of more useful HRP mutants and other heme-containing peroxidases.

  8. Proximity does not contribute to activity enhancement in the glucose oxidase-horseradish peroxidase cascade (United States)

    Zhang, Yifei; Tsitkov, Stanislav; Hess, Henry


    A proximity effect has been invoked to explain the enhanced activity of enzyme cascades on DNA scaffolds. Using the cascade reaction carried out by glucose oxidase and horseradish peroxidase as a model system, here we study the kinetics of the cascade reaction when the enzymes are free in solution, when they are conjugated to each other and when a competing enzyme is present. No proximity effect is found, which is in agreement with models predicting that the rapidly diffusing hydrogen peroxide intermediate is well mixed. We suggest that the reason for the activity enhancement of enzymes localized by DNA scaffolds is that the pH near the surface of the negatively charged DNA nanostructures is lower than that in the bulk solution, creating a more optimal pH environment for the anchored enzymes. Our findings challenge the notion of a proximity effect and provide new insights into the role of DNA scaffolds.

  9. Automated determination of asulam by enhanced chemiluminescence using luminol/peroxidase system. (United States)

    Sánchez, Francisco García; Díaz, Aurora Navas; Bracho, Visitación; Aguilar, Alfonso; Algarra, Manuel


    A flow injection system with chemiluminescence detection for the determination of asulam, enhancer of the system luminol-H(2)O(2)-horseradish peroxidase, is proposed. The method shows a moderate selectivity against other pesticides usually present in formulations of herbicides and in water. The procedure was applied to the determination of asulam in tap water samples and a recovery study was carried out in order to validate the method. The obtained results show acceptable recovery values (between 88.3 and 93.9%). The detection limit for asulam was 0.12 ng/mL. The precision of the method expressed as relative standard deviation was 1.55% (n = 8), at the 19 ng/mL level.

  10. Pluripotent cells display enhanced resistance to mutagenesis

    Directory of Open Access Journals (Sweden)

    Daniel J. Cooper


    Full Text Available Pluripotent cells have been reported to exhibit lower frequencies of point mutations and higher levels of DNA repair than differentiated cells. This predicts that pluripotent cells are less susceptible to mutagenic exposures than differentiated cells. To test this prediction, we used a lacI mutation-reporter transgene system to assess the frequency of point mutations in multiple lines of mouse pluripotent embryonic stem cells and induced pluripotent cells, as well as in multiple lines of differentiated fibroblast cells, before and after exposure to a moderate dose of the mutagen, methyl methanesulfonate. We also measured levels of key enzymes in the base excision repair (BER pathway in each cell line before and after exposure to the mutagen. Our results confirm that pluripotent cells normally maintain lower frequencies of point mutations than differentiated cells, and show that differentiated cells exhibit a large increase in mutation frequency following a moderate mutagenic exposure, whereas pluripotent cells subjected to the same exposure show no increase in mutations. This result likely reflects the higher levels of BER proteins detectable in pluripotent cells prior to exposure and supports our thesis that maintenance of enhanced genetic integrity is a fundamental characteristic of pluripotent cells.

  11. Ectopic expression of a horseradish peroxidase enhances growth rate and increases oxidative stress resistance in hybrid aspen. (United States)

    Kawaoka, Akiyoshi; Matsunaga, Etsuko; Endo, Saori; Kondo, Shinkichi; Yoshida, Kazuya; Shinmyo, Atsuhiko; Ebinuma, Hiroyasu


    We previously demonstrated that overexpression of the horseradish (Armoracia rusticana) peroxidase prxC1a gene stimulated the growth rate of tobacco (Nicotiana tabacum) plants. Here, the cauliflower mosaic virus 35S::prxC1a construct was introduced into hybrid aspen (Populus sieboldii x Populus grandidentata). The growth rate of these transformed hybrid aspen plants was substantially increased under greenhouse conditions. The average stem length of transformed plants was 25% greater than that of control plants. There was no other obvious phenotypic difference between the transformed and control plants. Fast-growing transformed hybrid aspen showed high levels of expression of prxC1a and had elevated peroxidase activities toward guaiacol and ascorbate. However, there was no increase of the endogenous class I ascorbate peroxidase activities in the transformed plants by separate assay and activity staining of native polyacrylamide gel electrophoresis. Furthermore, calli derived from the transformed hybrid aspen grew faster than those from control plants and were resistant to the oxidative stress imposed by hydrogen peroxide. Therefore, enhanced peroxidase activity affects plant growth rate and oxidative stress resistance.

  12. Silenced rice in both cytosolic ascorbate peroxidases displays pre-acclimation to cope with oxidative stress induced by 3-aminotriazole-inhibited catalase. (United States)

    Bonifacio, Aurenivia; Carvalho, Fabrício E L; Martins, Marcio O; Lima Neto, Milton C; Cunha, Juliana R; Ribeiro, Carolina W; Margis-Pinheiro, Marcia; Silveira, Joaquim A G


    The maintenance of H2O2 homeostasis and signaling mechanisms in plant subcellular compartments is greatly dependent on cytosolic ascorbate peroxidases (APX1 and APX2) and peroxisomal catalase (CAT) activities. APX1/2 knockdown plants were utilized in this study to clarify the role of increased cytosolic H2O2 levels as a signal to trigger the antioxidant defense system against oxidative stress generated in peroxisomes after 3-aminotriazole-inhibited catalase (CAT). Before supplying 3-AT, silenced APX1/2 plants showed marked changes in their oxidative and antioxidant profiles in comparison to NT plants. After supplying 3-AT, APX1/2 plants triggered up-expression of genes belonging to APX (OsAPX7 and OsAPX8) and GPX families (OsGPX1, OsGPX2, OsGPX3 and OsGPX5), but to a lower extent than in NT plants. In addition, APX1/2 exhibited lower glycolate oxidase (GO) activity, higher CO2 assimilation, higher cellular integrity and higher oxidation of GSH, whereas the H2O2 and lipid peroxidation levels remained unchanged. This evidence indicates that redox pre-acclimation displayed by silenced rice contributed to coping with oxidative stress generated by 3-AT. We suggest that APX1/2 plants were able to trigger alternative oxidative and antioxidant mechanisms involving signaling by H2O2, allowing these plants to display effective physiological responses for protection against oxidative damage generated by 3-AT, compared to non-transformed plants. Copyright © 2016 Elsevier GmbH. All rights reserved.

  13. Glycine post-synthetic modification of MIL-53(Fe) metal-organic framework with enhanced and stable peroxidase-like activity for sensitive glucose biosensing. (United States)

    Dong, Wenfei; Yang, Liaoyuan; Huang, Yuming


    A facile and rapid post-synthetic strategy was proposed to prepare a glycine functionalized MIL-53(Fe), namely glycine-MIL-53(Fe), by a simple mixing of water dispersible MIL-53(Fe) and glycine. The FT-IR, SEM, XRD and zeta potential were used to characterize the glycine-MIL-53(Fe). The result showed that glycine post-synthetic modification of MIL-53(Fe) did not change in the morphology and crystal structure of MIL-53(Fe). Interestingly, compared with MIL-53(Fe), the glycine-MIL-53(Fe) exhibits an enhanced peroxidase-like activity, which could catalyze the oxidation of TMB by H 2 O 2 to produce an intensive color reaction. Kinetic analysis indicated that the K m of glycine-MIL-53(Fe) for TMB was one-tenth of that of MIL-53(Fe). The glycine-MIL-53(Fe) as peroxidase mimetic displays better stability under alkaline or acidic conditions than MIL-53(Fe). The good performance of glycine-MIL-53(Fe) over MIL-53(Fe) may be attributed to the increase of affinity between TMB and the glycine-MIL-53(Fe). With these characteristics, a simple and sensitive method was developed for the detection of H 2 O 2 and glucose. The linear detection range for H 2 O 2 is 0.10-10μM with a detection limit of 49nM, and glucose could be linearly detected in the range from 0.25 to 10μM with a detection limit of 0.13μM. The proposed method was successfully used for glucose detection in human serum samples. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. Content dependent selection of image enhancement parameters for mobile displays (United States)

    Lee, Yoon-Gyoo; Kang, Yoo-Jin; Kim, Han-Eol; Kim, Ka-Hee; Kim, Choon-Woo


    Mobile devices such as cellular phones and portable multimedia player with capability of playing terrestrial digital multimedia broadcasting (T-DMB) contents have been introduced into consumer market. In this paper, content dependent image quality enhancement method for sharpness and colorfulness and noise reduction is presented to improve perceived image quality on mobile displays. Human visual experiments are performed to analyze viewers' preference. Relationship between the objective measures and the optimal values of image control parameters are modeled by simple lookup tables based on the results of human visual experiments. Content dependent values of image control parameters are determined based on the calculated measures and predetermined lookup tables. Experimental results indicate that dynamic selection of image control parameters yields better image quality.

  15. Enhanced amperometric response of a glucose oxidase and horseradish peroxidase based bienzyme glucose biosensor modified with a film of polymerized toluidine blue containing reduced graphene oxide

    International Nuclear Information System (INIS)

    Wang, Fang; Gong, Wencheng; Wang, Lili; Chen, Zilin


    Reduced graphene oxide (RGO) was used to construct a bienzyme biosensor containing horseradish peroxidase (HRP) and glucose oxidase (GOx). A poly(toluidine blue) (pTB) film containing RGO acted as both enzyme immobilization matrix and electron transfer mediator. The bienzyme biosensor was characterized by electrochemical techniques and displays a highly sensitive amperometric response to glucose and hydrogen peroxide (H 2 O 2 ) at a potential as low as −0.1 V (vs. SCE). It is shown that use of RGO causes a strong enhancement on the amperometric responses. H 2 O 2 formed by the action of GOx in the presence of oxygen can be further reduced by HRP in the pTB film contacting the RGO modified electrode. In the absence of oxygen, glucose oxidation proceeds by another mechanism in which electron transfer occurs from GOx to the electrode and with pTB acting as the mediator. Amperometric responses to glucose and H2O2 follow Michaelis-Menten kinetics. The experimental conditions were optimized, and under these conditions glucose can be determined in the 80 μM to 3.0 mM range with a detection limit of 50 μM. H 2 O 2 , in turn, can be quantified in up to 30.0 μM concentration with a detection limit of 0.2 μM. The bienzyme biosensor is reproducible, repeatable and stable. Finally, it has been successfully applied to the determination of glucose in plasma samples. (author)

  16. Long-term chemiluminescence signal is produced in the course of luminol oxidation catalyzed by enhancer-independent peroxidase purified from Jatropha curcas leaves. (United States)

    Duan, Peipei; Cai, Feng; Luo, Yongting; Chen, Yangxi; Zou, Shujuan


    Isoenzyme c of horseradish peroxidase (HRP-C) is widely used in enzyme immunoassay combined with chemiluminescence (CL) detection. For this application, HRP-C activity measurement is usually based on luminol oxidation in the presence of hydrogen peroxide (H2O2). However, this catalysis reaction was enhancer dependent. In this study, we demonstrated that Jatropha curcas peroxidase (JcGP1) showed high efficiency in catalyzing luminol oxidation in the presence of H2O2. Compared with HRP-C, the JcGP1-induced reaction was enhancer independent, which made the enzyme-linked immunosorbent assay (ELISA) simpler. In addition, the JcGP1 catalyzed reaction showed a long-term stable CL signal. We optimized the conditions for JcGP1 catalysis and determined the favorable conditions as follows: 50 mM Tris buffer (pH 8.2) containing 10 mM H2 O2, 14 mM luminol and 0.75 M NaCl. The optimum catalysis temperature was 30°C. The detection limit of JcGP1 under optimum condition was 0.2 pM. Long-term stable CL signal combined with enhancer-independent property indicated that JcGP1 might be a valuable candidate peroxidase for clinical diagnosis and enzyme immunoassay with CL detection. Copyright © 2014 John Wiley & Sons, Ltd.

  17. Withaferin-A displays enhanced anxiolytic efficacy without tolerance ...

    African Journals Online (AJOL)

    Withaferin-A dose-dependently (10 tob40 mg/kg) displayed anxiolytic activity, as measured by an increase in open arm exploration time in the elevated plus-maze (EPM), following intraperitoneal (i.p.) administration in rats. Acute administration of withaferin-A at 40.0 mg/kg significantly (P<0.05) increased open arm ...

  18. Construction and Characterization of Vitreoscilla Hemoglobin (VHb) with Enhanced Peroxidase Activity for Efficient Degradation of Textile Dye. (United States)

    Zhang, Zidong; Li, Wei; Li, Haichao; Zhang, Jing; Zhang, Yuebin; Cao, Yufeng; Ma, Jianzhang; Li, Zhengqiang


    Pollution resulting from the discharge of textile dyes into water systems has become a major global concern. Because peroxidases are known for their ability to decolorize and detoxify textile dyes, the peroxidase activity of Vitreoscilla hemoglobin (VHb) has recently been studied. It is found that VHb and variants of this enzyme show great promise for enzymatic decolorization of dyes and may play a role in achieving their successful removal from industrial wastewater. The level of VHb peroxidase activity correlates with two amino acid residues present within the conserved distal pocket, at positions 53 and 54. In this work, sitedirected mutagenesis of these residues was performed and resulted in improved VHb peroxidase activity. The double mutant, Q53H/P54C, shows the highest dye decolorization and removal efficiency, with 70% removal efficiency within 5 min. UV spectral studies of Q53H/P54C reveals a more compact structure and an altered porphyrin environment (λSoret = 413 nm) relative to that of wild-type VHb (λSoret = 406), and differential scanning calorimetry data indicate that the VHb variant protein structure is more stable. In addition, circular dichroism spectroscopic studies indicate that this variant's increased protein structural stability is due to an increase in helical structure, as deduced from the melting temperature, which is higher than 90°C. Therefore, the VHb variant Q53H/P54C shows promise as an excellent peroxidase, with excellent dye decolorization activity and a more stable structure than wild-type VHb under high-temperature conditions.

  19. Artificial intelligence enhancements to safety parameter display systems

    International Nuclear Information System (INIS)

    Hajek, B.K.; Hashemi, S.; Sharma, D.; Chandrasekaran, B.; Miller, D.W.


    Two prototype knowledge based systems have been developed at The Ohio State University to be the basis of an operator aid that can be attached to an existing nuclear power plant Safety Parameter Display System. The first system uses improved sensor validation techniques to provide input to a fault diagnosis process. The second system would use the diagnostic system output to synthesize corrective procedures to aid the control room licensed operator in plant recovery

  20. Synthesis and Evaluation of Amyloid β Derived and Amyloid β Independent Enhancers of the Peroxidase-like Activity of Heme. (United States)

    Wißbrock, Amelie; Kühl, Toni; Silbermann, Katja; Becker, Albert J; Ohlenschläger, Oliver; Imhof, Diana


    Labile heme has been suggested to have an impact in several severe diseases. In the context of Alzheimer's disease (AD), however, decreased levels of free heme have been reported. Therefore, we were looking for an assay system that can be used for heme concentration determination. From a biochemical point of view the peroxidase activity of the Aβ-heme complex seemed quite attractive to pursue this goal. As a consequence, a peptide that is able to increase the readout even in the case of a low heme concentration is favorable. The examination of Aβ- and non-Aβ-derived peptides in complex with heme revealed that the peroxidase-like activity significantly depends on the peptide sequence and length. A 23mer His-based peptide derived from human fatty acyl-CoA reductase 1 in complex with heme exhibited a significantly higher peroxidase activity than Aβ(40)-heme. Structural modeling of both complexes demonstrated that heme binding via a histidine can be supported by hydrogen bond interactions of a basic residue near the propionate carboxyl function of protoporphyrin IX. Furthermore, the interplay of Aβ-heme and the lipoprotein LDL as a potential physiological effector of Aβ was examined.

  1. Use of display technologies for augmented reality enhancement (United States)

    Harding, Kevin


    Augmented reality (AR) is seen as an important tool for the future of user interfaces as well as training applications. An important application area for AR is expected to be in the digitization of training and worker instructions used in the Brilliant Factory environment. The transition of work instructions methods from printed pages in a book or taped to a machine to virtual simulations is a long step with many challenges along the way. A variety of augmented reality tools are being explored today for industrial applications that range from simple programmable projections in the work space to 3D displays and head mounted gear. This paper will review where some of these tool are today and some of the pros and cons being considered for the future worker environment.

  2. A role for autoantibodies in enhancement of pro-inflammatory cytokine responses to a self-antigen, thyroid peroxidase

    DEFF Research Database (Denmark)

    Nielsen, Claus H; Brix, Thomas H; Leslie, R Graham Q


    The role of thyroid peroxidase (TPO) antibodies (TPOAbs) in the pathogenesis of autoimmune thyroid disease is unclear. We selected sera with a high concentration of TPOAbs from eleven patients with Hashimoto's thyroiditis (HT), ten healthy monozygotic co-twins to HT patients, and twelve healthy...... individuals with no familiar disposition to AITD, and mixed each serum with normal mononuclear cells (MNCs). Following challenge with TPO, the MNCs' production of the pro-inflammatory cytokines TNF-alpha, IL-6 and IFN-gamma, and the anti-inflammatory cytokine IL-10, correlated with the TPOAb content...

  3. CbRCI35, a cold responsive peroxidase from Capsella bursa-pastoris regulates reactive oxygen species homeostasis and enhances cold tolerance in tobacco

    Directory of Open Access Journals (Sweden)

    Juan Lin


    Full Text Available Low temperature affects gene regulatory networks and alters cellular metabolism to inhibit plant growth. Peroxidases are widely distributed in plants and play a large role in adjusting and controlling reactive oxygen species (ROS homeostasis in response to abiotic stresses such as low temperature. The Rare Cold-Inducible 35 gene from Capsella bursa-pastoris (CbRCI35 belongs to the type III peroxidase family and has been reported to be a cold responsive gene in plants. Here we performed an expressional characterization of CbRCI35 under cold and ionic liquid treatments. The promoter of CbRCI35 was also cloned and its activity was examined using the GUS reporter system. CbRCI35 protein was localized in the cytoplasm according to sequence prediction and GFP fusion assay. Heterologous expression tests revealed that CbRCI35 conferred enhanced resistance to low temperature and activated endogenous cold responsive signaling in tobacco. Furthermore, in the normal condition the ROS accumulation was moderately enhanced while after chilling exposure superoxide dismutase (SOD activity was increased in CbRCI53 transgenic plants. The ROS metabolism related genes expression was altered accordingly. We conclude that CbRCI35 modulates ROS homeostasis and contributes to cold tolerance in plants.

  4. Determination of metallothioneins based on the enhanced peroxidase-like activity of mercury-coated gold nanoparticles aggregated by metallothioneins

    International Nuclear Information System (INIS)

    Li, Xue-Jiao; Wang, Yong-Sheng; Yang, Sheng-Yuan; Tang, Xian; Zhou, Bin; Wang, Xiao-Feng; Zhu, Yu-Feng; Huang, Yan-Qin; He, Shun-Zhen; Liu, Lu


    We report on a photometric method for the determination of the metallothioneins (MTs). It is known that citrate capped gold nanoparticles (AuNPs) coated with traces of mercury possess peroxidase-like properties that can catalyze the oxidation of 2,2′-azino-bis(3-ethylbenzothiazoline- 6-sulfonate) (ABTS) to form a blue product in acetate buffer of pH 4.5. It is found that if the AuNPs are first aggregated by the cysteine-rich metallothioneins, the peroxidase-like properties of the resulting aggregates (AuNP-Hg-MTs) cause a largely accelerated oxidation of ABTS. The effect of adding MTs to such a solution is used to quantify the MTs by a kinetic assay. Changes in absorbance at 416 nm are linearly correlated to the concentration of MTs in the 4.3 to 49 nM range, and the detection limit is 1.3 nM. The method was successfully applied to the determination of MTs in (spiked) human urine. The strategy may pave the way for related detection platforms. (author)

  5. Impedimetric aptasensor for nuclear factor kappa B with peroxidase-like mimic coupled DNA nanoladders as enhancer. (United States)

    Peng, Kanfu; Zhao, Hongwen; Xie, Pan; Hu, Shuang; Yuan, Yali; Yuan, Ruo; Wu, Xiongfei


    In this work, we developed a sensitive and universal aptasensor for nuclear factor kappa B (NF-κB) detection based on peroxidase-like mimic coupled DNA nanoladders for signal amplification. The dsDNA formed by capture DNA S1 and NF-κB binding aptamer (NBA) was firstly assembled on electrode surface. The presence of target NF-κB then led to the leave of NBA from electrode surface and thus provided the binding sites for immobilizing initiator to trigger in situ formation of DNA nanoladders on electrode surface. Since the peroxidase-like mimic manganese (III) meso-tetrakis (4-Nmethylpyridyl)-porphyrin (MnTMPyP) interacts with DNA nanoladders via groove binding, the insoluble benzo-4-chlorohexadienone (4-CD) precipitation derived from the oxidation of 4-chloro-1-naphthol (4-CN) could be formed on electrode surface in the presence of H2O2, resulting in a significantly amplified EIS signal output for quantitative target analysis. As a result, the developed aptasensor showed a low detection limit of 7pM and a wide linear range of 0.01-20nM. Featured with high sensitivity and label-free capability, the proposed sensing scheme can thus offer new opportunities for achieving sensitive, selective and stable detection of different types of target proteins. Copyright © 2016 Elsevier B.V. All rights reserved.

  6. Dual-functional Pt-on-Pd supported on reduced graphene oxide hybrids: peroxidase-mimic activity and an enhanced electrocatalytic oxidation characteristic. (United States)

    Zhang, Xiahong; Wu, Genghuang; Cai, Zhixiong; Chen, Xi


    In this study, a facile hydrothermal method was developed to synthesize Pt-on-Pd supported on reduced graphene oxide (Pt-on-Pd/RGO) hybrids. Because of the synergistic effect between Pt-on-Pd and RGO, the obtained Pt-on-Pd/RGO had superior peroxidase-mimic activities in H2O2 reduction and TMB oxidation. The reaction medium was optimized and a sensing approach for H2O2 was developed with a linear range from 0.98 to 130.7 μM of H2O2. In addition, the characteristic of electrocatalytic oxidation of methanol was investigated. The peak current density value, j(f), for the Pt-on-Pd/RGO hybrid (328 mA mg(Pt)(-1)) was about 1.85 fold higher than that of commercial Pt black (177 mA mg(Pt)(-1)) and, also, more durable electrocatalytic activity could be obtained. For the first time, the dual-functional Pt-on-Pd/RGO with peroxidase-mimic activity and an enhanced electrocatalytic oxidation characteristic was reported. Copyright © 2014 Elsevier B.V. All rights reserved.

  7. The contribution of self-deceptive enhancement to display rules in the United States and Japan. (United States)

    Chung, Joanne M


    Socially desirable responding was tested as a mediator of American and Japanese college student differences in display rules. Americans endorsed the expression of anger, contempt, disgust, fear, happiness, and surprise more than the Japanese. Americans also exhibited more self-deceptive enhancement than the Japanese, and self-deceptive enhancement partially mediated country differences on the endorsement of anger, disgust, happiness, and surprise, but not contempt and fear. These findings highlight the role of self-deceptive enhancement in contributing to expressive display rules and support the point of view that socially desirable responding is a reflection of one's personality and culture rather than a statistical nuisance.

  8. Arabidopsis thaliana peroxidase N

    DEFF Research Database (Denmark)

    Mirza, Osman Asghar; Henriksen, A; Ostergaard, L


    The structure of the neutral peroxidase from Arabidopsis thaliana (ATP N) has been determined to a resolution of 1.9 A and a free R value of 20.5%. ATP N has the expected characteristic fold of the class III peroxidases, with a C(alpha) r.m.s.d. of 0.82 A when compared with horseradish peroxidase C...

  9. Dynamic Displays Enhance the Ability to Discriminate Genuine and Posed Facial Expressions of Emotion (United States)

    Namba, Shushi; Kabir, Russell S.; Miyatani, Makoto; Nakao, Takashi


    Accurately gauging the emotional experience of another person is important for navigating interpersonal interactions. This study investigated whether perceivers are capable of distinguishing between unintentionally expressed (genuine) and intentionally manipulated (posed) facial expressions attributed to four major emotions: amusement, disgust, sadness, and surprise. Sensitivity to this discrimination was explored by comparing unstaged dynamic and static facial stimuli and analyzing the results with signal detection theory. Participants indicated whether facial stimuli presented on a screen depicted a person showing a given emotion and whether that person was feeling a given emotion. The results showed that genuine displays were evaluated more as felt expressions than posed displays for all target emotions presented. In addition, sensitivity to the perception of emotional experience, or discriminability, was enhanced in dynamic facial displays, but was less pronounced in the case of static displays. This finding indicates that dynamic information in facial displays contributes to the ability to accurately infer the emotional experiences of another person. PMID:29896135

  10. DNA-enhanced peroxidase-like activity of layered double hydroxide nanosheets and applications in H2O2 and glucose sensing. (United States)

    Chen, Lijian; Sun, Kaifang; Li, Peipei; Fan, Xianzhong; Sun, Jianchao; Ai, Shiyun


    LDH nanosheets were obtained via continuous impaction and exfoliation by herring sperm DNA molecules using a constant vibration method. DNA-LDH nanohybrids were composed by electrostatic forces and they exhibited DNA-enhanced peroxidase-like activity. The morphology and structure of DNA-LDH nanohybrids were analyzed by transmission electron microscopy (TEM), selected-area electron diffraction (SAED), X-ray diffraction (XRD), and atomic force microscopy (AFM) characterization. On the basis of the high catalytic activity of DNA/CuAl-LDH nanosheets, a rapid, sensitive, and convenient approach was developed for colorimetric detection of H2O2 and blood glucose. This method can be potentially applied in medical diagnostics and biotechnology fields.

  11. Nanobody Based Immunoassay for Human Soluble Epoxide Hydrolase Detection Using Polymeric Horseradish Peroxidase (PolyHRP) for Signal Enhancement: The Rediscovery of PolyHRP? (United States)

    Li, Dongyang; Cui, Yongliang; Morisseau, Christophe; Gee, Shirley J; Bever, Candace S; Liu, Xiangjiang; Wu, Jian; Hammock, Bruce D; Ying, Yibin


    Soluble epoxide hydrolase (sEH) is a potential pharmacological target for treating hypertension, vascular inflammation, cancer, pain, and multiple cardiovascular related diseases. A variable domain of the heavy chain antibody (termed single domain antibody (sdAb), nanobody, or VHH) possesses the advantages of small size, high stability, ease of genetic manipulation, and ability for continuous manufacture, making such nanobody a superior choice as an immunoreagent. In this work, we developed an ultrasensitive nanobody based immunoassay for human sEH detection using polymeric horseradish peroxidase (PolyHRP) for signal enhancement. Llama nanobodies against human sEH were used as the detection antibody in sandwich enzyme linked immunosorbent assays (ELISA) with polyclonal anti-sEH as the capture antibody. A conventional sandwich ELISA using a horseradish peroxidase (HRP) labeled anti-hemeagglutinin (HA) tag as the tracer showed a marginal sensitivity (0.0015 optical density (OD)·mL/ng) and limit of detection (LOD) of 3.02 ng/mL. However, the introduction of the PolyHRP as the tracer demonstrated a 141-fold increase in the sensitivity (0.21 OD·mL/ng) and 57-fold decrease in LOD (0.05 ng/mL). Systematic comparison of three different tracers in four ELISA formats demonstrated the overwhelming advantage of PolyHRP as a label for nanobody based immunoassay. This enhanced sEH immunoassay was further evaluated in terms of selectivity against other epoxide hydrolases and detection of the target protein in human tissue homogenate samples. Comparison with an enzyme activity based assay and a Western blot for sEH detection reveals good correlation with the immunoassay. This work demonstrates increased competiveness of nanobodies for practical sEH protein detection utilizing PolyHRP. It is worthwhile to rediscover the promising potential of PolyHRP in nanobody and other affinity based methods after its low-profile existence for decades.

  12. Head-Mounted Display Technology for Low Vision Rehabilitation and Vision Enhancement (United States)

    Ehrlich, Joshua R.; Ojeda, Lauro V.; Wicker, Donna; Day, Sherry; Howson, Ashley; Lakshminarayanan, Vasudevan; Moroi, Sayoko E.


    Purpose To describe the various types of head-mounted display technology, their optical and human factors considerations, and their potential for use in low vision rehabilitation and vision enhancement. Design Expert perspective. Methods An overview of head-mounted display technology by an interdisciplinary team of experts drawing on key literature in the field. Results Head-mounted display technologies can be classified based on their display type and optical design. See-through displays such as retinal projection devices have the greatest potential for use as low vision aids. Devices vary by their relationship to the user’s eyes, field of view, illumination, resolution, color, stereopsis, effect on head motion and user interface. These optical and human factors considerations are important when selecting head-mounted displays for specific applications and patient groups. Conclusions Head-mounted display technologies may offer advantages over conventional low vision aids. Future research should compare head-mounted displays to commonly prescribed low vision aids in order to compare their effectiveness in addressing the impairments and rehabilitation goals of diverse patient populations. PMID:28048975

  13. The contribution of self-deceptive enhancement to display rules in the United States and Japan


    Chung, Joanne M.


    Socially desirable responding was tested as a mediator of American and Japanese college student differences in display rules. Americans endorsed the expression of anger, contempt, disgust, fear, happiness, and surprise more than the Japanese. Americans also exhibited more self-deceptive enhancement than the Japanese, and self-deceptive enhancement partially mediated country differences on the endorsement of anger, disgust, happiness, and surprise, but not contempt and fear. These findings hig...

  14. Evaluation of Fused Synthetic and Enhanced Vision Display Concepts for Low-Visibility Approach and Landing (United States)

    Bailey, Randall E.; Kramer, Lynda J.; Prinzel, Lawrence J., III; Wilz, Susan J.


    NASA is developing revolutionary crew-vehicle interface technologies that strive to proactively overcome aircraft safety barriers that would otherwise constrain the full realization of the next generation air transportation system. A piloted simulation experiment was conducted to evaluate the complementary use of Synthetic and Enhanced Vision technologies. Specific focus was placed on new techniques for integration and/or fusion of Enhanced and Synthetic Vision and its impact within a two-crew flight deck during low-visibility approach and landing operations. Overall, the experimental data showed that significant improvements in situation awareness, without concomitant increases in workload and display clutter, could be provided by the integration and/or fusion of synthetic and enhanced vision technologies for the pilot-flying and the pilot-not-flying. Improvements in lateral path control performance were realized when the Head-Up Display concepts included a tunnel, independent of the imagery (enhanced vision or fusion of enhanced and synthetic vision) presented with it. During non-normal operations, the ability of the crew to handle substantial navigational errors and runway incursions were neither improved nor adversely impacted by the display concepts. The addition of Enhanced Vision may not, of itself, provide an improvement in runway incursion detection without being specifically tailored for this application.

  15. Efficiency enhancement of liquid crystal projection displays using light recycle technology (United States)

    Wang, Y.


    A new technology developed at JPL using low absorption color filters with polarization and color recycle system, is able to enhance efficiency of a single panel liquid crytal display (LCD) projector to the same efficiency of a 3 panel LCD projector.

  16. Peroxidases in nanostructures

    Directory of Open Access Journals (Sweden)

    Ana Maria eCarmona-Ribeiro


    Full Text Available Peroxidases are enzymes catalyzing redox reactions that cleave peroxides. Their active redox centers have heme, cysteine thiols, selenium, manganese and other chemical moieties. Peroxidases and their mimetic systems have several technological and biomedical applications such as environment protection, energy production, bioremediation, sensors and immunoassays design and drug delivery devices. The combination of peroxidases or systems with peroxidase-like activity with nanostructures such as nanoparticles, nanotubes, thin films, liposomes, micelles, nanoflowers, nanorods and others is often an efficient strategy to improve catalytic activity, targeting and reusability.

  17. Gliding lizards use the position of the sun to enhance social display. (United States)

    Klomp, Danielle A; Stuart-Fox, Devi; Das, Indraneil; Ord, Terry J


    Effective communication requires animal signals to be readily detected by receivers in the environments in which they are typically given. Certain light conditions enhance the visibility of colour signals and these conditions can vary depending on the orientation of the sun and the position of the signaller. We tested whether Draco sumatranus gliding lizards modified their position relative to the sun to enhance the conspicuousness of their throat-fan (dewlap) during social display to conspecifics. The dewlap was translucent, and we found that lizards were significantly more likely to orient themselves perpendicular to the sun when displaying. This increases the dewlap's radiance, and likely, its conspicuousness, by increasing the amount of light transmitted through the ornament. This is a rare example of a behavioural adaptation for enhancing the visibility of an ornament to distant receivers. © 2017 The Author(s).

  18. Human engineering design considerations for the use of signal color enhancement in ASW displays

    Energy Technology Data Exchange (ETDEWEB)

    Banks, W.W.


    The Lawrence Livermore National Laboratory (LLNL) was requested to examine and define man-machine limits as part of the Office of Naval Technology's High Gain Initiative program (HGI). As an initial investigative area, LLNL's Systems and Human Performance effort focused upon color display interfaces and the use of color enhancement techniques to define human and system interface limits in signal detection and discrimination tasks. The knowledgeable and prudent use of color in different types of display is believed to facilitate human visual detection, discrimination and recognition in complex visual tasks. The consideration and understanding of the complex set of interacting variables associated with the prudent use of color is essential to optimize human performance, especially in the ASW community. The designers of advanced display technology and signal processing algorithms may be eventually called upon to present pre-processed information to ASW operators and researchers using the latest color enhancement techniques. These techniques, however, may be limited if one does not understand the complexity and limits of human information processing which reflects the assessed state of knowledge relevant to the use of color in displays. The initial sections of this report discuss various aspects of color presentation and the problems typically encountered, while the last section deals with a specific research proposal required to further our understanding and proper use of color enhancement methods.

  19. Impact of Adding a Pictorial Display to Enhance Recall of Cancer Patient Histories: A Randomized Trial. (United States)

    Wolch, Gary; Ghosh, Sunita; Boyington, Curtiss; Watanabe, Sharon M; Fainsinger, Robin; Burton-Macleod, Sarah; Thai, Vincent; Thai, JoAnn; Fassbender, Konrad


    Current health care delivery models have increased the need for safe and concise patient handover. Handover interventions in the literature have focused on the use of structured tools but have not evaluated their ability to facilitate retention of patient information. In this study, mock pictorial displays were generated in an attempt to create a snapshot of each patient's medical and social circumstances. These pictorial displays contained the patient's photograph and other disease- and treatment-related images. The objective of this randomized trial was to assess the ability of these snapshots to enhance delayed information recall by care providers. Participating physicians were given four advanced cancer patient histories to review, two at a time over two weeks. Pictorial image displays, referred to as the Electronic Whiteboard (EWB) were added, in a randomized manner to half of the textual histories. The impact of the EWB on information recall was tested in immediate and delayed time frames. Overall, patient information recall declined significantly over time, with or without the EWB. Still, this trial demonstrates significantly higher test scores after 24 hours with the addition of pictures to textual patient information, compared with textual information alone (P = 0.0002). A more modest improvement was seen with the addition of the EWB for questionnaires administered immediately after history review (P = 0.008). Most participants agreed that the EWB was a useful enhancement and that seeing a patient's photograph improved their ability to retain information. Most studies examining the institution of handover protocols in the health care setting have failed to harness the power of pictures and other representative images. This study demonstrates the ability of pictorial displays to improve both immediate and delayed recall of patient histories without increasing review time. These types of displays may be amenable to generation by software programs and

  20. Activity of the C-terminal-dependent vacuolar sorting signal of horseradish peroxidase C1a is enhanced by its secondary structure. (United States)

    Matsui, Takeshi; Tabayashi, Ayako; Iwano, Megumi; Shinmyo, Atsuhiko; Kato, Ko; Nakayama, Hideki


    Plant class III peroxidase (PRX) catalyzes the oxidation and oxidative polymerization of a variety of phenolic compounds while reducing hydrogen peroxide. PRX proteins are classified into apoplast type and vacuole type based on the absence or the presence of C-terminal propeptides, which probably function as vacuolar sorting signals (VSSs). In this study, in order to improve our understanding of vacuole-type PRX, we analyzed regulatory mechanisms of vacuolar sorting of a model vacuole-type PRX, the C1a isozyme of horseradish (Armoracia rusticana) (HRP C1a). Using cultured transgenic tobacco cells and protoplasts derived from horseradish leaves, we characterized HRP C1a's VSS, which is a 15 amino acid C-terminal propeptide (C15). We found that the C-terminal hexapeptide of C15 (C6), which is well conserved among vacuole-type PRX proteins, forms the core of the C-terminal-dependent VSS. We also found that the function of C6 is enhanced by the remaining N-terminal part of C15 which probably folds into an amphiphilic α-helix.

  1. Disruption of AtWNK8 Enhances Tolerance of Arabidopsis to Salt and Osmotic Stresses via Modulating Proline Content and Activities of Catalase and Peroxidase

    Directory of Open Access Journals (Sweden)

    Hong Liao


    Full Text Available With no lysine kinases (WNKs play important roles in plant growth and development. However, its role in salt and osmotic stress tolerance is unclear. Here, we report that AtWNK8 is mainly expressed in primary root, hypocotyl, stamen and pistil and is induced by NaCl and sorbitol treatment. Compared to the wild-type, the T-DNA knock-out wnk8 mutant was more tolerant to severe salinity and osmotic stresses, as indicated by 27% and 198% more fresh weight in the NaCl and sorbitol treatment, respectively. The wnk8 mutant also accumulated 1.43-fold more proline than the wild-type in the sorbitol treatment. Under NaCl and sorbitol stresses, catalase (CAT activity in wnk8 mutant was 1.92- and 3.7-times of that in Col-0, respectively. Similarly, under salt and osmotic stress conditions, peroxidase (POD activities in wnk8 mutant were 1.81- and 1.58-times of that in Col-0, respectively. Taken together, we revealed that maintaining higher CAT and POD activities might be one of the reasons that the disruption of AtWNK8 enhances the tolerance to salt stress, and accumulating more proline and higher activities of CAT and POD might result in the higher tolerance of WNK8 to osmotic stress.

  2. Preparation of a Superhydrophobic and Peroxidase-like Activity Array Chip for H2O2 Sensing by Surface-Enhanced Raman Scattering. (United States)

    Yu, Zhi; Park, Yeonju; Chen, Lei; Zhao, Bing; Jung, Young Mee; Cong, Qian


    In this paper, we propose a novel and simple method for preparing a dual-biomimetic functional array possessing both superhydrophobic and peroxidase-like activity that can be used for hydrogen peroxide (H2O2) sensing. The proposed method is an integration innovation that combines the above two properties and surface-enhanced Raman scattering (SERS). We integrated a series of well-ordered arrays of Au points (d = 1 mm) onto a superhydrophobic copper (Cu)/silver (Ag) surface by replicating an arrayed molybdenum template. Instead of using photoresists and the traditional lithography method, we utilized a chemical etching method (a substitution reaction between Cu and HAuCl4) with a Cu/Ag superhydrophobic surface as the barrier layer, which has the benefit of water repellency. The as-prepared Au points were observed to possess peroxidase-like activity, allowing for catalytic oxidation of the chromogenic molecule o-phenylenediamine dihydrochloride (OPD). Oxidation was evidenced by a color change in the presence of H2O2, which allows the array chip to act as an H2O2 sensor. In this study, the water repellency of the superhydrophobic surface was used to fabricate the array chip and increase the local reactant concentration during the catalytic reaction. As a result, the catalytic reaction occurred when only 2 μL of an aqueous sample (OPD/H2O2) was placed onto the Au point, and the enzymatic product, 2,3-diaminophenazine, showed a SERS signal distinguishable from that of OPD after mixing with 2 μL of colloidal Au. Using the dual-biomimetic functional array chip, quantitative analysis of H2O2 was performed by observing the change in the SERS spectra, which showed a concentration-dependent behavior for H2O2. This method allows for the detection of H2O2 at concentrations as low as 3 pmol per 2 μL of sample, which is a considerable advantage in H2O2 analysis. The as-prepared substrate was convenient for H2O2 detection because only a small amount of sample was required in

  3. Enhancing Electrophoretic Display Lifetime: Thiol-Polybutadiene Evaporation Barrier Property Response to Network Microstructure

    Energy Technology Data Exchange (ETDEWEB)

    Cook, Caitlyn Christian [California State Polytechnic State Univ., San Luis Obispo, CA (United States)


    An evaporation barrier is required to enhance the lifetime of electrophoretic deposition (EPD) displays. As EPD functions on the basis of reversible deposition and resuspension of colloids suspended in a solvent, evaporation of the solvent ultimately leads to device failure. Incorporation of a thiol-polybutadiene elastomer into EPD displays enabled display lifetime surpassing six months in counting and catalyzed rigid display transition into a flexible package. Final flexible display transition to mass production compels an electronic-ink approach to encapsulate display suspension within an elastomer shell. Final thiol-polybutadiene photosensitive resin network microstructure was idealized to be dense, homogeneous, and expose an elastic response to deformation. Research at hand details an approach to understanding microstructural change within display elastomers. Polybutadiene-based resin properties are modified via polymer chain structure, with and without added aromatic urethane methacrylate difunctionality, and in measuring network response to variation in thiol and initiator concentration. Dynamic mechanical analysis results signify that cross-linked segments within a difunctionalized polybutadiene network were on average eight times more elastically active than that of linked segments within a non-functionalized polybutadiene network. Difunctionalized polybutadiene samples also showed a 2.5 times greater maximum elastic modulus than non-functionalized samples. Hybrid polymer composed of both polybutadiene chains encompassed TE-2000 stiffness and B-1000 elasticity for use in encapsulating display suspension. Later experiments measured kinetic and rheological response due to alteration in dithiol cross-linker chain length via real time Fourier transform infrared spectroscopy and real-time dynamic rheology. Distinct differences were discovered between dithiol resin systems, as maximum thiol conversion achieved in short and long chain length dithiols was 86% and

  4. Enhanced Adsorption and Recovery of Uranyl Ions by NikR Mutant-Displaying Yeast

    Directory of Open Access Journals (Sweden)

    Kouichi Kuroda


    Full Text Available Uranium is one of the most important metal resources, and the technology for the recovery of uranyl ions (UO22+ from aqueous solutions is required to ensure a semi-permanent supply of uranium. The NikR protein is a Ni2+-dependent transcriptional repressor of the nickel-ion uptake system in Escherichia coli, but its mutant protein (NikRm is able to selectively bind uranyl ions in the interface of the two monomers. In this study, NikRm protein with ability to adsorb uranyl ions was displayed on the cell surface of Saccharomyces cerevisiae. To perform the binding of metal ions in the interface of the two monomers, two metal-binding domains (MBDs of NikRm were tandemly fused via linker peptides and displayed on the yeast cell surface by fusion with the cell wall-anchoring domain of yeast α-agglutinin. The NikRm-MBD-displaying yeast cells with particular linker lengths showed the enhanced adsorption of uranyl ions in comparison to the control strain. By treating cells with citrate buffer (pH 4.3, the uranyl ions adsorbed on the cell surface were recovered. Our results indicate that the adsorption system by yeast cells displaying tandemly fused MBDs of NikRm is effective for simple and concentrated recovery of uranyl ions, as well as adsorption of uranyl ions.

  5. Depth-enhanced three-dimensional-two-dimensional convertible display based on modified integral imaging. (United States)

    Park, Jae-Hyeung; Kim, Hak-Rin; Kim, Yunhee; Kim, Joohwan; Hong, Jisoo; Lee, Sin-Doo; Lee, Byoungho


    A depth-enhanced three-dimensional-two-dimensional convertible display that uses a polymer-dispersed liquid crystal based on the principle of integral imaging is proposed. In the proposed method, a lens array is located behind a transmission-type display panel to form an array of point-light sources, and a polymer-dispersed liquid crystal is electrically controlled to pass or to scatter light coming from these point-light sources. Therefore, three-dimensional-two-dimensional conversion is accomplished electrically without any mechanical movement. Moreover, the nonimaging structure of the proposed method increases the expressible depth range considerably. We explain the method of operation and present experimental results.

  6. Enzyme Technology of Peroxidases: Immobilization, Chemical and Genetic Modification (United States)

    Longoria, Adriana; Tinoco, Raunel; Torres, Eduardo

    An overview of enzyme technology applied to peroxidases is made. Immobilization on organic, inorganic, and hybrid supports; chemical modification of amino acids and heme group; and genetic modification by site-directed and random mutagenesis are included. Different strategies that were carried out to improve peroxidase performance in terms of stability, selectivity, and catalytic activity are analyzed. Immobilization of peroxidases on inorganic and organic materials enhances the tolerance of peroxidases toward the conditions normally found in many industrial processes, such as the presence of an organic solvent and high temperature. In addition, it is shown that immobilization helps to increase the Total Turnover Number at levels high enough to justify the use of a peroxidase-based biocatalyst in a synthesis process. Chemical modification of peroxidases produces modified enzymes with higher thermostability and wider substrate variability. Finally, through mutagenesis approaches, it is possible to produce modified peroxidases capable of oxidizing nonnatural substrates with high catalytic activity and affinity.

  7. Arabidopsis thaliana peroxidase N

    DEFF Research Database (Denmark)

    Mirza, Osman Asghar; Henriksen, A; Ostergaard, L


    The structure of the neutral peroxidase from Arabidopsis thaliana (ATP N) has been determined to a resolution of 1.9 A and a free R value of 20.5%. ATP N has the expected characteristic fold of the class III peroxidases, with a C(alpha) r.m.s.d. of 0.82 A when compared with horseradish peroxidase C...... (HRP C). HRP C is 54% identical to ATP N in sequence. When the structures of four class III plant peroxidases are superimposed, the regions with structural differences are non-randomly distributed; all are located in one half of the molecule. The architecture of the haem pocket of ATP N is very similar...... to that of HRP C, in agreement with the low small-molecule substrate specificity of all class III peroxidases. The structure of ATP N suggests that the pH dependence of the substrate turnover will differ from that of HRP C owing to differences in polarity of the residues in the substrate-access channel. Since...

  8. Mentalizing skills do not differentiate believers from non-believers, but credibility enhancing displays do.

    Directory of Open Access Journals (Sweden)

    David L R Maij

    Full Text Available The ability to mentalize has been marked as an important cognitive mechanism enabling belief in supernatural agents. In five studies we cross-culturally investigated the relationship between mentalizing and belief in supernatural agents with large sample sizes (over 67,000 participants in total and different operationalizations of mentalizing. The relative importance of mentalizing for endorsing supernatural beliefs was directly compared with credibility enhancing displays-the extent to which people observed credible religious acts during their upbringing. We also compared autistic with neurotypical adolescents. The empathy quotient and the autism-spectrum quotient were not predictive of belief in supernatural agents in all countries (i.e., The Netherlands, Switzerland and the United States, although we did observe a curvilinear effect in the United States. We further observed a strong influence of credibility enhancing displays on belief in supernatural agents. These findings highlight the importance of cultural learning for acquiring supernatural beliefs and ask for reconsiderations of the importance of mentalizing.

  9. Safety parameter display system: an operator support system for enhancement of safety in Indian PHWRs

    International Nuclear Information System (INIS)

    Subramaniam, K.; Biswas, T.


    Ensuring operational safety in nuclear power plants is important as operator errors are observed to contribute significantly to the occurrence of accidents. Computerized operator support systems, which process and structure information, can help operators during both normal and transient conditions, and thereby enhance safety and aid effective response to emergency conditions. An important operator aid being developed and described in this paper, is the safety parameter display system (SPDS). The SPDS is an event-independent, symptom-based operator aid for safety monitoring. Knowledge-based systems can provide operators with an improved quality of information. An information processing model of a knowledge based operator support system (KBOSS) developed for emergency conditions using an expert system shell is also presented. The paper concludes with a discussion of the design issues involved in the use of a knowledge based systems for real time safety monitoring and fault diagnosis. (author). 8 refs., 4 figs., 1 tab

  10. Cloning and analysis of the ascorbate peroxidase gene promoter ...

    African Journals Online (AJOL)

    Ascorbate peroxidase (APX) is known to catalyze the reduction of H2O2 to water and enhance plants' tolerance in stress environment. An ascorbate peroxidase protein (BnAPX) was previously isolated from Brassica napus in our laboratory and it was located in the chloroplast. In order to clarify the physiological function of ...


    Directory of Open Access Journals (Sweden)

    Elena Truta


    Full Text Available During vegetation of female and male hemp plants (Cannabis sativa L., five quantitative determinations of peroxidase activities were made (40 days, 55 days, 70 days, 85 days, 105 days. Peroxidase activity presented some differences in hemp plants, between females and males, during their vegetation cycle. In female plants, before anthesis were registered peaks of peroxidase activities. The blossoming of male plants was coincident with the increase of catalitic action of peroxidase. Generally, the male plants displayed greater levels of peroxidasic activity.

  12. Evaluation of Crude Oil Biodegradation Efficiency and Peroxidase ...

    African Journals Online (AJOL)


    Increase in biomass enhanced degradation efficiency above 80 % after 10 days for all concentration of crude oil studied. Peroxidase ... compounds by various bacteria and fungi (Gianfreda et al, 1999) ... into a clean plastic container. Microbial.

  13. Medial temporal lobe-dependent repetition suppression and enhancement due to implicit versus explicit processing of individual repeated search displays

    Directory of Open Access Journals (Sweden)

    Thomas eGeyer


    Full Text Available Using visual search, functional magnetic resonance imaging (fMRI and patient studies have demonstrated that medial temporal lobe (MTL structures differentiate repeated from novel displays – even when observers are unaware of display repetitions. This suggests a role for MTL in both explicit and, importantly, implicit learning of repeated sensory information (Greene et al., 2007. However, recent behavioral studies suggest, by examining visual search and recognition performance concurrently, that observers have explicit knowledge of at least some of the repeated displays (Geyer et al., 2010. The aim of the present fMRI study was thus to contribute new evidence regarding the contribution of MTL structures to explicit versus implicit learning in visual search. It was found that MTL activation was increased for explicit and, respectively, decreased for implicit relative to baseline displays. These activation differences were most pronounced in left anterior parahippocampal cortex, especially when observers were highly trained on the repeated displays. The data are taken to suggest that explicit and implicit memory processes are linked within MTL structures, but expressed via functionally separable mechanisms (repetition enhancement vs. -suppression. They further show that repetition effects in visual search would have to be investigated at the display level.

  14. Comparing the effectiveness of different displays in enhancing illusions of self-movement (vection

    Directory of Open Access Journals (Sweden)

    Bernhard E. Riecke


    Full Text Available Illusions of self-movement (vection can be used in Virtual Reality (VR and other applications to give users the embodied sensation that they are moving when physical movement is unfeasible or too costly. Whereas a large body of vection literature studied how various parameters of the presented visual stimulus affect vection, little is known how different display types might affect vection. As a step towards addressing this gap, we conducted three experiments to compare vection and usability parameters between commonly used VR displays, ranging from stereoscopic projection and 3D TV to high-end head-mounted display (HMD, NVIS SX111 and recent low-cost HMD (Oculus Rift. The last experiment also compared these two HMDs in their native full field of view FOV and a reduced, matched FOV of 72×45°. Participants moved along linear and curvilinear paths in the virtual environment, reported vection onset time, and rated vection intensity at the end of each trial. In addition, user ratings on immersion, motion sickness, vection, and overall preference were recorded retrospectively and compared between displays. Unexpectedly, there were no significant effects of display on vection measures. Reducing the FOV for the HMDs (from full to 72×45° decreased vection onset latencies, but did not affect vection intensity. As predicted, curvilinear paths yielded earlier and more intense vection. Although vection has often been proposed to predict or even cause motion sickness, we observed no correlation for any of the displays studied. In conclusion, perceived self-motion and other user experience measures proved surprisingly tolerant towards changes in display type as long as the FOV was roughly matched. This suggests that display choice for vection research and VR applications can be largely based on other considerations as long as the provided FOV is sufficiently large.

  15. Enhanced/synthetic vision and head-worn display technologies for terminal maneuvering area NextGen operations (United States)

    Arthur, Jarvis J., III; Prinzel, Lawrence J., III; Williams, Steven P.; Bailey, Randall E.; Shelton, Kevin J.; Norman, R. Mike


    NASA is researching innovative technologies for the Next Generation Air Transportation System (NextGen) to provide a "Better-Than-Visual" (BTV) capability as adjunct to "Equivalent Visual Operations" (EVO); that is, airport throughputs equivalent to that normally achieved during Visual Flight Rules (VFR) operations rates with equivalent and better safety in all weather and visibility conditions including Instrument Meteorological Conditions (IMC). These new technologies build on proven flight deck systems and leverage synthetic and enhanced vision systems. Two piloted simulation studies were conducted to access the use of a Head-Worn Display (HWD) with head tracking for synthetic and enhanced vision systems concepts. The first experiment evaluated the use a HWD for equivalent visual operations to San Francisco International Airport (airport identifier: KSFO) compared to a visual concept and a head-down display concept. A second experiment evaluated symbology variations under different visibility conditions using a HWD during taxi operations at Chicago O'Hare airport (airport identifier: KORD). Two experiments were conducted, one in a simulated San Francisco airport (KSFO) approach operation and the other, in simulated Chicago O'Hare surface operations, evaluating enhanced/synthetic vision and head-worn display technologies for NextGen operations. While flying a closely-spaced parallel approach to KSFO, pilots rated the HWD, under low-visibility conditions, equivalent to the out-the-window condition, under unlimited visibility, in terms of situational awareness (SA) and mental workload compared to a head-down enhanced vision system. There were no differences between the 3 display concepts in terms of traffic spacing and distance and the pilot decision-making to land or go-around. For the KORD experiment, the visibility condition was not a factor in pilot's rating of clutter effects from symbology. Several concepts for enhanced implementations of an unlimited field

  16. Expression of an alfalfa (Medicago sativa L.) peroxidase gene in transgenic Arabidopsis thaliana enhances resistance to NaCl and H2O2. (United States)

    Teng, K; Xiao, G Z; Guo, W E; Yuan, J B; Li, J; Chao, Y H; Han, L B


    Peroxidases (PODs) are enzymes that play important roles in catalyzing the reduction of H2O2 and the oxidation of various substrates. They function in many different and important biological processes, such as defense mechanisms, immune responses, and pathogeny. The POD genes have been cloned and identified in many plants, but their function in alfalfa (Medicago sativa L.) is not known, to date. Based on the POD gene sequence (GenBank accession No. L36157.1), we cloned the POD gene in alfalfa, which was named MsPOD. MsPOD expression increased with increasing H2O2. The gene was expressed in all of the tissues, including the roots, stems, leaves, and flowers, particularly in stems and leaves under light/dark conditions. A subcellular analysis showed that MsPOD was localized outside the cells. Transgenic Arabidopsis with MsPOD exhibited increased resistance to H2O2 and NaCl. Moreover, POD activity in the transgenic plants was significantly higher than that in wild-type Arabidopsis. These results show that MsPOD plays an important role in resistance to H2O2 and NaCl.

  17. Glassy carbon electrode modified with horse radish peroxidase/organic nucleophilic-functionalized carbon nanotube composite for enhanced electrocatalytic oxidation and efficient voltammetric sensing of levodopa

    Energy Technology Data Exchange (ETDEWEB)

    Shoja, Yalda; Rafati, Amir Abbas, E-mail:; Ghodsi, Javad


    A novel and selective enzymatic biosensor was designed and constructed for voltammetric determination of levodopa (L-Dopa) in aqueous media (phosphate buffer solution, pH = 7). Biosensor development was on the basis of to physically immobilizing of horse radish peroxidase (HRP) as electrochemical catalyst by sol–gel on glassy carbon electrode modified with organic nucleophilic carbon nanotube composite which in this composite p-phenylenediamine (pPDA) as organic nucleophile chemically bonded with functionalized MWCNT (MWCNT-COOH). The results of this study suggest that prepared bioorganic nucleophilic carbon nanotube composite (HRP/MWCNT-pPDA) shows fast electron transfer rate for electro oxidation of L-Dopa because of its high electrochemical catalytic activity toward the oxidation of L-Dopa, more −NH{sub 2} reactive sites and large effective surface area. Also in this work we measured L-Dopa in the presence of folic acid and uric acid as interferences. The proposed biosensor was characterized by scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX), FT-IR spectroscopy and cyclic voltammetry (CV). The differential pulse voltammetry (DPV) was used for determination of L-Dopa from 0.1 μM to 1.9 μM with a low detection limit of 40 nM (for S/N = 3) and sensitivity was about 35.5 μA/μM. Also this biosensor has several advantages such as rapid response, high stability and reproducibility. - Highlights: • Glassy carbon electrode modified by a novel composite in which pPDA as nucleophile is chemically attached to MWCNTs. • The developed biosensor exhibited excellent electrocatalytic activity in electrochemically determination of L-Dopa. • The biosensor showed acceptable sensitivity, reproducibility, detection limit, selectivity and stability. • MWCNT-pPDA provides a good electrical conductivity and large effective surface area for enzyme immobilization.

  18. Production and Purification of Peroxidase from Aspergillus niger.

    Directory of Open Access Journals (Sweden)

    Mohammed A. Jebor


    Full Text Available This study was conducted in the laboratories of Biology Department, College of Science, which deals with isolation and purification of peroxidase and optimization of process parameters to achieve maximum yield of peroxidase by Aspergillus niger. Solid-state fermentation of Aspergillus niger was carried out for enhanced production of peroxidase using hydrogen peroxide as the substrate of enzyme maximum activity of the enzyme was achieved under optimum growth conditions. The optimum conditions were the isolated of Aspergillus niger from soil and growth in synthetic medium, it gave high titer of peroxidase activity, the fructose as carbon source, peptone as nitrogen source, after 12 days of incubation, incubation temperature 25 °C and pH = 6.5. Peroxidase purified in four purification steps; precipitation with 70% saturation of ammonium sulfate, step of dialysis, the third by ion exchange chromatography using DEAE-Cellulose and fourth by gel filtration throughout Sephadex G-100. The specific activity of the purified enzyme was 150U/mg with 7.75 folds. The peroxidase was shown to have molecular weight of 40kDa in SDS-PAGA and about 40kDa in gel filtration.The optimum pH and temperature for peroxidase activity 7 and 35 C0 respectively.

  19. High-throughput sequencing enhanced phage display identifies peptides that bind mycobacteria

    CSIR Research Space (South Africa)

    Ngubane, NAC


    Full Text Available . The displayed peptides are flanked by two cysteine residues, which are oxidized during phage assembly to a disulfide bond, resulting in a loop constrained peptide. We initially used the traditional clone picking method to identify the enriched clones... of the library, 1.236109 heptapeptides, it represented sufficient depth to measure the quantitative enrich- ment of relevant peptides. To confirm successful enrichment during selection, we characterized the reduction in diversity of the pool in the consecutive...

  20. Horseradish peroxidase-loaded nanospheres attached to hollow gold nanoparticles as signal enhancers in an ultrasensitive immunoassay for alpha-fetoprotein

    International Nuclear Information System (INIS)

    Li, Ya; Yuan, Ruo; Chai, Yaqin; Zhuo, Ying; Su, Huilan; Zhang, Yuxia


    We report on a novel electrochemical signal amplification strategy for use in immunoassays. The highly responsive immunoelectrode was constructed in the following way: (1) The surface of a gold electrode was covered with a layer single-walled carbon nanotubes dispersed in chitosane functionalized with L-cysteine; (2) Gold nanoparticles containing protein A and anti-alpha-fetoprotein (anti-AFP) were then covalently attached to the surface via the thiol groups of the chitosane. The electrode is then exposed to the analyte (AFP) which then is bound by the antibody. In the next step, a gold-conjugated secondary antibody is added that was prepared in the following way: (1) Horseradish peroxidase was crosslinked and the resulting spheres were coated with hollow gold nanoparticles (hollow Au-NPs) to give nanospheres of ∼100 nm in diameter. (2) These were the coated with thionine and, in a last step, with secondary antibody. The use of these materials has several attractive features: The HRP-NPs functionalized with hollow Au-NPs possess a large surface area that can load the large amount of secondary antibody. Thionine (Thi) is highly redox active and improves the intensity of the signal. Carbon nanotubes were used because they possess an excellent electron transfer rate and large surface area. Following incubation of the modified electrode (a) with a sample containing AFP, (b) then with the secondary antibody, and (c) with washing buffer, the electrode is placed in a solution containing H 2 O 2 . The HRP in the smart secondary antibody causes the catalytic decomposition of H 2 O 2 and the results in an electrical current that is linearly related to the concentration of AFP in the 0.025 to 5.0 ng mL −1 concentration range. The detection limit for AFP is as low as 8.3 pg mL −1 . We believe that this novel kind of immunoassay represents a promising tool for use in sensitive clinical assays. (author)

  1. Advanced display object selection methods for enhancing user-computer productivity (United States)

    Osga, Glenn A.


    The User-Interface Technology Branch at NCCOSC RDT&E Division has been conducting a series of studies to address the suitability of commercial off-the-shelf (COTS) graphic user-interface (GUI) methods for efficiency and performance in critical naval combat systems. This paper presents an advanced selection algorithm and method developed to increase user performance when making selections on tactical displays. The method has also been applied with considerable success to a variety of cursor and pointing tasks. Typical GUI's allow user selection by: (1) moving a cursor with a pointing device such as a mouse, trackball, joystick, touchscreen; and (2) placing the cursor on the object. Examples of GUI objects are the buttons, icons, folders, scroll bars, etc. used in many personal computer and workstation applications. This paper presents an improved method of selection and the theoretical basis for the significant performance gains achieved with various input devices tested. The method is applicable to all GUI styles and display sizes, and is particularly useful for selections on small screens such as notebook computers. Considering the amount of work-hours spent pointing and clicking across all styles of available graphic user-interfaces, the cost/benefit in applying this method to graphic user-interfaces is substantial, with the potential for increasing productivity across thousands of users and applications.

  2. Enhancing multi-view autostereoscopic displays by viewing distance control (VDC) (United States)

    Jurk, Silvio; Duckstein, Bernd; Renault, Sylvain; Kuhlmey, Mathias; de la Barré, René; Ebner, Thomas


    Conventional multi-view displays spatially interlace various views of a 3D scene and form appropriate viewing channels. However, they only support sufficient stereo quality within a limited range around the nominal viewing distance (NVD). If this distance is maintained, two slightly divergent views are projected to the person's eyes, both covering the entire screen. With increasing deviations from the NVD the stereo image quality decreases. As a major drawback in usability, the manufacturer so far assigns this distance. We propose a software-based solution that corrects false view assignments depending on the distance of the viewer. Our novel approach enables continuous view adaptation based on the calculation of intermediate views and a column-bycolumn rendering method. The algorithm controls each individual subpixel and generates a new interleaving pattern from selected views. In addition, we use color-coded test content to verify its efficacy. This novel technology helps shifting the physically determined NVD to a user-defined distance thereby supporting stereopsis. The recent viewing positions can fall in front or behind the NVD of the original setup. Our algorithm can be applied to all multi-view autostereoscopic displays — independent of the ascent or the periodicity of the optical element. In general, the viewing distance can be corrected with a factor of more than 2.5. By creating a continuous viewing area the visualized 3D content is suitable even for persons with largely divergent intraocular distance — adults and children alike — without any deficiency in spatial perception.

  3. Peroxidase activity in root hairs of cress (lepidium sativum L.) Cytochemical localization and radioactive labelling of wall bound peroxidase

    International Nuclear Information System (INIS)

    Zaar, K.


    The ultrastructural localization of peroxidase activity in young, growing root hairs of cress (Lepidium sativum L.) after assay with 3,3'-diaminobenzidine is reported. Prominent peroxidase activity has been found in the dictyosomes and the associated vesicles, in ribosomes on ER-cisternae, as well as in the cell wall. On the basis of both ultrastructural and cytochemical evidence it is proposed that peroxidase in root hairs is synthesized on the ER- and within dictyosome cisternae packaged and transported in secretory vesicles and extruded into the cell wall particularily at the tip region of a root hair. The kinetic of Golgi apparatus mediated peroxidasesecretion was monitored by measuring the 55 Fe protoheme content of primary cell walls. Peroxidase secretion seems to be enhanced during stress incubation in destilled water. Secretory activity in root hairs is 20 times higher than in cells of the root body. (author)

  4. Critical issues in enhancing brightness in thin film phosphors for flat-panel display applications

    International Nuclear Information System (INIS)

    Singh, R.K.; Chen, Z.; Kumar, D.; Cho, K.; Ollinger, M.


    Thin film phosphors have potential applications in field emission flat-panel displays. However, they are limited by the lower cathodoluminescent brightness in comparison to phosphor powders. In this paper, we have investigated the critical parameters that need to be optimized to increase the brightness of phosphor thin films. Specifically, we studied the role of surface roughness and optical properties of the substrate on the brightness of the phosphor films. Thin Y 2 O 3 :Eu phosphor films were deposited on various substrates (lanthanum aluminate, quartz, sapphire, and silicon) with thicknesses varying from 50 to 500 nm. A model that accounts for diffuse and specular or scattering effects has been developed to understand the effects of the microstructure on the emission characteristics of the cathodoluminescent films. The results from the model show that both the optical properties of the substrate and the surface roughness of the films play a critical role in controlling the brightness of laser deposited phosphor films

  5. Enhancing the Security of Personal Identification Numbers with Three-Dimensional Displays

    Directory of Open Access Journals (Sweden)

    Mun-Kyu Lee


    Full Text Available Passwords and personal identification numbers (PINs are convenient and ubiquitous, but they are quite vulnerable to attackers who stand near the user (“shoulder-surfers”. This problem may be partially resolved by changing the user interface, but previous solutions of this kind still give shoulder-surfing attackers a significant advantage over brute force search. This paper provides a novel solution based on three dimensions, particularly suitable for glasses-free three-dimensional (3D displays found in many smartphones and handheld game consoles. A user at the “3D spot” may log in easily, while nearby shoulder-surfers gain no advantage. A detailed experimental usability analysis is performed to demonstrate the effectiveness of the proposed scheme in comparison to the existing methods.

  6. Topical antihistamines display potent anti-inflammatory activity linked in part to enhanced permeability barrier function

    DEFF Research Database (Denmark)

    Lin, Tzu-Kai; Man, Mao-Qiang; Santiago, Juan-Luis


    antagonists likely oppose mast cell-derived histamines. In four immunologically diverse, murine disease models, characterized by either inflammation alone (acute irritant contact dermatitis, acute allergic contact dermatitis) or by prominent barrier abnormalities (subacute allergic contact dermatitis, atopic...... of epidermal differentiation, leading to thickened cornified envelopes; and (ii) enhanced epidermal lipid synthesis and secretion. As barrier homeostasis was enhanced to a comparable extent in mast cell-deficient mice, with no further improvement following application of topical H1/2r antagonists, H1/2r...... dermatitis), topical H1/2r agonists aggravated, whereas H1/2r antagonists improved, inflammation and/or barrier function. The apparent ability of topical H1r/2r antagonists to target epidermal H1/2r could translate into increased efficacy in the treatment of inflammatory dermatoses, likely due to decreased...

  7. Enhancement of detectability by the use of coloured illumination for CT display

    International Nuclear Information System (INIS)

    Warren, R.C.; Simpson, J.


    A study has been made of the effect of coloured illumination on the detectability of both natural and artificial low-contrast signals immersed in CT noise. Enhancement of detectability relative to white light was found to be related to variations in visual acuity at different wavelengths. These results, together with previously published observations, suggest that an increase of detectability by changing viewing conditions can usually be achieved only at the expense of a reduction in resolution. (author)

  8. Development and clinical implementation of an enhanced display algorithm for use in networked electronic portal imaging

    International Nuclear Information System (INIS)

    Heuvel, Frank van den; Han, Ihn; Chungbin, Suzanne; Strowbridge, Amy; Tekyi-Mensah, Sam; Ragan, Don P.


    Purpose: To introduce and clinically validate a preprocessing algorithm that allows clinical images from an electronic portal imaging device (EPID) to be displayed on any computer monitor, without loss of clinical usability. The introduction of such a system frees EPI systems from the constraints of fixed viewing workstations and increases mobility of the images in a department. Methods and Materials: The preprocessing algorithm, together with its variable parameters is introduced. Clinically, the algorithm is tested using an observer study of 316 EPID images of the pelvic region in the framework of treatment of carcinoma of the cervix and endometrium. Both anterior-posterior (AP/PA) and latero-lateral (LAT) images were used. The images scored were taken from six different patients, five of whom were obese, female, and postmenopausal. The result is tentatively compared with results from other groups. The scoring system, based on the number of visible landmarks in the port, is proposed and validated. Validation was performed by having the observer panel score images with artificially induced noise levels. A comparative study was undertaken with a standard automatic window and leveling display technique. Finally, some case studies using different image sites and EPI detectors are presented. Results: The image quality for all images in this study was deemed to be clinically useful (mean score > 1). Most of the images received a score which was second highest (AP/PA landmarks ≥ 6 and LAT landmarks ≥ 5). Obesity, which has been an important factor determining the image quality, was not seen to be a factor here. Compared to standard techniques a highly significant improvement was determined with regard to clinical usefulness. The algorithm performs fast (less than 9 seconds) and needs no additional user interaction in most of the cases. The algorithm works well on both direct detection portal imagers and camera-based imagers whether analog or digital cameras

  9. Nanoemulsions of cancer chemopreventive agent benzyl isothiocyanate display enhanced solubility, dissolution, and permeability. (United States)

    Qhattal, Hussaini Syed Sha; Wang, Shu; Salihima, Tri; Srivastava, Sanjay K; Liu, Xinli


    Benzyl isothiocyanate (BITC), a compound found in cruciferous vegetables, is an effective chemopreventive agent. The objective of this study was to develop nanoemulsion formulations for the oral delivery of BITC. Optimized oil-in-water BITC nanoemulsions were prepared by a spontaneous self-nanoemulsification method and a homogenization-sonication method. Both nanoemulsions entrapped high amounts of BITC (15-17 mg/mL), with low polydispersity and good colloidal stability. The BITC nanoemulsions showed enhanced solubility and dissolution compared to pure BITC. These formulations markedly increased the apical to basolateral transport of BITC in Caco-2 cell monolayers. The apparent permeability values were 3.6 × 10(-6) cm/s for pure BITC and (1.1-1.3) × 10(-5) cm/s for BITC nanoemulsions. The nanoemulsions were easily taken up by human cancer cells A549 and SKOV-3 and inhibited tumor growth in vitro. This work shows for the first time that BITC can be formulated into nanoemulsions and may show promise in enhancing absorption and bioavailability.

  10. HER2-targeted liposomal doxorubicin displays enhanced anti-tumorigenic effects without associated cardiotoxicity

    International Nuclear Information System (INIS)

    Reynolds, Joseph G.; Geretti, Elena; Hendriks, Bart S.; Lee, Helen; Leonard, Shannon C.; Klinz, Stephan G.; Noble, Charles O.; Lücker, Petra B.; Zandstra, Peter W.; Drummond, Daryl C.; Olivier, Kenneth J.; Nielsen, Ulrik B.; Niyikiza, Clet; Agresta, Samuel V.; Wickham, Thomas J.


    Anthracycline-based regimens are a mainstay of early breast cancer therapy, however their use is limited by cardiac toxicity. The potential for cardiotoxicity is a major consideration in the design and development of combinatorial therapies incorporating anthracyclines and agents that target the HER2-mediated signaling pathway, such as trastuzumab. In this regard, HER2-targeted liposomal doxorubicin was developed to provide clinical benefit by both reducing the cardiotoxicity observed with anthracyclines and enhancing the therapeutic potential of HER2-based therapies that are currently available for HER2-overexpressing cancers. While documenting the enhanced therapeutic potential of HER2-targeted liposomal doxorubicin can be done with existing models, there has been no validated human cardiac cell-based assay system to rigorously assess the cardiotoxicity of anthracyclines. To understand if HER2-targeting of liposomal doxorubicin is possible with a favorable cardiac safety profile, we applied a human stem cell-derived cardiomyocyte platform to evaluate the doxorubicin exposure of human cardiac cells to HER2-targeted liposomal doxorubicin. To the best of our knowledge, this is the first known application of a stem cell-derived system for evaluating preclinical cardiotoxicity of an investigational agent. We demonstrate that HER2-targeted liposomal doxorubicin has little or no uptake into human cardiomyocytes, does not inhibit HER2-mediated signaling, results in little or no evidence of cardiomyocyte cell death or dysfunction, and retains the low penetration into heart tissue of liposomal doxorubicin. Taken together, this data ultimately led to the clinical decision to advance this drug to Phase I clinical testing, which is now ongoing as a single agent in HER2-expressing cancers. -- Highlights: ► Novel approach using stem cell-derived cardiomyocytes to assess preclinical safety. ► HER2-targeted liposomal doxorubicin has improved safety profile vs free doxorubicin

  11. Pulsed magnetic field from video display terminals enhances teratogenic effects of cytosine arabinoside in mice

    Energy Technology Data Exchange (ETDEWEB)

    Chiang, H.; Wu, R.Y.; Shao, B.J.; Fu, Y.D.; Yao, G.D.; Lu, D.J. [Zhejiang Medical Univ. (China)


    Eighty-nine Swiss Webster mice were randomly divided into four groups: a control group, a pulsed magnetic field (PMF) group, a cytosine arabinoside (ara-C, a teratogen) group, and a combined PMF + ara-C group. Mice in the PMF and PMF + ara-C groups were irradiated with a PMF (a sawtooth waveform with 52 {mu}s rise time, 12{mu}s decay time, and 15.6 kHz frequency) at a peak magnetic flux density of 40 {mu}T for 4 hours daily on days 6-17 of gestation. The mice in the ara-C and the PMF + ara-C groups were injected intraperitoneally on day 9 of gestation with 10 mg/kg of ara-C. The incidence of resorption and dead fetuses was not affected by PMF but was increased by ara-C injection. The malformation incidence of cleft palate (CP) and/or cleft lip (CL) was significantly higher in all three of the treated groups than in the control group (P < 0.05). If, however, statistical analyses had been done on litters rather than on individual fetuses, they would show that the incidence of CP and/or CL in the PMF group is not significantly greater than that in the control group. A significantly higher incidence of CP and/or CL was found in the PMF + ara-C group (49%) than the ara-C alone group (26.1%). These data suggest that PMF might enhance the development of ara-C-induced CP and/or CL. The incidence of minor variations in skeletal development, including reduction of skeletal calcification and loss of skeleton, was not statistically significant in the PMF group. However, it was higher in the two ara-C-treated groups, and there was no significant difference between the ara-C alone group and the ara-C + PMF group. From these results it is concluded that the very weak embryotoxic effects of PMF exposure may be revealed and enhanced in combination with a teratogenic agent.

  12. HER2-targeted liposomal doxorubicin displays enhanced anti-tumorigenic effects without associated cardiotoxicity

    Energy Technology Data Exchange (ETDEWEB)

    Reynolds, Joseph G.; Geretti, Elena; Hendriks, Bart S.; Lee, Helen; Leonard, Shannon C.; Klinz, Stephan G.; Noble, Charles O. [Merrimack Pharmaceuticals, 1 Kendall Square, Suite B7201, Cambridge, MA 02139 (United States); Lücker, Petra B.; Zandstra, Peter W. [University of Toronto, 160 College Street, Office 1116, Toronto, Ontario M5S 3E1 (Canada); Drummond, Daryl C.; Olivier, Kenneth J.; Nielsen, Ulrik B.; Niyikiza, Clet; Agresta, Samuel V. [Merrimack Pharmaceuticals, 1 Kendall Square, Suite B7201, Cambridge, MA 02139 (United States); Wickham, Thomas J., E-mail: [Merrimack Pharmaceuticals, 1 Kendall Square, Suite B7201, Cambridge, MA 02139 (United States)


    Anthracycline-based regimens are a mainstay of early breast cancer therapy, however their use is limited by cardiac toxicity. The potential for cardiotoxicity is a major consideration in the design and development of combinatorial therapies incorporating anthracyclines and agents that target the HER2-mediated signaling pathway, such as trastuzumab. In this regard, HER2-targeted liposomal doxorubicin was developed to provide clinical benefit by both reducing the cardiotoxicity observed with anthracyclines and enhancing the therapeutic potential of HER2-based therapies that are currently available for HER2-overexpressing cancers. While documenting the enhanced therapeutic potential of HER2-targeted liposomal doxorubicin can be done with existing models, there has been no validated human cardiac cell-based assay system to rigorously assess the cardiotoxicity of anthracyclines. To understand if HER2-targeting of liposomal doxorubicin is possible with a favorable cardiac safety profile, we applied a human stem cell-derived cardiomyocyte platform to evaluate the doxorubicin exposure of human cardiac cells to HER2-targeted liposomal doxorubicin. To the best of our knowledge, this is the first known application of a stem cell-derived system for evaluating preclinical cardiotoxicity of an investigational agent. We demonstrate that HER2-targeted liposomal doxorubicin has little or no uptake into human cardiomyocytes, does not inhibit HER2-mediated signaling, results in little or no evidence of cardiomyocyte cell death or dysfunction, and retains the low penetration into heart tissue of liposomal doxorubicin. Taken together, this data ultimately led to the clinical decision to advance this drug to Phase I clinical testing, which is now ongoing as a single agent in HER2-expressing cancers. -- Highlights: ► Novel approach using stem cell-derived cardiomyocytes to assess preclinical safety. ► HER2-targeted liposomal doxorubicin has improved safety profile vs free doxorubicin

  13. Dry etching of ITO by magnetic pole enhanced inductively coupled plasma for display and biosensing devices

    Energy Technology Data Exchange (ETDEWEB)

    Meziani, T. [European Commission, Joint Research Centre, Institute for Health and Consumer Protection, 21020 Ispra (Vatican City State, Holy See,) (Italy)]. E-mail:; Colpo, P. [European Commission, Joint Research Centre, Institute for Health and Consumer Protection, 21020 Ispra (Va) (Italy)]. E-mail:; Lambertini, V. [Centro Ricerche Fiat, Strada Torino 50, 10043 Orbassano (TO) (Italy); Ceccone, G. [European Commission, Joint Research Centre, Institute for Health and Consumer Protection, 21020 Ispra (Va) (Italy); Rossi, F. [European Commission, Joint Research Centre, Institute for Health and Consumer Protection, 21020 Ispra (Va) (Italy)


    The dry etching of indium tin oxide (ITO) layers deposited on glass substrates was investigated in a high density inductively coupled plasma (ICP) source. This innovative low pressure plasma source uses a magnetic core in order to concentrate the electromagnetic energy on the plasma and thus provides for higher plasma density and better uniformity. Different gas mixtures were tested containing mainly hydrogen, argon and methane. In Ar/H{sub 2} mixtures and at constant bias voltage (-100 V), the etch rate shows a linear dependence with input power varying the same way as the ion density, which confirms the hypothesis that the etching process is mainly physical. In CH{sub 4}/H{sub 2} mixtures, the etch rate goes through a maximum for 10% CH{sub 4} indicating a participation of the radicals to the etching process. However, the etch rate remains quite low with this type of gas mixture (around 10 nm/min) because the etching mechanism appears to be competing with a deposition process. With CH{sub 4}/Ar mixtures, a similar feature appeared but the etch rate was much higher, reaching 130 nm/min at 10% of CH{sub 4} in Ar. The increase in etch rate with the addition of a small quantity of methane indicates that the physical etching process is enhanced by a chemical mechanism. The etching process was monitored by optical emission spectroscopy that appeared to be a valuable tool for endpoint detection.

  14. Assessment of image display of contrast enhanced T1W images with fat suppression

    International Nuclear Information System (INIS)

    Miyazaki, Isao; Ishizaki, Keiko; Kobayashi, Kuninori; Katou, Masanobu


    The effects of imaging conditions and measures for their improvement were examined with regard to recognition of the effects of contrast on images when T 1 -weighted imaging with selective fat suppression was applied. Luminance at the target region was examined before and after contrast imaging using phantoms assuming pre- and post-imaging conditions. A clinical examination was performed on tumors revealed by breast examination, including those surrounded by mammary gland and by fat tissue. When fat suppression was used and imaging contrast was enhanced, the luminance level of fat tumors with the same structure as the prepared phantoms appeared to be high both before and after contrast imaging, and the effects of contrast were not distinguishable. This observation is attributable to the fact that the imaging conditions before and after contrast imaging were substantially different. To make a comparison between pre- and post-contrast images, it is considered necessary to perform imaging with fixed receiver gain and to apply the same imaging method for pre- and post-contrast images by adjusting post-contrast imaging conditions to those of pre-contrast imaging. (author)

  15. A Bacterial Pathogen Displaying Temperature-Enhanced Virulence of the Microalga Emiliania huxleyi. (United States)

    Mayers, Teaghan J; Bramucci, Anna R; Yakimovich, Kurt M; Case, Rebecca J


    Emiliania huxleyi is a globally abundant microalga that plays a significant role in biogeochemical cycles. Over the next century, sea surface temperatures are predicted to increase drastically, which will likely have significant effects on the survival and ecology of E. huxleyi. In a warming ocean, this microalga may become increasingly vulnerable to pathogens, particularly those with temperature-dependent virulence. Ruegeria is a genus of Rhodobacteraceae whose population size tracks that of E. huxleyi throughout the alga's bloom-bust lifecycle. A representative of this genus, Ruegeria sp. R11, is known to cause bleaching disease in a red macroalga at elevated temperatures. To investigate if the pathogenicity of R11 extends to microalgae, it was co-cultured with several cell types of E. huxleyi near the alga's optimum (18°C), and at an elevated temperature (25°C) known to induce virulence in R11. The algal populations were monitored using flow cytometry and pulse-amplitude modulated fluorometry. Cultures of algae without bacteria remained healthy at 18°C, but lower cell counts in control cultures at 25°C indicated some stress at the elevated temperature. Both the C (coccolith-bearing) and S (scale-bearing swarming) cell types of E. huxleyi experienced a rapid decline resulting in apparent death when co-cultured with R11 at 25°C, but had no effect on N (naked) cell type at either temperature. R11 had no initial negative impact on C and S type E. huxleyi population size or health at 18°C, but caused death in older co-cultures. This differential effect of R11 on its host at 18 and 25°C suggest it is a temperature-enhanced opportunistic pathogen of E. huxleyi. We also detected caspase-like activity in dying C type cells co-cultured with R11, which suggests that programmed cell death plays a role in the death of E. huxleyi triggered by R11 - a mechanism induced by viruses (EhVs) and implicated in E. huxleyi bloom collapse. Given that E. huxleyi has recently been

  16. A Bacterial Pathogen Displaying Temperature-Enhanced Virulence of the Microalga Emiliania huxleyi (United States)

    Mayers, Teaghan J.; Bramucci, Anna R.; Yakimovich, Kurt M.; Case, Rebecca J.


    Emiliania huxleyi is a globally abundant microalga that plays a significant role in biogeochemical cycles. Over the next century, sea surface temperatures are predicted to increase drastically, which will likely have significant effects on the survival and ecology of E. huxleyi. In a warming ocean, this microalga may become increasingly vulnerable to pathogens, particularly those with temperature-dependent virulence. Ruegeria is a genus of Rhodobacteraceae whose population size tracks that of E. huxleyi throughout the alga’s bloom–bust lifecycle. A representative of this genus, Ruegeria sp. R11, is known to cause bleaching disease in a red macroalga at elevated temperatures. To investigate if the pathogenicity of R11 extends to microalgae, it was co-cultured with several cell types of E. huxleyi near the alga’s optimum (18°C), and at an elevated temperature (25°C) known to induce virulence in R11. The algal populations were monitored using flow cytometry and pulse-amplitude modulated fluorometry. Cultures of algae without bacteria remained healthy at 18°C, but lower cell counts in control cultures at 25°C indicated some stress at the elevated temperature. Both the C (coccolith-bearing) and S (scale-bearing swarming) cell types of E. huxleyi experienced a rapid decline resulting in apparent death when co-cultured with R11 at 25°C, but had no effect on N (naked) cell type at either temperature. R11 had no initial negative impact on C and S type E. huxleyi population size or health at 18°C, but caused death in older co-cultures. This differential effect of R11 on its host at 18 and 25°C suggest it is a temperature-enhanced opportunistic pathogen of E. huxleyi. We also detected caspase-like activity in dying C type cells co-cultured with R11, which suggests that programmed cell death plays a role in the death of E. huxleyi triggered by R11 – a mechanism induced by viruses (EhVs) and implicated in E. huxleyi bloom collapse. Given that E. huxleyi has

  17. The effects of xylitol and sorbitol on lysozyme- and peroxidase-related enzymatic and candidacidal activities. (United States)

    Kim, Bum-Soo; Chang, Ji-Youn; Kim, Yoon-Young; Kho, Hong-Seop


    To investigate whether xylitol and sorbitol affect enzymatic and candidacidal activities of lysozyme, the peroxidase system, and the glucose oxidase-mediated peroxidase system. Xylitol and sorbitol were added to hen egg-white lysozyme, bovine lactoperoxidase, glucose oxidase-mediated peroxidase, and whole saliva in solution and on hydroxyapatite surfaces. The enzymatic activities of lysozyme, peroxidase, and glucose oxidase-mediated peroxidase were determined by the turbidimetric method, the NbsSCN assay, and production of oxidized o-dianisidine, respectively. Candidacidal activities were determined by comparing colony forming units using Candida albicans ATCC strains 10231, 11006, and 18804. While xylitol and sorbitol did not affect the enzymatic activity of hen egg-white lysozyme both in solution and on hydroxyapatite surfaces, they did inhibit the enzymatic activity of salivary lysozyme significantly in solution, but not on the surfaces. Xylitol and sorbitol enhanced the enzymatic activities of both bovine lactoperoxidase and salivary peroxidase significantly in a dose-dependent manner in solution, but not on the surfaces. Sorbitol, but not xylitol, inhibited the enzymatic activity of glucose oxidase-mediated peroxidase significantly. Both xylitol and sorbitol did not affect candidacidal activities of hen egg-white lysozyme, the bovine lactoperoxidase system, or the glucose oxidase-mediated bovine lactoperoxidase system. Xylitol and sorbitol inhibited salivary lysozyme activity, but enhanced both bovine lactoperoxidase and salivary peroxidase activities significantly in solution. Xylitol and sorbitol did not augment lysozyme- and peroxidase-related candidacidal activities. Copyright © 2015 Elsevier Ltd. All rights reserved.

  18. Oxidation of NAD dimers by horseradish peroxidase.


    Avigliano, L; Carelli, V; Casini, A; Finazzi-Agrò, A; Liberatore, F


    Horseradish peroxidase catalyses the oxidation of NAD dimers, (NAD)2, to NAD+ in accordance with a reaction that is pH-dependent and requires 1 mol of O2 per 2 mol of (NAD)2. Horseradish peroxidase also catalyses the peroxidation of (NAD)2 to NAD+. In contrast, bacterial NADH peroxidase does not catalyse the peroxidation or the oxidation of (NAD)2. A free-radical mechanism is proposed for both horseradish-peroxidase-catalysed oxidation and peroxidation of (NAD)2.

  19. The study of two methods for high pressure injection in CT enhancement to display the aortic dissecting aneurysm

    International Nuclear Information System (INIS)

    Wang Yang; Zhu Bin; Zhang Zhen


    Objective: To discuss the consequences of two different methods of high pressure injection in CT contrast enhancement to display the aortic dissecting aneurysm. Methods: 100 patients underwent Lightspeed 16 MS CT with contrast enhancement of Stellant D high pressure injector (Medrad), injecting speed of 4.0 mL/s and 80 ml dosage of contrast medium. All patients were divided into A and B groups with 50 in each. The single high pressure injection was applied to A group without isotonic Na chloride flush. B group underwent the same high pressure injection and followed by isotonic Na chloride flush. The method of evaluation was carried out by double blind observation. Results: A group revealed radiologic artifact up to 40 cases with positive rate of 80%. B group demonstrated the same kind of radiologic artifact in 26 cases with positive rate of 52%. Conclusions: Using normal saline (sodium chloride solution)flush after high pressure injection of contrast medium during MSCT angiography is obviously better to demonstrate the internal structures of treatvessels. (authors)

  20. Network, system, and status software enhancements for the autonomously managed electrical power system breadboard. Volume 4: Graphical status display (United States)

    Mckee, James W.


    This volume (4 of 4) contains the description, structured flow charts, prints of the graphical displays, and source code to generate the displays for the AMPS graphical status system. The function of these displays is to present to the manager of the AMPS system a graphical status display with the hot boxes that allow the manager to get more detailed status on selected portions of the AMPS system. The development of the graphical displays is divided into two processes; the creation of the screen images and storage of them in files on the computer, and the running of the status program which uses the screen images.

  1. Is targeted reconstruction necessary for evaluating contrast-enhanced chest computed tomography using a liquid crystal display monitor?

    International Nuclear Information System (INIS)

    Ozawa, Yoshiyuki; Oshima, Hidekazu; Kitase, Masanori; Shibamoto, Yuta; Hara, Masaki; Ohashi, Kazuya


    The aim of this study was to examine whether 20-cm field-of-view (FOV) targeted reconstruction (TR) on contrast-enhanced (CE) chest computed tomography (CT) might improve the diagnostic value compared with simple zooming (SZ) from whole-thorax FOV images using a 2 million (2M)-pixel liquid crystal display (LCD) monitor. We prospectively evaluated 44 patients. SZ images were magnified from a FOV of 26-34 cm (mean 29.7 cm). Parameters were 512 x 512 matrix and 3 mm thickness and interval. Images were reconstructed using a soft-tissue kernel. Three radiologists evaluated contour, spiculation, notch, pleural tag, invasion, and internal characteristics of the lesions using 5-scale scores. We also performed a phantom study to evaluate the spatial resolution of images. The diagnostic value of the TR images was similar to that of the SZ images, with the findings identified in 88%-100% of the cases. Artifacts from highdensity structures deteriorated the image quality in six (14%), and the SZ images were judged to be preferable in five of them. In the phantom study, there was little difference in spatial resolution between the two images. The SZ images from whole-thorax FOV on CE chest CT were similar in quality to TR images using a 2M-pixel LCD monitor. (author)

  2. Nd and Sc co-doped BiFeO{sub 3} nanopowders displaying enhanced ferromagnetism at room temperature

    Energy Technology Data Exchange (ETDEWEB)

    Hernández, N., E-mail: [Centro de Innovación, Investigación y Desarrollo en Ingeniería y Tecnología, Km. 10 Nueva carretera al Aeropuerto Internacional de Monterrey, PIIT Monterrey, CP 66600 Apodaca, Nuevo León (Mexico); González-González, V.A. [Centro de Innovación, Investigación y Desarrollo en Ingeniería y Tecnología, Km. 10 Nueva carretera al Aeropuerto Internacional de Monterrey, PIIT Monterrey, CP 66600 Apodaca, Nuevo León (Mexico); Facultad de Ingeniería Mecánica y Eléctrica, Universidad Autónoma de Nuevo León, Pedro de Alba S/N, San Nicolás de los Garza, Nuevo León 66450 (Mexico); Dzul-Bautista, I.B. [Centro de Innovación, Investigación y Desarrollo en Ingeniería y Tecnología, Km. 10 Nueva carretera al Aeropuerto Internacional de Monterrey, PIIT Monterrey, CP 66600 Apodaca, Nuevo León (Mexico); Gutiérrez, J.; Barandiarán, J.M. [Basque Center for Materials, Applications and Nanostructures (BCMaterials), Universidad del País Vasco (UPV/EHU), Parque Tecnológico de Bizkaia, Ed. 500, Derio 48160 (Spain); and others


    Highlights: • Will study the structure of materials obtained. • A well crystallized BiFeO{sub 3} doped material was obtained without further annealing. • The obtained nanoparticles have sizes less than 60 nm. • Enhanced ferromagnetic materials was obtained. - Abstract: We have developed a novel synthetic route for the preparation of single phase Nd{sub x}Bi{sub 1−x}Fe{sub 0.95}Sc{sub 0.05}O{sub 3} (NBFSO) nanopowder materials by a surfactant-assisted combustion-derived method. Rietveld fitting of the Powder X-ray diffraction data showed the nanopowder structure evolves from a distorted rhombohedral BiFeO{sub 3} crystalline structure (R3c, x = 0) to a orthorhombic structure (Pbnm, x = 0.10). Differential thermal analysis and thermogravimetric analysis (DTA/TGA) showed a crystallization temperature of 200 °C. Transmission electron microscopy (TEM) images revealed the presence of clusters formed by fine nanoparticles less than 60 nm in diameter. From Raman spectroscopy, the change from rhombohedral structure to cubic structure was observed by a drastic intensity reduction of the A{sub 1}{sup −2} and A{sub 1}{sup −3} Raman modes, with the A{sub 1}{sup −1} and A{sub 1}{sup −2} modes gradually merging together, indicating the merge of the orthorhombic phase. Despite the antiferromagnetic nature of bulk BiFeO{sub 3}, the NBFSO nanopowders obtained displayed a ferromagnetic hysteresis loop, with coercivities of 0.08 T and remanent magnetizations of 0.65–4.05 Am{sup 2}/kg when measured at room temperature. The increasing and uncompensated spins at the surface of nanoparticles and the canted internal spin by the tilt of FeO{sub 6} octahedral units and the structure transition appear to be the main reason for observed this ferromagnetic behavior.

  3. Development of advanced direct perception displays for nuclear power plants to enhance monitoring, control and fault management

    International Nuclear Information System (INIS)

    Jones, B.; Shaheen, S.; Moray, N.; Sanderson, P.; Reising, D.V.


    With recent theoretical and empirical research in basic and applied psychology, human factors, and engineering, it is now sufficient to define an integrated approach to the deign of advanced displays for present and future nuclear power plants. Traditionally, the conventional displays have shown operators the individual variables on gauges, meters, strip charts, etc. This design approach requires the operators to mentally integrate the separately displayed variables and determine the implications for the plant state. This traditional approach has been known as the single-sensor-single-indicator display design and it places an intolerable amount of mental workload on operators during transients and abnormal conditions. This report discusses a new alternative approach which is the use of direct perception interfaces. Direct perception a interfaces display the underlying physical and system constraints of the situation in a directly perceptual way, such that the viewer need not reason about what is seen to identify system states, but can identify the state of the system perceptually. It is expected that displays which show the dynamics of fundamental physical laws should better support operator decisions and diagnoses of plant states. The purpose of this research project is to develop a suite of direct perception displays for PWR nuclear power plant operations

  4. Volumetric 3D display with multi-layered active screens for enhanced the depth perception (Conference Presentation) (United States)

    Kim, Hak-Rin; Park, Min-Kyu; Choi, Jun-Chan; Park, Ji-Sub; Min, Sung-Wook


    Three-dimensional (3D) display technology has been studied actively because it can offer more realistic images compared to the conventional 2D display. Various psychological factors such as accommodation, binocular parallax, convergence and motion parallax are used to recognize a 3D image. For glass-type 3D displays, they use only the binocular disparity in 3D depth cues. However, this method cause visual fatigue and headaches due to accommodation conflict and distorted depth perception. Thus, the hologram and volumetric display are expected to be an ideal 3D display. Holographic displays can represent realistic images satisfying the entire factors of depth perception. But, it require tremendous amount of data and fast signal processing. The volumetric 3D displays can represent images using voxel which is a physical volume. However, it is required for large data to represent the depth information on voxel. In order to simply encode 3D information, the compact type of depth fused 3D (DFD) display, which can create polarization distributed depth map (PDDM) image having both 2D color image and depth image is introduced. In this paper, a new volumetric 3D display system is shown by using PDDM image controlled by polarization controller. In order to introduce PDDM image, polarization states of the light through spatial light modulator (SLM) was analyzed by Stokes parameter depending on the gray level. Based on the analysis, polarization controller is properly designed to convert PDDM image into sectioned depth images. After synchronizing PDDM images with active screens, we can realize reconstructed 3D image. Acknowledgment This work was supported by `The Cross-Ministry Giga KOREA Project' grant from the Ministry of Science, ICT and Future Planning, Korea

  5. Diagnostic accuracy of fracture detection in suspected non-accidental injury: the effect of edge enhancement and digital display on observer performance

    Energy Technology Data Exchange (ETDEWEB)

    Offiah, A.C. [Department of Radiology, Great Ormond Street Hospital for Children, London (United Kingdom) and Institute of Child Health, London (United Kingdom)]. E-mail:; Moon, L. [Department of Radiology, Great Ormond Street Hospital for Children, London (United Kingdom); Hall, C.M. [Department of Radiology, Great Ormond Street Hospital for Children, London (United Kingdom); Todd-Pokropek, A. [Department of Medical Physics and Bioengineering, University College London, London (United Kingdom)


    AIM: To compare the effect of varying degrees of edge enhancement and method of digital image display on fracture detection in suspected non-accidental injury (NAI). MATERIALS AND METHODS: Fifty radiographs from post-mortem skeletal surveys in 13 children with suspected NAI were selected. Images were obtained using a Fuji 5000R computed radiography system. Hard copies were printed with edge enhancement factors 0, 0.5 and 1.2. Images (edge enhancement 0.5) were also displayed on a 1K{sup 2} monitor. Six observers independently evaluated all 200 images for the presence of abnormality. Observers also scored each image for visualization of soft tissues, visualization of trabecular markings and overall image quality. The paired Student's t-test and location receiver operating curve (ROC) analysis were used to compare quality scores and diagnostic accuracy of each display method. Individual and pooled true-positive rates (sensitivity) were determined. For the purposes of ROC analysis, histology was taken as the gold standard. RESULTS: There was no difference in duration of hard and soft-copy reading sessions (p=0.76). After image manipulation soft-copy radiographs scored significantly better for image quality than hard copy (p<0.0001). Pooled observer sensitivity (at a specificity of 90%) was below 50% for all display methods. Diagnostic accuracy varied significantly between observers. Diagnostic accuracy of individual observers was not affected by display method. CONCLUSION: In suspected NAI, diagnostic accuracy of fracture detection is generally low. Diagnostic accuracy appears to be affected more by observer-related factors than by the method of digital image display.

  6. Fungal peroxidases : molecular aspects and applications

    NARCIS (Netherlands)

    Conesa, A.; Punt, P.J.; Hondel, C.A.M.J.J.


    Peroxidases are oxidoreductases that utilize hydrogen peroxide to catalyze oxidative reactions. A large number of peroxidases have been identified in fungal species and are being characterized at the molecular level. In this manuscript we review the current knowledge on the molecular aspects of this

  7. Peroxidase enzymes regulate collagen extracellular matrix biosynthesis. (United States)

    DeNichilo, Mark O; Panagopoulos, Vasilios; Rayner, Timothy E; Borowicz, Romana A; Greenwood, John E; Evdokiou, Andreas


    Myeloperoxidase and eosinophil peroxidase are heme-containing enzymes often physically associated with fibrotic tissue and cancer in various organs, without any direct involvement in promoting fibroblast recruitment and extracellular matrix (ECM) biosynthesis at these sites. We report herein novel findings that show peroxidase enzymes possess a well-conserved profibrogenic capacity to stimulate the migration of fibroblastic cells and promote their ability to secrete collagenous proteins to generate a functional ECM both in vitro and in vivo. Mechanistic studies conducted using cultured fibroblasts show that these cells are capable of rapidly binding and internalizing both myeloperoxidase and eosinophil peroxidase. Peroxidase enzymes stimulate collagen biosynthesis at a post-translational level in a prolyl 4-hydroxylase-dependent manner that does not require ascorbic acid. This response was blocked by the irreversible myeloperoxidase inhibitor 4-amino-benzoic acid hydrazide, indicating peroxidase catalytic activity is essential for collagen biosynthesis. These results suggest that peroxidase enzymes, such as myeloperoxidase and eosinophil peroxidase, may play a fundamental role in regulating the recruitment of fibroblast and the biosynthesis of collagen ECM at sites of normal tissue repair and fibrosis, with enormous implications for many disease states where infiltrating inflammatory cells deposit peroxidases. Copyright © 2015 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.

  8. Development of advanced direct perception displays for nuclear power plants to enhance monitoring, control and fault management

    International Nuclear Information System (INIS)

    Jones, B.G.; Shaheen, S.; Moray, N.


    Traditional Single-Sensor-Single Indicator (SSSI) displays are poorly matched to the cognitive abilities of operators, especially for large and complex systems. It is difficult for operators to monitor very large arrays of displays and controls, and to integrate the information displayed therein. In addition, standard operating procedures (SOPs) are bulky (running to many hundreds of pages) and difficult to use, and operators may become lost. For these reasons, and also because it is becoming increasingly difficult to find replacements for aging hardware components, there is a trend towards computerized graphical interfaces for nuclear power plants (NPPs). There is, however, little rational theory for display design in this domain. This report describes some recent theoretical developments and shows how to develop displays which will greatly reduce the cognitive load on the operator and allow the use of perceptual rather than cognitive mechanisms while using SON and to support state diagnosis and fault management. The report outlines the conceptual framework within which such a new approach could be developed, and provides an example of how the operating procedures for the start-up sequence of a NPP could be realized. A detailed description of a set of displays for a graphical interface for the SON of the feedwater system is provided as an example of how the proposed approach could be realized, and a general account of how it would fit into the overall start-up sequence is given. Examples of open-quotes direct perceptionclose quotes or open-quotes ecologicalclose quotes configural state space displays to support the use of the proposed direct manipulation SOP interface are provided, and also a critical discussion which identifies some difficulties which may be anticipated should the general approach herein advocated be adopted

  9. Enhancing DC Glow Discharge Tube Museuum Displays using a Theremin Controlled Helmholtz Coil to Demonstrate Magnetic Confinement (United States)

    Siu, Theodore; Wissel, Stephanie; Guttadora, Larry; Liao, Susan; Zwicker, Andrew


    Since their discovery in the mid 1800's, DC glow discharge apparatuses have commonly been used for spectral analysis, the demonstration of the Frank-Hertz experiment, and to study plasma breakdown voltages following from the Paschen Curve. A DC glow discharge tube museum display was outfitted with a Helmholtz Coil electromagnet in order to demonstrate magnetic confinement for a science museum display. A device commonly known as a ``theremin'' was designed and built in order to externally control the Helmholtz Coil current and the plasma current. Originally a musical instrument, a theremin has two variable capacitors connected to two radio frequency oscillators which determine pitch and volume. Using a theremin to control current and ``play'' the plasma adds appeal and durability by providing a new innovative means of interacting with a museum exhibit. Educationally, students can use the display to not only learn about plasma properties but also electronic properties of the human body.

  10. Characterization of a multi-seeded (msd) mutant of sorghum that displays significant enhancement in seed number (United States)

    Sorghum (Sorghum bicolor L. Moench) cultivars and germplasm display branched inflorescence or panicle, characterized by spikelets composed of a single sessile, fertile floret that develop into viable seed and one or two adjacent sterile pedicellate florets (Monoseeded [MSD] trait). Based on total nu...

  11. Wound-induced expression of horseradish peroxidase. (United States)

    Kawaoka, A; Kawamoto, T; Ohta, H; Sekine, M; Takano, M; Shinmyo, A


    Peroxidases have been implicated in the responses of plants to physiological stress and to pathogens. Wound-induced peroxidase of horseradish (Armoracia rusticana) was studied. Total peroxidase activity was increased by wounding in cell wall fractions extracted from roots, stems and leaves of horseradish. On the other hand, wounding decreased the peroxidase activity in the soluble fraction from roots. The enzyme activities of the basic isozymes were induced by wounding in horseradish leaves based on data obtained by fractionation of crude enzyme in isoelectric focusing gel electrophoresis followed by activity staining. We have previously isolated genomic clones for four peroxidase genes, namely, prxC1a, prxC1b, prxC2 and prxC3. Northern blot analysis using gene-specific probes showed that mRNA of prxC2, which encodes a basic isozyme, accumulated by wounding, while the mRNAs for other peroxidase genes were not induced. Tobacco (Nicotiana tabacum) plants were transformed with four chimeric gene constructs, each consisting of a promoter from one of the peroxidase genes and the β-glucuronidase (GUS) structural gene. High level GUS activity induced in response to wounding was observed in tobacco plants containing the prxC2-GUS construct.

  12. Peroxidase activity as a marker for estrogenicity

    International Nuclear Information System (INIS)

    Levy, J.; Liel, Y.; Glick, S.M.


    We examined the possibility that peroxidase activity might be a marker for estrogen activity in established estrogen-dependent tissues: dimethylbenz[a]anthracene (DMBA)-induced rat mammary tumours and human breast cancer. In DMBA-induced tumours undergoing regression after ovariectomy or tamoxifen treatment, tumour size decreased by 50%, estradiol receptors (ER) and progesterone receptors (PgR) decreased by 25 and 20%, respectively, but peroxidase activity paradoxically increased six- to sevenfold. In DMBA tumours stimulated by estradiol treatment or by the cessation of tamoxifen administration in intact rats, tumour size increased threefold. ER and PgR increased two- and threefold, respectively, while peroxidase activity decreased 50%. These data indicate an inverse relation between tumour growth, ER and PgR on the one hand, and peroxidase activity on the other. In the human breast cancers there was a singificant negative relation between the presence of ER and peroxidase activity. By using a calibrated Sephadex G-100 column it was shown that uterine peroxidase differs in molecular weight from the peroxidase of rat mammary tumours and that of human breast cancer. (author)

  13. Glycosylation and thermodynamic versus kinetic stability of horseradish peroxidase

    DEFF Research Database (Denmark)

    Tams, J.W.; Welinder, Karen G.


    Glycoprotein stability, glycoprotein unfolding, horseradish peroxidase, thermodynamic stability, kinetik stability......Glycoprotein stability, glycoprotein unfolding, horseradish peroxidase, thermodynamic stability, kinetik stability...

  14. Partnering and teamwork to create content for spherical display systems to enhance public literacy in earth system and ocean sciences (United States)

    Beaulieu, S. E.; Patterson, K.; Joyce, K.; Silva, T.; Madin, K.; Spargo, A.; Brickley, A.; Emery, M.


    Spherical display systems, also known as digital globes, are technologies that, in person or online, can be used to help visualize global datasets and earth system processes. Using the InterRidge Global Database of Active Submarine Hydrothermal Vent Fields and imagery from deep-sea vehicles, we are creating content for spherical display systems to educate and excite the public about dynamic geophysical and biological processes and exploration in the deep ocean. The 'Global Viewport for Virtual Exploration of Deep-Sea Hydrothermal Vents' is a collaboration between the Woods Hole Oceanographic Institution and the Ocean Explorium at New Bedford Seaport, hosting a Magic Planet and Science On a Sphere (SOS), respectively. The main activities in the first year of our project were geared towards team building and content development. Here we will highlight the partnering and teamwork involved in creating and testing the effectiveness of our new content. Our core team is composed of a lead scientist, educators at both institutions, graphic artists, and a professional evaluator. The new content addresses key principles of Earth Science Literacy and Ocean Literacy. We will share the collaborative, iterative process by which we developed two educational pieces, 'Life without sunlight' and 'Smoke and fire underwater' - each focusing on a different set of 3 literacy principles. We will share how we conducted our front-end and formative evaluations and how we focused on 2 NSF Informal Education Impact Categories for our evaluation questionnaire for the public. Each educational piece is being produced as a stand-alone movie and as an interactive, docent-led presentation integrating a number of other datasets available from NOAA's SOS Users Network. The proximity of our two institutions enables a unique evaluation of the learning attained with a stand-alone spherical display vs. live presentations with an SOS.

  15. Displays in scintigraphy

    International Nuclear Information System (INIS)

    Todd-Pokropek, A.E.; Pizer, S.M.


    Displays have several functions: to transmit images, to permit interaction, to quantitate features and to provide records. The main characteristics of displays used for image transmission are their resolution, dynamic range, signal-to-noise ratio and uniformity. Considerations of visual acuity suggest that the display element size should be much less than the data element size, and in current practice at least 256X256 for a gamma camera image. The dynamic range for image transmission should be such that at least 64 levels of grey (or equivalent) are displayed. Scanner displays are also considered, and in particular, the requirements of a whole-body camera are examined. A number of display systems and devices are presented including a 'new' heated object colour display system. Interaction with displays is considered, including background subtraction, contrast enhancement, position indication and region-of-interest generation. Such systems lead to methods of quantitation, which imply knowledge of the expected distributions. Methods for intercomparing displays are considered. Polaroid displays, which have for so long dominated the field, are in the process of being replaced by stored image displays, now that large cheap memories exist which give an equivalent image quality. The impact of this in nuclear medicine is yet to be seen, but a major effect will be to enable true quantitation. (author)

  16. New strategy for enhancement of microbial viability in simulated gastric conditions based on display of starch-binding domain on cell surface. (United States)

    Tarahomjoo, Shirin; Katakura, Yoshio; Shioya, Suteaki


    The C-terminal region of the peptidoglycan hydrolase (CPH) of Lactococcus lactis IL1403 fused to the linker region and the starch-binding domain (SBD) of the *-amylase of Streptococcus bovis 148 was produced intracellularly in Escherichia coli. The fusion protein (CPH-SBD) was able to bind to the cell surface of Lactobacillus casei NRRL B-441 and to corn starch. Therefore, adhesion of cells to corn starch was mediated by the fusion protein. At a cell density of 10(9) cfu/ml and a starch concentration of 5 mg/ml, CPH-SBD-displaying L. casei cells aggregated with corn starch, whereas the free cells of L. casei did not form any aggregates with corn starch. After incubation in simulated gastric juice (pH 3.0, 1 h), the survival percentages of free cells, amylose-coated free cells, and free cells mixed with corn starch were 0.074%, 7.2%, and 3.1% respectively. When CPH-SBD-displaying bacteria aggregated with corn starch, their survival percentage was 8% higher than that of free cells mixed with corn starch. The survival of the amylose-coated CPH-SBD-displaying L. casei cells was comparable to that of amylose-coated free cells, whereas the survival percentage of amylose-coated aggregates of CPH-SBD-displaying bacteria with corn starch was 28% higher than that of amylose-coated mixture of free cells with corn starch. These results demonstrate the potential usefulness of the cell-surface display technique for enhancement of the delivery of viable microorganisms to the intestinal tract.

  17. Bacterial Reaction Centers Purified with Styrene Maleic Acid Copolymer Retain Native Membrane Functional Properties and Display Enhanced Stability** (United States)

    Swainsbury, David J K; Scheidelaar, Stefan; van Grondelle, Rienk; Killian, J Antoinette; Jones, Michael R


    Integral membrane proteins often present daunting challenges for biophysical characterization, a fundamental issue being how to select a surfactant that will optimally preserve the individual structure and functional properties of a given membrane protein. Bacterial reaction centers offer a rare opportunity to compare the properties of an integral membrane protein in different artificial lipid/surfactant environments with those in the native bilayer. Here, we demonstrate that reaction centers purified using a styrene maleic acid copolymer remain associated with a complement of native lipids and do not display the modified functional properties that typically result from detergent solubilization. Direct comparisons show that reaction centers are more stable in this copolymer/lipid environment than in a detergent micelle or even in the native membrane, suggesting a promising new route to exploitation of such photovoltaic integral membrane proteins in device applications. PMID:25212490

  18. Dental Pulp Cells Isolated from Teeth with Superficial Caries Retain an Inflammatory Phenotype and Display an Enhanced Matrix Mineralization Potential

    Directory of Open Access Journals (Sweden)

    Reem El-Gendy


    Full Text Available We have isolated dental pulp cells (DPCs from three healthy (hDPCs and three carious (cDPCs donors and shown that compared to hDPCs cells isolated from superficial carious lesions show higher clonogenic potential; show an equivalent proportion of cells with putative stem cell surface markers; show enhanced matrix mineralization capability; have enhanced angiogenic marker expression and retain the inflammatory phenotype in vitro characteristic of superficial caries lesions in vivo. Our findings suggest that cDPCs may be used for further investigation of the cross talk between inflammatory, angiogenic and mineralization pathways in repair of carious pulp. In addition cells derived from carious pulps (almost always discarded may have potential for future applications in mineralized tissue repair and regeneration.

  19. The B7-1 cytoplasmic tail enhances intracellular transport and mammalian cell surface display of chimeric proteins in the absence of a linear ER export motif.

    Directory of Open Access Journals (Sweden)

    Yi-Chieh Lin

    Full Text Available Membrane-tethered proteins (mammalian surface display are increasingly being used for novel therapeutic and biotechnology applications. Maximizing surface expression of chimeric proteins on mammalian cells is important for these applications. We show that the cytoplasmic domain from the B7-1 antigen, a commonly used element for mammalian surface display, can enhance the intracellular transport and surface display of chimeric proteins in a Sar1 and Rab1 dependent fashion. However, mutational, alanine scanning and deletion analysis demonstrate the absence of linear ER export motifs in the B7 cytoplasmic domain. Rather, efficient intracellular transport correlated with the presence of predicted secondary structure in the cytoplasmic tail. Examination of the cytoplasmic domains of 984 human and 782 mouse type I transmembrane proteins revealed that many previously identified ER export motifs are rarely found in the cytoplasmic tail of type I transmembrane proteins. Our results suggest that efficient intracellular transport of B7 chimeric proteins is associated with the structure rather than to the presence of a linear ER export motif in the cytoplasmic tail, and indicate that short (less than ~ 10-20 amino acids and unstructured cytoplasmic tails should be avoided to express high levels of chimeric proteins on mammalian cells.

  20. Induction of 33-kD and 60-kD peroxidases during ethylene-induced senescence of cucumber cotyledons

    International Nuclear Information System (INIS)

    Abeles, F.B.; Dunn, L.J.; Morgens, P.; Callahan, A.; Dinterman, R.E.; Schmidt, J.


    Ethylene enhanced the senescence of cucumber (Cucumis sativus L. cv Poinsett 76) cotyledons. The effect of 10 microliters per liter ethylene was inhibited by 1 millimolar silver thiosulfate, an inhibitor of ethylene action. An increase in proteins with molecular weights of 33 to 30 kilodaltons and lower molecular weights (25, 23, 20, 16, 12 and 10 kilodaltons) were observed in sodium dodecyl sulfate-polyacrylamide gel electrophoresis gels after ethylene enhanced senescence. The measurement of DNase and RNase activity in gels indicated that these new proteins were not nucleases. Two proteins from ethylene-treated cotyledons were purified on the basis of their association with a red chromaphore and subsequently were identified as peroxidases. The molecular weights and isoelectric points (pI) of two of these peroxidases were 33 kilodaltons (cationic, pI = 8.9) and 60 kilodaltons (anionic, pI = 4.0). The observation that [ 35 S]Na 2 SO 4 was incorporated into these proteins during ethylene-enhanced senescence suggests that these peroxidases represent newly synthesized proteins. Antibodies to the 33-kilodalton peroxidase precipitated two in vitro translation products from RNA isolated from ethylene-treated but not from control cucumber seedlings. This indicates that the increase in 33-kilodalton peroxidase activity represents de novo protein synthesis. Both forms of peroxidase degraded chlorophyll in vitro, which is consistent with the hypothesis that peroxidases have catabolic or scavenging functions in senescent tissues

  1. Development and image quality assessment of a contrast-enhancement algorithm for display of digital chest radiographs

    International Nuclear Information System (INIS)

    Rehm, K.


    This dissertation presents a contrast-enhancement algorithm Artifact-Suppressed Adaptive Histogram Equalization (ASAHE). This algorithm was developed as part of a larger effort to replace the film radiographs currently used in radiology departments with digital images. Among the expected benefits of digital radiology are improved image management and greater diagnostic accuracy. Film radiographs record X-ray transmission data at high spatial resolution, and a wide dynamic range of signal. Current digital radiography systems record an image at reduced spatial resolution and with coarse sampling of the available dynamic range. These reductions have a negative impact on diagnostic accuracy. The contrast-enhancement algorithm presented in this dissertation is designed to boost diagnostic accuracy of radiologists using digital images. The ASAHE algorithm is an extension of an earlier technique called Adaptive Histogram Equalization (AHE). The AHE algorithm is unsuitable for chest radiographs because it over-enhances noise, and introduces boundary artifacts. The modifications incorporated in ASAHE suppress the artifacts and allow processing of chest radiographs. This dissertation describes the psychophysical methods used to evaluate the effects of processing algorithms on human observer performance. An experiment conducted with anthropomorphic phantoms and simulated nodules showed the ASAHE algorithm to be superior for human detection of nodules when compared to a computed radiography system's algorithm that is in current use. An experiment conducted using clinical images demonstrating pneumothoraces (partial lung collapse) indicated no difference in human observer accuracy when ASAHE images were compared to computed radiography images, but greater ease of diagnosis when ASAHE images were used. These results provide evidence to suggest that Artifact-Suppressed Adaptive Histogram Equalization can be effective in increasing diagnostic accuracy and efficiency

  2. Investigation on luminescence enhancement and decay characteristics of long afterglow nanophosphors for dark-vision display applications

    Energy Technology Data Exchange (ETDEWEB)

    Swati, G.; Chawla, S.; Mishra, S.; Rajesh, B.; Vijayan, N.; Sivaiah, B.; Dhar, A.; Haranath, D., E-mail:


    Graphical abstract: - Highlights: • Synthesis and structural characterization has been performed on long afterglow SrAl{sub 2}O{sub 4}:Eu{sup 2+}, Dy{sup 3+} nanophosphor having afterglow time of ∼12 h. • Studied the effect of various fuels used for synthesis of nanophosphors on the decay and luminescence characteristics. Interestingly, afterglow times varied significantly with different fuels used for the synthesis of the nanophosphor. • Excitation by different illuminants has profound influence on the luminescence intensity and afterglow times of the synthesized nanophosphor. • Such studies could be guidelines for appropriate usage of nanophosphor under different lighting environment. - Abstract: Long afterglow SrAl{sub 2}O{sub 4}:Eu{sup 2+},Dy{sup 3+} nanophosphors were synthesized via a facile but effectual auto-combustion technique followed by post-annealing treatment at elevated temperatures. The influence of various fuels during synthesis and thereafter improvement in the luminescence decay characteristics under various illuminant irradiations of long afterglow nanophosphors have been reported. Extensive studies on structural, morphological and luminescent properties of the as-synthesized afterglow nanophosphors have been presented. Powder X-ray diffraction studies confirm the presence of high-purity, single-phase monoclinic nanophosphors. HRTEM investigations confirm the formation of nanophosphors of particle size less than 50 nm. Photoluminescence emission is attributed to the characteristic d–f transition (4f{sup 6}5d{sup 1}→4f{sup 7}) of Eu{sup 2+} ions and was positioned at 512 nm. As-synthesized nanophosphors exhibit considerable confinement effects resulting into blue shift in emission maxima as compared to their bulk counterparts. The mechanism underlined for long afterglow has been discussed using trapping–detrapping model. The nanophosphor being multifunctional finds many interesting applications including dark-vision display

  3. Streptococcus mutans Displays Altered Stress Responses While Enhancing Biofilm Formation by Lactobacillus casei in Mixed-Species Consortium. (United States)

    Wen, Zezhang T; Liao, Sumei; Bitoun, Jacob P; De, Arpan; Jorgensen, Ashton; Feng, Shihai; Xu, Xiaoming; Chain, Patrick S G; Caufield, Page W; Koo, Hyun; Li, Yihong


    Like Streptococcus mutans , lactobacilli are commonly isolated from carious sites, although their exact role in caries development remains unclear. This study used mixed-species models to analyze biofilm formation by major groups of oral lactobacilli, including L. casei, L. fermentum, L. rhamnosus, L. salivarius ssp. salivarius , and L. gasseri . The results showed that lactobacilli did not form good biofilms when grown alone, although differences existed between different species. When grown together with S. mutans , biofilm formation by L. gasseri and L. rhamnosus was increased by 2-log ( P L. fermentum reduced by >1-log ( P L. casei enhanced biofilm formation by ~2-log when grown with S. mutans wild-type, but no such effects were observed with S. mutans deficient of glucosyltransferase GtfB and adhesin P1. Both S. mutans and L. casei in dual-species enhanced resistance to acid killing with increases of survival rate by >1-log ( P survival rates following exposure to hydrogen peroxide ( P L. casei as either up- or down-regulated when compared to those grown alone. The up-regulated genes include those for superoxide dismutase, NADH oxidase, and members of the mutanobactin biosynthesis cluster. Among the down-regulated genes were those for GtfB and alternative sigma factor SigX. These results further suggest that interactions between S. mutans and oral lactobacilli are species-specific and may have significant impact on cariogenic potential of the community.

  4. Phenotypic and genetic characteristics associated with Listeria monocytogenes food chain isolates displaying enhanced and diminished cold tolerance

    DEFF Research Database (Denmark)

    Hingston, P.; Chen, J.; Laing, C.

    between strains with varied cold tolerance. The objective of this study was to determine if Lm isolates with enhanced cold tolerance, exhibit other high risk characteristics that may add to their survival and/or pathogenicity. To accomplish this, 166 predominantly food/food plant Lm isolates were tested...... in brainheart infusion broth, for their ability to tolerate cold (4°C), salt (6% NaCl, 25°C), acid (pH 5, 25°C), and desiccation (33% RH, 20°C) stress. Isolates were considered tolerant or sensitive if they exhibited survival characteristics > or ... with a truncated version (n=47). Cold tolerant isolates were more likely to be tolerant to the other three stresses than intermediate and cold sensitive isolates. Similarly, cold sensitive isolates were more likely to be sensitive to the other stresses. Cold tolerant isolates had shorter (p=0.012) lag phases...

  5. Streptococcus mutans Displays Altered Stress Responses While Enhancing Biofilm Formation by Lactobacillus casei in Mixed-Species Consortium

    Directory of Open Access Journals (Sweden)

    Zezhang T. Wen


    Full Text Available Like Streptococcus mutans, lactobacilli are commonly isolated from carious sites, although their exact role in caries development remains unclear. This study used mixed-species models to analyze biofilm formation by major groups of oral lactobacilli, including L. casei, L. fermentum, L. rhamnosus, L. salivarius ssp. salivarius, and L. gasseri. The results showed that lactobacilli did not form good biofilms when grown alone, although differences existed between different species. When grown together with S. mutans, biofilm formation by L. gasseri and L. rhamnosus was increased by 2-log (P < 0.001, while biofilms by L. fermentum reduced by >1-log (P < 0.001. L. casei enhanced biofilm formation by ~2-log when grown with S. mutans wild-type, but no such effects were observed with S. mutans deficient of glucosyltransferase GtfB and adhesin P1. Both S. mutans and L. casei in dual-species enhanced resistance to acid killing with increases of survival rate by >1-log (P < 0.001, but drastically reduced the survival rates following exposure to hydrogen peroxide (P < 0.001, as compared to the respective mono-species cultures. When analyzed by RNA-seq, more than 134 genes were identified in S. mutans in dual-species with L. casei as either up- or down-regulated when compared to those grown alone. The up-regulated genes include those for superoxide dismutase, NADH oxidase, and members of the mutanobactin biosynthesis cluster. Among the down-regulated genes were those for GtfB and alternative sigma factor SigX. These results further suggest that interactions between S. mutans and oral lactobacilli are species-specific and may have significant impact on cariogenic potential of the community.

  6. A mammalian conserved element derived from SINE displays enhancer properties recapitulating Satb2 expression in early-born callosal projection neurons.

    Directory of Open Access Journals (Sweden)

    Kensuke Tashiro

    Full Text Available Short interspersed repetitive elements (SINEs are highly repeated sequences that account for a significant proportion of many eukaryotic genomes and are usually considered "junk DNA". However, we previously discovered that many AmnSINE1 loci are evolutionarily conserved across mammalian genomes, suggesting that they may have acquired significant functions involved in controlling mammalian-specific traits. Notably, we identified the AS021 SINE locus, located 390 kbp upstream of Satb2. Using transgenic mice, we showed that this SINE displays specific enhancer activity in the developing cerebral cortex. The transcription factor Satb2 is expressed by cortical neurons extending axons through the corpus callosum and is a determinant of callosal versus subcortical projection. Mouse mutants reveal a crucial function for Sabt2 in corpus callosum formation. In this study, we compared the enhancer activity of the AS021 locus with Satb2 expression during telencephalic development in the mouse. First, we showed that the AS021 enhancer is specifically activated in early-born Satb2(+ neurons. Second, we demonstrated that the activity of the AS021 enhancer recapitulates the expression of Satb2 at later embryonic and postnatal stages in deep-layer but not superficial-layer neurons, suggesting the possibility that the expression of Satb2 in these two subpopulations of cortical neurons is under genetically distinct transcriptional control. Third, we showed that the AS021 enhancer is activated in neurons projecting through the corpus callosum, as described for Satb2(+ neurons. Notably, AS021 drives specific expression in axons crossing through the ventral (TAG1(-/NPY(+ portion of the corpus callosum, confirming that it is active in a subpopulation of callosal neurons. These data suggest that exaptation of the AS021 SINE locus might be involved in enhancement of Satb2 expression, leading to the establishment of interhemispheric communication via the corpus callosum

  7. Streptococcus mutans Displays Altered Stress Responses While Enhancing Biofilm Formation by Lactobacillus casei in Mixed-Species Consortium (United States)

    Wen, Zezhang T.; Liao, Sumei; Bitoun, Jacob P.; De, Arpan; Jorgensen, Ashton; Feng, Shihai; Xu, Xiaoming; Chain, Patrick S. G.; Caufield, Page W.; Koo, Hyun; Li, Yihong


    Like Streptococcus mutans, lactobacilli are commonly isolated from carious sites, although their exact role in caries development remains unclear. This study used mixed-species models to analyze biofilm formation by major groups of oral lactobacilli, including L. casei, L. fermentum, L. rhamnosus, L. salivarius ssp. salivarius, and L. gasseri. The results showed that lactobacilli did not form good biofilms when grown alone, although differences existed between different species. When grown together with S. mutans, biofilm formation by L. gasseri and L. rhamnosus was increased by 2-log (P 1-log (P mutans wild-type, but no such effects were observed with S. mutans deficient of glucosyltransferase GtfB and adhesin P1. Both S. mutans and L. casei in dual-species enhanced resistance to acid killing with increases of survival rate by >1-log (P mutans in dual-species with L. casei as either up- or down-regulated when compared to those grown alone. The up-regulated genes include those for superoxide dismutase, NADH oxidase, and members of the mutanobactin biosynthesis cluster. Among the down-regulated genes were those for GtfB and alternative sigma factor SigX. These results further suggest that interactions between S. mutans and oral lactobacilli are species-specific and may have significant impact on cariogenic potential of the community. PMID:29326887

  8. A peroxidase related to the mammalian antimicrobial protein myeloperoxidase in the Euprymna-Vibrio mutualism. (United States)

    Weis, V M; Small, A L; McFall-Ngai, M J


    Many animal-bacteria cooperative associations occur in highly modified host organs that create a unique environment for housing and maintaining the symbionts. It has been assumed that these specialized organs develop through a program of symbiosis-specific or -enhanced gene expression in one or both partners, but a clear example of this process has been lacking. In this study, we provide evidence for the enhanced production of an enzyme in the symbiotic organ of the squid Euprymna scolopes, which harbors a culture of the luminous bacterium Vibrio fischeri. Our data show that this enzyme has a striking biochemical similarity to mammalian myeloperoxidase (MPO; EC 1.11.17), an antimicrobial dianisidine peroxidase that occurs in neutrophils. MPO and the squid peroxidase catalyze the same reaction, have similar apparent subunit molecular masses, and a polyclonal antibody to native human MPO specifically localized a peroxidase-like protein to the bacteria-containing regions of the symbiotic organ. We also provide evidence that a previously described squid cDNA encodes the protein (LO4) that is responsible for the observed dianisidine peroxidase activity. An antibody made against a fragment of LO4 immunoprecipiated dianisidine peroxidase activity from extracts of the symbiotic organ, and reacted against these extracts and human MPO in Western blot analysis. These data suggest that related biochemical mechanisms for the control of bacterial number and growth operate in associations that are as functionally diverse as pathogenesis and mutualism, and as phylogenetically distant as molluscs and mammals.

  9. Guaiacol Peroxidase Zymography for the Undergraduate Laboratory (United States)

    Wilkesman, Jeff; Castro, Diana; Contreras, Lellys M.; Kurz, Liliana


    This laboratory exercise presents a novel way to introduce undergraduate students to the specific detection of enzymatic activity by electrophoresis. First, students prepare a crude peroxidase extract and then analyze the homogenate via electrophoresis. Zymography, that is, a SDS-PAGE method to detect enzyme activity, is used to specifically…

  10. Heterologous Expression of Peroxidases : Chapter 12

    NARCIS (Netherlands)

    Christien Lokman; S. de Weert


    This monograph describes many applications of peroxidase-based biocatalysis in the biotechnology industry. The need for such a book emerges from the considerable amount of new data regarding the phylogeny, reaction mechanisms, thermodynamic characterization and structural features of fungal and

  11. "Chitin-specific" peroxidases in plants. (United States)

    Maksimov, I V; Cherepanova, E A; Khairullin, R M


    The activity of various plant peroxidases and the ability of their individual isoforms to bind chitin was studied. Some increase in peroxidase activity was observed in crude extracts in the presence of chitin. Activated peroxidases of some species fell in the fraction not sorbed on chitin and those of other species can bind chitin. Only anionic isoperoxidases from oat (Avena sativa), rice (Oryza sativa), horseradish (Armoracia rusticana), garden radish (Raphanus sativus var. radicula), peanut (Arachis hypogaea), and tobacco (Nicotiana tabacum Link et Otto) were sorbed on chitin. Both anionic and cationic isoforms from pea (Pisum sativum), galega(Galega orientalis), cucumber (Cucumis sativus), and zucchini (Cucurbita pepo L.) were sorbed on chitin. Peroxidase activation under the influence of chitin was correlated to the processes that occur during hypersensitive reaction and lignification of sites, in which pathogenic fungus penetrates into a plant. The role of chitin-specific isoperoxidases in inhibition of fungal growth and connection of this phenomenon with structural characteristics of isoperoxidases are also discussed.

  12. Peroxidase-like activity of magnetoferritin

    Czech Academy of Sciences Publication Activity Database

    Melníková, V.; Pospíšková, K.; Mitróová, Z.; Kopčanský, P.; Šafařík, Ivo


    Roč. 181, 3-4 (2014), s. 295-301 ISSN 0026-3672 R&D Projects: GA MŠk(CZ) LD13021 Institutional support: RVO:67179843 Keywords : magnetoferritin * magnetic nanoparticles * peroxidase-like activity * hydrogen peroxide * oxidative stress Subject RIV: CE - Biochemistry Impact factor: 3.741, year: 2014

  13. Occurrence and properties of Petunia peroxidase a

    NARCIS (Netherlands)

    Hendriks, T.


    Peroxidases are probably the most extensively studied enzymes in higher plants. Various isoenzymes occur as soluble proteins in the apoplast and in the vacuole, or are bound to membranes and cell walls. Their occurrence is often organ-specific and developmentally controlled, and there is

  14. Thyroid peroxidase autoantibodies in euthyroid subjects

    NARCIS (Netherlands)

    Prummel, Mark F.; Wiersinga, Wilmar M.


    Thyroid peroxidase (TPO) is a key enzyme in the formation of thyroid hormones and a major autoantigen in autoimmune thyroid diseases. Titers of TPO antibodies also correlate with the degree of lymphocytic infiltration in euthyroid subjects, and they are frequently present in euthyroid subjects

  15. Bordetella pertussis Isolates from Argentinean Whooping Cough Patients Display Enhanced Biofilm Formation Capacity Compared to Tohama I Reference Strain. (United States)

    Arnal, Laura; Grunert, Tom; Cattelan, Natalia; de Gouw, Daan; Villalba, María I; Serra, Diego O; Mooi, Frits R; Ehling-Schulz, Monika; Yantorno, Osvaldo M


    Pertussis is a highly contagious disease mainly caused by Bordetella pertussis. Despite the massive use of vaccines, since the 1950s the disease has become re-emergent in 2000 with a shift in incidence from infants to adolescents and adults. Clearly, the efficacy of current cellular or acellular vaccines, formulated from bacteria grown in stirred bioreactors is limited, presenting a challenge for future vaccine development. For gaining insights into the role of B. pertussis biofilm development for host colonization and persistence within the host, we examined the biofilm forming capacity of eight argentinean clinical isolates recovered from 2001 to 2007. All clinical isolates showed an enhanced potential for biofilm formation compared to the reference strain Tohama I. We further selected the clinical isolate B. pertussis 2723, exhibiting the highest biofilm biomass production, for quantitative proteomic profiling by means of two-dimensional fluorescence difference gel electrophoresis (2D-DIGE) coupled with mass spectrometry, which was accompanied by targeted transcriptional analysis. Results revealed an elevated expression of several virulence factors, including adhesins involved in biofilm development. In addition, we observed a higher expression of energy metabolism enzymes in the clinical isolate compared to the Tohama I strain. Furthermore, all clinical isolates carried a polymorphism in the bvgS gene. This mutation was associated to an increased sensitivity to modulation and a faster rate of adhesion to abiotic surfaces. Thus, the phenotypic biofilm characteristics shown by the clinical isolates might represent an important, hitherto underestimated, adaptive strategy for host colonization and long time persistence within the host.

  16. Becoming a Peroxidase: Cardiolipin-Induced Unfolding of Cytochrome c (United States)

    Muenzner, Julia; Toffey, Jason R.; Hong, Yuning; Pletneva, Ekaterina V.


    Interactions of cytochrome c (cyt c) with a unique mitochondrial glycerophospholipid cardiolipin (CL) are relevant for the protein’s function in oxidative phosphorylation and apoptosis. Binding to CL-containing membranes promotes cyt c unfolding and dramatically enhances the protein’s peroxidase activity, which is critical in early stages of apoptosis. We have employed a collection of seven dansyl variants of horse heart cyt c to probe the sequence of steps in this functional transformation. Kinetic measurements have unraveled four distinct processes during CL-induced cyt c unfolding: rapid protein binding to CL liposomes; rearrangements of protein substructures with small unfolding energies; partial insertion of the protein into the lipid bilayer; and extensive protein restructuring leading to “open” extended structures. While early rearrangements depend on a hierarchy of foldons in the native structure, the later process of large-scale unfolding is influenced by protein interactions with the membrane surface. The opening of the cyt c structure exposes the heme group, which enhances the protein’s peroxidase activity and also frees the C-terminal helix to aid in the translocation of the protein through CL membranes. PMID:23713573

  17. Genotypes Associated with Listeria monocytogenes Isolates Displaying Impaired or Enhanced Tolerances to Cold, Salt, Acid, or Desiccation Stress (United States)

    Hingston, Patricia; Chen, Jessica; Dhillon, Bhavjinder K.; Laing, Chad; Bertelli, Claire; Gannon, Victor; Tasara, Taurai; Allen, Kevin; Brinkman, Fiona S. L.; Truelstrup Hansen, Lisbeth; Wang, Siyun


    sequencing of L. monocytogenes isolates in combination with stress tolerance profiling, will enhance the ability to identify genetic elements associated with higher risk strains. PMID:28337186

  18. Peroxidase gene discovery from the horseradish transcriptome. (United States)

    Näätsaari, Laura; Krainer, Florian W; Schubert, Michael; Glieder, Anton; Thallinger, Gerhard G


    Horseradish peroxidases (HRPs) from Armoracia rusticana have long been utilized as reporters in various diagnostic assays and histochemical stainings. Regardless of their increasing importance in the field of life sciences and suggested uses in medical applications, chemical synthesis and other industrial applications, the HRP isoenzymes, their substrate specificities and enzymatic properties are poorly characterized. Due to lacking sequence information of natural isoenzymes and the low levels of HRP expression in heterologous hosts, commercially available HRP is still extracted as a mixture of isoenzymes from the roots of A. rusticana. In this study, a normalized, size-selected A. rusticana transcriptome library was sequenced using 454 Titanium technology. The resulting reads were assembled into 14871 isotigs with an average length of 1133 bp. Sequence databases, ORF finding and ORF characterization were utilized to identify peroxidase genes from the 14871 isotigs generated by de novo assembly. The sequences were manually reviewed and verified with Sanger sequencing of PCR amplified genomic fragments, resulting in the discovery of 28 secretory peroxidases, 23 of them previously unknown. A total of 22 isoenzymes including allelic variants were successfully expressed in Pichia pastoris and showed peroxidase activity with at least one of the substrates tested, thus enabling their development into commercial pure isoenzymes. This study demonstrates that transcriptome sequencing combined with sequence motif search is a powerful concept for the discovery and quick supply of new enzymes and isoenzymes from any plant or other eukaryotic organisms. Identification and manual verification of the sequences of 28 HRP isoenzymes do not only contribute a set of peroxidases for industrial, biological and biomedical applications, but also provide valuable information on the reliability of the approach in identifying and characterizing a large group of isoenzymes.

  19. The study of ascorbate peroxidase, catalase and peroxidase during in vitro regeneration of Argyrolobium roseum. (United States)

    Habib, Darima; Chaudhary, Muhammad Fayyaz; Zia, Muhammad


    Here, we demonstrate the micropropagation protocol of Argyrolobium roseum (Camb.), an endangered herb exhibiting anti-diabetic and immune-suppressant properties, and antioxidant enzymes pattern is evaluated. Maximum callogenic response (60 %) was observed from leaf explant at 1.0 mg L(-1) 1-nephthalene acetic acid (NAA) and 0.5 mg L(-1) 6-benzyl aminopurine (BA) in Murashige and Skoog (MS) medium using hypocotyl and root explants (48 % each). Addition of AgNO3 and PVP in the culture medium led to an increase in callogenic response up to 86 % from leaf explant and 72 % from hypocotyl and root explants. The best shooting response was observed in the presence of NAA, while maximum shoot length and number of shoots were achieved based on BA-supplemented MS medium. The regenerated shoots were rooted and successfully acclimatized under greenhouse conditions. Catalase and peroxidase enzymes showed ascending pattern during in vitro plant development from seed while ascorbate peroxidase showed descending pattern. Totally reverse response of these enzymes was observed during callus induction from three different explants. During shoot induction, catalase and peroxidase increased at high rate while there was a mild reduction in ascorbate peroxidase activity. Catalase and peroxidase continuously increased; on the other hand, ascorbate peroxidase activity decreased during root development and acclimatization states. The protocol described here can be employed for the mass propagation and genetic transformation of this rare herb. This study also highlights the importance and role of ascorbate peroxidase, catalase, and peroxidase in the establishment of A. roseum in vitro culture through callogenesis and organogenesis.

  20. Peroxidase isozyme profiles in some sweet cherry rootstocks and ...

    African Journals Online (AJOL)



    , 2005). Santamour (1980) defined role of peroxidase in graft compatibility as; 1) lignification is essential for a strong and permanent graft union; 2) peroxidase isoenzymes mediate the polymeri- zation of cinnamic alcohols to ...

  1. Luffa aegyptiaca (Gourd) Fruit Juice as a Source of Peroxidase


    Yadav, R. S. S.; Yadav, K. S.; Yadav, H. S.


    Peroxidases have turned out to be potential biocatalyst for a variety of organic reactions. The research work reported in this communication was done with the objective of finding a convenient rich source of peroxidase which could be used as a biocatalyst for organic synthetic reactions. The studies made have shown that Luffa aegyptiaca (gourd) fruit juice contains peroxidase activity of the order of 180 enzyme unit/mL. The K m values of this peroxidase for the substrates guaiacol and hydroge...

  2. Effect of Vitamin C on Glutathione Peroxidase Activities in Pregnant ...

    African Journals Online (AJOL)

    Glutathione peroxidase is one of the most important antioxidant enzymes in humans. We studied the relationship between serum glutathione peroxidase activity and vitamin C ingestion during normal pregnancy in women attending antenatal clinic in the University of Ilorin Teaching Hospital, Ilorin. Glutathione peroxidase ...

  3. Comparative study of peroxidase purification from apple and orange ...

    African Journals Online (AJOL)

    This paper reports the isolation and purification of peroxidase from low cost material; moreover, no significant work has been done on the isolation and purification of peroxidase from such cost effective sources (apple and orange seeds). Peroxidases had attracted considerable interest in recent years because of their ...

  4. Functional displays

    International Nuclear Information System (INIS)

    Angelis De, F.; Haentjens, J.


    The Functional Displays are directly derived from the Man-Machine Design key document: Function-Based Task Analysis. The presentation defines and describes the goals-means structure of the plant function along with applicable control volumes and parameters of interest. The purpose of the subject is to show, through an example of a preliminary design, what the main parts of a function are. (3 figs.)

  5. Display hardware

    International Nuclear Information System (INIS)

    Myers, D.R.


    To appreciate the limitations and possibilities of computer graphics it is necessary to have some acquaintance with the available technology. The aim of this chapter is to mention briefly the different display types and their 'ball-park' price ranges. It must be stressed that prices change rapidly, and so those quoted here are only intended to give an idea of the cost at the time of writing.

  6. Characteristics of estrogen-induced peroxidase in mouse uterine luminal fluid

    International Nuclear Information System (INIS)

    Jellinck, P.H.; Newbold, R.R.; McLachlan, J.A.


    Peroxidase activity in the uterine luminal fluid of mice treated with diethylstilbestrol was measured by the guaiacol assay and also by the formation of 3H2O from [2-3H]estradiol. In the radiometric assay, the generation of 3H2O and 3H-labeled water-soluble products was dependent on H2O2 (25 to 100 microM), with higher concentrations being inhibitory. Tyrosine or 2,4-dichlorophenol strongly enhanced the reaction catalyzed either by the luminal fluid peroxidase or the enzyme in the CaCl2 extract of the uterus, but decreased the formation of 3H2O from [2-3H]estradiol by lactoperoxidase in the presence of H2O2 (80 microM). NADPH, ascorbate, and cytochrome c inhibited both luminal fluid and uterine tissue peroxidase activity to the same extent, while superoxide dismutase showed a marginal activating effect. Lactoferrin, a major protein component of uterine luminal fluid, was shown not to contribute to its peroxidative activity, and such an effect by prostaglandin synthase was also ruled out. However, it was not possible to exclude eosinophil peroxidase, brought to the uterus after estrogen stimulation, as being the source of peroxidase activity in uterine luminal fluid

  7. Guaiacol peroxidase zymography for the undergraduate laboratory. (United States)

    Wilkesman, Jeff; Castro, Diana; Contreras, Lellys M; Kurz, Liliana


    This laboratory exercise presents a novel way to introduce undergraduate students to the specific detection of enzymatic activity by electrophoresis. First, students prepare a crude peroxidase extract and then analyze the homogenate via electrophoresis. Zymography, that is, a SDS-PAGE method to detect enzyme activity, is used to specifically detect peroxidase activity and furthermore, to analyze the total protein profile. After the assay, students may estimate the apparent molecular mass of the enzyme and discuss its structure. After the 4-h experiment, students gain knowledge concerning biological sample preparation, gel preparation, electrophoresis, and the importance of specific staining procedures for the detection of enzymatic activity. Copyright © 2014 The International Union of Biochemistry and Molecular Biology.

  8. A redox-dependent dimerization switch regulates activity and tolerance for reactive oxygen species of barley seed glutathione peroxidase

    DEFF Research Database (Denmark)

    Navrot, Nicolas; Skjoldager, Nicklas; Bunkenborg, Jakob


    Monomeric and dimeric forms of recombinant barley (Hordeum vulgare subsp. vulgare) glutathione peroxidase 2 (HvGpx2) are demonstrated to display distinctly different functional properties in vitro. Monomeric HvGpx2 thus has five fold higher catalytic efficiency than the dimer towards tert-butyl h...

  9. Computational Modeling of the Catalytic Cycle of Glutathione Peroxidase Nanomimic. (United States)

    Kheirabadi, Ramesh; Izadyar, Mohammad


    To elucidate the role of a derivative of ebselen as a mimic of the antioxidant selenoenzyme glutathione peroxidase, density functional theory and solvent-assisted proton exchange (SAPE) were applied to model the reaction mechanism in a catalytic cycle. This mimic plays the role of glutathione peroxidase through a four-step catalytic cycle. The first step is described as the oxidation of 1 in the presence of hydrogen peroxide, while selenoxide is reduced by methanthiol at the second step. In the third step of the reaction, the reduction of selenenylsulfide occurs by methanthiol, and the selenenic acid is dehydrated at the final step. Based on the kinetic parameters, step 4 is the rate-determining step (RDS) of the reaction. The bond strength of the atoms involved in the RDS is discussed with the quantum theory of atoms in molecules (QTAIM). Low value of electron density, ρ(r), and positive Laplacian values are the evidence for the covalent nature of the hydrogen bonds rupture (O 30 -H 31 , O 33 -H 34 ). A change in the sign of the Laplacian, L(r), from the positive value in the reactant to a negative character at the transition state indicates the depletion of the charge density, confirming the N 5 -H 10 and O 11 -Se 1 bond breaking. The analysis of electron location function (ELF) and localized orbital locator (LOL) of the Se 1 -N 5 and Se 1 -O 11 bonds have been done by multi-WFN program. High values of ELF and LOL at the transition state regions between the Se, N, and O atoms display the bond formation. Finally, the main donor-acceptor interaction energies were analyzed using the natural bond orbital analysis for investigation of their stabilization effects on the critical bonds at the RDS.

  10. Effect of caffeine on peroxidase activity and gamma-ray-induced oxic and anoxic damage in Hordeum vulgare

    International Nuclear Information System (INIS)

    Balachandran, R.; Kesavan, P.C.


    The influence of caffeine during and after gamma radiation of barley seeds was studied using seedling injury and peroxidase activity as parameters. The radiation-induced stimulation of peroxidase activity is evident in eight-day only seedlings but not in embryos (i.e. immediately after irradiation). Caffeine present during irradiation of seeds soaked in oxygenated water diminishes seedling injury and also reduces the peroxidase activity to the level observed in eight-day old seedlings of unirradiated seeds. Caffeine, however, produces just the opposite effect (i.e. enhances the seedling injury and peroxidase activity of eight-day old seedlings) when applied during irradiation of seeds soaked in oxygen-free water. There is no evidence that caffeine effects enzyme activity under in vitro conditions. (author)

  11. Gd{sub 90}Co{sub 2.5}Fe{sub 7.5} alloy displaying enhanced magnetocaloric properties

    Energy Technology Data Exchange (ETDEWEB)

    Provenzano, V., E-mail: [Materials Science and Engineering Division, NIST, Gaithersburg, MD 20899-8552 (United States); Shull, R.D., E-mail: [Materials Science and Engineering Division, NIST, Gaithersburg, MD 20899-8552 (United States); Kletetschka, G., E-mail: [Faculty of Science, Charles University, Prague 12843 (Czech Republic); Institute of Geology, Academy of Science of the Czech Republic, v.v.i., Prague 16500 (Czech Republic); Stutzman, P.E., E-mail: [Materials and Structural Systems Division, NIST, Gaithersburg, MD 20899-861 (United States)


    Highlights: • The Gd{sub 90}Co{sub 2.5}Fe{sub 7.5} alloy displays superior magnetocaloric properties than Gd. • Alloy’s superior properties at relatively low field values: 400, 800 kA/m (0.5, 1 T). • We proposed two possible mechanisms for the Gd-based alloy enhanced properties. • We indicated a pathway for further improving the alloy magnetocaloric properties. - Abstract: We report on the discovery of a new Gd{sub 90}Co{sub 2.5}Fe{sub 7.5} alloy exhibiting superior magnetocaloric properties compared to those of gadolinium. We present magnetically-derived entropy change, ΔS{sub M}, computed from magnetic data, and thermally-derived temperature change, ΔT{sub ad}, obtained from direct thermal measurements together with their respective MCE peaks for the alloy and gadolinium. The MCE peaks of the alloy are taller and broader than the corresponding MCE peaks of gadolinium. Correspondingly, the refrigeration capacity (RC) values of the alloy computed from magnetic and thermal MCEs for field changes, ΔH, of 400 kA/m (0.5 T) and 800 kA/m (1 T) are about 20% larger than those of gadolinium. Two possible mechanisms are proposed to account for the improved magnetocaloric properties of gadolinium alloyed with small amounts of Co and Fe, thereby pointing out a different methodology to use in the search for improved low field magnetic refrigerants.

  12. Engineering a horseradish peroxidase C stable to radical attacks by mutating multiple radical coupling sites. (United States)

    Kim, Su Jin; Joo, Jeong Chan; Song, Bong Keun; Yoo, Young Je; Kim, Yong Hwan


    Peroxidases have great potential as industrial biocatalysts. In particular, the oxidative polymerization of phenolic compounds catalyzed by peroxidases has been extensively examined because of the advantage of this method over other conventional chemical methods. However, the industrial application of peroxidases is often limited because of their rapid inactivation by phenoxyl radicals during oxidative polymerization. In this work, we report a novel protein engineering approach to improve the radical stability of horseradish peroxidase isozyme C (HRPC). Phenylalanine residues that are vulnerable to modification by the phenoxyl radicals were identified using mass spectrometry analysis. UV-Vis and CD spectra showed that radical coupling did not change the secondary structure or the active site of HRPC. Four phenylalanine (Phe) residues (F68, F142, F143, and F179) were each mutated to alanine residues to generate single mutants to examine the role of these sites in radical coupling. Despite marginal improvement of radical stability, each single mutant still exhibited rapid radical inactivation. To further reduce inactivation by radical coupling, the four substitution mutations were combined in F68A/F142A/F143A/F179A. This mutant demonstrated dramatic enhancement of radical stability by retaining 41% of its initial activity compared to the wild-type, which was completely inactivated. Structure and sequence alignment revealed that radical-vulnerable Phe residues of HPRC are conserved in homologous peroxidases, which showed the same rapid inactivation tendency as HRPC. Based on our site-directed mutagenesis and biochemical characterization, we have shown that engineering radical-vulnerable residues to eliminate multiple radical coupling can be a good strategy to improve the stability of peroxidases against radical attack. © 2014 Wiley Periodicals, Inc.

  13. Immobilization of Peroxidase onto Magnetite Modified Polyaniline

    Directory of Open Access Journals (Sweden)

    Eduardo Fernandes Barbosa


    Full Text Available The present study describes the immobilization of horseradish peroxidase (HRP on magnetite-modified polyaniline (PANImG activated with glutaraldehyde. After the optimization of the methodology, the immobilization of HRP on PANImG produced the same yield (25% obtained for PANIG with an efficiency of 100% (active protein. The optimum pH for immobilization was displaced by the effect of the partition of protons produced in the microenvironment by the magnetite. The tests of repeated use have shown that PANImG-HRP can be used for 13 cycles with maintenance of 50% of the initial activity.

  14. Use of computer aids including expert systems to enhance diagnosis of NPP safety status and operator response. VDU displays in accidents - Interact

    International Nuclear Information System (INIS)

    Humble, P.; Welbourne, D.


    This report describes NNC development of a demonstration concept called Interact of Visual Display Unit (VDU) displays, integrating on-screen control of plant actions. Most plant vendors now propose on-screen control and it is being included on some plants. The integration of Station Operating Instructions (SOI) into VDU presentation of plants is being developed rapidly. With on-screen control, SOIs can be displayed with control targets able to initiate plant control, directly as called for in the SOIs. Interact displays information and control options, using a cursor to simulate on-screen display and plant control. The displays show a method which integrates soft control and SOI information into a single unified presentation. They simulate the SOI for an accident, on-screen, with simulated inserted plant values

  15. Assessing two different peroxidases´ potential for application in recalcitrant organic compound bioremediation

    Directory of Open Access Journals (Sweden)

    Nelson Caicedo


    Full Text Available This work shows the promising future presented by the following enzymes: Chloroperoxidase (CPO from Caldariomyces fumago and royal palm peroxidase (Roystonea regia, PPR. These peroxidases were obtained from different sources (microbial and vegetable and used as biocatalysts for applicating them in bioremediation of recalcitrant organic compounds. Each one of the enzymes' peroxidase catalytic activity was evaluated in organic phase systems, using different model compounds such as: PAHs (pyrene and anthracene, organic-nitrogenated compounds (diphenylamine, monoaromatic phenolic molecules (guayacol and dyes (methyl orange and ABTS. The reaction systems were composed of mono-phase water mixtures and organic miscible solvent (methanol, ethanol, isopropanol, acetonitrile, tetrahydrofuran, dimethyl sulfoxide and dimethyl formamide, on which both peroxidases' catalytic activity was evaluated. The two enzymes' catalytic activity was observed on the evaluated substrates in most of these assays. However, PPR did not show biocatalytic oxidation for methyl orange dye and some PAHs. This enzyme did show the best tolerance to the evaluated solvents. Its catalytic activity was appreciably enhanced when low hydrophobic solvents were used. The kcat was calculated from this experimental data (as kinetic parameter leading to each enzyme's biocatalytic performance on substrates being compared.

  16. [Cell surface peroxidase--generator of superoxide anion in wheat root cells under wound stress]. (United States)

    Chasov, A V; Gordon, L Kh; Kolesnikov, O P; Minibaeva, F V


    Development of wound stress in excised wheat roots is known to be accompanied with an increase in reactive oxygen species (ROS) production, fall of membrane potential, release of K+ from cells, alkalization of extracellular solution, changes in respiration and metabolism of structural lipids. Dynamics of superoxide release correlates with changes in other physiological parameters, indicating the cross-reaction of these processes. Activity of peroxidase in extracellular solution after a 1 h incubation and removal of roots was shown to be stimulated by the range of organic acids, detergents, metals, and to be inhibited by cyanide. Superoxide production was sensitive to the addition of Mn2+ and H2O2. Increase in superoxide production correlates with the enhancement of peroxidase activity at the application of organic acids and detergents. The results obtained indicate that cell surface peroxidase is one of the main generators of superoxide in wounded wheat root cells. Different ways of stimulation of the ROS producing activity in root cells is supposed. By controlling superoxide and hydrogen peroxide formation, the cell surface peroxidase can control the adaptation processes in stressed plant cells.

  17. Chemical Composition and Rheological Properties of Set Yoghurt Prepared from Skimmed Milk Treated with Horseradish Peroxidase

    Directory of Open Access Journals (Sweden)

    Yan Wen


    Full Text Available The aim of this work is to determine the impact of an enzymatic treatment on the fermentation and rheological properties of set yoghurt prepared from skimmed milk. Skimmed bovine milk was treated with horseradish peroxidase added at the level of 645 U per g of proteins in the presence (addition level of 7.8 mmol per L of milk or absence of ferulic acid as a cross-linking agent, and used to prepare set yoghurt with commercial direct vat set starter culture. The evaluation showed that the treatment of skimmed milk with horseradish peroxidase enhanced its apparent viscosity, and storage and loss moduli. The prepared yoghurt contained protein, fat and total solids at 3.49–3.59, 0.46–0.52 and 15.23–15.43 %, respectively, had titratable acidity of 0.83–0.88 %, and no significant difference in the composition was found among the yoghurt samples (p>0.05. Compared to the control yoghurt, the yoghurt prepared from the milk treated with horseradish peroxidase had a higher apparent viscosity, storage and loss moduli and flow behavior indices, especially when ferulic acid was added. Yoghurt samples from the skimmed milk treated either with horseradish peroxidase only or with the additional ferulic acid treatment had better structural reversibility, because their hysteresis loop area during rheological analysis was larger (p<0.05.

  18. Display technologies for augmented reality (United States)

    Lee, Byoungho; Lee, Seungjae; Jang, Changwon; Hong, Jong-Young; Li, Gang


    With the virtue of rapid progress in optics, sensors, and computer science, we are witnessing that commercial products or prototypes for augmented reality (AR) are penetrating into the consumer markets. AR is spotlighted as expected to provide much more immersive and realistic experience than ordinary displays. However, there are several barriers to be overcome for successful commercialization of AR. Here, we explore challenging and important topics for AR such as image combiners, enhancement of display performance, and focus cue reproduction. Image combiners are essential to integrate virtual images with real-world. Display performance (e.g. field of view and resolution) is important for more immersive experience and focus cue reproduction may mitigate visual fatigue caused by vergence-accommodation conflict. We also demonstrate emerging technologies to overcome these issues: index-matched anisotropic crystal lens (IMACL), retinal projection displays, and 3D display with focus cues. For image combiners, a novel optical element called IMACL provides relatively wide field of view. Retinal projection displays may enhance field of view and resolution of AR displays. Focus cues could be reconstructed via multi-layer displays and holographic displays. Experimental results of our prototypes are explained.

  19. Direct Electrochemistry of Horseradish Peroxidase-Gold Nanoparticles Conjugate

    Directory of Open Access Journals (Sweden)

    Chanchal K. Mitra


    Full Text Available We have studied the direct electrochemistry of horseradish peroxidase (HRP coupled to gold nanoparticles (AuNP using electrochemical techniques, which provide some insight in the application of biosensors as tools for diagnostics because HRP is widely used in clinical diagnostics kits. AuNP capped with (i glutathione and (ii lipoic acid was covalently linked to HRP. The immobilized HRP/AuNP conjugate showed characteristic redox peaks at a gold electrode. It displayed good electrocatalytic response to the reduction of H2O2, with good sensitivity and without any electron mediator. The covalent linking of HRP and AuNP did not affect the activity of the enzyme significantly. The response of the electrode towards the different concentrations of H2O2 showed the characteristics of Michaelis Menten enzyme kinetics with an optimum pH between 7.0 to 8.0. The preparation of the sensor involves single layer of enzyme, which can be carried out efficiently and is also highly reproducible when compared to other systems involving the layer-by-layer assembly, adsorption or encapsulation of the enzyme. The immobilized AuNP-HRP can be used for immunosensor applications

  20. Oxidative degradation of alkylphenols by horseradish peroxidase. (United States)

    Sakuyama, Hisae; Endo, Yasushi; Fujimoto, Kenshiro; Hatana, Yasuhiko


    Alkylphenols such as bisphenol A (2,2-bis(4-hydroxyphenyl)propane; BPA), p-nonylphenol (p-NP), and p-octylphenol (p-OP) that are known as endocrine disrupters were oxidized by horseradish (Armoracia rusticana) peroxidase (HRP) with H2O2. The optimal pHs for BPA, p-NP, and p-OP were 8.0, 7.0, and 5.0, respectively. The optimal temperature for BPA was 20 degrees C. Although BPA was rapidly degraded by HRP, its degradation depended on the concentration of HRP. Most of the oxidation products of BPA were polymers, although some 4-isopropenylphenol was produced. When male Japanese medaka (Oryzias latipes) were exposed to BPA, vitellogenin in the blood increased. However, no increased vitellogenin was observed in medaka exposed to HRP-oxidized BPA. The enzymatic oxidation of BPA using HRP was able to eliminate its estrogen-like activity.

  1. Radioimmunoassays for catalase and glutathion peroxidase

    International Nuclear Information System (INIS)

    Baret, A.; Courtiere, A.; Lorry, D.; Puget, K.; Michelson, A.M.


    Specific and sensitive radioimmunoassays for human, bovine and rat catalase (CAT) and glutathion Peroxidase (GPX) are described. The obtained values are expressed as enzymatic units per μg of immunoreactive protein. They appear to closely correspond to specific activities of the purified enzymes determined by colorimetric protein-assay. Indeed, the values of the specific activities of purified human CAT is 57.9 k/mg and that of purified rat GPX is 180 units/mg. This result validates the present RIAs and the association of the two techniques allows the determination of a further parameter. In conclusion, RIAs for CAT and GPX can be applied with great specificity and sensitivity to a wide variety of human, rat and bovine medias

  2. TLR2−/− Mice Display Decreased Severity of Giardiasis via Enhanced Proinflammatory Cytokines Production Dependent on AKT Signal Pathway

    Directory of Open Access Journals (Sweden)

    Xin Li


    Full Text Available Giardia infection is one of the most common causes of waterborne diarrheal disease in a wide array of mammalian hosts, including humans globally. Although numerous studies have indicated that adaptive immune responses are important for Giardia defense, however, whether the host innate immune system such as TLRs recognizes Giardia remains poorly understood. TLR2 plays a crucial role in pathogen recognition, innate immunity activation, and the eventual pathogen elimination. In this study, we investigated the role of TLR2 as a non-protective inflammatory response on controlling the severity of giardiasis. RT-PCR analysis suggested that TLR2 expression was increased in vitro. We demonstrated that Giardia lamblia-induced cytokines expression by the activation of p38 and ERK pathways via TLR2. Interestingly, the expression of IL-12 p40, TNF-α, and IL-6, but not IFN-γ, was enhanced in TLR2-blocked and TLR2−/− mouse macrophages exposed to G. lamblia trophozoites compared with wild-type (WT mouse macrophages. Further analysis demonstrated that G. lamblia trophozoites reduced cytokines secretion by activating AKT pathway in WT mouse macrophages. Immunohistochemical staining in G. lamblia cysts infected TLR2−/− and WT mice showed that TLR2 was highly expressed in duodenum in infected WT mice. Also, infected TLR2−/− and AKT-blocked mice showed an increased production of IL-12 p40 and IFN-γ compared with infected WT mice at the early stage during infection. Interestingly, infected TLR2−/− and AKT-blocked mice displayed a decreased parasite burden, an increased weight gain rate, and short parasite persistence. Histological morphometry showed shortened villus length, hyperplastic crypt and decreased ratio of villus height/crypt depth in infected WT mice compared with in infected TLR2−/− and AKT-blocked mice. Together, our results suggested that TLR2 deficiency leads to alleviation of giardiasis and reduction of parasite burden through

  3. Expression, purification and characterization of a peroxidase from ...

    African Journals Online (AJOL)

    Peroxidase is one of the key enzymes of the cellular antioxidant defense system, which is mostly involved in the reduction of hydrogen peroxide. Here, a peroxidase gene, named ThPOD1 was isolated from a cDNA library, which was generated from root tissue of Tamarix hispida that was exposed to 0.4 M NaCl. The cDNA ...

  4. Apple and quince peroxidase activity in response to essential oils ...

    African Journals Online (AJOL)

    Enzymatic browning arises by peroxidase in fruits. However, essential oils are recognized as natural antioxidant agents. So in this study, the effect of thyme, coriander and rosemary essential oils were evaluated on the reduction of peroxidase activity in apples (Malus domestica Mill. cv Golden delicious), (M. domestica Mill.

  5. Production of lignin peroxidase by Ganoderma leucidum using solid ...

    African Journals Online (AJOL)

    The main objectives of this study were to optimize the culture conditions for the production of lignin peroxidase by Ganoderma leucidum, economic utilization of waste corn cobs as inducers substrate by pollution free fermentation technology and to optimize the solid state fermentation (SSF) process for lignin peroxidase ...

  6. Heat stable peroxidases from Vigna species (V) | Mbassi | African ...

    African Journals Online (AJOL)

    Shoots of three landraces of a Vigna species from two climatic areas of Cameroon were evaluated for their content of heat-resistant peroxidases. The peroxidase activity in the three landraces was detected with a greater catalytic efficiency for oxidation of O-dianisidine relative to ABTS (2, 2'-azino-bis-(3- ...

  7. The relationship between lignin peroxidase and manganese peroxidase production capacities and cultivation periods of mushrooms. (United States)

    Xu, Jian Z; Zhang, Jun L; Hu, Kai H; Zhang, Wei G


    Mushrooms are able to secrete lignin peroxidase (LiP) and manganese peroxidase (MnP), and able to use the cellulose as sources of carbon. This article focuses on the relation between peroxidase-secreting capacity and cultivation period of mushrooms with non-laccase activity. Methylene blue and methyl catechol qualitative assay and spectrophotometry quantitative assay show LiP secreting unvaryingly accompanies the MnP secreting in mushroom strains. The growth rates of hyphae are detected by detecting the dry hyphal mass. We link the peroxidase activities to growth rate of mushrooms and then probe into the relationship between them. The results show that there are close relationships between LiP- and/or MnP-secretory capacities and the cultivation periods of mushrooms. The strains with high LiP and MnP activities have short cultivation periods. However, those strains have long cultivation periods because of the low levels of secreted LiP and/or MnP, even no detectable LiP and/or MnP activity. This study provides the first evidence on the imitate relation between the level of secreted LiP and MnP activities and cultivation periods of mushrooms with non-laccase activity. Our study has significantly increased the understanding of the role of LiP and MnP in the growth and development of mushrooms with non-laccase activity. © 2012 The Authors. Microbial Biotechnology © 2012 Society for Applied Microbiology and Blackwell Publishing Ltd.

  8. Purification, characterization and stability of barley grain peroxidase BP1, a new type of plant peroxidase

    DEFF Research Database (Denmark)

    Rasmussen, Christine B; Henriksen, Anette; Abelskov, A. Katrine


    peroxidase isoenzyme C (HRP C). However, when measuring the specific activity of BP 1 at pH 4.0 in the presence of 1 mM CaCl2, the enzyme was as competent as HRP C at neutral pH towards a variety of substrates (mM mg(-1) min(-1)): coniferyl alcohol (930+/-48), caffeic acid (795+/-53), ABTS (2,2(1)-azino...

  9. Incorporation of carbohydrate residues into peroxidase isoenzymes in horseradish roots. (United States)

    Lew, J Y; Shannon, L M


    Sliced root tissue of the horseradish plant (Armoracia rusticana), when incubated with mannose-U-(14)C, incorporated radioactivity into peroxidase isoenzymes. Over 90% of the radioactivity in the highly purified peroxidase isoenzymes was present in the neutral sugar residues of the molecule, i.e. fucose, arabinose, xylose, mannose. When the root slices were incubated simultaneously with leucine-4,5-(3)H and mannose-U-(14)C, cycloheximide strongly inhibited leucine incorporation into the peptide portion of peroxidase isoenzymes but had little effect on the incorporation of (14)C into the neutral sugars. These results indicated that synthesis of the peptide portion of peroxidase was completed before the monosaccharide residues were attached to the molecule. This temporal relationship between the synthesis of protein and the attachment of carbohydrate residues in the plant glycoprotein, horseradish peroxidase, appears to be similar to that reported for glycoprotein biosynthesis in many mammalian systems.

  10. Luffa aegyptiaca (Gourd) Fruit Juice as a Source of Peroxidase. (United States)

    Yadav, R S S; Yadav, K S; Yadav, H S


    Peroxidases have turned out to be potential biocatalyst for a variety of organic reactions. The research work reported in this communication was done with the objective of finding a convenient rich source of peroxidase which could be used as a biocatalyst for organic synthetic reactions. The studies made have shown that Luffa aegyptiaca (gourd) fruit juice contains peroxidase activity of the order of 180 enzyme unit/mL. The K(m) values of this peroxidase for the substrates guaiacol and hydrogen peroxide were 2.0 and 0.2 mM, respectively. The pH and temperature optima were 6.5 and 60°C, respectively. Like other peroxidases, it followed double displacement type mechanism. Sodium azide inhibited the enzyme competitively with K(i) value of 3.35 mM.

  11. Luffa aegyptiaca (Gourd Fruit Juice as a Source of Peroxidase

    Directory of Open Access Journals (Sweden)

    R. S. S. Yadav


    Full Text Available Peroxidases have turned out to be potential biocatalyst for a variety of organic reactions. The research work reported in this communication was done with the objective of finding a convenient rich source of peroxidase which could be used as a biocatalyst for organic synthetic reactions. The studies made have shown that Luffa aegyptiaca (gourd fruit juice contains peroxidase activity of the order of 180 enzyme unit/mL. The Km values of this peroxidase for the substrates guaiacol and hydrogen peroxide were 2.0 and 0.2 mM, respectively. The pH and temperature optima were 6.5 and 60°C, respectively. Like other peroxidases, it followed double displacement type mechanism. Sodium azide inhibited the enzyme competitively with Ki value of 3.35 mM.

  12. Formation of a tyrosine adduct involved in lignin degradation by Trametopsis cervina lignin peroxidase: a novel peroxidase activation mechanism (United States)

    Yuta Miki; Rebecca Pogni; Sandra Acebes; Fatima Lucas; Elena Fernandez-Fueyo; Maria Camilla Baratto; Maria I. Fernandez; Vivian De Los Rios; Francisco J. Ruiz-duenas; Adalgisa Sinicropi; Riccardo Basosi; Kenneth E. Hammel; Victor Guallar; Angel T. Martinez


    LiP (lignin peroxidase) from Trametopsis cervina has an exposed catalytic tyrosine residue (Tyr181) instead of the tryptophan conserved in other lignin-degrading peroxidases. Pristine LiP showed a lag period in VA (veratryl alcohol) oxidation. However, VA-LiP (LiP after treatment with H2O2...

  13. The Use of Gestural Modes to Enhance Expressive Conducting at All Levels of Entering Behavior through the Use of Illustrators, Affect Displays and Regulators (United States)

    Mathers, Andrew


    In this article, I discuss the use of illustrators, affect displays and regulators, which I consider to be non-verbal communication categories through which conductors can employ a more varied approach to body use, gesture and non-verbal communication. These categories employ the use of a conductor's hands and arms, face, eyes and body in a way…

  14. Peroxidase gene expression during tomato fruit ripening

    International Nuclear Information System (INIS)

    Biggs, M.S.; Flurkey, W.H.; Handa, A.K.


    Auxin oxidation has been reported to play a critical role in the initiation of pear fruit ripening and a tomato fruit peroxidase (POD) has been shown to have IAA-oxidase activity. However, little is known about changes in the expression of POD mRNA in tomato fruit development. They are investigating the expression of POD mRNA during tomato fruit maturation. Fruit pericarp tissues from six stages of fruit development and ripening (immature green, mature green, breaker, turning, ripe, and red ripe fruits) were used to extract poly (A) + RNAs. These RNAs were translated in vitro in a rabbit reticulocyte lysate system using L- 35 S-methionine. The 35 S-labeled products were immunoprecipitated with POD antibodies to determine the relative proportions of POD mRNA. High levels of POD mRNA were present in immature green and mature green pericarp, but declined greatly by the turning stage of fruit ripening. In addition, the distribution of POD mRNA on free vs bound polyribosomes will be presented, as well as the presence or absence of POD mRNA in other tomato tissues

  15. Size-dependent tuning of horseradish peroxidase bioreactivity by gold nanoparticles (United States)

    Wu, Haohao; Liu, Yi; Li, Meng; Chong, Yu; Zeng, Mingyong; Lo, Y. Martin; Yin, Jun-Jie


    Molecules with diverse biological functions, such as heme peroxidases, can be useful tools for identifying potential biological effects of gold nanoparticles (AuNPs) at the molecular level. Here, using UV-Vis, circular dichroism, dynamic light scattering, and electron spin resonance spectroscopy, we report tuning of horseradish peroxidase (HRP) bioactivity by reactant-free AuNPs with diameters of 5, 10, 15, 30 and 60 nm (Au-5 nm, Au-10 nm, Au-15 nm, Au-30 nm and Au-60 nm). HRP conjugation to AuNPs was observed with only Au-5 nm and Au-10 nm prominently increasing the α-helicity of the enzyme to extents inversely related to their size. Au-5 nm inhibited both HRP peroxidase activity toward 3,3',5,5'-tetramethylbenzidine and HRP compound I/II reactivity toward 5,5-dimethyl-1-pyrroline N-oxide. Au-5 nm enhanced the HRP peroxidase activity toward ascorbic acid and the HRP compound I/II reactivity toward redox-active residues in the HRP protein moiety. Further, Au-5 nm also decreased the catalase- and oxidase-like activities of HRP. Au-10 nm showed similar, but weaker effects, while Au-15 nm, Au-30 nm and Au-60 nm had no effect. Results suggest that AuNPs can size-dependently enhance or inhibit HRP bioreactivity toward substrates with different redox potentials via a mechanism involving extension of the HRP substrate access channel and decline in the redox potentials of HRP catalytic intermediates.Molecules with diverse biological functions, such as heme peroxidases, can be useful tools for identifying potential biological effects of gold nanoparticles (AuNPs) at the molecular level. Here, using UV-Vis, circular dichroism, dynamic light scattering, and electron spin resonance spectroscopy, we report tuning of horseradish peroxidase (HRP) bioactivity by reactant-free AuNPs with diameters of 5, 10, 15, 30 and 60 nm (Au-5 nm, Au-10 nm, Au-15 nm, Au-30 nm and Au-60 nm). HRP conjugation to AuNPs was observed with only Au-5 nm and Au-10 nm prominently increasing the

  16. Peroxidase-Catalyzed Oxidative Coupling of Phenols in the Presence of Geosorbents

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Qingguo; Weber, Walter J., Jr.


    This study focuses on elucidation of the reaction behaviors of peroxidase-mediated phenol coupling in the presence of soil/sediment materials. Our goal is a mechanistic understanding of the influences of geosorbent materials on enzymatic coupling reactions in general and the development of methods for predicting such influences. Extensive experimental investigations of coupling reactions were performed under strategically selected conditions in systems containing model geosorbents having different properties and chemical characteristics. The geosorbents tested were found to influence peroxidase-mediated phenol coupling through one or both of two principal mechanisms; i.e., (1) mitigation of enzyme inactivation and/or (2) participation in cross-coupling reactions. Such influences were found to correlate with the chemical characteristics of the sorbent materials and to be simulated well by a modeling approach designed in this paper. The results of the study have important implications for potential engineering implementation and enhancement of enzymatic coupling reactions in soil/subsurface remediation practice.

  17. Tetra(p-tolyl)borate-functionalized solvent polymeric membrane: a facile and sensitive sensing platform for peroxidase and peroxidase mimetics. (United States)

    Wang, Xuewei; Qin, Wei


    The determination of peroxidase activities is the basis for enzyme-labeled bioaffinity assays, peroxidase-mimicking DNAzymes- and nanoparticles-based assays, and characterization of the catalytic functions of peroxidase mimetics. Here, a facile, sensitive, and cost-effective solvent polymeric membrane-based peroxidase detection platform is described that utilizes reaction intermediates with different pKa values from those of substrates and final products. Several key but long-debated intermediates in the peroxidative oxidation of o-phenylenediamine (o-PD) have been identified and their charge states have been estimated. By using a solvent polymeric membrane functionalized by an appropriate substituted tetraphenylborate as a receptor, those cationic intermediates could be transferred into the membrane from the aqueous phase to induce a large cationic potential response. Thus, the potentiometric indication of the o-PD oxidation catalyzed by peroxidase or its mimetics can be fulfilled. Horseradish peroxidase has been detected with a detection limit at least two orders of magnitude lower than those obtained by spectrophotometric techniques and traditional membrane-based methods. As an example of peroxidase mimetics, G-quadruplex DNAzymes were probed by the intermediate-sensitive membrane and a label-free thrombin detection protocol was developed based on the catalytic activity of the thrombin-binding G-quadruplex aptamer. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Optical efficiency enhancement in white organic light-emitting diode display with high color gamut using patterned quantum dot film and long pass filter (United States)

    Kim, Hyo-Jun; Shin, Min-Ho; Kim, Young-Joo


    A new structure for white organic light-emitting diode (OLED) displays with a patterned quantum dot (QD) film and a long pass filter (LPF) was proposed and evaluated to realize both a high color gamut and high optical efficiency. Since optical efficiency is a critical parameter in white OLED displays with a high color gamut, a red or green QD film as a color-converting component and an LPF as a light-recycling component are introduced to be adjusted via the characteristics of a color filter (CF). Compared with a conventional white OLED without both a QD film and the LPF, it was confirmed experimentally that the optical powers of red and green light in a new white OLED display were increased by 54.1 and 24.7% using a 30 wt % red QD film and a 20 wt % green QD film with the LPF, respectively. In addition, the white OLED with both a QD film and the LPF resulted in an increase in the color gamut from 98 to 107% (NTSC x,y ratio) due to the narrow emission linewidth of the QDs.

  19. Petunia peroxidase a: isolation, purification and characteristics. (United States)

    Hendriks, T; Wijsman, H J; van Loon, L C


    The fast-moving anionic peroxidase isoenzyme variant PRXa was purified from leaves of petunia (Petunia hybrida). Over 1300-fold purification was achieved by subjecting extracellular extracts to two sequential acetone precipitations and resuspending the pellets at pH 5.0 and pH 8.0, respectively, followed by gel filtration and chromatofocusing. The purified enzyme had an absorbance ratio (A405 nm/A280 nm) of 3.6, a molecular mass of about 37 kDa and a pI of 3.8. Three molecular forms with slightly different molecular masses were separated by concanavalin-A--Sepharose affinity chromatography, indicating that these three forms differ in their carbohydrate moieties. The absorption spectrum of PRXa had maxima at 496 and 636 nm and a Soret band at 405 nm. Spectra of compounds I and IV were obtained by titrating a batch of PRXa stored for several months at -20 degrees C with H2O2. The addition of 1 mol H2O2/mol freshly purified PRXa caused the formation of compound II, indicating that freshly isolated PRXa contains a bound hydrogen donor which is lost upon storage. Compound III was obtained from both preparations in the presence of excess H2O2. The pH optimum of PRXa for the reaction with H2O2 and guaiacol was 5.0 and its specific activity 61 mkat/g protein. Among various aromatic compounds, coniferyl alcohol was polymerized by PRXa to presumed lignin-like material. The extracellular localization and high affinity of PRXa for the cinnamic acid derivatives suggest that this isoenzyme functions in the polymerization or cross-linking of lignin in the plant cell wall.

  20. Apple and quince peroxidase activity in response to essential oils ...

    African Journals Online (AJOL)



    Sep 28, 2011 ... activities of edible coatings enriched with natural plant extracts such as rosemary ..... its oxidation by ascorbate peroxidase activity (Talano et al., 2008). ... delicious and quince improved the antioxidant protection of the fruits ...

  1. Studies of peroxidase isozyme profile in mungbean mutants

    International Nuclear Information System (INIS)

    Auti, S.G.; Apparao, B.J.


    Peroxidase is an important oxygen-scavenging enzyme. The activity of peroxidase is often correlated with growth, development and hormonal activity. Traditional methods of cultivar identification usually involve observation and recording of morphological characters or description such as yield, height, weight, earliness etc. which vary with environmental conditions and often misleading. So molecular markers like protein and isozymes profiles, RFLP, RAPDs markers etc. are widely employed in varietal identification of cultivars. It plays important role in respiration and is an indicator of oxidative status of plants. Electrophoretic techniques have been used to group species and identify cultivars. Such identification has various advantages including the unique pattern of protein or isozymes bands for each pure cultivar under any set of environmental conditions. Peroxidase isozyme serves as very good marker for any mutational studies. In the present investigation, peroxidase isozyme profiles of various mutants of mungbean was studied employing the technique of electrophoresis

  2. Effect of heat treatment on polyphenol oxidase and peroxidase ...

    African Journals Online (AJOL)



    Dec 18, 2006 ... enzymes in plant and its resistance to heat has been reported by a ... sintered glass funnel and washed with cold acetone under low vacuum ... Peroxidase activity was determined by measuring the colour deve- lopment at ...

  3. Cloning and characterization of an ascorbate peroxidase gene ...

    African Journals Online (AJOL)



    May 29, 2012 ... Real-time quantitative polymerase chain reaction was used to explore expression patterns of. MaAPX1 in ... and the activity of a number of enzymatic systems, including ... peroxidase (APX), glutathione reductase and catalase.

  4. Production of manganese peroxidase by white rot fungi from potato ...

    African Journals Online (AJOL)



    Jan 18, 2010 ... production rate of the MnP using the potato-processing wastewater-based medium were higher (ca. 2.5- ... Ligninolytic enzymes, such as manganese peroxidase ... not currently reached industrial levels except for the laccase.

  5. Cell wall bound anionic peroxidases from asparagus byproducts. (United States)

    Jaramillo-Carmona, Sara; López, Sergio; Vazquez-Castilla, Sara; Jimenez-Araujo, Ana; Rodriguez-Arcos, Rocio; Guillen-Bejarano, Rafael


    Asparagus byproducts are a good source of cationic soluble peroxidases (CAP) useful for the bioremediation of phenol-contaminated wastewaters. In this study, cell wall bound peroxidases (POD) from the same byproducts have been purified and characterized. The covalent forms of POD represent >90% of the total cell wall bound POD. Isoelectric focusing showed that whereas the covalent fraction is constituted primarily by anionic isoenzymes, the ionic fraction is a mixture of anionic, neutral, and cationic isoenzymes. Covalently bound peroxidases were purified by means of ion exchange chromatography and affinity chromatography. In vitro detoxification studies showed that although CAP are more effective for the removal of 4-CP and 2,4-DCP, anionic asparagus peroxidase (AAP) is a better option for the removal of hydroxytyrosol (HT), the main phenol present in olive mill wastewaters.

  6. Platelet crossmatch tests using radiolabelled staphylococcal protein A or peroxidase anti-peroxidase in alloimmunised patients

    International Nuclear Information System (INIS)

    Yam, P.; Petz, L.D.; Scott, E.P.; Santos, S.


    Refractoriness to random-donor platelets as a result of alloimmunization remains a major problem in long-term platelet transfusion therapy despite the use of HLA-matched platelets. A study has been made of two methods for detection of platelet associated IgG as platelet crossmatch tests for the selection of platelet donors. These methods use radiolabelled staphylococcal protein A( 125 I-SPA) and peroxidase anti-peroxidase (PAP), respectively. One hundred and ten crossmatch tests using 125 I-SPA were performed retrospectively in 18 alloimmunized patients. The results indicated that the predictive value of a positive or a negative test was 87%; the sensitivity was 73% and the specificity was 95%. Results with the PAP test were similar. The HLA types were known for 48 donor-recipient pairs. With few exceptions, there was a correlation between the results of the platelet crossmatch tests and the effectiveness of platelet transfusion regardless of the degree of HLA match. These results indicate that platelet crossmatch tests may be valuable even when closely HLA matched donors are not available. A large-scale prospective study is warranted, particularly in highly immunized patients. (author)

  7. Seasonal changes of peroxidase and catalase activities in leaves of several arborescent species subject to different industrial air pollutions in Upper Silesia

    Energy Technology Data Exchange (ETDEWEB)

    Raczek, E.; Stolarek, J.


    Year-round investigations of seasonal patterns of peroxidase and catalase activities in leaves of several deciduous and coniferous arborescent species in forests of Upper Silesia subjected to various amounts of industrial gases and dusts were carried out. The samples of leaves of Betula verrucosa EHRH, Quercus robur L., Q. rubra L., Pinus nigra ARNOLD, and P. silvestris L. were collected at different distances from an iron smelting plant. It was found that raising level of the pollution enhances peroxidase activity in leaves and needles. The induction of peroxidase activity by pollutants exhibited seasonal changes specific for the species and was subjected to the effect of temperature of the environment and was also related to the natural resistivity of a given species. In contrast to peroxidase, the patterns of catalase activity changes did not appear to be specifically influenced by industrial air pollutants. 22 references, 5 figures, 4 tables.

  8. Structure of soybean seed coat peroxidase: a plant peroxidase with unusual stability and haem-apoprotein interactions

    DEFF Research Database (Denmark)

    Henriksen, A; Mirza, O; Indiani, C


    Soybean seed coat peroxidase (SBP) is a peroxidase with extraordinary stability and catalytic properties. It belongs to the family of class III plant peroxidases that can oxidize a wide variety of organic and inorganic substrates using hydrogen peroxide. Because the plant enzyme is a heterogeneous...... glycoprotein, SBP was produced recombinant in Escherichia coli for the present crystallographic study. The three-dimensional structure of SBP shows a bound tris(hydroxymethyl)aminomethane molecule (TRIS). This TRIS molecule has hydrogen bonds to active site residues corresponding to the residues that interact...... with the small phenolic substrate ferulic acid in the horseradish peroxidase C (HRPC):ferulic acid complex. TRIS is positioned in what has been described as a secondary substrate-binding site in HRPC, and the structure of the SBP:TRIS complex indicates that this secondary substrate-binding site could...

  9. Development of data enhancement and display techniques for stream-sediment data collected in the national uranium resource evaluation program of the United States Department of Energy

    International Nuclear Information System (INIS)

    Koch, G.S. Jr.; Howarth, R.J.; Carpenter, R.H.; Schuenemeyer, J.H.


    The objective of this study was to combine statistical, mapping, and geological techniques in order to evaluate and appropriately display geochemical data for the identification of uranium associated halos utilizing the NURE hydrogeochemical and stream sediment reconnaissance data base. A set of computer-based procedures implemented in a time-sharing interactive mode on a Control Data Corporation Cyber 70 and 174 computer was developed. Techniques of data analysis are developed. Results of the data analysis for the Southeastern area, Seguin quadrangle, and Pueblo quadrangle are presented. Conclusions are drawn and recommendations are stated

  10. Optimization of lignin peroxidase, manganese peroxidase, and Lac production from Ganoderma lucidum under solid state fermentation of pineapple leaf


    Sudha Hariharan; Padma Nambisan


    This study was undertaken to isolate ligninase-producing white-rot fungi for use in the extraction of fibre from pineapple leaf agriwaste. Fifteen fungal strains were isolated from dead tree trunks and leaf litter. Ligninolytic enzymes (lignin peroxidase (LiP), manganese peroxidase (MnP), and laccase (Lac)), were produced by solid-state fermentation (SSF) using pineapple leaves as the substrate. Of the isolated strains, the one showing maximum production of ligninolytic enzymes was identified...

  11. Photosynthetic pigments and peroxidase activity of Lepidium sativum L. during assisted Hg phytoextraction. (United States)

    Smolinska, Beata; Leszczynska, Joanna


    The study was conducted to evaluate metabolic answer of Lepidium sativum L. on Hg, compost, and citric acid during assisted phytoextraction. The chlorophyll a and b contents, total carotenoids, and activity of peroxidase were determined in plants exposed to Hg and soil amendments. Hg accumulation in plant shoots was also investigated. The pot experiments were provided in soil artificially contaminated by Hg and/or supplemented with compost and citric acid. Hg concentration in plant shoots and soil substrates was determined by cold vapor atomic absorption spectroscopy (CV-AAS) method after acid mineralization. The plant photosynthetic pigments and peroxidase activity were measured by standard spectrophotometric methods. The study shows that L. sativum L. accumulated Hg in its aerial tissues. An increase in Hg accumulation was noticed when soil was supplemented with compost and citric acid. Increasing Hg concentration in plant shoots was correlated with enhanced activation of peroxidase activity and changes in total carotenoid concentration. Combined use of compost and citric acid also decreased the chlorophyll a and b contents in plant leaves. Presented study reveals that L. sativum L. is capable of tolerating Hg and its use during phytoextraction assisted by combined use of compost and citric acid lead to decreasing soil contamination by Hg.

  12. Facile synthesis of enzyme-embedded magnetic metal-organic frameworks as a reusable mimic multi-enzyme system: mimetic peroxidase properties and colorimetric sensor. (United States)

    Hou, Chen; Wang, Yang; Ding, Qinghua; Jiang, Long; Li, Ming; Zhu, Weiwei; Pan, Duo; Zhu, Hao; Liu, Mingzhu


    This work reports a facile and easily-achieved approach for enzyme immobilization by embedding glucose oxidase (GOx) in magnetic zeolitic imidazolate framework 8 (mZIF-8) via a de novo approach. As a demonstration of the power of such materials, the resulting GOx embedded mZIF-8 (mZIF-8@GOx) was utilized as a colorimetric sensor for rapid detection of glucose. This method was constructed on the basis of metal-organic frameworks (MOFs), which possessed very fascinating peroxidase-like properties, and the cascade reaction for the visual detection of glucose was combined into one step through the mZIF-8@GOx based mimic multi-enzyme system. After characterization by electron microscopy, X-ray diffraction, nitrogen sorption, fourier transform infrared spectroscopy and vibrating sample magnetometry, the as-prepared mZIF-8@GOx was confirmed with the robust core-shell structure, the monodisperse nanoparticle had an average diameter of about 200 nm and displayed superparamagnetism with a saturation magnetization value of 40.5 emu g(-1), it also exhibited a large surface area of 396.10 m(2) g(-1). As a peroxidase mimic, mZIF-8 was verified to be highly stable and of low cost, and showed a strong affinity towards H2O2. Meanwhile, the mZIF-8 embedded GOx also exhibited improved activity, stability and greatly enhanced selectivity in glucose detection. Moreover, the mZIF-8@GOx had excellent recyclability with high activity (88.7% residual activity after 12 times reuse).

  13. Improving the oxidative stability of a high redox potential fungal peroxidase by rational design. (United States)

    Sáez-Jiménez, Verónica; Acebes, Sandra; Guallar, Victor; Martínez, Angel T; Ruiz-Dueñas, Francisco J


    Ligninolytic peroxidases are enzymes of biotechnological interest due to their ability to oxidize high redox potential aromatic compounds, including the recalcitrant lignin polymer. However, different obstacles prevent their use in industrial and environmental applications, including low stability towards their natural oxidizing-substrate H2O2. In this work, versatile peroxidase was taken as a model ligninolytic peroxidase, its oxidative inactivation by H2O2 was studied and different strategies were evaluated with the aim of improving H2O2 stability. Oxidation of the methionine residues was produced during enzyme inactivation by H2O2 excess. Substitution of these residues, located near the heme cofactor and the catalytic tryptophan, rendered a variant with a 7.8-fold decreased oxidative inactivation rate. A second strategy consisted in mutating two residues (Thr45 and Ile103) near the catalytic distal histidine with the aim of modifying the reactivity of the enzyme with H2O2. The T45A/I103T variant showed a 2.9-fold slower reaction rate with H2O2 and 2.8-fold enhanced oxidative stability. Finally, both strategies were combined in the T45A/I103T/M152F/M262F/M265L variant, whose stability in the presence of H2O2 was improved 11.7-fold. This variant showed an increased half-life, over 30 min compared with 3.4 min of the native enzyme, under an excess of 2000 equivalents of H2O2. Interestingly, the stability improvement achieved was related with slower formation, subsequent stabilization and slower bleaching of the enzyme Compound III, a peroxidase intermediate that is not part of the catalytic cycle and leads to the inactivation of the enzyme.

  14. Improving the oxidative stability of a high redox potential fungal peroxidase by rational design.

    Directory of Open Access Journals (Sweden)

    Verónica Sáez-Jiménez

    Full Text Available Ligninolytic peroxidases are enzymes of biotechnological interest due to their ability to oxidize high redox potential aromatic compounds, including the recalcitrant lignin polymer. However, different obstacles prevent their use in industrial and environmental applications, including low stability towards their natural oxidizing-substrate H2O2. In this work, versatile peroxidase was taken as a model ligninolytic peroxidase, its oxidative inactivation by H2O2 was studied and different strategies were evaluated with the aim of improving H2O2 stability. Oxidation of the methionine residues was produced during enzyme inactivation by H2O2 excess. Substitution of these residues, located near the heme cofactor and the catalytic tryptophan, rendered a variant with a 7.8-fold decreased oxidative inactivation rate. A second strategy consisted in mutating two residues (Thr45 and Ile103 near the catalytic distal histidine with the aim of modifying the reactivity of the enzyme with H2O2. The T45A/I103T variant showed a 2.9-fold slower reaction rate with H2O2 and 2.8-fold enhanced oxidative stability. Finally, both strategies were combined in the T45A/I103T/M152F/M262F/M265L variant, whose stability in the presence of H2O2 was improved 11.7-fold. This variant showed an increased half-life, over 30 min compared with 3.4 min of the native enzyme, under an excess of 2000 equivalents of H2O2. Interestingly, the stability improvement achieved was related with slower formation, subsequent stabilization and slower bleaching of the enzyme Compound III, a peroxidase intermediate that is not part of the catalytic cycle and leads to the inactivation of the enzyme.

  15. Invisible Display in Aluminum

    DEFF Research Database (Denmark)

    Prichystal, Jan Phuklin; Hansen, Hans Nørgaard; Bladt, Henrik Henriksen


    Bang & Olufsen a/s has been working with ideas for invisible integration of displays in metal surfaces. Invisible integration of information displays traditionally has been possible by placing displays behind transparent or semitransparent materials such as plastic or glass. The wish for an integ......Bang & Olufsen a/s has been working with ideas for invisible integration of displays in metal surfaces. Invisible integration of information displays traditionally has been possible by placing displays behind transparent or semitransparent materials such as plastic or glass. The wish...... for an integrated display in a metal surface is often ruled by design and functionality of a product. The integration of displays in metal surfaces requires metal removal in order to clear the area of the display to some extent. The idea behind an invisible display in Aluminum concerns the processing of a metal...

  16. X-Windows Widget for Image Display (United States)

    Deen, Robert G.


    XvicImage is a high-performance XWindows (Motif-compliant) user interface widget for displaying images. It handles all aspects of low-level image display. The fully Motif-compliant image display widget handles the following tasks: (1) Image display, including dithering as needed (2) Zoom (3) Pan (4) Stretch (contrast enhancement, via lookup table) (5) Display of single-band or color data (6) Display of non-byte data (ints, floats) (7) Pseudocolor display (8) Full overlay support (drawing graphics on image) (9) Mouse-based panning (10) Cursor handling, shaping, and planting (disconnecting cursor from mouse) (11) Support for all user interaction events (passed to application) (12) Background loading and display of images (doesn't freeze the GUI) (13) Tiling of images.

  17. Immune Escape Variants of H9N2 Influenza Viruses Containing Deletions at the Hemagglutinin Receptor Binding Site Retain Fitness In Vivo and Display Enhanced Zoonotic Characteristics. (United States)

    Peacock, Thomas P; Benton, Donald J; James, Joe; Sadeyen, Jean-Remy; Chang, Pengxiang; Sealy, Joshua E; Bryant, Juliet E; Martin, Stephen R; Shelton, Holly; Barclay, Wendy S; Iqbal, Munir


    H9N2 avian influenza viruses are enzootic in poultry across Asia and North Africa, where they pose a threat to human health as both zoonotic agents and potential pandemic candidates. Poultry vaccination against H9N2 viruses has been employed in many regions; however, vaccine effectiveness is frequently compromised due to antigenic drift arising from amino acid substitutions in the major influenza virus antigen hemagglutinin (HA). Using selection with HA-specific monoclonal antibodies, we previously identified H9N2 antibody escape mutants that contained deletions of amino acids in the 220 loop of the HA receptor binding sites (RBSs). Here we analyzed the impact of these deletions on virus zoonotic infection characteristics and fitness. We demonstrated that mutant viruses with RBS deletions are able to escape polyclonal antiserum binding and are able to infect and be transmitted between chickens. We showed that the deletion mutants have increased binding to human-like receptors and greater replication in primary human airway cells; however, the mutant HAs also displayed reduced pH and thermal stability. In summary, we infer that variant influenza viruses with deletions in the 220 loop could arise in the field due to immune selection pressure; however, due to reduced HA stability, we conclude that these viruses are unlikely to be transmitted from human to human by the airborne route, a prerequisite for pandemic emergence. Our findings underscore the complex interplay between antigenic drift and viral fitness for avian influenza viruses as well as the challenges of predicting which viral variants may pose the greatest threats for zoonotic and pandemic emergence. IMPORTANCE Avian influenza viruses, such as H9N2, cause disease in poultry as well as occasionally infecting humans and are therefore considered viruses with pandemic potential. Many countries have introduced vaccination of poultry to try to control the disease burden; however, influenza viruses are able to

  18. Enhancing the color gamut of white displays using novel deep-blue organic fluorescent dyes to form color-changed thin films with improved efficiency (United States)

    Liu, Wei-Ting; Huang, Wen-Yao


    This study used the novel fluorescence based deep-blue-emitting molecule BPVPDA in an organic fluorescent color thin film to exhibit deep blue color with CIE coordinates of (0.13, 0.16). The developed original organic RGB color thin film technology enables the optimization of the distinctive features of an organic light emitting diode (OLED) and thin-film-transistor (TFT) LCD display. The color filter structure maintains the same high resolution to obtain a higher level of brightness in comparison with conventional organic RGB color thin film. The image-processing engine is designed to achieve a sharp text image for a TFT LCD with organic color thin films. The organic color thin films structure uses an organic dye dopant in a limpid photoresist. With this technology, the following characteristics can be obtained: 1. high color reproduction of gamut ratio, and 2. improved luminous efficiency with organic color fluorescent thin film. This performance is among the best results ever reported for a color-filter used on TFT-LCD or OLED.

  19. Oxidation of eugenol by purified human term placental peroxidase. (United States)

    Zhang, R; Kulkarni, K A; Kulkarni, A P


    The oxidation of eugenol by purified human term placental peroxidase (HTPP) was examined. Spectral analyses indicated that, similar to horseradish peroxidase, HTPP is capable of catalyzing the oxidation of eugenol. The accumulated stable product in the reaction medium due to eugenol oxidation by HTPP was tentatively identified as quinone methide of eugenol (EQM). The EQM formation exhibited a pH optimum of 8.0 and was dependent on incubation time, amount of HTPP and the concentration of both eugenol and hydrogen peroxide. The specific activity of approx 2.8 micromoles of EQM/min/mg protein was observed with different preparations of HTPP. The EQM formation was significantly suppressed by glutathione and ascorbic acid. The classical peroxidase inhibitors viz. potassium cyanide and sodium azide blocked the reaction in a concentration manner. Collectively, the results suggest that eugenol may undergo peroxidative metabolism in human placenta. Copyright 2000 Harcourt Publishers Ltd.

  20. European display scene (United States)

    Bartlett, Christopher T.


    The manufacture of Flat Panel Displays (FPDs) is dominated by Far Eastern sources, particularly in Active Matrix Liquid Crystal Displays (AMLCD) and Plasma. The United States has a very powerful capability in micro-displays. It is not well known that Europe has a very active research capability which has lead to many innovations in display technology. In addition there is a capability in display manufacturing of organic technologies as well as the licensed build of Japanese or Korean designs. Finally, Europe has a display systems capability in military products which is world class.

  1. Handbook of display technology

    CERN Document Server

    Castellano, Joseph A


    This book presents a comprehensive review of technical and commercial aspects of display technology. It provides design engineers with the information needed to select proper technology for new products. The book focuses on flat, thin displays such as light-emitting diodes, plasma display panels, and liquid crystal displays, but it also includes material on cathode ray tubes. Displays include a large number of products from televisions, auto dashboards, radios, and household appliances, to gasoline pumps, heart monitors, microwave ovens, and more.For more information on display tech

  2. The cDNA sequence of a neutral horseradish peroxidase. (United States)

    Bartonek-Roxå, E; Eriksson, H; Mattiasson, B


    A cDNA clone encoding a horseradish (Armoracia rusticana) peroxidase has been isolated and characterized. The cDNA contains 1378 nucleotides excluding the poly(A) tail and the deduced protein contains 327 amino acids which includes a 28 amino acid leader sequence. The predicted amino acid sequence is nine amino acids shorter than the major isoenzyme belonging to the horseradish peroxidase C group (HRP-C) and the sequence shows 53.7% identity with this isoenzyme. The described clone encodes nine cysteines of which eight correspond well with the cysteines found in HRP-C. Five potential N-glycosylation sites with the general sequence Asn-X-Thr/Ser are present in the deduced sequence. Compared to the earlier described HRP-C this is three glycosylation sites less. The shorter sequence and fewer N-glycosylation sites give the native isoenzyme a molecular weight of several thousands less than the horseradish peroxidase C isoenzymes. Comparison with the net charge value of HRP-C indicates that the described cDNA clone encodes a peroxidase which has either the same or a slightly less basic pI value, depending on whether the encoded protein is N-terminally blocked or not. This excludes the possibility that HRP-n could belong to either the HRP-A, -D or -E groups. The low sequence identity (53.7%) with HRP-C indicates that the described clone does not belong to the HRP-C isoenzyme group and comparison of the total amino acid composition with the HRP-B group does not place the described clone within this isoenzyme group. Our conclusion is that the described cDNA clone encodes a neutral horseradish peroxidase which belongs to a new, not earlier described, horseradish peroxidase group.

  3. RUN1 and REN1 Pyramiding in Grapevine (Vitis vinifera cv. Crimson Seedless) Displays an Improved Defense Response Leading to Enhanced Resistance to Powdery Mildew (Erysiphe necator) (United States)

    Agurto, Mario; Schlechter, Rudolf O.; Armijo, Grace; Solano, Esteban; Serrano, Carolina; Contreras, Rodrigo A.; Zúñiga, Gustavo E.; Arce-Johnson, Patricio


    Fungal pathogens are the cause of the most common diseases in grapevine and among them powdery mildew represents a major focus for disease management. Different strategies for introgression of resistance in grapevine are currently undertaken in breeding programs. For example, introgression of several resistance genes (R) from different sources for making it more durable and also strengthening the plant defense response. Taking this into account, we cross-pollinated P09-105/34, a grapevine plant carrying both RUN1 and REN1 pyramided loci of resistance to Erysiphe necator inherited from a pseudo-backcrossing scheme with Muscadinia rotundifolia and Vitis vinifera ‘Dzhandzhal Kara,’ respectively, with the susceptible commercial table grape cv. ‘Crimson Seedless.’ We developed RUN1REN1 resistant genotypes through conventional breeding and identified them by marker assisted selection. The characterization of defense response showed a highly effective defense mechanism against powdery mildew in these plants. Our results reveal that RUN1REN1 grapevine plants display a robust defense response against E. necator, leading to unsuccessful fungal establishment with low penetration rate and poor hypha development. This resistance mechanism includes reactive oxygen species production, callose accumulation, programmed cell death induction and mainly VvSTS36 and VvPEN1 gene activation. RUN1REN1 plants have a great potential as new table grape cultivars with durable complete resistance to E. necator, and are valuable germplasm to be included in grape breeding programs to continue pyramiding with other sources of resistance to grapevine diseases. PMID:28553300

  4. Peroxidase activity in Spondias dulcis = Atividade da peroxidase em Spondias dulcis

    Directory of Open Access Journals (Sweden)

    Lúcio Cardozo-Filho


    Full Text Available In this study, the best conditions to obtain crude extracts showingPeroxidase activity from Spondia dulcis (caja-mango were evaluated. Fresh fruits (25 g were blended in different sodium phosphate buffer (0.05 to 0.2 M with a pH varying from 3.0 to 9.0. The muddy material was centrifuged for 20 minutes. In order to improve POD activity, the crude extract was submitted to precipitation with ammonium sulfate at 90% saturation. This precipitated was re-suspended in sodium phosphate buffer 0.2 M pH 6.5 and then, optimum pH for activity assay (pH varying from 5.0 to 9.0 and thermal stability (exposure to different temperatures varying from 30 to 75ºC for periods between 0 to 15 minutes were determined. The best conditions for activity assay were in phosphate buffer 0.2 M at pH7.0. The results obtained for thermal inactivation study suggest that the heating at 75ºCfor 15 minutes inactivated 95% of initial POD activity.Foram avaliadas, neste trabalho, algumas condições para a obtenção de extratos brutos com atividade peroxidase de Spondias dulcis (cajá-manga. Frutas frescas (25 g foram trituradas com tampão fosfato de sódio (0,05 a 0,2 M em pHs diferentes (3,0 a 9,0. O material obtido foi centrifugado por 20 min. O extrato bruto foi submetido à precipitação com sulfato de amônio até 90% de saturação. Este precipitado foi ressuspenso em tampão fosfato de sódio 0,2 M pH 6,5 e, assim, o pH ótimo para o ensaio de atividade (pH que varia de 5,0 a 9,0 e a estabilidade térmica (exposição a temperaturas de 30, 60, 65, 70 e 75ºC por um período de 0 a 15 min. deste foram determinados. As melhores condições encontradas para o ensaio de atividade foram em tampão fosfato 0,2 M pH 7,0. Os resultados para a inativação térmica sugerem que o aquecimento a 75ºC por 15 mininativa 95% da atividade de POD inicial.

  5. A Compressive Superresolution Display

    KAUST Repository

    Heide, Felix; Gregson, James; Wetzstein, Gordon; Raskar, Ramesh; Heidrich, Wolfgang


    In this paper, we introduce a new compressive display architecture for superresolution image presentation that exploits co-design of the optical device configuration and compressive computation. Our display allows for superresolution, HDR, or glasses-free 3D presentation.

  6. A Compressive Superresolution Display

    KAUST Repository

    Heide, Felix


    In this paper, we introduce a new compressive display architecture for superresolution image presentation that exploits co-design of the optical device configuration and compressive computation. Our display allows for superresolution, HDR, or glasses-free 3D presentation.

  7. Arabidopsis ATP A2 peroxidase. Expression and high-resolution structure of a plant peroxidase with implications for lignification

    DEFF Research Database (Denmark)

    Ostergaard, L; Teilum, K; Mirza, O


    Lignins are phenolic biopolymers synthesized by terrestrial, vascular plants for mechanical support and in response to pathogen attack. Peroxidases have been proposed to catalyse the dehydrogenative polymerization of monolignols into lignins, although no specific isoenzyme has been shown...... to be involved in lignin biosynthesis. Recently we isolated an extracellular anionic peroxidase, ATP A2, from rapidly lignifying Arabidopsis cell suspension culture and cloned its cDNA. Here we show that the Atp A2 promoter directs GUS reporter gene expression in lignified tissues of transgenic plants. Moreover......-coumaryl and coniferyl alcohols are preferred by ATP A2, while the oxidation of sinapyl alcohol will be sterically hindered in ATP A2 as well as in all other plant peroxidases due to an overlap with the conserved Pro-139. We suggest ATP A2 is involved in a complex regulation of the covalent cross-linking in the plant...

  8. Breast Cancer Cells in Three-dimensional Culture Display an Enhanced Radioresponse after Coordinate Targeting of Integrin ?5?1 and Fibronectin

    Energy Technology Data Exchange (ETDEWEB)

    Nam, Jin-Min; Onodera, Yasuhito; Bissell, Mina J; Park, Catherine C


    Tactics to selectively enhance cancer radioresponse are of great interest. Cancer cells actively elaborate and remodel their extracellular matrix (ECM) to aid in survival and progression. Previous work has shown that {beta}1-integrin inhibitory antibodies can enhance the growth-inhibitory and apoptotic responses of human breast cancer cell lines to ionizing radiation, either when cells are cultured in three-dimensional laminin-rich ECM (3D lrECM) or grown as xenografts in mice. Here, we show that a specific {alpha} heterodimer of {beta}1-integrin preferentially mediates a prosurvival signal in human breast cancer cells that can be specifically targeted for therapy. 3D lrECM culture conditions were used to compare {alpha}-integrin heterodimer expression in malignant and nonmalignant cell lines. Under these conditions, we found that expression of {alpha}5{beta}1-integrin was upregulated in malignant cells compared with nonmalignant breast cells. Similarly, we found that normal and oncofetal splice variants of fibronectin, the primary ECM ligand of {alpha}5{beta}1-integrin, were also strikingly upregulated in malignant cell lines compared with nonmalignant acini. Cell treatment with a peptide that disrupts the interactions of {alpha}5{beta}1-integrin with fibronectin promoted apoptosis in malignant cells and further heightened the apoptotic effects of radiation. In support of these results, an analysis of gene expression array data from breast cancer patients revealed an association of high levels of {alpha}5-integrin expression with decreased survival. Our findings offer preclinical validation of fibronectin and {alpha}5{beta}1-integrin as targets for breast cancer therapy.

  9. Liquid crystal display

    International Nuclear Information System (INIS)

    Takami, K.


    An improved liquid crystal display device is described which can display letters, numerals and other necessary patterns in the night time using a minimized amount of radioactive material. To achieve this a self-luminous light source is placed in a limited region corresponding to a specific display area. (U.K.)

  10. Inecalcitol, an analog of 1,25D₃, displays enhanced antitumor activity through the induction of apoptosis in a squamous cell carcinoma model system (United States)

    Ma, Yingyu; Yu, Wei-Dong; Hidalgo, Alejandro A.; Luo, Wei; Delansorne, Remi; Johnson, Candace S.; Trump, Donald L.


    Epidemiological data suggest an important role of vitamin D signaling in cancer development and progression, and experimental studies demonstrate that the active vitamin D metabolite 1α, 25-dihydroxyvitamin D₃ (1,25D₃) has broad spectrum antitumor activity. Hypercalcemia has often been suggested to limit the clinical application of these data. The 14-epi-analog of 1,25D₃, inecalcitol [19-nor-14-epi-23-yne-1,25-(OH)₂D₃; TX522], was developed to have superagonistic antitumor activities but low hypercalcemia potential. We examined the antitumor activity of inecalcitol and the underlying mechanisms in a murine squamous cell carcinoma (SCC) model system. In vitro, compared with 1,25D₃, inecalcitol showed enhanced vitamin D receptor (VDR)-mediated transcriptional activity. Inecalcitol suppressed SCC cell proliferation in a dose-dependent manner with an IC₅₀ value 30 times lower than that of 1,25D₃. Both inecalcitol and 1,25D₃ induced a comparable level of G₀/G₁ cell cycle arrest in SCC cells. The level of apoptosis induced by inecalcitol was markedly higher than that of 1,25D₃. Apoptosis was mediated through the activation of the caspase 8/10- caspase 3 pathway. Further, inecalcitol markedly inhibited the mRNA and protein expression of c-IAP1 and XIAP compared with 1,25D₃. In vivo, inecalcitol inhibits SCC tumor growth in a dose-dependent fashion. Notably, inecalcitol induced a significantly higher level of apoptosis in the SCC xenograft model. While in vitro inecalcitol demonstrates apparent enhanced VDR binding and antiproliferative effects compared to 1,25D₃, in vivo these advantages disappear; at doses of inecalcitol that have equivalent antitumor effects, similar hypercalcemia is seen. This may be explained by the pharmacokinetics of 1,25D₃ vs. inecalcitol and attributed to the much shorter serum half-life of inecalcitol.We show that inecalcitol has potent antitumor activity in the SCC model system, and this is associated with a

  11. Liquid Crystal Airborne Display (United States)


    Cum.nings, J. P., et al., Properties and Limitations oe Liquid Crystals for Aircraft Displays, Honeywell Corporate Researc ."I Center, Final Report HR-72...basic module could be used to build displays for both the commercial and military! 157- marhecs, and so would establi sh a broad and sizable market ... market for the display becomes a reality; therein lies, f TABLE 16 THE COURSE OF FUTURE DISPLAY DEVELOPMENT Today 1976-77 1980 1985 Display Size 2" 1 3.2

  12. Direct electrochemistry and electrocatalysis of horseradish peroxidase based on halloysite nanotubes/chitosan nanocomposite film

    Energy Technology Data Exchange (ETDEWEB)

    Sun Xiumei; Zhang Yao; Shen Hebai [Department of Chemistry, College of Life and Environmental Sciences, Shanghai Normal University, 100 Guilin Road, Shanghai 200234 (China); Jia Nengqin, E-mail: [Department of Chemistry, College of Life and Environmental Sciences, Shanghai Normal University, 100 Guilin Road, Shanghai 200234 (China)


    The novel halloysite nanotubes/chitosan (HNTs/Chi) composite films were firstly explored to utilize for the immobilization of horseradish peroxidase (HRP) and their bioelectrochemical properties were studied, in which the biopolymer chitosan was used as a binder to increase film adherence on glassy carbon (GC) electrode. UV-vis and FTIR spectroscopy demonstrated that HRP in the composite film could retain its native secondary structure. A pair of well-defined redox peaks of HRP was obtained at the HRP/HNTs/Chi composite film-modified electrode, exhibiting its fast direct electron transfer (DET). Furthermore, the immobilized HRP displayed its good electrocatalytic activity for the reduction of hydrogen peroxide (H{sub 2}O{sub 2}). The results demonstrate that the HNTs/Chi composite film may improve the enzyme loading with the retention of bioactivity and greatly promote the direct electron transfer, which can be attributed to its unique tubular structure, high specific surface area, and good biocompatibility.

  13. Cross reactivities of rabbit anti-chicken horse radish peroxidase ...

    African Journals Online (AJOL)

    The cross reactivities of rabbit anti chicken horse radish peroxidase (conjugate) was tested with sera of Chicken, Ducks, Geese, Guinea fowl, Hawks, Pigeons and Turkeys in indirect enzyme linked immunosorbent assay (ELISA) technique. Sera from mammalian species (Bat, Equine and swine) were used as negative ...

  14. The glucose oxidase-peroxidase assay for glucose (United States)

    The glucose oxidase-peroxidase assay for glucose has served as a very specific, sensitive, and repeatable assay for detection of glucose in biological samples. It has been used successfully for analysis of glucose in samples from blood and urine, to analysis of glucose released from starch or glycog...

  15. Calorimetric studies of the thermal denaturation of cytochrome c peroxidase

    International Nuclear Information System (INIS)

    Kresheck, G.C.; Erman, J.E.


    Two endotherms are observed by differential scanning calorimetry during the thermal denaturation of cytochrome c peroxidase at pH 7.0. The transition midpoint temperatures (t/sub m/) were 43.9 +- 1.4 and 63.3 +- 1.6 0 C, independent of concentration. The two endotherms were observed at all pH values between 4 and 8, with the transition temperatures varying with pH. Precipitation was observed between pH 4 and 6, and only qualitative data are presented for this region. The thermal unfolding of cytochrome c peroxidase was sensitive to the presence and ligation state of the heme. Only a single endotherm was observed for the unfolding of the apoprotein, and this transition was similar to the high-temperature transition in the holoenzyme. Addition of KCN to the holoenzyme increases the midpoint of the high-temperature transition whereas the low-temperature transition was increased upon addition of KF. Binding of the natural substrate ferricytochrome c to the enzyme increases the low-temperature transition by 4.8 +- 1.3 0 C but has no effect on the high-temperature transition at pH 7. The presence of cytochrome c peroxidase decreases the stability of cytochrome c, and both proteins appear to unfold simultaneously. The results are discussed in terms of the two domains evident in the X-ray crystallographic structure of cytochrome c peroxidase

  16. Hepatic and erythrocytic glutathione peroxidase activity in liver diseases. (United States)

    Cordero, R; Ortiz, A; Hernández, R; López, V; Gómez, M M; Mena, P


    Hepatic and erythrocytic glutathione peroxidase activity, together with malondialdehyde levels, were determined as indicators of peroxidation in 83 patients from whom liver biopsies had been taken for diagnostic purposes. On histological study, the patients were classified into groups as minimal changes (including normal liver), steatosis, alcoholic hepatitis, hepatic cirrhosis, light to moderately active chronic hepatitis, and severe chronic active hepatitis. The glutathione peroxidase activity in erythrocytes showed no significant changes in any liver disease group. In the hepatic study, an increased activity was observed in steatosis with respect to the minimal changes group, this increased activity induced by the toxic agent in the initial stages of the alcoholic hepatic disease declining as the hepatic damage progressed. There was a negative correlation between the levels of hepatic malondialdehyde and hepatic glutathione peroxidase in subjects with minimal changes. This suggested the existence of an oxidative equilibrium in this group. This equilibrium is broken in the liver disease groups as was manifest in a positive correlation between malondialdehyde and glutathione peroxidase activity.

  17. Polyamines, peroxidase and proteins involved in the senescence ...

    African Journals Online (AJOL)

    Senescence is the natural aging process at the cellular level or range of phenomena associated with this process. The objective of this review was to show the involvement of substances that may be related to senescence in plants, such as polyamines, peroxidase and proteins. These substances were related with the ...

  18. Glutathione peroxidases of the potato cyst nematode Globodera Rostochiensis

    NARCIS (Netherlands)

    Jones, J.T.; Reavy, B.; Smant, G.; Prior, A.E.


    We report the cloning and characterisation of full-length DNAs complementary to RNA (cDNAs) encoding two glutathione peroxidases (GpXs) from a plant parasitic nematode, the potato cyst nematode (PCN) Globodera rostochiensis. One protein has a functional signal peptide that targets the protein for

  19. Expression, purification and characterization of a peroxidase from ...

    African Journals Online (AJOL)



    Jan 24, 2012 ... from a cDNA library, which was generated from root tissue of Tamarix hispida that was exposed to ... enzymes, peroxidase (POD) plays an important role in .... ThPOD1 protein under various conditions, 3 month old T. hispida.

  20. Decolourization of Direct Blue 2 by peroxidases obtained from an ...

    African Journals Online (AJOL)

    Also, an increase in toxicity, determined by Vibrio fisheri, was observed after the enzymatic oxidation of the dye. Results suggest that the oxidation of DB2 with peroxidases can be recommended as a pretreatment step before a conventional treatment process. Keywords: decolourization, Direct Blue 2, industrial waste, ...

  1. Molecular cloning and characterization of a new peroxidase gene ...

    African Journals Online (AJOL)

    length cDNA of O.violaceus peroxidase gene (OvRCI, GenBank. Acc. No. AY428037) was 1220 bp and contained an 1128 bp open reading frame encoding a protein of 375 amino acids. Homology analysis and molecular modeling revealed that ...

  2. Towards uncovering the roles of switchgrass peroxidases in plant processes

    Directory of Open Access Journals (Sweden)

    Aaron eSaathoff


    Full Text Available Herbaceous perennial plants selected as potential biofuel feedstocks had been understudied at the genomic and functional genomic levels. Recent investments, primarily by the U.S. Department of Energy, have led to the development of a number of molecular resources for bioenergy grasses, such as the partially annotated genome for switchgrass (Panicum virgatum L., and some related diploid species. In its current version, the switchgrass genome contains 65,878 gene models arising from the A and B genomes of this tetraploid grass. The availability of these gene sequences provides a framework to exploit transcriptomic data obtained from next generation sequencing platforms to address questions of biological importance. One such question pertains to discovery of genes and proteins important for biotic and abiotic stress responses, and how these components might affect biomass quality and stress response in plants engineered for a specific end purpose. It can be expected that production of switchgrass on marginal lands will expose plants to diverse stresses, including herbivory by insects. Class III plant peroxidases have been implicated in many developmental responses such as lignification and in the adaptive responses of plants to insect feeding. Here, we have analyzed the class III peroxidases encoded by the switchgrass genome, and have mined available transcriptomic datasets to develop a first understanding of the expression profiles of the class III peroxidases in different plant tissues. Lastly, we have identified switchgrass peroxidases that appear to be orthologs of enzymes shown to play key roles in lignification and plant defense responses to hemipterans.

  3. Isolation of an ascorbate peroxidase in Brassica napus and analysis ...

    African Journals Online (AJOL)



    Apr 5, 2010 ... domain; APX, ascorbate peroxidase; Bn-APX, Brassica napus ascorbate ... Brassica napus, which is widely grown as the oilseed crop of rape or canola, .... grew on the SD-Leu-Trp-His-Ade medium and were verified by PCR.

  4. Effect of heat treatment on polyphenol oxidase and peroxidase ...

    African Journals Online (AJOL)

    Effect of heat treatment (55°C/20 min) on polyphenol oxidase (PPO) and peroxidase (POD) activities and total phenolic compounds was investigated in Algerian dates (Deglet Nour variety) at Tamar (fully ripe) stage and in dates stored for 5 months at ambient temperature and in cold storage (10°C). Results obtained ...

  5. 21 CFR 864.7675 - Leukocyte peroxidase test. (United States)


    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Leukocyte peroxidase test. 864.7675 Section 864.7675 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Hematology Kits and Packages § 864.7675 Leukocyte...

  6. Effect of industrial wastewater ontotal protein and the peroxidase ...

    African Journals Online (AJOL)

    The aim of this study is to investigate the effects of industrial wastewaters on protein and the peroxidase activity in Lycopersicon esculentum Mill., Capsicum annuum L., Phaseolus vulgaris L. and Vicia faba L. Industrial wastewaters were taken from Dardanel Fisheries Company, Tekel alcoholic drinks companies' ...

  7. Efficient production of Arthromyces ramosus peroxidase by Aspergillus awamori

    NARCIS (Netherlands)

    Lokman, B.C.; Joosten, V.; Hovenkamp, J.; Gouka, R.J.; Verrips, C.T.; Hondel, C.A.M.J.J. van den


    The heterologous production of Arthromyces ramosus peroxidase (ARP) was analysed in the filamentous fungus Aspergillus awamori under control of the inducible endoxylanase promoter. Secretion of active ARP was achieved up to 800 mg l-1 in shake flask cultures. Western blot analysis showed that an

  8. Frequency of anti thyroid peroxidase antibody in patients of vitiligo

    International Nuclear Information System (INIS)

    Zhokhar, A.; Shaikh, Z.I.


    Objective: The objective of this study was to compare the frequency of anti thyroid peroxidase antibody in patients suffering from vitiligo with healthy control group. Type of Study: Case control study. Settings: Dermatology Department, Military Hospital, Rawalpindi, from 20th March 2010 to 20th July 2011. Material and Methods: Fifty clinically diagnosed patients of vitiligo, age = 18 yrs and both genders with no history of thyroid disease, past or current use of drugs for thyroid disorder or thyroid surgery were included as cases (Group A). Fifty healthy individuals with no evidence of vitiligo or thyroid disorder on history and physical examination and with no family history of vitiligo, matched for age and gender with cases, were included as control (Group B). Serum anti thyroid peroxidase (anti TPO) antibodies were measured using enzyme linked immunosorbent assay (ELISA) in both cases and control. Results: Eight (16%) patients in Group A were anti-thyroid peroxidase antibody positive and forty two (84%) patients were negative while one (2%) patient was anti-thyroid peroxidase antibody positive in Group B and forty nine (98%) patients were negative (p = 0.001). Conclusion: Anti TPO antibody is significantly more common in patients of vitiligo as compared to general population. (author)

  9. Thylakoid-bound ascorbate peroxidase increases resistance to salt ...

    African Journals Online (AJOL)

    Reactive oxygen species (ROS) are cellular indicators of stress. In plants, they function as secondary messengers in response to environmental stress. Ascorbate peroxidase (APX) is an important enzyme directly involved in the scavenging of ROS. In this study, we aimed at identifying the function of the Brassica napus ...

  10. Candida albicans biofilm on titanium: effect of peroxidase precoating

    Directory of Open Access Journals (Sweden)

    Mohamed Ahariz


    Full Text Available Mohamed Ahariz1, Philippe Courtois1,21Laboratory of Experimental Hormonology, Université Libre de Bruxelles, Brussels, 2UER de Biologie Médicale, Haute Ecole Francisco Ferrer, Brussels, BelgiumAbstract: The present study aimed to document Candida albicans biofilm development on titanium and its modulation by a peroxidase-precoated material which can generate antimicrobials, such as hypoiodite or hypothiocyanite, from hydrogen peroxide, iodide, or thiocyanate. For this purpose, titanium (powder or foil was suspended in Sabouraud liquid medium inoculated with C. albicans ATCC10231. After continuous stirring for 2–21 days at room temperature, the supernatant was monitored by turbidimetry at 600 nm and titanium washed three times in sterile Sabouraud broth. Using the tetrazolium salt MTT-formazan assay, the titanium-adherent fungal biomass was measured as 7.50 ± 0.60 × 106 blastoconidia per gram of titanium powder (n = 30 and 0.50 ± 0.04 × 106 blastoconidia per cm² of titanium foil (n = 12. The presence of yeast on the surface of titanium was confirmed by microscopy both on fresh preparations and after calcofluor white staining. However, in the presence of peroxidase systems (lactoperoxidase with substrates such as hydrogen peroxide donor, iodide, or thiocyanate, Candida growth in both planktonic and attached phases appeared to be inhibited. Moreover, this study demonstrates the possible partition of peroxidase systems between titanium material (peroxidase-precoated and liquid environment (containing peroxidase substrates to limit C. albicans biofilm formation.Keywords: adhesion, material, oral, yeast

  11. Induction of Laccase, Lignin Peroxidase and Manganese Peroxidase Activities in White-Rot Fungi Using Copper Complexes

    Directory of Open Access Journals (Sweden)

    Martina Vrsanska


    Full Text Available Ligninolytic enzymes, such as laccase, lignin peroxidase and manganese peroxidase, are biotechnologically-important enzymes. The ability of five white-rot fungal strains Daedaleopsis confragosa, Fomes fomentarius, Trametes gibbosa, Trametes suaveolens and Trametes versicolor to produce these enzymes has been studied. Three different copper(II complexes have been prepared ((Him[Cu(im4(H2O2](btc·3H2O, where im = imidazole, H3btc = 1,3,5-benzenetricarboxylic acid, [Cu3(pmdien3(btc](ClO43·6H2O and [Cu3(mdpta3(btc](ClO43·4H2O, where pmdien = N,N,N′,N′′,N′′-pentamethyl-diethylenetriamine and mdpta = N,N-bis-(3-aminopropylmethyl- amine, and their potential application for laccase and peroxidases induction have been tested. The enzyme-inducing activities of the complexes were compared with that of copper sulfate, and it has been found that all of the complexes are suitable for the induction of laccase and peroxidase activities in white-rot fungi; however, the newly-synthesized complex M1 showed the greatest potential for the induction. With respect to the different copper inducers, this parameter seems to be important for enzyme activity, which depends also on the fungal strains.

  12. Ligninolytic enzymes of the fungus Irpex lacteus (Polyporus tulipiferae): isolation and characterization of lignin peroxidase

    Czech Academy of Sciences Publication Activity Database

    Rothschild, N.; Novotný, Čeněk; Šašek, Václav; Dosoretz, C. G.


    Roč. 31, - (2002), s. 627-633 ISSN 0141-0229 Institutional research plan: CEZ:AV0Z5020903 Keywords : lignin * peroxidase * heme peroxidase Subject RIV: EE - Microbiology, Virology Impact factor: 1.773, year: 2002

  13. OLED displays and lighting

    CERN Document Server

    Koden, Mitsuhiro


    Organic light-emitting diodes (OLEDs) have emerged as the leading technology for the new display and lighting market. OLEDs are solid-state devices composed of thin films of organic molecules that create light with the application of electricity. OLEDs can provide brighter, crisper displays on electronic devices and use less power than conventional light-emitting diodes (LEDs) or liquid crystal displays (LCDs) used today. This book covers both the fundamentals and practical applications of flat and flexible OLEDs.

  14. Scalable Resolution Display Walls

    KAUST Repository

    Leigh, Jason; Johnson, Andrew; Renambot, Luc; Peterka, Tom; Jeong, Byungil; Sandin, Daniel J.; Talandis, Jonas; Jagodic, Ratko; Nam, Sungwon; Hur, Hyejung; Sun, Yiwen


    This article will describe the progress since 2000 on research and development in 2-D and 3-D scalable resolution display walls that are built from tiling individual lower resolution flat panel displays. The article will describe approaches and trends in display hardware construction, middleware architecture, and user-interaction design. The article will also highlight examples of use cases and the benefits the technology has brought to their respective disciplines. © 1963-2012 IEEE.

  15. JAVA Stereo Display Toolkit (United States)

    Edmonds, Karina


    This toolkit provides a common interface for displaying graphical user interface (GUI) components in stereo using either specialized stereo display hardware (e.g., liquid crystal shutter or polarized glasses) or anaglyph display (red/blue glasses) on standard workstation displays. An application using this toolkit will work without modification in either environment, allowing stereo software to reach a wider audience without sacrificing high-quality display on dedicated hardware. The toolkit is written in Java for use with the Swing GUI Toolkit and has cross-platform compatibility. It hooks into the graphics system, allowing any standard Swing component to be displayed in stereo. It uses the OpenGL graphics library to control the stereo hardware and to perform the rendering. It also supports anaglyph and special stereo hardware using the same API (application-program interface), and has the ability to simulate color stereo in anaglyph mode by combining the red band of the left image with the green/blue bands of the right image. This is a low-level toolkit that accomplishes simply the display of components (including the JadeDisplay image display component). It does not include higher-level functions such as disparity adjustment, 3D cursor, or overlays all of which can be built using this toolkit.

  16. Displays and simulators (United States)

    Mohon, N.

    A 'simulator' is defined as a machine which imitates the behavior of a real system in a very precise manner. The major components of a simulator and their interaction are outlined in brief form, taking into account the major components of an aircraft flight simulator. Particular attention is given to the visual display portion of the simulator, the basic components of the display, their interactions, and their characteristics. Real image displays are considered along with virtual image displays, and image generators. Attention is given to an advanced simulator for pilot training, a holographic pancake window, a scan laser image generator, the construction of an infrared target simulator, and the Apollo Command Module Simulator.

  17. Apoplastic peroxidases are required for salicylic acid-mediated defense against Pseudomonas syringae. (United States)

    Mammarella, Nicole D; Cheng, Zhenyu; Fu, Zheng Qing; Daudi, Arsalan; Bolwell, G Paul; Dong, Xinnian; Ausubel, Frederick M


    Reactive oxygen species (ROS) generated by NADPH oxidases or apoplastic peroxidases play an important role in the plant defense response. Diminished expression of at least two Arabidopsis thaliana peroxidase encoding genes, PRX33 (At3g49110) and PRX34 (At3g49120), as a consequence of anti-sense expression of a heterologous French bean peroxidase gene (asFBP1.1), were previously shown to result in reduced levels of ROS following pathogen attack, enhanced susceptibility to a variety of bacterial and fungal pathogens, and reduced levels of callose production and defense-related gene expression in response to the microbe associated molecular pattern (MAMP) molecules flg22 and elf26. These data demonstrated that the peroxidase-dependent oxidative burst plays an important role in the elicitation of pattern-triggered immunity (PTI). Further work reported in this paper, however, shows that asFBP1.1 antisense plants are not impaired in all PTI-associated responses. For example, some but not all flg22-elicited genes are induced to lower levels by flg22 in asFPB1.1, and callose deposition in asFPB1.1 is similar to wild-type following infiltration with a Pseudomonas syringae hrcC mutant or with non-host P. syringae pathovars. Moreover, asFPB1.1 plants did not exhibit any apparent defect in their ability to mount a hypersensitive response (HR). On the other hand, salicylic acid (SA)-mediated activation of PR1 was dramatically impaired in asFPB1.1 plants. In addition, P. syringae-elicited expression of many genes known to be SA-dependent was significantly reduced in asFBP1.1 plants. Consistent with this latter result, in asFBP1.1 plants the key regulator of SA-mediated responses, NPR1, showed both dramatically decreased total protein abundance and a failure to monomerize, which is required for its translocation into the nucleus. Copyright © 2014 Elsevier Ltd. All rights reserved.

  18. Displays enabling mobile multimedia (United States)

    Kimmel, Jyrki


    With the rapid advances in telecommunications networks, mobile multimedia delivery to handsets is now a reality. While a truly immersive multimedia experience is still far ahead in the mobile world, significant advances have been made in the constituent audio-visual technologies to make this become possible. One of the critical components in multimedia delivery is the mobile handset display. While such alternatives as headset-style near-to-eye displays, autostereoscopic displays, mini-projectors, and roll-out flexible displays can deliver either a larger virtual screen size than the pocketable dimensions of the mobile device can offer, or an added degree of immersion by adding the illusion of the third dimension in the viewing experience, there are still challenges in the full deployment of such displays in real-life mobile communication terminals. Meanwhile, direct-view display technologies have developed steadily, and can provide a development platform for an even better viewing experience for multimedia in the near future. The paper presents an overview of the mobile display technology space with an emphasis on the advances and potential in developing direct-view displays further to meet the goal of enabling multimedia in the mobile domain.

  19. A tetravalent virus-like particle vaccine designed to display domain III of dengue envelope proteins induces multi-serotype neutralizing antibodies in mice and macaques which confer protection against antibody dependent enhancement in AG129 mice.

    Directory of Open Access Journals (Sweden)

    Viswanathan Ramasamy


    Full Text Available Dengue is one of the fastest spreading vector-borne diseases, caused by four antigenically distinct dengue viruses (DENVs. Antibodies against DENVs are responsible for both protection as well as pathogenesis. A vaccine that is safe for and efficacious in all people irrespective of their age and domicile is still an unmet need. It is becoming increasingly apparent that vaccine design must eliminate epitopes implicated in the induction of infection-enhancing antibodies.We report a Pichia pastoris-expressed dengue immunogen, DSV4, based on DENV envelope protein domain III (EDIII, which contains well-characterized serotype-specific and cross-reactive epitopes. In natural infection, <10% of the total neutralizing antibody response is EDIII-directed. Yet, this is a functionally relevant domain which interacts with the host cell surface receptor. DSV4 was designed by in-frame fusion of EDIII of all four DENV serotypes and hepatitis B surface (S antigen and co-expressed with unfused S antigen to form mosaic virus-like particles (VLPs. These VLPs displayed EDIIIs of all four DENV serotypes based on probing with a battery of serotype-specific anti-EDIII monoclonal antibodies. The DSV4 VLPs were highly immunogenic, inducing potent and durable neutralizing antibodies against all four DENV serotypes encompassing multiple genotypes, in mice and macaques. DSV4-induced murine antibodies suppressed viremia in AG129 mice and conferred protection against lethal DENV-4 virus challenge. Further, neither murine nor macaque anti-DSV4 antibodies promoted mortality or inflammatory cytokine production when passively transferred and tested in an in vivo dengue disease enhancement model of AG129 mice.Directing the immune response to a non-immunodominant but functionally relevant serotype-specific dengue epitope of the four DENV serotypes, displayed on a VLP platform, can help minimize the risk of inducing disease-enhancing antibodies while eliciting effective tetravalent

  20. Accelerating the peroxidase-like activity of gold nanoclusters at neutral pH for colorimetric detection of heparin and heparinase activity. (United States)

    Hu, Lianzhe; Liao, Hong; Feng, Lingyan; Wang, Min; Fu, Wensheng


    The peroxidase-like catalytic activity of gold nanoclusters (NCs) is quite low around physiological pH, which greatly limits their biological applications. Herein, we found heparin can greatly accelerate the peroxidase-like activity of Au-NCs at neutral pH. The catalytic activity of Au-NCs toward the peroxidase substrate 3,3',5,5'-tetramethylbenzidine (TMB) oxidation by H2O2 was 25-fold increased in the presence of heparin at pH 7. The addition of heparin not only accelerated the initial catalytic rate of Au-NCs, but also prevented the Au-NCs from catalyst deactivation. This allows the sensitive colorimetric detection of heparin at neutral pH. In the presence of heparinase, heparin was hydrolyzed into small fragments, weakening the enhancement effect of catalytic activity. Based on this phenomenon, the sensitive colorimetric determination of heparinase in biological samples was also developed.

  1. Purification and characterization of an intracellular peroxidase from Streptomyces cyaneus.


    Mliki, A; Zimmermann, W


    An intracellular peroxidase (EC from Streptomyces cyaneus was purified to homogeneity. The enzyme had a molecular weight of 185,000 and was composed of two subunits of equal size. It had an isoelectric point of 6.1. The enzyme had a peroxidase activity toward o-dianisidine with a Km of 17.8 microM and a pH optimum of 5.0. It also showed catalase activity with a Km of 2.07 mM H2O2 and a pH optimum of 8.0. The purified enzyme did not catalyze C alpha-C beta bond cleavage of 1,3-dihydr...

  2. Visual merchandising window display

    Directory of Open Access Journals (Sweden)

    Opris (Cas. Stanila M.


    Full Text Available Window display plays a major part in the selling strategies; it does not only include the simple display of goods, nowadays it is a form of art, also having the purpose of sustaining the brand image. This article wants to reveal the tools that are essential in creating a fabulous window display. Being a window designer is not an easy job, you have to always think ahead trends, to have a sense of colour, to know how to use light to attract customers in the store after only one glance at the window. The big store window displays are theatre scenes: with expensive backgrounds, special effects and high fashion mannequins. The final role of the displays is to convince customers to enter the store and trigger the purchasing act which is the final goal of the retail activity.

  3. Enzymatic decolourisation of Methyl Orange and Bismarck Brown using crude peroxidase from Armoracia rusticana (United States)

    Ambatkar, Mugdha; Mukundan, Usha


    The decolourisation of Methyl Orange (MO) and Bismarck Brown (BB) by crude peroxidase from Armoracia rusticana (Horseradish) was studied by varying different reaction parameters. The pH of the reaction mixture, initial dye concentration, amount of enzyme and hydrogen peroxide concentration were optimised for ambient temperatures (30 ± 2 °C). The optimum pH for decolourisation was 4.0 (72.95 %) and 3.0 (79.24 %) for MO and BB, respectively. Also it was found that the Chemical Oxygen Demand of the enzyme-treated sample was significantly lower than that of the untreated controls for both dyes. The addition of a complex iron salt like Ferric EDTA was found to enhance the decolourisation of both dyes at pH 6.0, showing an increase of 8.69 % and 14.17 % in the decolourisation of MO and of BB, respectively. The present study explores the potential of crude peroxidase from horseradish to decolourise representative monoazo and diazo dyes, MO and BB, respectively. An attempt has been made to utilise a crude enzyme with appreciable activity obtained after minimal processing for the decolourisation of the aforesaid dyes. The findings of this study would find application in the enzymatic treatment of wastewater containing azo dyes.

  4. Potential Applications of Peroxidases in the Fine Chemical Industries (United States)

    Casella, Luigi; Monzani, Enrico; Nicolis, Stefania

    A description of selected types of reactions catalyzed by heme peroxidases is given. In particular, the discussion is focused mainly on those of potential interest for fine chemical synthesis. The division into subsections has been done fromthe point of view of the enzyme action, i.e., giving emphasis to themechanismof the enzymatic reaction, and from that of the substrate, i.e., analyzing the type of transformation promoted by the enzyme. These two approaches have several points in common.

  5. Kinetic mechanism and nucleotide specificity of NADH peroxidase

    International Nuclear Information System (INIS)

    Stoll, V.S.; Blanchard, J.S.


    NADH peroxidase is a flavoprotein isolated from Streptococcus faecalis which catalyzes the pyridine nucleotide-dependent reduction of hydrogen peroxide to water. Initial velocity, product, and dead-end inhibition studies have been performed at pH 7.5 and support a ping-pong kinetic mechanism. In the absence of hydrogen peroxide, both transhydrogenation between NADH and thioNAD, and isotope exchange between [ 14 C]NADH and NAD, have been demonstrated, although in both these experiments, the maximal velocity of nucleotide exchange was less than 1.5% the maximal velocity of the peroxidatic reaction. We propose that NADH binds tightly to both oxidized and two-electron reduced enzyme. NADH oxidation proceeds stereospecifically with the transfer of the 4S hydrogen to enzyme, and then, via exchange, to water. No primary tritium kinetic isotope effect was observed, and no statistically significant primary deuterium kinetic isotope effects on V/K were determined, although primary deuterium kinetic isotope effects on V were observed in the presence and absence of sodium acetate. NADH peroxidase thus shares with other flavoprotein reductases striking kinetic, spectroscopic, and stereochemical similarities. On this basis, we propose a chemical mechanism for the peroxide cleaving reaction catalyzed by NADH peroxidase which involves the obligate formation of a flavinperoxide, and peroxo bond cleavage by nucleophilic attack by enzymatic dithiols

  6. Microlaser-based displays (United States)

    Bergstedt, Robert; Fink, Charles G.; Flint, Graham W.; Hargis, David E.; Peppler, Philipp W.


    Laser Power Corporation has developed a new type of projection display, based upon microlaser technology and a novel scan architecture, which provides the foundation for bright, extremely high resolution images. A review of projection technologies is presented along with the limitations of each and the difficulties they experience in trying to generate high resolution imagery. The design of the microlaser based projector is discussed along with the advantage of this technology. High power red, green, and blue microlasers have been designed and developed specifically for use in projection displays. These sources, in combination with high resolution, high contrast modulator, produce a 24 bit color gamut, capable of supporting the full range of real world colors. The new scan architecture, which reduces the modulation rate and scan speeds required, is described. This scan architecture, along with the inherent brightness of the laser provides the fundamentals necessary to produce a 5120 by 4096 resolution display. The brightness and color uniformity of the display is excellent, allowing for tiling of the displays with far fewer artifacts than those in a traditionally tiled display. Applications for the display include simulators, command and control centers, and electronic cinema.

  7. Mn(II) regulation of lignin peroxidases and manganese-dependent peroxidases from lignin-degrading white rot fungi

    International Nuclear Information System (INIS)

    Bonnarme, P.; Jeffries, T.W.


    Two families of peroxidases-lignin peroxidase (LiP) and manganese-dependent lignin peroxidase (MnP)-are formed by the lignin-degrading white rot basidiomycete Phanerochaete chrysosporium and other white rot fungi. Isoenzymes of these enzyme families carry out reactions important to the biodegradation of lignin. This research investigated the regulation of LiP and MnP production by Mn(II). In liquid culture, LiP titers varied as an inverse function of and MnP titers varied as a direct function of the Mn(II) concentration. The extracellular isoenzyme profiles differed radically at low and high Mn(II) levels, whereas other fermentation parameters, including extracellular protein concentrations, the glucose consumption rate, and the accumulation of cell dry weight, did not change significantly with the Mn(II) concentration. In the absence of Mn(II), extracellular LiP isoenzymes predominated, whereas in the presence of Mn(II), MnP isoenzymes were dominant. The release of 14 CO 2 from 14 C-labeled dehydrogenative polymerizate lignin was likewise affected by Mn(II). The rate of 14 CO 2 release increased at low Mn(II) and decreased at high Mn(II) concentrations. This regulatory effect of Mn(II) occurred with five strains of P. chrysosporium, two other species of Phanerochaete, three species of Phlebia, Lentinula edodes, and Phellinus pini

  8. MacA is a second cytochrome c peroxidase of Geobacter sulfurreducens. (United States)

    Seidel, Julian; Hoffmann, Maren; Ellis, Katie E; Seidel, Antonia; Spatzal, Thomas; Gerhardt, Stefan; Elliott, Sean J; Einsle, Oliver


    The metal-reducing δ-proteobacterium Geobacter sulfurreducens produces a large number of c-type cytochromes, many of which have been implicated in the transfer of electrons to insoluble metal oxides. Among these, the dihemic MacA was assigned a central role. Here we have produced G. sulfurreducens MacA by recombinant expression in Escherichia coli and have solved its three-dimensional structure in three different oxidation states. Sequence comparisons group MacA into the family of diheme cytochrome c peroxidases, and the protein indeed showed hydrogen peroxide reductase activity with ABTS(-2) as an electron donor. The observed K(M) was 38.5 ± 3.7 μM H(2)O(2) and v(max) was 0.78 ± 0.03 μmol of H(2)O(2)·min(-1)·mg(-1), resulting in a turnover number k(cat) = 0.46 · s(-1). In contrast, no Fe(III) reductase activity was observed. MacA was found to display electrochemical properties similar to other bacterial diheme peroxidases, in addition to the ability to electrochemically mediate electron transfer to the soluble cytochrome PpcA. Differences in activity between CcpA and MacA can be rationalized with structural variations in one of the three loop regions, loop 2, that undergoes conformational changes during reductive activation of the enzyme. This loop is adjacent to the active site heme and forms an open loop structure rather than a more rigid helix as in CcpA. For the activation of the protein, the loop has to displace the distal ligand to the active site heme, H93, in loop 1. A H93G variant showed an unexpected formation of a helix in loop 2 and disorder in loop 1, while a M297H variant that altered the properties of the electron transfer heme abolished reductive activation.

  9. Solar active region display system (United States)

    Golightly, M.; Raben, V.; Weyland, M.


    The Solar Active Region Display System (SARDS) is a client-server application that automatically collects a wide range of solar data and displays it in a format easy for users to assimilate and interpret. Users can rapidly identify active regions of interest or concern from color-coded indicators that visually summarize each region's size, magnetic configuration, recent growth history, and recent flare and CME production. The active region information can be overlaid onto solar maps, multiple solar images, and solar difference images in orthographic, Mercator or cylindrical equidistant projections. Near real-time graphs display the GOES soft and hard x-ray flux, flare events, and daily F10.7 value as a function of time; color-coded indicators show current trends in soft x-ray flux, flare temperature, daily F10.7 flux, and x-ray flare occurrence. Through a separate window up to 4 real-time or static graphs can simultaneously display values of KP, AP, daily F10.7 flux, GOES soft and hard x-ray flux, GOES >10 and >100 MeV proton flux, and Thule neutron monitor count rate. Climatologic displays use color-valued cells to show F10.7 and AP values as a function of Carrington/Bartel's rotation sequences - this format allows users to detect recurrent patterns in solar and geomagnetic activity as well as variations in activity levels over multiple solar cycles. Users can customize many of the display and graph features; all displays can be printed or copied to the system's clipboard for "pasting" into other applications. The system obtains and stores space weather data and images from sources such as the NOAA Space Environment Center, NOAA National Geophysical Data Center, the joint ESA/NASA SOHO spacecraft, and the Kitt Peak National Solar Observatory, and can be extended to include other data series and image sources. Data and images retrieved from the system's database are converted to XML and transported from a central server using HTTP and SOAP protocols, allowing

  10. ENERGY STAR Certified Displays (United States)

    U.S. Environmental Protection Agency — Certified models meet all ENERGY STAR requirements as listed in the Version 7.0 ENERGY STAR Program Requirements for Displays that are effective as of July 1, 2016....

  11. Improvements in data display

    International Nuclear Information System (INIS)

    Ellis, G.W.


    An analog signal processor is described in this patent for connecting a source of analog signals to a cathode ray tube display in order to extend the dynamic range of the display. This has important applications in the field of computerised X-ray tomography since significant medical information, such as tumours in soft tissue, is often represented by minimal level changes in image density. Cathode ray tube displays are limited to approximately 15 intensity levels. Thus if both strong and weak absorption of the X-rays occurs, the dynamic range of the transmitted signals will be too large to permit small variations to be examined directly on a cathode ray display. Present tomographic image reconstruction methods are capable of quantising X-ray absorption density measurements into 256 or more distinct levels and a description is given of the electronics which enables the upper and lower range of intensity levels to be independently set and continuously varied. (UK)

  12. Gamma camera display system

    International Nuclear Information System (INIS)

    Stout, K.J.


    A gamma camera having an array of photomultipliers coupled via pulse shaping circuitry and a resistor weighting circuit to a display for forming an image of a radioactive subject is described. A linearizing circuit is coupled to the weighting circuit, the linearizing circuit including a nonlinear feedback circuit with diode coupling to the weighting circuit for linearizing the correspondence between points of the display and points of the subject. 4 Claims, 5 Drawing Figures

  13. Flexible displays, rigid designs?

    DEFF Research Database (Denmark)

    Hornbæk, Kasper


    Rapid technological progress has enabled a wide range of flexible displays for computing devices, but the user experience--which we're only beginning to understand--will be the key driver for successful designs.......Rapid technological progress has enabled a wide range of flexible displays for computing devices, but the user experience--which we're only beginning to understand--will be the key driver for successful designs....

  14. Hairy root transgene expression analysis of a secretory peroxidase (PvPOX1) from common bean infected by Fusarium wilt. (United States)

    Xue, Renfeng; Wu, Xingbo; Wang, Yingjie; Zhuang, Yan; Chen, Jian; Wu, Jing; Ge, Weide; Wang, Lanfen; Wang, Shumin; Blair, Matthew W


    Plant peroxidases (POXs) are one of the most important redox enzymes in the defense responses. However, the large number of different plant POX genes makes it necessary to carefully confirm the function of each paralogous POX gene in specific tissues and disease interactions. Fusarium wilt is a devastating disease of common bean caused by Fusarium oxysporum f. sp. phaseoli. In this study, we evaluated a peroxidase gene, PvPOX1, from a resistant common bean genotype, CAAS260205 and provided direct evidence for PvPOX1's role in resistance by transforming the resistant allele into a susceptible common bean genotype, BRB130, via hairy root transformation using Agrobacterium rhizogenes. Analysis of PvPOX1 gene over-expressing hairy roots showed it increased resistance to Fusarium wilt both in the roots and the rest of transgenic plants. Meanwhile, the PvPOX1 expressive level, the peroxidase activity and hydrogen peroxide (H 2 O 2 ) accumulation were also enhanced in the interaction. The result showed that the PvPOX1 gene played an essential role in Fusarium wilt resistance through the occurrence of reactive oxygen species (ROS) induced hypersensitive response. Therefore, PvPOX1 expression was proven to be a valuable gene for further analysis which can strengthen host defense response against Fusarium wilt through a ROS activated resistance mechanism. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Covalent Immobilization of Peroxidase onto Hybrid Membranes for the Construction of Optical Biosensor

    Directory of Open Access Journals (Sweden)

    Lyubov Yotova


    Full Text Available The aim of this study is to covalently immobilize horse radish peroxidase (HRP onto new hybrid membranes synthesized by the sol-gel method based on silica precursors, dendrimers and cellulose derivatives. This new system will be used for designing biosensor. For investigation of the properties of membranes, HRP was used as a modeling enzyme. Kinetic parameters, pH and temperature optimum were determined, and the structure of the membranes surface was examined. Results showed higher relative and residual activity of HRP immobilized onto membranes with cellulose acetate butyrate with high molecular weight CAB/H. This novel biosensor could offer a simple, cheap and rapid tool with enhanced sensing performance as well as having potentials to find application in medicine, pharmacy, food and process control and environmental monitoring.

  16. Polyphenol oxidase and peroxidase expression in four pineapple varieties (Ananas comosus L.) after a chilling injury. (United States)

    Raimbault, Astrid-Kim; Marie-Alphonsine, Paul-Alex; Horry, Jean-Pierre; Francois-Haugrin, Madlyn; Romuald, Karell; Soler, Alain


    Pineapple internal browning (IB) is a chilling injury that produces enzymatic browning associated with flesh translucency. Pineapple biodiversity allowed the investigation of how polyphenol oxidase (PPO) and peroxidase (POD) activities with their different isoforms are involved in the IB mechanism. Fruits of four varieties that expressed IB symptoms differently, Smooth Cayenne (SCay) and the hybrids MD2, Flhoran 41 (Flh 41), and Flhoran 53 (Flh 53), were stressed by cold. The susceptible varieties showed classical brown spots but different patterns of IB, whereas MD2 and controls showed no IB. Enzymatic activities were measured on fruit protein extracts and PPO and POD isoforms separated on mini-gels (PhastSystem). Only PPO activity was significantly enhanced in the presence of IB. Up to six PPO isoforms were identified in the susceptible varieties. PPO was barely detectable in the nonsusceptible variety MD2 and in controls. The number of PPO isoforms and the total PPO activity after chilling are varietal characteristics.

  17. Insight into the mechanism revealing the peroxidase mimetic catalytic activity of quaternary CuZnFeS nanocrystals: colorimetric biosensing of hydrogen peroxide and glucose (United States)

    Dalui, Amit; Pradhan, Bapi; Thupakula, Umamahesh; Khan, Ali Hossain; Kumar, Gundam Sandeep; Ghosh, Tanmay; Satpati, Biswarup; Acharya, Somobrata


    Artificial enzyme mimetics have attracted immense interest recently because natural enzymes undergo easy denaturation under environmental conditions restricting practical usefulness. We report for the first time chalcopyrite CuZnFeS (CZIS) alloyed nanocrystals (NCs) as novel biomimetic catalysts with efficient intrinsic peroxidase-like activity. Novel peroxidase activities of CZIS NCs have been evaluated by catalytic oxidation of the peroxidase substrate 3,3',5,5'-tetramethylbenzidine (TMB) in the presence of hydrogen peroxide (H2O2). CZIS NCs demonstrate the synergistic effect of elemental composition and photoactivity towards peroxidase-like activity. The quaternary CZIS NCs show enhanced intrinsic peroxidase-like activity compared to the binary NCs with the same constituent elements. Intrinsic peroxidase-like activity has been correlated with the energy band position of CZIS NCs extracted using scanning tunneling spectroscopy and ultraviolet photoelectron spectroscopy. Kinetic analyses indicate Michaelis-Menten enzyme kinetic model catalytic behavior describing the rate of the enzymatic reaction by correlating the reaction rate with substrate concentration. Typical color reactions arising from the catalytic oxidation of TMB over CZIS NCs with H2O2 have been utilized to establish a simple and sensitive colorimetric assay for detection of H2O2 and glucose. CZIS NCs are recyclable catalysts showing high efficiency in multiple uses. Our study may open up the possibility of designing new photoactive multi-component alloyed NCs as enzyme mimetics in biotechnology applications.Artificial enzyme mimetics have attracted immense interest recently because natural enzymes undergo easy denaturation under environmental conditions restricting practical usefulness. We report for the first time chalcopyrite CuZnFeS (CZIS) alloyed nanocrystals (NCs) as novel biomimetic catalysts with efficient intrinsic peroxidase-like activity. Novel peroxidase activities of CZIS NCs have been

  18. Information rich display design

    International Nuclear Information System (INIS)

    Welch, Robin; Braseth, Alf Ove; Veland, Oeystein


    This paper presents the concept Information Rich Displays. The purpose of Information Rich Displays (IRDs) is to condensate prevailing information in process displays in such a way that each display format (picture) contains more relevant information for the user. Compared to traditional process control displays, this new concept allows the operator to attain key information at a glance and at the same time allows for improved monitoring of larger portions of the process. This again allows for reduced navigation between both process and trend displays and ease the cognitive demand on the operator. This concept has been created while working on designing display prototypes for the offshore petroleum production facilities of tomorrow. Offshore installations basically consist of wells, separation trains (where oil, gas and water are separated from each other), an oil tax measurement system (where oil quality is measured and the pressure increased to allow for export), gas compression (compression of gas for export) and utility systems (water treatment, chemical systems etc.). This means that an offshore control room operator has to deal with a complex process that comprises several functionally different systems. The need for a new approach to offshore display format design is in particular based on shortcomings in today's designs related to the keyhole effect, where the display format only reveals a fraction of the whole process. Furthermore, the upcoming introduction of larger off- and on-shore operation centres will increase the size and complexity of the operators' work domain. In the light of the increased demands on the operator, the proposed IRDs aim to counter the negative effects this may have on the workload. In this work we have attempted to classify the wide range of different roles an operator can have in different situations. The information content and amount being presented to the operator in a display should be viewed in context of the roles the

  19. Effective Peroxidase-Like Activity of Co-Aminoclay [CoAC] and Its Application for Glucose Detection

    Directory of Open Access Journals (Sweden)

    Han Pill Song


    Full Text Available In this study, we describe a novel peroxidase-like activity of Co-aminoclay [CoAC] present at pH ~5.0 and its application to fluorescent biosensor for the determination of H2O2 and glucose. It is synthesized with aminoclays (ACs entrapping cationic metals such as Fe, Cu, Al, Co., Ce, Ni, Mn, and Zn to find enzyme mimicking ACs by sol–gel ambient conditions. Through the screening of catalytic activities by the typical colorimetric reaction employing 2,2′-azino-bis(3-ethylbenzo-thiazoline-6-sulfonic aciddiammonium salt (ABTS as a substrate with or without H2O2, Fe, Cu, and CoACs are found to exhibit peroxidase-like activity, as well as oxidase-like activity was observed from Ce and MnACs. Among them, CoAC shows exceptionally high peroxidase-like activity, presumably due to its ability to induce electron transfer between substrates and H2O2. CoAC is then used to catalyze the oxidation of Amplex® UltraRed (AUR into a fluorescent end product, which enables a sensitive fluorescent detection of H2O2. Moreover, a highly sensitive and selective glucose biosensing strategy is developed, based on enzyme cascade reaction between glucose oxidase (GOx and CoAC. Using this strategy, a highly linear fluorescence enhancement is verified when the concentration of glucose is increased in a wide range from 10 μM to 1 mM with a lower detection limit of 5 μM. The practical diagnostic capability of the assay system is also verified by its use to detect glucose in human blood serum. Based on these results, it is anticipated that CoAC can serve as potent peroxidase mimetics for the detection of clinically important target molecules.

  20. Peroxidase synthesis and activity in the interaction of soybean with Phytophthora megasperma f. sp. glycinea (Pmg)

    International Nuclear Information System (INIS)

    Chibbar, R.N.; Esnault, R.; Lee, D.; van Huystee, R.B.; Ward, E.W.B.


    Changes, in peroxidase (EC1.11.1.7) have been reported following infection. However, determinations of biosynthesis of quantities of the peroxidase protein molecule have not been made! In this study hypocotyl of soybean seedlings (Glycine max; cv Harosoy, susceptible; cv Harosoy 63, resistant) were inoculated with zoospores of Pmg. Incorporation of 35 S-methionine (supplied with inoculum) in TCA precipitates was measured. Peroxidase synthesis was measured by immuno precipitation using antibodies against a cationic and an anionic peroxidase derived from peanut cells. Specific peroxidase activity increased rapidly from 5 to 9 h following infection in the resistant reaction but not in the susceptible reaction or the water controls. There was increased synthesis of the anionic peroxidase but not of the cationic peroxidase in the resistant reaction. The anionic peroxidase did not increase in the susceptible until 15 h. The ratio of peroxidase synthesis to total protein synthesis decreased in inoculated tissues compared to control. Peroxidase synthesis is, therefore, a relative minor host response to infection

  1. Dichroic Liquid Crystal Displays (United States)

    Bahadur, Birendra

    The following sections are included: * INTRODUCTION * DICHROIC DYES * Chemical Structure * Chemical and Photochemical Stability * THEORETICAL MODELLING * DEFECTS CAUSED BY PROLONGED LIGHT IRRADIATION * CHEMICAL STRUCTURE AND PHOTOSTABILITY * OTHER PARAMETERS AFFECTING PHOTOSTABILITY * CELL PREPARATION * DICHROIC PARAMETERS AND THEIR MEASUREMENTS * Order Parameter and Dichroic Ratio Of Dyes * Absorbance, Order Parameter and Dichroic Ratio Measurements * IMPACT OF DYE STRUCTURE AND LIQUID CRYSTAL HOST ON PHYSICAL PROPERTIES OF A DICHROIC MIXTURE * Order Parameter and Dichroic Ratio * EFFECT OF LENGTH OF DICHROIC DYES ON THE ORDER PARAMETER * EFFECT OF THE BREADTH OF DYE ON THE ORDER PARAMETER * EFFECT OF THE HOST ON THE ORDER PARAMETER * TEMPERATURE VARIATION OF THE ORDER PARAMETER OF DYES IN A LIQUID CRYSTAL HOST * IMPACT OF DYE CONCENTRATION ON THE ORDER PARAMETER * Temperature Range * Viscosity * Dielectric Constant and Anisotropy * Refractive Indices and Birefringence * solubility43,153-156 * Absorption Wavelength and Auxochromic Groups * Molecular Engineering of Dichroic Dyes * OPTICAL, ELECTRO-OPTICAL AND LIFE PARAMETERS * Colour And CIE Colour space120,160-166 * CIE 1931 COLOUR SPACE * CIE 1976 CHROMATICITY DIAGRAM * CIE UNIFORM COLOUR SPACES & COLOUR DIFFERENCE FORMULAE120,160-166 * Electro-Optical Parameters120 * LUMINANCE * CONTRAST AND CONTRAST RATIO * SWITCHING SPEED * Life Parameters and Failure Modes * DICHROIC MIXTURE FORMULATION * Monochrome Mixture * Black Mixture * ACHROMATIC BLACK MIXTURE FOR HEILMEIER DISPLAYS * Effect of Illuminant on Display Colour * Colour of the Field-On State * Effect of Dye Linewidth * Optimum Centroid Wavelengths * Effect of Dye Concentration * Mixture Formulation Using More Than Three Dyes * ACHROMATIC MIXTURE FOR WHITE-TAYLOR TYPE DISPLAYS * HEILMEIER DISPLAYS * Theoretical Modelling * Threshold Characteristic * Effects of Dye Concentration on Electro-optical Parameters * Effect of Cholesteric Doping * Effect of Alignment

  2. On Integrity of Flexible Displays (United States)

    Bouten, Piet C. P.

    Nowadays two display types are dominant in the display market: the bulky cathode ray tube (CRT) and liquid crystal displays (LCD). Both types use glass as substrate material. The LCD display is the dominant player for mobile applications, in for instance mobile phones and portable computers. In the development of displays and their applications a clear interest exists to replace the rigid rectangular display cells by free-shaped, curved or even roll-up cells. These types of applications require flexible displays.

  3. Demonstration of Lignin-to-Peroxidase Direct Electron Transfer (United States)

    Sáez-Jiménez, Verónica; Baratto, Maria Camilla; Pogni, Rebecca; Rencoret, Jorge; Gutiérrez, Ana; Santos, José Ignacio; Martínez, Angel T.; Ruiz-Dueñas, Francisco Javier


    Versatile peroxidase (VP) is a high redox-potential peroxidase of biotechnological interest that is able to oxidize phenolic and non-phenolic aromatics, Mn2+, and different dyes. The ability of VP from Pleurotus eryngii to oxidize water-soluble lignins (softwood and hardwood lignosulfonates) is demonstrated here by a combination of directed mutagenesis and spectroscopic techniques, among others. In addition, direct electron transfer between the peroxidase and the lignin macromolecule was kinetically characterized using stopped-flow spectrophotometry. VP variants were used to show that this reaction strongly depends on the presence of a solvent-exposed tryptophan residue (Trp-164). Moreover, the tryptophanyl radical detected by EPR spectroscopy of H2O2-activated VP (being absent from the W164S variant) was identified as catalytically active because it was reduced during lignosulfonate oxidation, resulting in the appearance of a lignin radical. The decrease of lignin fluorescence (excitation at 355 nm/emission at 400 nm) during VP treatment under steady-state conditions was accompanied by a decrease of the lignin (aromatic nuclei and side chains) signals in one-dimensional and two-dimensional NMR spectra, confirming the ligninolytic capabilities of the enzyme. Simultaneously, size-exclusion chromatography showed an increase of the molecular mass of the modified residual lignin, especially for the (low molecular mass) hardwood lignosulfonate, revealing that the oxidation products tend to recondense during the VP treatment. Finally, mutagenesis of selected residues neighboring Trp-164 resulted in improved apparent second-order rate constants for lignosulfonate reactions, revealing that changes in its protein environment (modifying the net negative charge and/or substrate accessibility/binding) can modulate the reactivity of the catalytic tryptophan. PMID:26240145

  4. Cu-Hemin Metal-Organic-Frameworks/Chitosan-Reduced Graphene Oxide Nanocomposites with Peroxidase-Like Bioactivity for Electrochemical Sensing

    International Nuclear Information System (INIS)

    Wang, Li; Yang, Han; He, Juan; Zhang, Yayun; Yu, Jie; Song, Yonghai


    Graphical abstract: A simple, sensitive and effective method to detect hydrogen peroxide based on a hybrid Cu-hemin metal-organic-frameworks (MOFs)/chitosan-functionalized reduced graphene oxide (CS-rGO) nanocomposite was achieved via Cu-hemin MOFs constructing with CS-rGO in room temperature. The Cu-hemin MOFs/CS-rGO nanomaterials exhibited a unique peroxidase-like activity and good electrical conductivity as well as some novel properties. And the as-prepared electrode resulted in a perfect electrochemical performance towards reduction of hydrogen peroxide which was superior to natural enzymes and some inorganic mimic enzymes. - Highlights: • A hybrid Cu-hemin MOF/CS-rGO with a unique peroxidase-like activity was prepared. • The CS-rGO improved electrical conductivity of the nanocomposites greatly. • The 3D porous structure enhanced the catalytic activity of hemin for H 2 O 2 . • A novel sensitive electrochemical biosensing for H 2 O 2 detection was achieved. - Abstract: Herein, a Cu-hemin metal-organic-frameworks (MOFs)/chitosan (CS)-reduced graphene oxide (CS-rGO) nanocomposite with unique peroxidase-like bioactivity and good electrical conductivity was prepared for electrochemical H 2 O 2 sensing for the first time. The prepared Cu-hemin MOFs/CS-rGO nanocomposites were well characterized by scanning electron microscopy, energy dispersive X-ray spectroscopy, thermogravimetric analysis, Fourier transform infrared spectroscopy, X-ray powder diffraction, UV–vis spectroscopy and electrochemical techniques. The results showed that after the Cu-hemin MOFs were formed on the CS-rGO surface, the crystalline structure of the Cu-hemin MOFs was kept while the size of Cu-hemin MOFs was decreased and the electrical conductivity of the nanocomposites was enhanced greatly as compared with that of Cu-hemin MOFs. The unique peroxidase-like bioactivity and good electrical conductivity as well as some novel properties of Cu-hemin MOFs/CS-rGO nanocomposites resulted in

  5. Paediatric dose display

    International Nuclear Information System (INIS)

    Griffin, D.W.; Derges, S.; Hesslewood, S.


    A compact, inexpensive unit, based on an 8085 microprocessor, has been designed for calculating doses of intravenous radioactive injections for children. It has been used successfully for over a year. The dose is calculated from the body surface area and the result displayed in MBq. The operator can obtain the required dose on a twelve character alphanumeric display by entering the age of the patient and the adult dose using a hexadecimal keyboard. Circuit description, memory map and input/output, and firmware are dealt with. (U.K.)

  6. Cu–hemin metal-organic frameworks with peroxidase-like activity as peroxidase mimics for colorimetric sensing of glucose

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Fenfen; He, Juan; Zeng, Mulang; Hao, Juan; Guo, Qiaohui; Song, Yonghai; Wang, Li, E-mail: [Jiangxi Normal University, Key Laboratory of Functional Small Organic Molecule, Ministry of Education, College of Chemistry and Chemical Engineering (China)


    In this work, a facile strategy to synthesize Cu–hemin metal-organic frameworks (MOFs) with peroxidase-like activity was reported. The prepared Cu–hemin MOFs were characterized by various techniques such as scanning electron microscopy, transmission electron microscopy, X-ray powder diffraction, Fourier transform infrared spectroscopy, UV–visible absorbance spectra, and so on. The results showed that the prepared Cu–hemin MOFs looked like a ball-flower with an average diameter of 10 μm and provided a large specific surface area. The Cu–hemin MOFs possessing peroxidase-like activity could be used to catalyze the peroxidase substrate of 3,3,5,5-tetramethylbenzidine in the presence of H{sub 2}O{sub 2}, which was employed to detect H{sub 2}O{sub 2} quantitatively with the linear range from 1.0 μM to 1.0 mM and the detection limit was 0.42 μM. Furthermore, with the additional help of glucose oxidase, a sensitive and selective method to detect glucose was developed by using the Cu–hemin MOFs as catalyst and the linear range was from 10.0 μM to 3.0 mM and the detection limit was 6.9 μM. This work informs researchers of the advantages of MOFs for preparing biomimetic catalysts and extends the functionality of MOFs for biosensor application.Graphical Abstract.

  7. Hierarchical hybrid peroxidase catalysts for remediation of phenol wastewater

    KAUST Repository

    Duan, Xiaonan


    We report a new family of hierarchical hybrid catalysts comprised of horseradish peroxidase (HRP)-magnetic nanoparticles for advanced oxidation processes and demonstrate their utility in the removal of phenol from water. The immobilized HRP catalyzes the oxidation of phenols in the presence of H2O2, producing free radicals. The phenoxy radicals react with each other in a non-enzymatic process to form polymers, which can be removed by precipitation with salts or condensation. The hybrid peroxidase catalysts exhibit three times higher activity than free HRP and are able to remove three times more phenol from water compared to free HRP under similar conditions. In addition, the hybrid catalysts reduce substrate inhibition and limit inactivation from reaction products, which are common problems with free or conventionally immobilized enzymes. Reusability is improved when the HRP-magnetic nanoparticle hybrids are supported on micron-scale magnetic particles, and can be retained with a specially designed magnetically driven reactor. The performance of the hybrid catalysts makes them attractive for several industrial and environmental applications and their development might pave the way for practical applications by eliminating most of the limitations that have prevented the use of free or conventionally immobilized enzymes. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Horseradish peroxidase-modified porous silicon for phenol monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Kermad, A., E-mail: [Unité de Recherche Matériaux et Energies Renouvelables (URMER), Département de Physique, Faculté des Sciences, Université Abou Baker Belkaid, B.P. 119, Tlemcen 13000 (Algeria); Sam, S., E-mail: [Centre de Recherche en Technologie des Semi-conducteurs pour l’Energétique (CRTSE), 02 Bd. Frantz-Fanon, B.P. 140, Alger-7 merveilles, Algiers (Algeria); Ghellai, N., E-mail: [Unité de Recherche Matériaux et Energies Renouvelables (URMER), Département de Physique, Faculté des Sciences, Université Abou Baker Belkaid, B.P. 119, Tlemcen 13000 (Algeria); Khaldi, K., E-mail: [Unité de Recherche Matériaux et Energies Renouvelables (URMER), Département de Physique, Faculté des Sciences, Université Abou Baker Belkaid, B.P. 119, Tlemcen 13000 (Algeria); Gabouze, N., E-mail: [Centre de Recherche en Technologie des Semi-conducteurs pour l’Energétique (CRTSE), 02 Bd. Frantz-Fanon, B.P. 140, Alger-7 merveilles, Algiers (Algeria)


    Highlights: • Horseradish peroxidase enzyme (HRP) was covalently immobilized on porous silicon (PSi) surface. • Multistep strategy was used allowing the maintaining of the enzymatic activity of the immobilized enzyme. • Direct electron transfer has occurred between the immobilized enzyme and the surface. • Electrochemical measurements showed a response of HRP-modified PSi toward phenol in the presence of H{sub 2}O{sub 2}. -- Abstract: In this study, horseradish peroxidase enzyme (HRP) was covalently immobilized on porous silicon (PSi) surface using multistep strategy. First, acid terminations were generated on hydrogenated PSi surface by thermal hydrosilylation of undecylenic acid. Then, the carboxyl-terminated monolayer was transformed to active ester (succinimidyl ester) using N-hydroxysuccinimide (NHS) in the presence of the coupling agent N-ethyl-N′-(3-dimethylaminopropyl) carbodiimide (EDC). Subsequently, the enzyme was anchored on the surface via an amidation reaction. The structure of the PSi layers was observed by scanning electron microscopy (SEM). Infrared spectroscopy (FTIR) and contact angle measurements confirmed the efficiency of the modification at each step of the functionalization. Cyclic voltammetry was recorded using the HRP-modified PSi as working electrode. The results show that the enzymatic activity of the immobilized HRP is preserved and in the presence of hydrogen peroxide, the enzyme oxidizes phenolic molecules which were subsequently reduced at the modified-PSi electrode.

  9. Horseradish peroxidase-modified porous silicon for phenol monitoring

    International Nuclear Information System (INIS)

    Kermad, A.; Sam, S.; Ghellai, N.; Khaldi, K.; Gabouze, N.


    Highlights: • Horseradish peroxidase enzyme (HRP) was covalently immobilized on porous silicon (PSi) surface. • Multistep strategy was used allowing the maintaining of the enzymatic activity of the immobilized enzyme. • Direct electron transfer has occurred between the immobilized enzyme and the surface. • Electrochemical measurements showed a response of HRP-modified PSi toward phenol in the presence of H 2 O 2 . -- Abstract: In this study, horseradish peroxidase enzyme (HRP) was covalently immobilized on porous silicon (PSi) surface using multistep strategy. First, acid terminations were generated on hydrogenated PSi surface by thermal hydrosilylation of undecylenic acid. Then, the carboxyl-terminated monolayer was transformed to active ester (succinimidyl ester) using N-hydroxysuccinimide (NHS) in the presence of the coupling agent N-ethyl-N′-(3-dimethylaminopropyl) carbodiimide (EDC). Subsequently, the enzyme was anchored on the surface via an amidation reaction. The structure of the PSi layers was observed by scanning electron microscopy (SEM). Infrared spectroscopy (FTIR) and contact angle measurements confirmed the efficiency of the modification at each step of the functionalization. Cyclic voltammetry was recorded using the HRP-modified PSi as working electrode. The results show that the enzymatic activity of the immobilized HRP is preserved and in the presence of hydrogen peroxide, the enzyme oxidizes phenolic molecules which were subsequently reduced at the modified-PSi electrode

  10. Hierarchical hybrid peroxidase catalysts for remediation of phenol wastewater

    KAUST Repository

    Duan, Xiaonan; Corgié , Sté phane C.; Aneshansley, Daniel J.; Wang, Peng; Walker, Larry P.; Giannelis, Emmanuel P.


    We report a new family of hierarchical hybrid catalysts comprised of horseradish peroxidase (HRP)-magnetic nanoparticles for advanced oxidation processes and demonstrate their utility in the removal of phenol from water. The immobilized HRP catalyzes the oxidation of phenols in the presence of H2O2, producing free radicals. The phenoxy radicals react with each other in a non-enzymatic process to form polymers, which can be removed by precipitation with salts or condensation. The hybrid peroxidase catalysts exhibit three times higher activity than free HRP and are able to remove three times more phenol from water compared to free HRP under similar conditions. In addition, the hybrid catalysts reduce substrate inhibition and limit inactivation from reaction products, which are common problems with free or conventionally immobilized enzymes. Reusability is improved when the HRP-magnetic nanoparticle hybrids are supported on micron-scale magnetic particles, and can be retained with a specially designed magnetically driven reactor. The performance of the hybrid catalysts makes them attractive for several industrial and environmental applications and their development might pave the way for practical applications by eliminating most of the limitations that have prevented the use of free or conventionally immobilized enzymes. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Refreshing Refreshable Braille Displays. (United States)

    Russomanno, Alexander; O'Modhrain, Sile; Gillespie, R Brent; Rodger, Matthew W M


    The increased access to books afforded to blind people via e-publishing has given them long-sought independence for both recreational and educational reading. In most cases, blind readers access materials using speech output. For some content such as highly technical texts, music, and graphics, speech is not an appropriate access modality as it does not promote deep understanding. Therefore blind braille readers often prefer electronic braille displays. But, these are prohibitively expensive. The search is on, therefore, for a low-cost refreshable display that would go beyond current technologies and deliver graphical content as well as text. And many solutions have been proposed, some of which reduce costs by restricting the number of characters that can be displayed, even down to a single braille cell. In this paper, we demonstrate that restricting tactile cues during braille reading leads to poorer performance in a letter recognition task. In particular, we show that lack of sliding contact between the fingertip and the braille reading surface results in more errors and that the number of errors increases as a function of presentation speed. These findings suggest that single cell displays which do not incorporate sliding contact are likely to be less effective for braille reading.

  12. Small - Display Cartography

    DEFF Research Database (Denmark)

    Nissen, Flemming; Hvas, Anders; Münster-Swendsen, Jørgen

    Service Communication and finally, Part IV: Concluding remarks and topics for further research on small-display cartography. Part II includes a separate Appendix D consisting of a cartographic design specification. Part III includes a separate Appendix C consisting of a schema specification, a separate...

  13. Nuclear image display controller

    International Nuclear Information System (INIS)

    Roth, D.A.


    In a nuclear imaging system the digitized x and y coordinates of gamma ray photon emission events address memory locations corresponding to the coordinates. The respective locations are incremented each time they are addressed so at the end of a selected time or event count period the locations contain digital values or raw data corresponding to the intensity of pixels comprising an image frame. The raw data for a frame is coupled to one input of an arithmetic logic unit (ALU) whose output is coupled to a display controller memory. The output of the controller memory is coupled to another ALU input with a feedback bus and is also coupled to a further signal processing circuit which includes means for converting processed data to analog video signals for television display. The ALU is selectively controlled to let raw image data pass through to the display controllor memory or alternately to add (or subtract) raw data for the last image frame developed to the raw data for preceding frames held in the display controller to thereby produce the visual effect on the television screen of an isotope flowing through anatomy

  14. Plant state display device

    International Nuclear Information System (INIS)

    Kadota, Kazuo; Ito, Toshiichiro.


    The device of the present invention conducts information processing suitable for a man to solve a problem in a plant such as a nuclear power plant incorporating a great amount of information, where safety is required and provides information to an operator. Namely, theories and rules with respect to the flow and balanced state of materials and energy upon plant start-up, and a vapor cycle of operation fluids are symbolized and displayed on the display screen of the device. Then, the display of the plant information suitable to the information processing for a man to dissolve problems is provided. Accordingly, a mechanism for analyzing a purpose of the plant is made more definite, thereby enabling to prevent an erroneous judgement of an operator and occurrence of plant troubles. In addition, a simular effect can also be expected when the theories and rules with respect to the flow and the balanced state of materials and energy and thermohydrodynamic behavior of the operation fluids in a state of after-heat removing operation during shutdown of the plant are symbolized and displayed. (I.S.)

  15. Designing inhibitors of cytochrome c/cardiolipin peroxidase complexes: mitochondria-targeted imidazole-substituted fatty acids. (United States)

    Jiang, Jianfei; Bakan, Ahmet; Kapralov, Alexandr A; Silva, K Ishara; Huang, Zhentai; Amoscato, Andrew A; Peterson, James; Garapati, Venkata Krishna; Saxena, Sunil; Bayir, Hülya; Atkinson, Jeffrey; Bahar, Ivet; Kagan, Valerian E


    Mitochondria have emerged as the major regulatory platform responsible for the coordination of numerous metabolic reactions as well as cell death processes, whereby the execution of intrinsic apoptosis includes the production of reactive oxygen species fueling oxidation of cardiolipin (CL) catalyzed by cytochrome (Cyt) c. As this oxidation occurs within the peroxidase complex of Cyt c with CL, the latter represents a promising target for the discovery and design of drugs with antiapoptotic mechanisms of action. In this work, we designed and synthesized a new group of mitochondria-targeted imidazole-substituted analogs of stearic acid TPP-n-ISAs with various positions of the attached imidazole group on the fatty acid (n = 6, 8, 10, 13, and 14). By using a combination of absorption spectroscopy and EPR protocols (continuous wave electron paramagnetic resonance and electron spin echo envelope modulation) we demonstrated that TPP-n-ISAs indeed were able to potently suppress CL-induced structural rearrangements in Cyt c, paving the way to its peroxidase competence. TPP-n-ISA analogs preserved the low-spin hexa-coordinated heme-iron state in Cyt c/CL complexes whereby TPP-6-ISA displayed a significantly more effective preservation pattern than TPP-14-ISA. Elucidation of these intermolecular stabilization mechanisms of Cyt c identified TPP-6-ISA as an effective inhibitor of the peroxidase function of Cyt c/CL complexes with a significant antiapoptotic potential realized in mouse embryonic cells exposed to ionizing irradiation. These experimental findings were detailed and supported by all-atom molecular dynamics simulations. Based on the experimental data and computation predictions, we identified TPP-6-ISA as a candidate drug with optimized antiapoptotic potency. Copyright © 2014 Elsevier Inc. All rights reserved.

  16. Improved Soluble ScFv ELISA Screening Approach for Antibody Discovery Using Phage Display Technology. (United States)

    Tohidkia, Mohammad R; Sepehri, Maryam; Khajeh, Shirin; Barar, Jaleh; Omidi, Yadollah


    Phage display technology (PDT) is a powerful tool for the isolation of recombinant antibody (Ab) fragments. Using PDT, target molecule-specific phage-Ab clones are enriched through the "biopanning" process. The individual specific binders are screened by the monoclonal scFv enzyme-linked immunosorbent assay (ELISA) that may associate with inevitable false-negative results. Thus, in this study, three strategies were investigated for optimization of the scFvs screening using Tomlinson I and J libraries, including (1) optimizing the expression of functional scFvs, (2) improving the sensitivity of ELISA, and (3) preparing different samples containing scFvs. The expression of all scFv Abs was significantly enhanced when scFv clones were cultivated in the terrific broth (TB) medium at the optimum temperature of 30 °C. The protein A-conjugated with horseradish peroxidase (HRP) was found to be a well-suited reagent for the detection of Ag-bound scFvs in comparison with either anti-c-myc Ab or the mixing procedure. Based on our findings, it seems there is no universal media supplement for an improved expression of all scFvs derived from both Tomlinson I and J libraries. We thus propose that expression of scFv fragments in a microplate scale is largely dependent on a variety of parameters, in particular the scFv clones and relevant sequences.

  17. Enhanced

    Directory of Open Access Journals (Sweden)

    Martin I. Bayala


    Full Text Available Land Surface Temperature (LST is a key parameter in the energy balance model. However, the spatial resolution of the retrieved LST from sensors with high temporal resolution is not accurate enough to be used in local-scale studies. To explore the LST–Normalised Difference Vegetation Index relationship potential and obtain thermal images with high spatial resolution, six enhanced image sharpening techniques were assessed: the disaggregation procedure for radiometric surface temperatures (TsHARP, the Dry Edge Quadratic Function, the Difference of Edges (Ts∗DL and three models supported by the relationship of surface temperature and water stress of vegetation (Normalised Difference Water Index, Normalised Difference Infrared Index and Soil wetness index. Energy Balance Station data and in situ measurements were used to validate the enhanced LST images over a mixed agricultural landscape in the sub-humid Pampean Region of Argentina (PRA, during 2006–2010. Landsat Thematic Mapper (TM and Moderate Resolution Imaging Spectroradiometer (EOS-MODIS thermal datasets were assessed for different spatial resolutions (e.g., 960, 720 and 240 m and the performances were compared with global and local TsHARP procedures. Results suggest that the Ts∗DL technique is the most adequate for simulating LST to high spatial resolution over the heterogeneous landscape of a sub-humid region, showing an average root mean square error of less than 1 K.

  18. Position display device

    International Nuclear Information System (INIS)

    Nishizawa, Yukio.


    Object: To provide a device capable of easily and quickly reading mutual mounting relations of control bodies such as control rods mounted on a nuclear reactor and positions to which the control bodies are driven. Structure: A scanning circuit is provided to scan positions of controllably mounted control bodies such as control rods. Values detected by scanning the positions are converted into character signals according to the values and converted into preranked color signals. The character signals and color signals are stored in a memory circuit by synchronous signals in synchronism with the scanning in the scanning circuit. Outputs of the memory circuit are displayed by a display unit such as a color Braun tube in accordance with the synchronous signals to provide color representations according to positions to which control bodies are driven in the same positional relation as the mounting of the control bodies. (Kamimura, M.)

  19. Multichannel waveform display system

    International Nuclear Information System (INIS)

    Kolvankar, V.G.


    For any multichannel data acquisition system, a multichannel paper chart recorder undoubtedly forms an essential part of the system. When deployed on-line, it instantaneously provides, for visual inspection, hard copies of the signal waveforms on common time base at any desired sensitivity and time resolution. Within the country, only a small range of these strip chart recorder s is available, and under stringent specifications imported recorders are often procured. The cost of such recorders may range from 1 to 5 lakhs of rupees in foreign exchange. A system to provide on the oscilloscope a steady display of multichannel waveforms, refreshed from the digital data stored in the memory is developed. The merits and demerits of the display system are compared with that built around a conventional paper chart recorder. Various illustrations of multichannel seismic event data acquired at Gauribidanur seismic array station are also presented. (author). 2 figs

  20. Refrigerated display cabinets; Butikskyla

    Energy Technology Data Exchange (ETDEWEB)

    Fahlen, Per


    This report summarizes experience from SP research and assignments regarding refrigerated transport and storage of food, mainly in the retail sector. It presents the fundamentals of heat and mass transfer in display cabinets with special focus on indirect systems and secondary refrigerants. Moreover, the report includes a brief account of basic food hygiene and the related regulations. The material has been compiled for educational purposes in the Masters program at Chalmers Technical University.

  1. Helicopter Display Improvement Study (United States)


    PRESSURE INDICATOR 43 TURN A N D SLIP INDICATOR 21 ENGINE AND SDG OIL IN TEMPERATURE INDICATOR 44 COURSE INDICATOR 22 RADIO MAGNETIC COMPASS INDICATOR... compass seemed to present a problem to several H-l series pilots In that It was poorly located and should be moved. Possible locations Included...the UH-lNs standby compass . Both H/L and L/L pilots agreed that internal, white light was the best system currently in use. INDIVIDUAL DISPLAYS

  2. Thyroid Autoantibodies Display both “Original Antigenic Sin” and Epitope Spreading


    McLachlan, Sandra M.; Rapoport, Basil


    Evidence for original antigenic sin in spontaneous thyroid autoimmunity is revealed by autoantibody interactions with immunodominant regions on thyroid autoantigens, thyroglobulin (Tg), thyroid peroxidase (TPO), and the thyrotropin receptor (TSHR) A-subunit. In contrast, antibodies induced by immunization of rabbits or mice recognize diverse epitopes. Recognition of immunodominant regions persists despite fluctuations in autoantibody levels following treatment or over time. The enhancement of...

  3. Dyes for displays (United States)

    Claussen, U.


    The improvement of contrast and visibility of LCD by two different means was undertaken. The two methods are: (1) development of fluorescent dyes to increase the visibility of fluorescent activated displays (FLAD); and (2) development of dichroic dyes to increase the contrast of displays. This work was done in close cooperation with the electronic industry, where the newly synthesized dyes were tested. The targets for the chemical synthesis were selected with the help of computer model calculations. A marketable range of dyes was developed. Since the interest of the electronic industries concerning FLAD was low, the investigations were stopped. Dichroic dyes, especially black mixtures with good light fastness, order parameter, and solubility in nematic phases were developed. The application of these dyes is restricted to indoor use because of an increase of viscosity below -10 C. Applications on a technical scale, e.g., for the automotive industry, will be possible if the displays work at temperatures down to -40 C. This problem requires a complex optimization of the dye/nematic phase system.

  4. Qinshan plant display system: experience to date

    International Nuclear Information System (INIS)

    Bin, L.; Jiangdong, Y.; Weili, C.; Haidong, W.; Wangtian, L.; Lockwood, R.; Doucet, R.; Trask, D.; Judd, R.


    The two CANDU 6 units operated by the Third Qinshan Nuclear Power Corporation (TQNPC) include, as part of a control centre upgrade, a new plant display system (PDS). The PDS provides plant operators with new display and monitoring functionality designed to compliment the DCC capability. It includes new overview and trend displays (e.g., critical safety parameter monitor and user-defined trends), and enhanced annunciation based on AECL's Computerized Alarm Message List System (CAMLS) including an alarm interrogation capability. This paper presents a review of operating experience gained since the PDS was commissioned more than three years ago. It includes feedback provided by control room operators and trainers, PDS maintainers, and AECL development and support staff. It also includes an overview of improvements implemented since the PDS and suggestions for the future enhancements. (author)

  5. Direct Electrochemistry of Horseradish Peroxidase on NiO Nanoflower Modified Electrode and Its Electrocatalytic Activity

    Directory of Open Access Journals (Sweden)

    Lijun Yan


    Full Text Available In this paper nickel oxide (NiO nanoflower was synthesized and used for the realization of direct electrochemistry of horseradish peroxidase (HRP. By using carbon ionic liquid electrode (CILE as the substrate electrode, NiO-HRP composite was casted on the surface of CILE with chitosan (CTS as the film forming material and the modified electrode was denoted as CTS/NiO-HRP/CILE. UV-Vis absorption and FT-IR spectra confirmed that HRP retained its native structure after mixed with NiO nanoflower. Direct electron transfer of HRP on the modified electrode was investigated by cyclic voltammetry with a pair of quasi-reversible redox waves appeared, indicating that the presence of NiO nanoflower on the electrode surface could accelerate the electron transfer rate between the electroactive center of HRP and the substrate electrode. Electrochemical behaviors of HRP on the modified electrode were carefully investigated. The HRP modified electrode showed excellent electrocatalytic activity to the reduction of trichloroacetic acid with wider linear range and lower detection limit. Therefore the presence of NiO nanoflower could provide a friendly biocompatible interface for immobilizing biomolecules and keeping their native structure. The fabricated electrochemical biosensor displayed the advantages such as high sensitivity, good reproducibility and long-term stability. This work is licensed under a Creative Commons Attribution 4.0 International License.

  6. Asparagus byproducts as a new source of peroxidases. (United States)

    Jaramillo-Carmona, Sara; Lopez, Sergio; Vazquez-Castilla, Sara; Rodriguez-Arcos, Rocio; Jimenez-Araujo, Ana; Guillen-Bejarano, Rafael


    Soluble peroxidase (POD) from asparagus byproducts was purified by ion exchange chromatographies, and its kinetic and catalytic properties were studied. The isoelectric point of the purified isoperoxidases was 9.1, and the optimum pH and temperature values were 4.0 and 25 °C, respectively. The cationic asparagus POD (CAP) midpoint inactivation temperature was 57 °C, which favors its use in industrial processes. The Km values of cationic asparagus POD for H₂O₂ and ABTS were 0.318 and 0.634 mM, respectively. The purified CAP is economically obtained from raw materials using a simple protocol and possesses features that make it advantageous for the potential use of this enzyme in a large number of processes with demonstrated requirements of thermostable POD. The results indicate that CAP can be used as a potential candidate for removing phenolic contaminants.

  7. Erythrocytic glutathione peroxidase: Its relationship to plasma selenium in man

    International Nuclear Information System (INIS)

    Perona, G.; Cellerino, R.; Guidi, G.C.; Moschini, G.; Stievano, B.M.; Tregnaghi, C.


    Erythrocytic glutathione-peroxidase (GSH-Px) activity and plasma selenium concentrations were measured in 14 patients: 7 with iron deficiency and 7 with raised serum iron levels. The decreased enzymatic activity in iron deficiency was confirmed. Plasma selenium was significantly lower in patients with lower serum iron; furthermore there is a significant correlation between serum iron and plasma selenium concentrations. Another correlation even more significant was found between plasma selenium and enzyme activity in all the cases we studied. These data suggests that the importance of iron for GSH-Px activity may be merely due to its relationship with selenium and that plasma selenium concentration may be of critical importance for enzyme activity. (author)

  8. Double Antibody EIA of Cortisol Using Peroxidase As Label

    International Nuclear Information System (INIS)

    Karim, F.M.; Hamad, A.W.R.; Hashim, A.M.


    An enzyme immunoassay (EIA) technique for plasma cortisol was established by using cortisol-3 (carboxymethyl) oxime covalently linked to the horseradish peroxidase as the label. An antibody raised in the rabbits against cortisol-3-(carboxy-methyl) oxime-bovline serum albumin was used as the first anti-body. Sheep anti-rabbit gamma-globulin serum with 8 percent poly-ethyleneglycol were used to separate antibody-bound and free cortisol. The enzyme activity of the bound fraction was measured with ortho-phenylene diamine as substrate. The procedure performed at room temperature was evaluated by sensitivity (50 pg/ tube). The correlation coefficient between our enzyme immunoassay technique and radioimmunoassay technique for determination of plasma cortisol was 97 percent

  9. Polymerization reactivity of sulfomethylated alkali lignin modified with horseradish peroxidase. (United States)

    Yang, Dongjie; Wu, Xiaolei; Qiu, Xueqing; Chang, Yaqi; Lou, Hongming


    Alkali lignin (AL) was employed as raw materials in the present study. Sulfomethylation was conducted to improve the solubility of AL, while sulfomethylated alkali lignin (SAL) was further polymerized by horseradish peroxidase (HRP). HRP modification caused a significant increase in molecular weight of SAL which was over 20 times. It was also found to increase the amount of sulfonic and carboxyl groups while decrease the amount of phenolic and methoxyl groups in SAL. The adsorption quantity of self-assembled SAL film was improved after HRP modification. Sulfonation and HRP modification were mutually promoted. The polymerization reactivity of SAL in HRP modification was increased with its sulfonation degree. Meanwhile, HRP modification facilitated SAL's radical-sulfonation reaction. Copyright © 2014. Published by Elsevier Ltd.

  10. Purification of peroxidase from Horseradish (Armoracia rusticana) roots. (United States)

    Lavery, Christopher B; Macinnis, Morgan C; Macdonald, M Jason; Williams, Joanna Bassey; Spencer, Colin A; Burke, Alicia A; Irwin, David J G; D'Cunha, Godwin B


    Peroxidase (EC from horseradish ( Armoracia rusticana ) roots was purified using a simple, rapid, three-step procedure: ultrasonication, ammonium sulfate salt precipitation, and hydrophobic interaction chromatography on phenyl Sepharose CL-4B. The preparation gave an overall yield of 71%, 291-fold purification, and a high specific activity of 772 U mg(-1) protein. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis revealed that the purified enzyme was homogeneous and had a molecular weight of approximately 40 kDa. The isolated enzyme had an isoelectric point of 8.8 and a Reinheitszahl value of 3.39 and was stable when stored in the presence of glycerol at -20 degrees C, with >95% retention of original enzyme activity for at least 6 months. Maximal activity of purified horseradish peroxidase (HRP) was obtained under different optimized conditions: substrate (guaiacol and H(2)O(2)) concentrations (0.5 and 0.3 mM, respectively), type of buffer (50 mM phosphate buffer), pH (7.0), time (1.0 min), and temperature of incubation (30 degrees C). In addition, the effect of HRP and H(2)O(2) in a neutral-buffered aqueous solution for the oxidation of phenol and 2-chlorophenol substrates was also studied. Different conditions including concentrations of phenol/2-chlorophenol, H(2)O(2), and enzyme, time, pH, and temperature were standardized for the maximal activity of HRP with these substrates; under these optimal conditions 89.6 and 91.4% oxidations of phenol and 2-chlorophenol were obtained, respectively. The data generated from this work could have direct implications in studies on the commercial production of this biotechnologically important enzyme and its stability in different media.

  11. The Roles of Glutathione Peroxidases during Embryo Development. (United States)

    Ufer, Christoph; Wang, Chi Chiu


    Embryo development relies on the complex interplay of the basic cellular processes including proliferation, differentiation, and apoptotic cell death. Precise regulation of these events is the basis for the establishment of embryonic structures and the organ development. Beginning with fertilization of the oocyte until delivery the developing embryo encounters changing environmental conditions such as varying levels of oxygen, which can give rise to reactive oxygen species (ROS). These challenges are met by the embryo with metabolic adaptations and by an array of anti-oxidative mechanisms. ROS can be deleterious by modifying biological molecules including lipids, proteins, and nucleic acids and may induce abnormal development or even embryonic lethality. On the other hand ROS are vital players of various signaling cascades that affect the balance between cell growth, differentiation, and death. An imbalance or dysregulation of these biological processes may generate cells with abnormal growth and is therefore potentially teratogenic and tumorigenic. Thus, a precise balance between processes generating ROS and those decomposing ROS is critical for normal embryo development. One tier of the cellular protective system against ROS constitutes the family of selenium-dependent glutathione peroxidases (GPx). These enzymes reduce hydroperoxides to the corresponding alcohols at the expense of reduced glutathione. Of special interest within this protein family is the moonlighting enzyme glutathione peroxidase 4 (Gpx4). This enzyme is a scavenger of lipophilic hydroperoxides on one hand, but on the other hand can be transformed into an enzymatically inactive cellular structural component. GPx4 deficiency - in contrast to all other GPx family members - leads to abnormal embryo development and finally produces a lethal phenotype in mice. This review is aimed at summarizing the current knowledge on GPx isoforms during embryo development and tumor development with an emphasis on

  12. Thyroid peroxidase: evidence for disease gene exclusion in Pendred's syndrome. (United States)

    Gausden, E; Armour, J A; Coyle, B; Coffey, R; Hochberg, Z; Pembrey, M; Britton, K E; Grossman, A; Reardon, W; Trembath, R


    Pendred's syndrome is an association between congenital neurosensory deafness and goitre with abnormal discharge of iodide following perchlorate challenge, indicating a defect of iodide organification. Although Pendred's syndrome may cause up to 7.5% of all cases of congenital deafness, the molecular basis of the association between the hearing loss and the thyroid organification defect remains unknown. We chose to investigate the role of the thyroid peroxidase (TPO) gene as the genetic defect in Pendred's syndrome. A highly informative variable number tandem repeat (VNTR), located 1.5 kb downstream of exon 10 of the TPO gene, was used to search for genetic linkage in multiple sibships affected by Pendred's syndrome. Seven kindreds were recruited from the UK, each with at least two affected members. We have also examined a large inbred Israeli family with two affected offspring and five unaffected children. Individuals were assigned affected status based on the characteristic clinical features of Pendred's syndrome, namely the presence of congenital sensorineural hearing loss and the appearance in early life of a goitre. Additionally, at least one affected member from each sibship had a characteristic positive perchlorate discharge test (Morgans & Trotter, 1958). PCR amplification of genomic DNA at the TPO VNTR allowed assignment of genotypes to each individual and the calculation of a two-point LOD score. In six of the nine sibships analysed we found obligatory recombination between TPO and Pendred's syndrome. Non-complementation observed in affected parents with an affected offspring excluded TPO in an affected sibship with genotype sharing and supports a hypothesis of genetic homogeneity for Pendred's syndrome. In two sibships, mutation of the TPO gene as the cause of Pendred's syndrome could not be excluded. These data suggest that defects at the thyroid peroxidase locus on chromosome 2 are not the major cause of Pendred's syndrome.

  13. Handbook of Visual Display Technology

    CERN Document Server

    Cranton, Wayne; Fihn, Mark


    The Handbook of Visual Display Technology is a unique work offering a comprehensive description of the science, technology, economic and human interface factors associated with the displays industry. An invaluable compilation of information, the Handbook will serve as a single reference source with expert contributions from over 150 international display professionals and academic researchers. All classes of display device are covered including LCDs, reflective displays, flexible solutions and emissive devices such as OLEDs and plasma displays, with discussion of established principles, emergent technologies, and particular areas of application. The wide-ranging content also encompasses the fundamental science of light and vision, image manipulation, core materials and processing techniques, display driving and metrology.

  14. Book Display as Adult Service

    Directory of Open Access Journals (Sweden)

    Matthew S. Moore


    Full Text Available 無Book display as an adult service is defined as choosing and positioning adult books from the collection to increase their circulation. The author contrasts bookstore arrangement for sales versus library arrangement for access. The paper considers the library-as-a-whole as a display, examines the right size for an in-library display, and discusses mass displays, end-caps, on-shelf displays, and the Tiffany approach. The author proposes that an effective display depends on an imaginative, unifying theme, and that book displays are part of the joy of libraries.

  15. Magnetic resonance spectral characterization of the heme active site of Coprinus cinereus peroxidase

    International Nuclear Information System (INIS)

    Lukat, G.S.; Rodgers, K.R.; Jabro, M.N.; Goff, H.M.


    Examination of the peroxidase isolated from the inkcap Basidiomycete Coprinus cinereus shows that the 42,000-dalton enzyme contains a protoheme IX prosthetic group. Reactivity assays and the electronic absorption spectra of native Coprinus peroxidase and several of its ligand complexes indicate that this enzyme has characteristics similar to those reported for horseradish peroxidase. In this paper, the authors characterize the H 2 O 2 -oxidized forms of Coprinus peroxidase compounds I, II, and III by electronic absorption and magnetic resonance spectroscopies. Electron paramagnetic resonance (EPR) and nuclear magnetic resonance (NMR) studies of this Coprinus peroxidase indicate the presence of high-spin Fe(III) in the native protein and a number of differences between the heme site of Coprinus peroxidase and horseradish peroxidase. Carbon-13 (of the ferrous CO adduct) and nitrogen-15 (of the cyanide complex) NMR studies together with proton NMR studies of the native and cyanide-complexed Caprinus peroxidase are consistent with coordination of a proximal histidine ligand. The EPR spectrum of the ferrous NO complex is also reported. Protein reconstitution with deuterated hemin has facilitated the assignment of the heme methyl resonances in the proton NMR spectrum

  16. Use of an immuno-peroxidase staining method for the detection of ...

    African Journals Online (AJOL)

    Immunopurified antigens of axenic E. histolytica were used to produce rabbit hyper-immune sera. Immunoglobulin G (IgG) was purified from hyper-immune sera and coupled to peroxidase using a two-step procedure. The IgG-peroxidase conjugate was then evaluated by detection of E. histolytica in 128 stool samples and ...

  17. Purification and characterization of an intracellular catalase-peroxidase from Penicillium simplicissimum

    NARCIS (Netherlands)

    Fraaije, Marco W.; Roubroeks, Hanno P.; Hagen, Wilfred R.; Berkel, Willem J.H. van


    The first dimeric catalase-peroxidase of eucaryotic origin, an intracellular hydroperoxidase from Penicillium simplicissimum which exhibited both catalase and peroxidase activities, has been isolated. The enzyme has an apparent molecular mass of about 170 kDa and is composed of two identical

  18. NCAP projection displays (United States)

    Havens, John R.; Ishioka, J.; Jones, Philip J.; Lau, Aldrich; Tomita, Akira; Asano, A.; Konuma, Nobuhiro; Sato, Kazuhiko; Takemoto, Iwao


    Projectors based on polymer-eNCAPsulated liquid crystals can provide bright displays suitable for use in conference rooms with normal lighting. Contrast is generated by light scattering among the droplets, rather than by light absorption with crossed polarizers. We have demonstrated a full-color, compact projector showing 1200 ANSI lumens with 200 watts of lamp power - a light efficiency of 6 lumens/watt. This projector is based on low-voltage NCAP material, highly reflective CMOS die, and matched illumination and projection optics. We will review each of these areas and discuss the integrated system performance.

  19. Glutathione Peroxidase-1 Suppresses the Unfolded Protein Response upon Cigarette Smoke Exposure

    Directory of Open Access Journals (Sweden)

    Patrick Geraghty


    Full Text Available Oxidative stress provokes endoplasmic reticulum (ER stress-induced unfolded protein response (UPR in the lungs of chronic obstructive pulmonary (COPD subjects. The antioxidant, glutathione peroxidase-1 (GPx-1, counters oxidative stress induced by cigarette smoke exposure. Here, we investigate whether GPx-1 expression deters the UPR following exposure to cigarette smoke. Expression of ER stress markers was investigated in fully differentiated normal human bronchial epithelial (NHBE cells isolated from nonsmoking, smoking, and COPD donors and redifferentiated at the air liquid interface. NHBE cells from COPD donors expressed heightened ATF4, XBP1, GRP78, GRP94, EDEM1, and CHOP compared to cells from nonsmoking donors. These changes coincided with reduced GPx-1 expression. Reintroduction of GPx-1 into NHBE cells isolated from COPD donors reduced the UPR. To determine whether the loss of GPx-1 expression has a direct impact on these ER stress markers during smoke exposure, Gpx-1−/− mice were exposed to cigarette smoke for 1 year. Loss of Gpx-1 expression enhanced cigarette smoke-induced ER stress and apoptosis. Equally, induction of ER stress with tunicamycin enhanced antioxidant expression in mouse precision-cut lung slices. Smoke inhalation also exacerbated the UPR response during respiratory syncytial virus infection. Therefore, ER stress may be an antioxidant-related pathophysiological event in COPD.

  20. Painting Reproductions on Display

    Directory of Open Access Journals (Sweden)

    Joanna Iranowska


    Full Text Available Paintings in museums might occasionally be replaced by a photoprint mimicking the original. This article is an investigation of what constitutes a good reproduction of an artwork (oil painting that is meant to be displayed. The article discusses what the usefulness of reproductions depends on, applying the Valuation Studies approach, which means the primary concern is with the practice of valuing itself. In other words, the study focuses on how museum experts evaluate reproduc-tions of oil paintings. The article analyses three cases of displaying digitally prin-ted copies of Edvard Munch's oil paintings between 2013 and 2015 in the Munch Museum and in the National Gallery in Oslo. The study is based on a series of semi-structured interviews with the experts, working at and for the museums, that were involved in producing and exhibiting of the photoprints: curators, con-servators, museum educators, and external manufacturers. The interviews were grouped into five clusters, which I have chosen to call registers of valuing following Frank Heuts and Annemarie Mol (2013. The described valuation practices have to do with delivering experiences to the public, obtaining mimetic resemblance, solving ethical aspects, exhibitions' budget, and last but not least, with the time perspective.

  1. Unsolicited displays of insights

    DEFF Research Database (Denmark)

    Brouwer, Catherine E.


    This study is based on videorecorded interactional data from a specific type of institutional setting which consists of a variety of 'language stimulation activities' for bilingual children in Danish preschools. Bilingual children, with a variety of linguistic backgrounds, take part in these acti......This study is based on videorecorded interactional data from a specific type of institutional setting which consists of a variety of 'language stimulation activities' for bilingual children in Danish preschools. Bilingual children, with a variety of linguistic backgrounds, take part...... in these activities in small groups together with a specialized preschool teacher. One pervasive feature of this kind of data is the ongoing orientation to, and guidance from the adult towards the children on what the main business of their interaction is - what they relevantly are doing. In this light, the paper......: Unsolicited displays may lead to side sequences, they may lead to a shift in the main business of the talk, or they may be explicitly or implicitly ignored. The paper discusses whether and how these unsolicited displays of understanding then can be thought of as leading to opportunities for (language...

  2. User interface design in safety parameter display systems

    International Nuclear Information System (INIS)

    Schultz, E.E. Jr.; Johnson, G.L.


    The extensive installation of computerized safety Parameter Display Systems (SPDSs) in nuclear power plants since the Three-Mile Island accident has enhanced plant safety. It has also raised new issues of how best to ensure an effective interface between human operators and the plant via computer systems. New developments in interface technologies since the current generation of SPDSs was installed can contribute to improving display interfaces. These technologies include new input devices, three-dimensional displays, delay indicators, and auditory displays. Examples of how they might be applied to improve current SPDSs are given. These examples illustrate how the new use interface technology could be applied to future nuclear plant displays

  3. Latest development of display technologies

    International Nuclear Information System (INIS)

    Gao Hong-Yue; Yao Qiu-Xiang; Liu Pan; Zheng Zhi-Qiang; Liu Ji-Cheng; Zheng Hua-Dong; Zeng Chao; Yu Ying-Jie; Sun Tao; Zeng Zhen-Xiang


    In this review we will focus on recent progress in the field of two-dimensional (2D) and three-dimensional (3D) display technologies. We present the current display materials and their applications, including organic light-emitting diodes (OLEDs), flexible OLEDs quantum dot light emitting diodes (QLEDs), active-matrix organic light emitting diodes (AMOLEDs), electronic paper (E-paper), curved displays, stereoscopic 3D displays, volumetric 3D displays, light field 3D displays, and holographic 3D displays. Conventional 2D display devices, such as liquid crystal devices (LCDs) often result in ambiguity in high-dimensional data images because of lacking true depth information. This review thus provides a detailed description of 3D display technologies. (topical review)

  4. Influence of Phytophthora capsici L. inoculation on disease severity, necrosis length, peroxidase and catalase activity, and phenolic content of resistant and susceptible pepper (Capsicum annuum L.) plants


    KOÇ, Esra; ÜSTÜN, Ayşen Sülün


    This study explored the level of infection caused by different inoculum concentrations (102, 103, and 104 zoospores mL-1) of Phytophthora capsici in 3 pepper cultivars at days 2, 4, and 6. The effect that the infection induced on the peroxidase (POX), catalase (CAT), and phenolics of resistant and sensitive seedlings, as well as the defense mechanism against the pathogen, were also investigated. The resistance of PM-702 against the isolate used was high, whereas KM-Hot and DEM-8 displayed sen...

  5. Leader Affect and Leadership Effectiveness: How leader affective displays influence follower outcomes


    Visser, Victoria


    textabstractThe aim of this dissertation is to uncover the relationship between leader affective displays and leadership effectiveness. Five empirical studies were conducted to test the influence of several leader affective displays on different follower outcomes that indicate leadership effectiveness. The results showed that leader happy displays enhance followers’ creative performance, whereas leader sad displays enhance followers’ analytical performance. In addition, a leader displaying ha...

  6. 3D display system using monocular multiview displays (United States)

    Sakamoto, Kunio; Saruta, Kazuki; Takeda, Kazutoki


    A 3D head mounted display (HMD) system is useful for constructing a virtual space. The authors have researched the virtual-reality systems connected with computer networks for real-time remote control and developed a low-priced real-time 3D display for building these systems. We developed a 3D HMD system using monocular multi-view displays. The 3D displaying technique of this monocular multi-view display is based on the concept of the super multi-view proposed by Kajiki at TAO (Telecommunications Advancement Organization of Japan) in 1996. Our 3D HMD has two monocular multi-view displays (used as a visual display unit) in order to display a picture to the left eye and the right eye. The left and right images are a pair of stereoscopic images for the left and right eyes, then stereoscopic 3D images are observed.

  7. Polymer Dispersed Liquid Crystal Displays (United States)

    Doane, J. William

    The following sections are included: * INTRODUCTION AND HISTORICAL DEVELOPMENT * PDLC MATERIALS PREPARATION * Polymerization induced phase separation (PIPS) * Thermally induced phase separation (TIPS) * Solvent induced phase separation (SIPS) * Encapsulation (NCAP) * RESPONSE VOLTAGE * Dielectric and resistive effects * Radial configuration * Bipolar configuration * Other director configurations * RESPONSE TIME * DISPLAY CONTRAST * Light scattering and index matching * Incorporation of dyes * Contrast measurements * PDLC DISPLAY DEVICES AND INNOVATIONS * Reflective direct view displays * Large-scale, flexible displays * Switchable windows * Projection displays * High definition spatial light modulator * Haze-free PDLC shutters: wide angle view displays * ENVIRONMENTAL STABILITY * ACKNOWLEDGEMENTS * REFERENCES

  8. A putative peroxidase cDNA from turnip and analysis of the encoded protein sequence. (United States)

    Romero-Gómez, S; Duarte-Vázquez, M A; García-Almendárez, B E; Mayorga-Martínez, L; Cervantes-Avilés, O; Regalado, C


    A putative peroxidase cDNA was isolated from turnip roots (Brassica napus L. var. purple top white globe) by reverse transcriptase-polymerase chain reaction (RT-PCR) and rapid amplification of cDNA ends (RACE). Total RNA extracted from mature turnip roots was used as a template for RT-PCR, using a degenerated primer designed to amplify the highly conserved distal motif of plant peroxidases. The resulting partial sequence was used to design the rest of the specific primers for 5' and 3' RACE. Two cDNA fragments were purified, sequenced, and aligned with the partial sequence from RT-PCR, and a complete overlapping sequence was obtained and labeled as BbPA (Genbank Accession No. AY423440, named as podC). The full length cDNA is 1167bp long and contains a 1077bp open reading frame (ORF) encoding a 358 deduced amino acid peroxidase polypeptide. The putative peroxidase (BnPA) showed a calculated Mr of 34kDa, and isoelectric point (pI) of 4.5, with no significant identity with other reported turnip peroxidases. Sequence alignment showed that only three peroxidases have a significant identity with BnPA namely AtP29a (84%), and AtPA2 (81%) from Arabidopsis thaliana, and HRPA2 (82%) from horseradish (Armoracia rusticana). Work is in progress to clone this gene into an adequate host to study the specific role and possible biotechnological applications of this alternative peroxidase source.

  9. Amphitrite ornata Dehaloperoxidase (DHP): Investigations of Structural Factors That Influence the Mechanism of Halophenol Dehalogenation Using ;Peroxidase-like; Myoglobin Mutants and ;Myoglobin-like; DHP Mutants

    Energy Technology Data Exchange (ETDEWEB)

    Du, Jing; Huang, Xiao; Sun, Shengfang; Wang, Chunxue; Lebioda, Lukasz; Dawson, John H. (SC)


    Dehaloperoxidase (DHP), discovered in the marine terebellid polychaete Amphitrite ornata, is the first heme-containing globin with a peroxidase activity. The sequence and crystal structure of DHP argue that it evolved from an ancient O{sub 2} transport and storage globin. Thus, DHP retains an oxygen carrier function but also has the ability to degrade halophenol toxicants in its living environment. Sperm whale myoglobin (Mb) in the ferric state has a peroxidase activity {approx}10 times lower than that of DHP. The catalytic activity enhancement observed in DHP appears to have been generated mainly by subtle changes in the positions of the proximal and distal histidine residues that appeared during DHP evolution. Herein, we report investigations into the mechanism of action of DHP derived from examination of 'peroxidase-like' Mb mutants and 'Mb-like' DHP mutants. The dehalogenation ability of wild-type Mb is augmented in the peroxidase-like Mb mutants (F43H/H64L, G65T, and G65I Mb) but attenuated in the Mb-like T56G DHP variant. X-ray crystallographic data show that the distal His residues in G65T Mb and G65I are positioned {approx}0.3 and {approx}0.8 {angstrom}, respectively, farther from the heme iron compared to that in the wild-type protein. The H93K/T95H double mutant Mb with the proximal His shifted to the 'DHP-like' position has an increased peroxidase activity. In addition, a better dehaloperoxidase (M86E DHP) was generated by introducing a negative charge near His89 to enhance the imidazolate character of the proximal His. Finally, only minimal differences in dehalogenation activities are seen among the exogenous ligand-free DHP, the acetate-bound DHP, and the distal site blocker L100F DHP mutant. Thus, we conclude that binding of halophenols in the internal binding site (i.e., distal cavity) is not essential for catalysis. This work provides a foundation for a new structure-function paradigm for peroxidases and for the

  10. Amphitrite ornata dehaloperoxidase (DHP): investigations of structural factors that influence the mechanism of halophenol dehalogenation using "peroxidase-like" myoglobin mutants and "myoglobin-like" DHP mutants. (United States)

    Du, Jing; Huang, Xiao; Sun, Shengfang; Wang, Chunxue; Lebioda, Lukasz; Dawson, John H


    Dehaloperoxidase (DHP), discovered in the marine terebellid polychaete Amphitrite ornata, is the first heme-containing globin with a peroxidase activity. The sequence and crystal structure of DHP argue that it evolved from an ancient O(2) transport and storage globin. Thus, DHP retains an oxygen carrier function but also has the ability to degrade halophenol toxicants in its living environment. Sperm whale myoglobin (Mb) in the ferric state has a peroxidase activity ∼10 times lower than that of DHP. The catalytic activity enhancement observed in DHP appears to have been generated mainly by subtle changes in the positions of the proximal and distal histidine residues that appeared during DHP evolution. Herein, we report investigations into the mechanism of action of DHP derived from examination of "peroxidase-like" Mb mutants and "Mb-like" DHP mutants. The dehalogenation ability of wild-type Mb is augmented in the peroxidase-like Mb mutants (F43H/H64L, G65T, and G65I Mb) but attenuated in the Mb-like T56G DHP variant. X-ray crystallographic data show that the distal His residues in G65T Mb and G65I are positioned ∼0.3 and ∼0.8 Å, respectively, farther from the heme iron compared to that in the wild-type protein. The H93K/T95H double mutant Mb with the proximal His shifted to the "DHP-like" position has an increased peroxidase activity. In addition, a better dehaloperoxidase (M86E DHP) was generated by introducing a negative charge near His89 to enhance the imidazolate character of the proximal His. Finally, only minimal differences in dehalogenation activities are seen among the exogenous ligand-free DHP, the acetate-bound DHP, and the distal site blocker L100F DHP mutant. Thus, we conclude that binding of halophenols in the internal binding site (i.e., distal cavity) is not essential for catalysis. This work provides a foundation for a new structure-function paradigm for peroxidases and for the molecular evolution of the dual-function enzyme DHP.

  11. Glutathione peroxidases of the potato cyst nematode Globodera Rostochiensis. (United States)

    Jones, J T; Reavy, B; Smant, G; Prior, A E


    We report the cloning and characterisation of full-length DNAs complementary to RNA (cDNAs) encoding two glutathione peroxidases (GpXs) from a plant parasitic nematode, the potato cyst nematode (PCN) Globodera rostochiensis. One protein has a functional signal peptide that targets the protein for secretion from animal cells while the other is predicted to be intracellular. Both genes are expressed in all parasite stages tested. The mRNA encoding the intracellular GpX is present throughout the nematode second stage juvenile and is particularly abundant in metabolically active tissues including the genital primordia. The mRNA encoding the secreted GpX is restricted to the hypodermis, the outermost cellular layer of the nematode, a location from which it is likely to be secreted to the parasite surface. Biochemical studies confirmed the secreted protein as a functional GpX and showed that, like secreted GpXs of other parasitic nematodes, it does not metabolise hydrogen peroxide but has a preference for larger hydroperoxide substrates. The intracellular protein is likely to have a role in metabolism of active oxygen species derived from internal body metabolism while the secreted protein may protect the parasite from host defences. Other functional roles for this protein are discussed.

  12. Thyroid Peroxidase Antibody and Screening for Postpartum Thyroid Dysfunction

    Directory of Open Access Journals (Sweden)

    Mohamed A. Adlan


    Full Text Available Postpartum thyroid dysfunction (PPTD is a common disorder which causes considerable morbidity in affected women. The availability of effective treatment for hypothyroid PPTD, the occurrence of the disease in subsequent pregnancies and the need to identify subjects who develop long term hypothyroidism, has prompted discussion about screening for this disorder. There is currently no consensus about screening as investigations hitherto have been variable in their design, definitions and assay frequency and methodology. There is also a lack of consensus about a suitable screening tool although thyroid peroxidase antibody (TPOAb is a leading contender. We present data about the use of TPOAb in early pregnancy and its value as a screening tool. Although its positive predictive value is moderate, its sensitivity and specificity when used in early pregnancy are comparable or better compared to other times during pregnancy and the postpartum period. Recent studies have also confirmed this strategy to be cost effective and to compare favourably with other screening strategies. We also explore the advantages of universal screening.

  13. Colorimetric peroxidase mimetic assay for uranyl detection in sea water

    KAUST Repository

    Zhang, Dingyuan


    Uranyl (UO2 2+) is a form of uranium in aqueous solution that represents the greatest risk to human health because of its bioavailability. Different sensing techniques have been used with very sensitive detection limits especially the recently reported uranyl-specific DNAzymes systems. However, to the best of our knowledge, few efficient detection methods have been reported for uranyl sensing in seawater. Herein, gold nanoclusters (AuNCs) are employed in an efficient spectroscopic method to detect uranyl ion (UO2 2+) with a detection limit of 1.86 ÎM. In the absence of UO2 2+, the BSA-stabilized AuNCs (BSA-AuNCs) showed an intrinsic peroxidase-like activity. In the presence of UO2 2+, this activity can be efficiently restrained. The preliminary quenching mechanism and selectivity of UO2 2+ was also investigated and compared with other ions. This design strategy could be useful in understanding the binding affinity of protein-stabilized AuNCs to UO2 2+ and consequently prompt the recycling of UO2 2+ from seawater.

  14. Silica Sol-Gel Entrapment of the Enzyme Chloro peroxidase

    International Nuclear Information System (INIS)

    Le, T.; Chan, S.; Ebaid, B.; Sommerhalter, M.


    The enzyme chloro peroxidase (CPO) was immobilized in silica sol-gel beads prepared from tetramethoxysilane. The average pore diameter of the silica host structure (∼3 nm) was smaller than the globular CPO diameter (∼6 nm) and the enzyme remained entrapped after sol-gel maturation. The catalytic performance of the entrapped enzyme was assessed via the pyrogallol peroxidation reaction. Sol-gel beads loaded with 4 μg CPO per mL sol solution reached 9-12% relative activity compared to free CPO in solution. Enzyme kinetic analysis revealed a decrease in K_cat but no changes in K_M or K_I . Product release or enzyme damage might thus limit catalytic performance. Yet circular dichroism and visible absorption spectra of transparent CPO sol-gel sheets did not indicate enzyme damage. Activity decline due to methanol exposure was shown to be reversible in solution. To improve catalytic performance the sol-gel protocol was modified. The incorporation of 5, 20, or 40% methyltrimethoxysilane resulted in more brittle sol-gel beads but the catalytic performance increased to 14% relative to free CPO in solution. The use of more acidic casting buffers (ph 4.5 or 5.5 instead of 6.5) resulted in a more porous silica host reaching up to 18% relative activity

  15. Thermal and high pressure inactivation kinetics of blueberry peroxidase. (United States)

    Terefe, Netsanet Shiferaw; Delon, Antoine; Versteeg, Cornelis


    This study for the first time investigated the stability and inactivation kinetics of blueberry peroxidase in model systems (McIlvaine buffer, pH=3.6, the typical pH of blueberry juice) during thermal (40-80°C) and combined high pressure-thermal processing (0.1-690MPa, 30-90°C). At 70-80°C, the thermal inactivation kinetics was best described by a biphasic model with ∼61% labile and ∼39% stable fractions at temperature between 70 and 75°C. High pressure inhibited the inactivation of the enzyme with no inactivation at pressures as high as 690MPa and temperatures less than 50°C. The inactivation kinetics of the enzyme at 60-70°C, and pressures higher than 500MPa was best described by a first order biphasic model with ∼25% labile fraction and 75% stable fraction. The activation energy values at atmospheric pressure were 548.6kJ/mol and 324.5kJ/mol respectively for the stable and the labile fractions. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.

  16. High performance visual display for HENP detectors

    CERN Document Server

    McGuigan, M; Spiletic, J; Fine, V; Nevski, P


    A high end visual display for High Energy Nuclear Physics (HENP) detectors is necessary because of the sheer size and complexity of the detector. For BNL this display will be of special interest because of STAR and ATLAS. To load, rotate, query, and debug simulation code with a modern detector simply takes too long even on a powerful work station. To visualize the HENP detectors with maximal performance we have developed software with the following characteristics. We develop a visual display of HENP detectors on BNL multiprocessor visualization server at multiple level of detail. We work with general and generic detector framework consistent with ROOT, GAUDI etc, to avoid conflicting with the many graphic development groups associated with specific detectors like STAR and ATLAS. We develop advanced OpenGL features such as transparency and polarized stereoscopy. We enable collaborative viewing of detector and events by directly running the analysis in BNL stereoscopic theatre. We construct enhanced interactiv...

  17. Crosstalk evaluation in stereoscopic displays

    NARCIS (Netherlands)

    Wang, L.; Teunissen, C.; Tu, Yan; Chen, Li; Zhang, P.; Zhang, T.; Heynderickx, I.E.J.


    Substantial progress in liquid-crystal display and polarization film technology has enabled several types of stereoscopic displays. Despite all progress, some image distortions still exist in these 3-D displays, of which interocular crosstalk - light leakage of the image for one eye to the other eye

  18. Inhibition of Heme Peroxidase During Phenol Derivatives Oxidation. Possible Molecular Cloaking of the Active Center

    Directory of Open Access Journals (Sweden)

    Juozas Kulys


    Full Text Available Abstract: Ab initio quantum chemical calculations have been applied to the study of the molecular structure of phenol derivatives and oligomers produced during peroxidasecatalyzed oxidation. The interaction of substrates and oligomers with Arthromyces ramosus peroxidase was analyzed by docking methods. The most possible interaction site of oligomers is an active center of the peroxidase. The complexation energy increases with increasing oligomer length. However, the complexed oligomers do not form a precise (for the reaction hydrogen bonding network in the active center of the enzyme. It seems likely that strong but non productive docking of the oligomers determines peroxidase inhibition during the reaction.

  19. LHCb Event display

    CERN Document Server

    Trisovic, Ana


    The LHCb Event Display was made for educational purposes at the European Organization for Nuclear Research, CERN in Geneva, Switzerland. The project was implemented as a stand-alone application using C++ and ROOT, a framework developed by CERN for data analysis. This paper outlines the development and architecture of the application in detail, as well as the motivation for the development and the goals of the exercise. The application focuses on the visualization of events recorded by the LHCb detector, where an event represents a set of charged particle tracks in one proton-proton collision. Every particle track is coloured by its type and can be selected to see its essential information such as mass and momentum. The application allows students to save this information and calculate the invariant mass for any pair of particles. Furthermore, the students can use additional calculating tools in the application and build up a histogram of these invariant masses. The goal for the students is to find a $D^0$ par...

  20. Colorimetry for CRT displays. (United States)

    Golz, Jürgen; MacLeod, Donald I A


    We analyze the sources of error in specifying color in CRT displays. These include errors inherent in the use of the color matching functions of the CIE 1931 standard observer when only colorimetric, not radiometric, calibrations are available. We provide transformation coefficients that prove to correct the deficiencies of this observer very well. We consider four different candidate sets of cone sensitivities. Some of these differ substantially; variation among candidate cone sensitivities exceeds the variation among phosphors. Finally, the effects of the recognized forms of observer variation on the visual responses (cone excitations or cone contrasts) generated by CRT stimuli are investigated and quantitatively specified. Cone pigment polymorphism gives rise to variation of a few per cent in relative excitation by the different phosphors--a variation larger than the errors ensuing from the adoption of the CIE standard observer, though smaller than the differences between some candidate cone sensitivities. Macular pigmentation has a larger influence, affecting mainly responses to the blue phosphor. The estimated combined effect of all sources of observer variation is comparable in magnitude with the largest differences between competing cone sensitivity estimates but is not enough to disrupt very seriously the relation between the L and M cone weights and the isoluminance settings of individual observers. It is also comparable with typical instrumental colorimetric errors, but we discuss these only briefly.

  1. Web Extensible Display Manager

    Energy Technology Data Exchange (ETDEWEB)

    Slominski, Ryan [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Larrieu, Theodore L. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)


    Jefferson Lab's Web Extensible Display Manager (WEDM) allows staff to access EDM control system screens from a web browser in remote offices and from mobile devices. Native browser technologies are leveraged to avoid installing and managing software on remote clients such as browser plugins, tunnel applications, or an EDM environment. Since standard network ports are used firewall exceptions are minimized. To avoid security concerns from remote users modifying a control system, WEDM exposes read-only access and basic web authentication can be used to further restrict access. Updates of monitored EPICS channels are delivered via a Web Socket using a web gateway. The software translates EDM description files (denoted with the edl suffix) to HTML with Scalable Vector Graphics (SVG) following the EDM's edl file vector drawing rules to create faithful screen renderings. The WEDM server parses edl files and creates the HTML equivalent in real-time allowing existing screens to work without modification. Alternatively, the familiar drag and drop EDM screen creation tool can be used to create optimized screens sized specifically for smart phones and then rendered by WEDM.

  2. Expression of Glutathione Peroxidase and Glutathione Reductase and Level of Free Radical Processes under Toxic Hepatitis in Rats

    Directory of Open Access Journals (Sweden)

    Igor Y. Iskusnykh


    Full Text Available Correlation between intensity of free radical processes estimated by biochemiluminesce parameters, content of lipoperoxidation products, and changes of glutathione peroxidase (GP, EC and glutathione reductase (GR, EC activities at rats liver injury, after 12, 36, 70, 96, 110, and 125 hours & tetrachloromethane administration have been investigated. The histological examination of the liver sections of rats showed that prominent hepatocytes with marked vacuolisation and inflammatory cells which were arranged around the necrotic tissue are more at 96 h after exposure to CCl4. Moreover maximum increase in GR and GP activities, 2.1 and 2.5 times, respectively, was observed at 96 h after exposure to CCl4, what coincided with the maximum of free radical oxidation processes. Using a combination of reverse transcription and real-time polymerase chain reaction, expression of the glutathione peroxidase and glutathione reductase genes (Gpx1 and Gsr was analyzed by the determination of their respective mRNAs in the rat liver tissue under toxic hepatitis conditions. The analyses of Gpx1 and Gsr expression revealed that the transcript levels increased in 2.5- and 3.0-folds, respectively. Western blot analysis revealed that the amounts of hepatic Gpx1 and Gsr proteins increased considerably after CCl4 administration. It can be proposed that the overexpression of these enzymes could be a mechanism of enhancement of hepatocytes tolerance to oxidative stress.

  3. Three-Dimensional Graphene Supported Bimetallic Nanocomposites with DNA Regulated-Flexibly Switchable Peroxidase-Like Activity. (United States)

    Yuan, Fang; Zhao, Huimin; Zang, Hongmei; Ye, Fei; Quan, Xie


    A synergistic bimetallic enzyme mimetic catalyst, three-dimensional (3D) graphene/Fe3O4-AuNPs, was successfully fabricated which exhibited flexibly switchable peroxidase-like activity. Compared to the traditional 2D graphene-based monometallic composite, the introduced 3D structure, which was induced by the addition of glutamic acid, and bimetallic anchoring approach dramatically improved the catalytic activity, as well as the catalysis velocity and its affinity for substrate. Herein, Fe3O4NPs acted as supporters for AuNPs, which contributed to enhance the efficiency of electron transfer. On the basis of the measurement of Mott-Schottky plots of graphene and metal anchored hybrids, the catalysis mechanism was elucidated by the decrease of Fermi level resulted from the chemical doping behavior. Notably, the catalytic activity was able to be regulated by the adsorption and desorption of single-stranded DNA molecules, which laid a basis for its utilization in the construction of single-stranded DNA-based colorimetric biosensors. This strategy not only simplified the operation process including labeling, modification, and imprinting, but also protected the intrinsic affinity between the target and biological probe. Accordingly, based on the peroxidase-like activity and its controllability, our prepared nanohybrids was successfully adopted in the visualized and label-free sensing detections of glucose, sequence-specific DNA, mismatched nucleotides, and oxytetracycline.

  4. Ascorbate Peroxidase and Catalase Activities and Their Genetic Regulation in Plants Subjected to Drought and Salinity Stresses

    Directory of Open Access Journals (Sweden)

    Adriano Sofo


    Full Text Available Hydrogen peroxide (H2O2, an important relatively stable non-radical reactive oxygen species (ROS is produced by normal aerobic metabolism in plants. At low concentrations, H2O2 acts as a signal molecule involved in the regulation of specific biological/physiological processes (photosynthetic functions, cell cycle, growth and development, plant responses to biotic and abiotic stresses. Oxidative stress and eventual cell death in plants can be caused by excess H2O2 accumulation. Since stress factors provoke enhanced production of H2O2 in plants, severe damage to biomolecules can be possible due to elevated and non-metabolized cellular H2O2. Plants are endowed with H2O2-metabolizing enzymes such as catalases (CAT, ascorbate peroxidases (APX, some peroxiredoxins, glutathione/thioredoxin peroxidases, and glutathione sulfo-transferases. However, the most notably distinguished enzymes are CAT and APX since the former mainly occurs in peroxisomes and does not require a reductant for catalyzing a dismutation reaction. In particular, APX has a higher affinity for H2O2 and reduces it to H2O in chloroplasts, cytosol, mitochondria and peroxisomes, as well as in the apoplastic space, utilizing ascorbate as specific electron donor. Based on recent reports, this review highlights the role of H2O2 in plants experiencing water deficit and salinity and synthesizes major outcomes of studies on CAT and APX activity and genetic regulation in drought- and salt-stressed plants.

  5. Display systems for NPP control

    International Nuclear Information System (INIS)

    Rozov, S.S.


    Main trends in development of display systems used as the means for image displaying in NPP control systems are considered. It is shown that colour display devices appear to be the most universal means for concentrated data presentation. Along with digital means the display systems provide for high-speed response, sufficient for operative control of executive mechanisms. A conclusion is drawn that further development of display systems will move towards creation of large colour fields (on reflection base or with multicolour gas-discharge elements)

  6. Polyphenol oxidase and peroxidase in different sugarcane cultivars, in Presidente Prudente region; Polifenoloxidases e peroxidase em diferentes variedades de cana-de-acucar na regiao de Presidente Prudente

    Energy Technology Data Exchange (ETDEWEB)

    Marques, Tadeu A.; Gomes, Danilo B.; Marques, Patricia A.A.; Alves, Vagner C. [Universidade do Oeste Paulista (UNOESTE), Presidente Prudente, SP (Brazil). Curso de Agronomia], Emails:,,


    The objective in present work was compare three sugarcane cultivars (RB 72-454, RB 86-7515, IAC 86-2480), evaluating the content of polyphenoloxidase and peroxidase. These determinations had aimed at to detect possible differences between varieties thus and being to differentiate them with regard to the products most interesting to be elaborated, ethanol production or sugar production. The varieties had presented differences of behavior for studied enzymes. The activity of polyphenoloxidase was superior the activity of peroxidase. The enzyme peroxidase was presented in bigger indices in the dry and cold periods. The enzyme polyphenoloxidase was presented well changeable, but with strong trend of bigger values in the rainy periods. It can be said that distinct periods for the best use of the varieties in the sugar production or alcohol exist. (author)

  7. Real-time flight test data distribution and display (United States)

    Nesel, Michael C.; Hammons, Kevin R.


    Enhancements to the real-time processing and display systems of the NASA Western Aeronautical Test Range are described. Display processing has been moved out of the telemetry and radar acquisition processing systems super-minicomputers into user/client interactive graphic workstations. Real-time data is provided to the workstations by way of Ethernet. Future enhancement plans include use of fiber optic cable to replace the Ethernet.

  8. Structure of the horseradish peroxidase isozyme C genes. (United States)

    Fujiyama, K; Takemura, H; Shibayama, S; Kobayashi, K; Choi, J K; Shinmyo, A; Takano, M; Yamada, Y; Okada, H


    We have isolated, cloned and characterized three cDNAs and two genomic DNAs corresponding to the mRNAs and genes for the horseradish (Armoracia rusticana) peroxidase isoenzyme C (HPR C). The amino acid sequence of HRP C1, deduced from the nucleotide sequence of one of the cDNA clone, pSK1, contained the same primary sequence as that of the purified enzyme established by Welinder [FEBS Lett. 72, 19-23 (1976)] with additional sequences at the N and C terminal. All three inserts in the cDNA clones, pSK1, pSK2 and pSK3, coded the same size of peptide (308 amino acid residues) if these are processed in the same way, and the amino acid sequence were homologous to each other by 91-94%. Functional amino acids, including His40, His170, Tyr185 and Arg183 and S-S-bond-forming Cys, were conserved in the three isozymes, but a few N-glycosylation sites were not the same. Two HRP C isoenzyme genomic genes, prxC1 and prxC2, were tandem on the chromosomal DNA and each gene consisted of four exons and three introns. The positions in the exons interrupted by introns were the same in two genes. We observed a putative promoter sequence 5' upstream and a poly(A) signal 3' downstream in both genes. The gene product of prxC1 might be processed with a signal sequence of 30 amino acid residues at the N terminus and a peptide consisting of 15 amino acid residues at the C terminus.

  9. Prostaglandin endoperoxide H synthases: peroxidase hydroperoxide specificity and cyclooxygenase activation. (United States)

    Liu, Jiayan; Seibold, Steve A; Rieke, Caroline J; Song, Inseok; Cukier, Robert I; Smith, William L


    The cyclooxygenase (COX) activity of prostaglandin endoperoxide H synthases (PGHSs) converts arachidonic acid and O2 to prostaglandin G2 (PGG2). PGHS peroxidase (POX) activity reduces PGG2 to PGH2. The first step in POX catalysis is formation of an oxyferryl heme radical cation (Compound I), which undergoes intramolecular electron transfer forming Intermediate II having an oxyferryl heme and a Tyr-385 radical required for COX catalysis. PGHS POX catalyzes heterolytic cleavage of primary and secondary hydroperoxides much more readily than H2O2, but the basis for this specificity has been unresolved. Several large amino acids form a hydrophobic "dome" over part of the heme, but when these residues were mutated to alanines there was little effect on Compound I formation from H2O2 or 15-hydroperoxyeicosatetraenoic acid, a surrogate substrate for PGG2. Ab initio calculations of heterolytic bond dissociation energies of the peroxyl groups of small peroxides indicated that they are almost the same. Molecular Dynamics simulations suggest that PGG2 binds the POX site through a peroxyl-iron bond, a hydrogen bond with His-207 and van der Waals interactions involving methylene groups adjoining the carbon bearing the peroxyl group and the protoporphyrin IX. We speculate that these latter interactions, which are not possible with H2O2, are major contributors to PGHS POX specificity. The distal Gln-203 four residues removed from His-207 have been thought to be essential for Compound I formation. However, Q203V PGHS-1 and PGHS-2 mutants catalyzed heterolytic cleavage of peroxides and exhibited native COX activity. PGHSs are homodimers with each monomer having a POX site and COX site. Cross-talk occurs between the COX sites of adjoining monomers. However, no cross-talk between the POX and COX sites of monomers was detected in a PGHS-2 heterodimer comprised of a Q203R monomer having an inactive POX site and a G533A monomer with an inactive COX site.

  10. Association of antithyroid peroxidase antibody with fibromyalgia in rheumatoid arthritis. (United States)

    Ahmad, Jowairiyya; Blumen, Helena; Tagoe, Clement E


    To investigate how autoimmune thyroiditis (ATD) affects the clinical presentation of established rheumatoid arthritis (RA) with particular reference to fibromyalgia and chronic widespread pain (CWP). A cohort of 204 patients with RA for whom the presence or absence of autoimmune thyroid antibodies was documented was examined for the relationships between thyroid autoantibodies and fibromyalgia or CWP. We identified 29 % who tested positive for antithyroid peroxidase antibodies (TPOAb). The anti-thyroglobulin antibody (TgAb) was found in 24 %. Among the thyroid autoantibody-positive patients, 40 % had a diagnosis of fibromyalgia or CWP versus 17 % for antibody negative patients. Logistic regression analyses (adjusted by age, sex, diabetes and BMI) indicated that TPOAb-positive patients were more likely to have fibromyalgia or CWP, with an odds ratio (OR) of 4.641, 95 % confidence interval (CI) (2.110-10.207) P fibromyalgia, OR 4.458, 95 % CI (1.950-10.191), P fibromyalgia was not significant (P > .05). Additional logistic regression analyses (adjusted by age, sex and BMI) indicated a significant relationship between TPOAb and fibromyalgia or CWP in patients without diabetes and those without hypothyroidism (OR of 4.873, 95 % CI (1.877-12.653), P = .001 and OR of 4.615 95 % CI (1.810-11.770), P = .001, respectively). There may be a positive association between the ATD antibody TPOAb, and fibromyalgia syndrome and CWP in patients with established RA.

  11. Changes in peroxidases associated with radiation-induced sprout inhibition in garlic (Allium sativum L.)

    International Nuclear Information System (INIS)

    Croci, C.A.; Curvetto, N.R.; Orioli, G.A.; Arguello, J.A.


    The effects of an acute dose of γ-rays (10 Gy) to post-dormant garlic cloves on inner sprout growth and changes in peroxidases and soluble proteins were evaluated up to 100 days of storage in darkness at 19±1 0 C and 42±2% relative humidity. Radiation-induced inhibition of sprout growth became evident after 25 days of treatment and was synchronous with a marked increase in peroxidase activity. Thin-layer isoelectric focusing revealed that radiation induced an increase in the number of anodic peroxidase isoenzymes at 100 days, suggesting modifications in the vascularization process. Neither the soluble protein content nor the protein pattern were affected by irradiation. These results are discussed in terms of a possible mediating effect of peroxidase on radiation-induced sprout inhibition in garlic. (author)

  12. Degradation of disperse dye from textile effluent by free and immobilized Cucurbita pepo peroxidase (United States)

    Boucherit, N.; Abouseoud, M.; Adour, L.


    Disperse dyes constitute the largest group of dyes used in local textile industry. This work evaluates the potential of the Cucurbita peroxidase(C-peroxidase) extracted from courgette in the decolourization of disperse dye in free and immobilized form. The optimal conditions for immobilization of C-peroxidase in Ca-alginate were identified. The immobilization was optimized at 2%(w/v) of sodium alginate and 0.2 M of calcium chloride. After optimization of treatment parameters, the results indicate that at pH 2, dye concentration: 80 mg/L(for FCP) and 180 mg/L(for ICP), H2O2 dose: 0,02M (for FCP) and 0,12M(for ICP), the decolourization by free and immobilized C-peroxidase were 72.02% and 69.71 % respectively. The degradation pathway and the metabolic products formed after the degradation were also predicted using UV-vis spectroscopy analysis.

  13. A catalytic approach to estimate the redox potential of heme-peroxidases

    International Nuclear Information System (INIS)

    Ayala, Marcela; Roman, Rosa; Vazquez-Duhalt, Rafael


    The redox potential of heme-peroxidases varies according to a combination of structural components within the active site and its vicinities. For each peroxidase, this redox potential imposes a thermodynamic threshold to the range of oxidizable substrates. However, the instability of enzymatic intermediates during the catalytic cycle precludes the use of direct voltammetry to measure the redox potential of most peroxidases. Here we describe a novel approach to estimate the redox potential of peroxidases, which directly depends on the catalytic performance of the activated enzyme. Selected p-substituted phenols are used as substrates for the estimations. The results obtained with this catalytic approach correlate well with the oxidative capacity predicted by the redox potential of the Fe(III)/Fe(II) couple

  14. Changes in peroxidases associated with radiation-induced sprout inhibition in garlic (Allium sativum L. )

    Energy Technology Data Exchange (ETDEWEB)

    Croci, C.A.; Curvetto, N.R.; Orioli, G.A. (Universidad Nacional del Sur, Bahia Blanca (Argentina)); Arguello, J.A. (Universidad Nacional de Cordoba (Argentina). Dept. de Biologia Aplicada)


    The effects of an acute dose of {gamma}-rays (10 Gy) to post-dormant garlic cloves on inner sprout growth and changes in peroxidases and soluble proteins were evaluated up to 100 days of storage in darkness at 19+-1{sup 0}C and 42+-2% relative humidity. Radiation-induced inhibition of sprout growth became evident after 25 days of treatment and was synchronous with a marked increase in peroxidase activity. Thin-layer isoelectric focusing revealed that radiation induced an increase in the number of anodic peroxidase isoenzymes at 100 days, suggesting modifications in the vascularization process. Neither the soluble protein content nor the protein pattern were affected by irradiation. These results are discussed in terms of a possible mediating effect of peroxidase on radiation-induced sprout inhibition in garlic. (author).

  15. Identification of novel genetic Loci associated with thyroid peroxidase antibodies and clinical thyroid disease

    NARCIS (Netherlands)

    Medici, M.; Porcu, E.; Pistis, G.; Teumer, A.; Brown, S.J.; Jensen, R.A.; Rawal, R.; Roef, G.L.; Plantinga, T.S.; Vermeulen, S.; Lahti, J.; Simmonds, M.J.; Husemoen, L.L.; Freathy, R.M.; Shields, B.M.; Pietzner, D.; Nagy, R.; Broer, L.; Chaker, L.; Korevaar, T.I.; Plia, M.G.; Sala, C.; Volker, U.; Richards, J.B.; Sweep, F.C.; Gieger, C.; Corre, T.; Kajantie, E.; Thuesen, B.; Taes, Y.E.; Visser, W.E.; Hattersley, A.T.; Kratzsch, J.; Hamilton, A.; Li, W.; Homuth, G.; Lobina, M.; Mariotti, S.; Soranzo, N.; Cocca, M.; Nauck, M.; Spielhagen, C.; Ross, A.; Arnold, A.; Bunt, M. van de; Liyanarachchi, S.; Heier, M.; Grabe, H.J.; Masciullo, C.; Galesloot, T.E.; Lim, E.M.; Reischl, E.; Leedman, P.J.; Lai, S.; Delitala, A.; Bremner, A.P.; Philips, D.I.; Beilby, J.P.; Mulas, A.; Vocale, M.; Abecasis, G.; Forsen, T.; James, A.; Widen, E.; Hui, J.; Prokisch, H.; Rietzschel, E.E.; Palotie, A.; Feddema, P.; Fletcher, S.J.; Schramm, K.; Rotter, J.I.; Kluttig, A.; Radke, D.; Traglia, M.; Surdulescu, G.L.; He, H.; Franklyn, J.A.; Tiller, D.; Vaidya, B.; Meyer, T.; Jorgensen, T.; Eriksson, J.G.; O'Leary, P.C.; Wichmann, E.; Hermus, A.R.M.M.; Psaty, B.M.; Ittermann, T.; Hofman, A.; Bosi, E.; Schlessinger, D.; Wallaschofski, H.; Pirastu, N.; Aulchenko, Y.S.; Chapelle, A. dela; Netea-Maier, R.T.; Gough, S.C.; Meyer Zu Schwabedissen, H.; Frayling, T.M.; Kaufman, J.M.; Smit, J.W.; Kiemeney, B.; et al.,


    Autoimmune thyroid diseases (AITD) are common, affecting 2-5% of the general population. Individuals with positive thyroid peroxidase antibodies (TPOAbs) have an increased risk of autoimmune hypothyroidism (Hashimoto's thyroiditis), as well as autoimmune hyperthyroidism (Graves' disease). As the

  16. Identification of Novel Genetic Loci Associated with Thyroid Peroxidase Antibodies and Clinical Thyroid Disease

    NARCIS (Netherlands)

    M. Medici (Marco); E. Porcu (Eleonora); G. Pistis (Giorgio); A. Teumer (Alexander); S.J. Brown (Stephen); R.A. Jensen (Richard); R. Rawal (R.); G.L. Roef (Greet); T.S. Plantinga (Theo S.); S.H.H.M. Vermeulen (Sita); J. Lahti (Jari); M.C. Simmonds (Mark); L.L.N. Husemoen (Lise Lotte); R.M. Freathy (Rachel); B.M. Shields (Beverley); D. Pietzner (Diana); R. Nagy (Rebecca); L. Broer (Linda); L. Chaker (Layal); T.I.M. Korevaar (Tim); M.G. Plia (Maria Grazia); C. Sala (Cinzia); U. Völker (Uwe); J.B. Richards (Brent); F.C. Sweep (Fred); C. Gieger (Christian); T. Corre (Tanguy); E. Kajantie (Eero); L. Thuesen (Leif); Y.E. Taes (Youri); W.E. Visser (Wil Edward); A.T. Hattersley (Andrew); J. Kratzsch (Jürgen); A. Hamilton (Amy); W. Li (Wei); G. Homuth (Georg); M. Lobina (Monia); S. Mariotti (Stefano); N. Soranzo (Nicole); M. Cocca (Massimiliano); M. Nauck (Matthias); C. Spielhagen (Christin); H.A. Ross (Alec); A.M. Arnold (Alice); M. van de Bunt (Martijn); S. Liyanarachchi (Sandya); M. Heier (Margit); H.J. Grabe (Hans Jörgen); C. Masciullo (Corrado); T.E. Galesloot (Tessel); E.M. Lim (Ee Mun); G. Reischl (Gunilla); P.J. Leedman (Peter); S. Lai (Sandra); A. Delitala (Alessandro); A. Bremner (Alexandra); D.I.W. Philips (David I.); J.P. Beilby (John); A. Mulas (Antonella); M. Vocale (Matteo); G.R. Abecasis (Gonçalo); T. Forsen (Tom); A. James (Alan); E. Widen (Elisabeth); J. Hui (Jennie); H. Prokisch (Holger); E.E. Rietzschel (Ernst); A. Palotie (Aarno); W. Feddema (Wouter); S.J. Fletcher (Stephen); K. Schramm (Katharina); J.I. Rotter (Jerome); A. Kluttig (Alexander); D. Radke (Dörte); M. Traglia (Michela); G. Surdulescu (Gabriela); H. He (Hao); J.A. Franklyn (Jayne); D. Tiller (Daniel); B. Vaidya (Bijay); T. Meyer (Thorsten); T. Jorgensen (Torben); K. Hagen (Knut); P.C. O'Leary (Peter); E. Wichmann (Eric); A.R.M.M. Hermus (Ad); B.M. Psaty (Bruce); T. Ittermann (Till); A. Hofman (Albert); E. Bosi (Emanuele); D. Schlessinger (David); H. Wallaschofski (Henri); N. Pirastu (Nicola); Y.S. Aulchenko (Yurii); A. de la Chapelle (Albert); R.T. Netea-Maier (Romana ); J.E. Gough (Julie); H. Meyer zu Schwabedissen (Henriette); T.M. Frayling (Timothy); J.-M. Kaufman (Jean-Marc); A. Linneberg (Allan); K. Räikkönen (Katri); J.W.A. Smit (Jan); L.A.L.M. Kiemeney (Bart); F. Rivadeneira Ramirez (Fernando); A.G. Uitterlinden (André); J.P. Walsh (John); C. Meisinger (Christa); M. den Heijer (Martin); T.J. Visser (Theo); T.D. Spector (Timothy); S.G. Wilson (Scott); H. Völzke (Henry); A.R. Cappola (Anne); D. Toniolo (Daniela); S. Sanna (Serena); S. Naitza (Silvia); R.P. Peeters (Robin)


    textabstractAutoimmune thyroid diseases (AITD) are common, affecting 2-5% of the general population. Individuals with positive thyroid peroxidase antibodies (TPOAbs) have an increased risk of autoimmune hypothyroidism (Hashimoto's thyroiditis), as well as autoimmune hyperthyroidism (Graves'

  17. Epitope recognition patterns of thyroid peroxidase autoantibodies in healthy individuals and patients with Hashimoto's thyroiditis*

    DEFF Research Database (Denmark)

    Nielsen, Claus H; Brix, Thomas H; Gardas, Andrzej


    Thyroid peroxidase antibodies (TPOAb) are markers of autoimmune thyroid disease (AITD), including Hashimoto's thyroiditis (HT), but naturally occurring TPOAb are also detectable in healthy, euthyroid individuals. In AITD, circulating TPOAb react mainly with two immunodominant regions (IDR), IDR...

  18. Identification of Novel Genetic Loci Associated with Thyroid Peroxidase Antibodies and Clinical Thyroid Disease

    NARCIS (Netherlands)

    Medici, M.; Porcu, E.; Pistis, G.; Teumer, A.; Brown, S.J.; Jensen, R.A.; Rawal, R.; Roef, G.L.; Plantinga, T.S.; Vermeulen, S.H.; Lahti, J.; Simmonds, M.J.; Husemoen, L.L.N.; Freathy, R.M.; Shields, B.M.; Pietzner, D.; Nagy, R.; Broer, L.; Chaker, L.; Korevaar, T.I.M.; Plia, M.G.; Sala, C.; Volker, U.; Richards, J.B.; Sweep, F.C.; Gieger, C.; Corre, T.; Kajantie, E.; Thuesen, B.; Taes, Y.E.; Visser, W.E.; Hattersley, A.T.; Kratzsch, J.; Hamilton, A.; Li, W.; Homuth, G.; Lobina, M.; Mariotti, S.; Soranzo, N.; Cocca, M.; Nauck, M.; Spielhagen, C.; Ross, A.; Arnold, A.; van de Bunt, M.; Liyanarachchi, S.; Heier, M.; Grabe, H.J.; Masciullo, C.; Galesloot, T.E.; Lim, E.M.; Reischl, E.; Leedman, P.J.; Lai, S.; Delitala, A.; Bremner, A.P.; Philips, D.I.W.; Beilby, J.P.; Mulas, A.; Vocale, M.; Abecasis, G.; Forsen, T.; James, A.; Widen, E.; Hui, J.; Prokisch, H.; Rietzschel, E.E.; Palotie, A.; Feddema, P.; Fletcher, S.J.; Schramm, K.; Rotter, J.I.; Kluttig, A.; Radke, D.; Traglia, M.; Surdulescu, G.L.; He, H.L.; Franklyn, J.A.; Tiller, D.; Vaidya, B.; Meyer, T.; Jorgensen, T.; Eriksson, J.G.; O'Leary, P.C.; Wichmann, E.; Hermus, A.R.; Psaty, B.M.; Ittermann, T.; Hofman, A.; Bosi, E.; Schlessinger, D.; Wallaschofski, H.; Pirastu, N.; Aulchenko, Y.S.; de la Chapelle, A.; Netea-Maier, R.T.; Gough, S.C.L.; Meyer zu Schwabedissen, H.; Frayling, T.M.; den Heijer, M.; Naitza, S.; Peeters, R.P.


    Autoimmune thyroid diseases (AITD) are common, affecting 2-5% of the general population. Individuals with positive thyroid peroxidase antibodies (TPOAbs) have an increased risk of autoimmune hypothyroidism (Hashimoto's thyroiditis), as well as autoimmune hyperthyroidism (Graves' disease). As the

  19. The effect of acid rain stress on chlorophyll, peroxidase of the conservation of rare earth elements

    International Nuclear Information System (INIS)

    Chongling, Y.; Yetang, H.; Xianke, Y.; Shunzhen, F.; Shanql, W.


    Full text: Based on pot experiment, the effect of acid rain stress on chlorophyll, peroxidase of wheat, the relationship of them and the conservation of rare earth elements has been studied. The result showed: stress of acid rain resulted in decrease of chlorophyll content and a/b values, chlorophyll a/b value and chlorophyll content is positive correlation with pH value of acid rain: peroxidase activity was gradually rise with pH value decrease, which indirectly increased decomposition intensity of chlorophyll. Decreased content and a/b value of chlorophyll further speeded blade decay affected the transport and transformation of light energy and metabolism of carbohydrates. After being treated by rare earth elements content and pH value of chlorophyll and peroxidase activity could be relatively stable. Therefore, under lower acidity condition, rare earth elements can influence the effect of acid rain on chlorophyll and peroxidase activity of wheat

  20. Augmenting digital displays with computation (United States)

    Liu, Jing

    As we inevitably step deeper and deeper into a world connected via the Internet, more and more information will be exchanged digitally. Displays are the interface between digital information and each individual. Naturally, one fundamental goal of displays is to reproduce information as realistically as possible since humans still care a lot about what happens in the real world. Human eyes are the receiving end of such information exchange; therefore it is impossible to study displays without studying the human visual system. In fact, the design of displays is rather closely coupled with what human eyes are capable of perceiving. For example, we are less interested in building displays that emit light in the invisible spectrum. This dissertation explores how we can augment displays with computation, which takes both display hardware and the human visual system into consideration. Four novel projects on display technologies are included in this dissertation: First, we propose a software-based approach to driving multiview autostereoscopic displays. Our display algorithm can dynamically assign views to hardware display zones based on multiple observers' current head positions, substantially reducing crosstalk and stereo inversion. Second, we present a dense projector array that creates a seamless 3D viewing experience for multiple viewers. We smoothly interpolate the set of viewer heights and distances on a per-vertex basis across the arrays field of view, reducing image distortion, crosstalk, and artifacts from tracking errors. Third, we propose a method for high dynamic range display calibration that takes into account the variation of the chrominance error over luminance. We propose a data structure for enabling efficient representation and querying of the calibration function, which also allows user-guided balancing between memory consumption and the amount of computation. Fourth, we present user studies that demonstrate that the ˜ 60 Hz critical flicker fusion

  1. CDNA cloning, characterization and expression of an endosperm-specific barley peroxidase

    DEFF Research Database (Denmark)

    Rasmussen, Søren Kjærsgård; Welinder, K.G.; Hejgaard, J.


    A barley peroxidase (BP 1) of pI ca. 8.5 and M(r) 37000 has been purified from mature barley grains. Using antibodies towards peroxidase BP 1, a cDNA clone (pcR7) was isolated from cDNA expression library. The nucleotide sequence of pcR7 gave a derived amino acid sequence identical to the 158 C...

  2. Thiol peroxidases mediate specific genome-wide regulation of gene expression in response to hydrogen peroxide


    Fomenko, Dmitri E.; Koc, Ahmet; Agisheva, Natalia; Jacobsen, Michael; Kaya, Alaattin; Malinouski, Mikalai; Rutherford, Julian C.; Siu, Kam-Leung; Jin, Dong-Yan; Winge, Dennis R.; Gladyshev, Vadim N.


    Hydrogen peroxide is thought to regulate cellular processes by direct oxidation of numerous cellular proteins, whereas antioxidants, most notably thiol peroxidases, are thought to reduce peroxides and inhibit H2O2 response. However, thiol peroxidases have also been implicated in activation of transcription factors and signaling. It remains unclear if these enzymes stimulate or inhibit redox regulation and whether this regulation is widespread or limited to a few cellular components. Herein, w...

  3. Airway Peroxidases Catalyze Nitration of the β2-Agonist Salbutamol and Decrease Its Pharmacological Activity


    Reszka, Krzysztof J.; Sallans, Larry; Macha, Stephen; Brown, Kari; McGraw, Dennis W.; Kovacic, Melinda Butsch; Britigan, Bradley E.


    β2-Agonists are the most effective bronchodilators for the rapid relief of asthma symptoms, but for unclear reasons, their effectiveness may be decreased during severe exacerbations. Because peroxidase activity and nitrogen oxides are increased in the asthmatic airway, we examined whether salbutamol, a clinically important β2-agonist, is subject to potentially inactivating nitration. When salbutamol was exposed to myeloperoxidase, eosinophil peroxidase or lactoperoxidase in the presence of hy...

  4. The Effect of Citrus Aurantium, Foeniculum Vulgare and Rosmarinus Officinalis Essential Oils on Peroxidase Activity


    Maryam Mohajerani (PhD); Afsaneh Aghae i ( MSc )


    Background and objective: Peroxidases catalyze protein oxidation and lipid peroxidation. The activity of these enzymes in nerve cells is involved in causing disorders such as Alzheimer's and Parkinson's disease. This study investigated the effect of Citrus aurantium, Foeniculum vulgare and Rosmarinus officinalis essential oils on activity of peroxidase enzyme. Methods: All three medicinal plants were dried at room temperature. Their essential oil was extracted by steam distillation ...

  5. Halide peroxidase in tissues that interact with bacteria in the host squid Euprymna scolopes. (United States)

    Small, A L; McFall-Ngai, M J


    An enzyme with similarities to myeloperoxidase, the antimicrobial halide peroxidase in mammalian neutrophils, occurs abundantly in the light organ tissue of Euprymna scolopes, a squid that maintains a beneficial association with the luminous bacterium Vibrio fischeri. Using three independent assays typically applied to the analysis of halide peroxidase enzymes, we directly compared the activity of the squid enzyme with that of human myeloperoxidase. One of these methods, the diethanolamine assay, confirmed that the squid peroxidase requires halide ions for its activity. The identification of a halide peroxidase in a cooperative bacterial association suggested that this type of enzyme can function not only to control pathogens, but also to modulate the interactions of host animals with their beneficial partners. To determine whether the squid peroxidase functions under both circumstances, we examined its distribution in a variety of host tissues, including those that typically interact with bacteria and those that do not. Tissues interacting with bacteria included those that have specific cooperative associations with bacteria (i.e., the light organ and accessory nidamental gland) and those that have transient nonspecific interactions with bacteria (i.e., the gills, which clear the cephalopod circulatory system of invading microorganisms). These bacteria-associated tissues were compared with the eye, digestive gland, white body, and ink-producing tissues, which do not typically interact directly with bacteria. Peroxidase enzyme assays, immunocytochemical localization, and DNA-RNA hybridizations showed that the halide-dependent peroxidase is consistently expressed in high concentration in tissues that interact bacteria. Elevated levels of the peroxidase were also found in the ink-producing tissues, which are known to have enzymatic pathways associated with antimicrobial activity. Taken together, these data suggest that the host uses a common biochemical response to

  6. Display Parameters and Requirements (United States)

    Bahadur, Birendra

    The following sections are included: * INTRODUCTION * HUMAN FACTORS * Anthropometry * Sensory * Cognitive * Discussions * THE HUMAN VISUAL SYSTEM - CAPABILITIES AND LIMITATIONS * Cornea * Pupil and Iris * Lens * Vitreous Humor * Retina * RODS - NIGHT VISION * CONES - DAY VISION * RODS AND CONES - TWILIGHT VISION * VISUAL PIGMENTS * MACULA * BLOOD * CHOROID COAT * Visual Signal Processing * Pathways to the Brain * Spatial Vision * Temporal Vision * Colour Vision * Colour Blindness * DICHROMATISM * Protanopia * Deuteranopia * Tritanopia * ANOMALOUS TRICHROMATISM * Protanomaly * Deuteranomaly * Tritanomaly * CONE MONOCHROMATISM * ROD MONOCHROMATISM * Using Colour Effectively * COLOUR MIXTURES AND THE CHROMATICITY DIAGRAM * Colour Matching Functions and Chromaticity Co-ordinates * CIE 1931 Colour Space * CIE PRIMARIES * CIE COLOUR MATCHING FUNCTIONS AND CHROMATICITY CO-ORDINATES * METHODS FOR DETERMINING TRISTIMULUS VALUES AND COLOUR CO-ORDINATES * Spectral Power Distribution Method * Filter Method * CIE 1931 CHROMATICITY DIAGRAM * ADDITIVE COLOUR MIXTURE * CIE 1976 Chromaticity Diagram * CIE Uniform Colour Spaces and Colour Difference Formulae * CIELUV OR L*u*v* * CIELAB OR L*a*b* * CIE COLOUR DIFFERENCE FORMULAE * Colour Temperature and CIE Standard Illuminants and source * RADIOMETRIC AND PHOTOMETRIC QUANTITIES * Photopic (Vλ and Scotopic (Vλ') Luminous Efficiency Function * Photometric and Radiometric Flux * Luminous and Radiant Intensities * Incidence: Illuminance and Irradiance * Exitance or Emittance (M) * Luminance and Radiance * ERGONOMIC REQUIREMENTS OF DISPLAYS * ELECTRO-OPTICAL PARAMETERS AND REQUIREMENTS * Contrast and Contrast Ratio * Luminance and Brightness * Colour Contrast and Chromaticity * Glare * Other Aspects of Legibility * SHAPE AND SIZE OF CHARACTERS * DEFECTS AND BLEMISHES * FLICKER AND DISTORTION * ANGLE OF VIEW * Switching Speed * Threshold and Threshold Characteristic * Measurement Techniques For Electro-optical Parameters * RADIOMETRIC

  7. The Ustilago maydis effector Pep1 suppresses plant immunity by inhibition of host peroxidase activity.

    Directory of Open Access Journals (Sweden)

    Christoph Hemetsberger

    Full Text Available The corn smut Ustilago maydis establishes a biotrophic interaction with its host plant maize. This interaction requires efficient suppression of plant immune responses, which is attributed to secreted effector proteins. Previously we identified Pep1 (Protein essential during penetration-1 as a secreted effector with an essential role for U. maydis virulence. pep1 deletion mutants induce strong defense responses leading to an early block in pathogenic development of the fungus. Using cytological and functional assays we show that Pep1 functions as an inhibitor of plant peroxidases. At sites of Δpep1 mutant penetrations, H₂O₂ strongly accumulated in the cell walls, coinciding with a transcriptional induction of the secreted maize peroxidase POX12. Pep1 protein effectively inhibited the peroxidase driven oxidative burst and thereby suppresses the early immune responses of maize. Moreover, Pep1 directly inhibits peroxidases in vitro in a concentration-dependent manner. Using fluorescence complementation assays, we observed a direct interaction of Pep1 and the maize peroxidase POX12 in vivo. Functional relevance of this interaction was demonstrated by partial complementation of the Δpep1 mutant defect by virus induced gene silencing of maize POX12. We conclude that Pep1 acts as a potent suppressor of early plant defenses by inhibition of peroxidase activity. Thus, it represents a novel strategy for establishing a biotrophic interaction.

  8. Eosinophil peroxidase signals via epidermal growth factor-2 to induce cell proliferation.

    LENUS (Irish Health Repository)

    Walsh, Marie-Therese


    Eosinophils exert many of their inflammatory effects in allergic disorders through the degranulation and release of intracellular mediators, including a set of cationic granule proteins that include eosinophil peroxidase. Studies suggest that eosinophils are involved in remodeling. In previous studies, we showed that eosinophil granule proteins activate mitogen-activated protein kinase signaling. In this study, we investigated the receptor mediating eosinophil peroxidase-induced signaling and downstream effects. Human cholinergic neuroblastoma IMR32 and murine melanoma B16.F10 cultures, real-time polymerase chain reaction, immunoprecipitations, and Western blotting were used in the study. We showed that eosinophil peroxidase caused a sustained increase in both the expression of epidermal growth factor-2 (HER2) and its phosphorylation at tyrosine 1248, with the consequent activation of extracellular-regulated kinase 1\\/2. This, in turn, promoted a focal adhesion kinase-dependent egress of the cyclin-dependent kinase inhibitor p27(kip) from the nucleus to the cytoplasm. Eosinophil peroxidase induced a HER2-dependent up-regulation of cell proliferation, indicated by an up-regulation of the nuclear proliferation marker Ki67. This study identifies HER2 as a novel mediator of eosinophil peroxidase signaling. The results show that eosinophil peroxidase, at noncytotoxic levels, can drive cell-cycle progression and proliferation, and contribute to tissue remodeling and cell turnover in airway disease. Because eosinophils are a feature of many cancers, these findings also suggest a role for eosinophils in tumorigenesis.

  9. Structure-activity relationships and molecular docking of thirteen synthesized flavonoids as horseradish peroxidase inhibitors. (United States)

    Mahfoudi, Reguia; Djeridane, Amar; Benarous, Khedidja; Gaydou, Emile M; Yousfi, Mohamed


    For the first time, the structure-activity relationships of thirteen synthesized flavonoids have been investigated by evaluating their ability to modulate horseradish peroxidase (HRP) catalytic activity. Indeed, a modified spectrophotometrically method was carried out and optimized using 4-methylcatechol (4-MC) as peroxidase co-substrate. The results show that these flavonoids exhibit a great capacity to inhibit peroxidase with Ki values ranged from 0.14±0.01 to 65±0.04mM. Molecular docking has been achieved using Auto Dock Vina program to discuss the nature of interactions and the mechanism of inhibition. According to the docking results, all the flavonoids have shown great binding affinity to peroxidase. These molecular modeling studies suggested that pyran-4-one cycle acts as an inhibition key for peroxidase. Therefore, potent peroxidase inhibitors are flavonoids with these structural requirements: the presence of the hydroxyl (OH) group in 7, 5 and 4' positions and the absence of the methoxy (O-CH 3 ) group. Apigenin contributed better in HRP inhibitory activity. The present study has shown that the studied flavonoids could be promising HRP inhibitors, which can help in developing new molecules to control thyroid diseases. Copyright © 2017 Elsevier Inc. All rights reserved.

  10. Purification and characterization of lignin peroxidases from Penicillium decumbens P6

    Energy Technology Data Exchange (ETDEWEB)

    Yang, J.S.; Yuan, H.L.; Wang, H.X.; Chen, W.X. [China Agricultural University, Beijing (China). College of Biological Science


    Peroxidases are essential enzymes in biodegradation of lignin and lignite which have been investigated intensively in the white-rot fungi. This is the first report of purification and characterization of lignin peroxidase from Penicillium sp. P6 as lignite degradation fungus. The results indicated that the lignin peroxidase of Penicillium decumbens P6 had physical and chemical properties and a N-terminal amino acid sequence different from the lignin peroxidases of white-rot fungi. The lignin peroxidase was isolated from a liquid culture of P. decumbens P6. This enzyme had a molecular weight of 46.3 KDa in SDS-PAGE and exhibited greater activity, temperature stability and wider pH range than those previously reported. The isolation procedure involved (NH{sub 4}){sub 2}SO{sub 4} precipitation, ion-exchange chromatography on DEAE-cellulose and CM-cellulose, gel filtration on Sephadex G-100, and non-denaturing, discontinuous polyacrylamide gel electrophoresis. The K{sub m} and V{sub max} values of this enzyme using veratryl alcohol as substrate were 0.565 mmol L{sup -1} and 0.088 mmol (mg protein){sup -1} min{sup -1} respectively. The optimum pH of P6 lignin peroxidase was 4.0, and 70.6% of the relative activity was remained at pH 9.0. The optimum temperature of the enzyme was 45{sup o}C.

  11. Laser illuminated flat panel display

    Energy Technology Data Exchange (ETDEWEB)

    Veligdan, J.T.


    A 10 inch laser illuminated flat panel Planar Optic Display (POD) screen has been constructed and tested. This POD screen technology is an entirely new concept in display technology. Although the initial display is flat and made of glass, this technology lends itself to applications where a plastic display might be wrapped around the viewer. The display screen is comprised of hundreds of planar optical waveguides where each glass waveguide represents a vertical line of resolution. A black cladding layer, having a lower index of refraction, is placed between each waveguide layer. Since the cladding makes the screen surface black, the contrast is high. The prototype display is 9 inches wide by 5 inches high and approximately I inch thick. A 3 milliwatt HeNe laser is used as the illumination source and a vector scanning technique is employed.

  12. Flat panel planar optic display

    Energy Technology Data Exchange (ETDEWEB)

    Veligdan, J.T. [Brookhaven National Lab., Upton, NY (United States). Dept. of Advanced Technology


    A prototype 10 inch flat panel Planar Optic Display, (POD), screen has been constructed and tested. This display screen is comprised of hundreds of planar optic class sheets bonded together with a cladding layer between each sheet where each glass sheet represents a vertical line of resolution. The display is 9 inches wide by 5 inches high and approximately 1 inch thick. A 3 milliwatt HeNe laser is used as the illumination source and a vector scanning technique is employed.

  13. The peroxidase and oxidase-like activity of NiCo{sub 2}O{sub 4} mesoporous spheres: Mechanistic understanding and colorimetric biosensing

    Energy Technology Data Exchange (ETDEWEB)

    Su, Li, E-mail: [Collaborative Innovation Center of Henan Province for Green Manufacturing of Fine Chemicals, Key Laboratory of Green Chemical Media and Reactions, Ministry of Education, Henan Normal University, Xinxiang, Henan 453007 (China); Henan Key Laboratory of Green Chemical Media and Reactions, School of Chemistry and Chemical Engineering, Henan Normal University, Xinxiang, Henan 453007 (China); Dong, Wenpei; Wu, Chengke; Gong, Yijun; Zhang, Yan; Li, Ling; Mao, Guojiang; Feng, Suling [Collaborative Innovation Center of Henan Province for Green Manufacturing of Fine Chemicals, Key Laboratory of Green Chemical Media and Reactions, Ministry of Education, Henan Normal University, Xinxiang, Henan 453007 (China); Henan Key Laboratory of Green Chemical Media and Reactions, School of Chemistry and Chemical Engineering, Henan Normal University, Xinxiang, Henan 453007 (China)


    The synthesized NiCo{sub 2}O{sub 4} mesoporous spheres (MS) displayed intrinsic peroxidase and oxidase-like activity were firstly reported. The catalytic mechanism of the oxidase-like activity of NiCo{sub 2}O{sub 4} MS was analyzed in detail using the electron spin resonance (ESR) method. It is found that NiCo{sub 2}O{sub 4} MS could directly oxidize 3,3′,5,5′-tetramethylbenzidine (TMB) but did not produce {sup 1}O{sub 2} and ·OH. And the mechanism of the peroxidase-like activity of NiCo{sub 2}O{sub 4} MS was also verified that the oxidation of TMB stemmed from not only ·OH but also {sup 1}O{sub 2}. Based on the NiCo{sub 2}O{sub 4} MS showed excellent peroxidase-like activity over a broad temperature range, especially at normal body temperature, a detection tool was designed for glucose determination in diabetics' serum samples. And this detection method based on NiCo{sub 2}O{sub 4} MS gave a lower limit of detection than the method using Co{sub 3}O{sub 4} NPs and NiO NPs, as the single-component oxides of NiCo{sub 2}O{sub 4}. Our study may open up the possibility to make a great influence on the next generation of enzyme mimetics system. - Highlights: • NiCo{sub 2}O{sub 4} MS were found to possess the peroxidase and oxidase-like activity. • The peroxidase-like activity of NiCo{sub 2}O{sub 4} MS was stemmed from not only ·OH but also {sup 1}O{sub 2}. • The oxidase-like activity may stem from NiCo{sub 2}O{sub 4} MS′ oxidation rather than ·OH and {sup 1}O{sub 2}. • A colorimetric detection tool is designed for glucose determination in serum samples.

  14. Effects of heme-PrP complex on cell-free conversion and peroxidase-linked immunodetection of prions in blood-based assays. (United States)

    Soutyrine, Andrei; Yogasingam, Nishandan; Huang, Hongsheng; Mitchell, Gordon


    Prion protein (PrP) binding to natural and synthetic porphyrins has been previously demonstrated but the effects of endogenous heme interactions with PrP remain uncertain. This study investigated implications of this interaction in blood-based peroxidase-linked prion immunodetection and seeded conversion of cellular prion (PrP(C)) into disease associated form (PrP(Sc)). Heme binding to recombinant PrP(C) enhanced intrinsic peroxidase activity (POD) by 2.5-fold and POD inherent to denatured blood accounted for over 84% of luminol-based substrate oxidation in a prion immunodetection assay. An immuno-capture assay showed that 75-98% of blood POD was attributable to binding of PrP(C) with endogenous heme. Additionally, 10 μM heme inhibited (PPrP(C) to PrP(Sc) through the protein misfolding cycling amplification assay. We conclude that the observed effects can interfere with cell-free conversion and peroxidase-linked immunodetection of prions in blood-based assays. These results indicate that heme-PrP interactions could modulate intrinsic POD and protect PrP(C) from conversion into PrP(Sc). Crown Copyright © 2015. Published by Elsevier Ltd. All rights reserved.

  15. Influence of radiation damage repair inhibitor on superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD) in different sensitive crops

    International Nuclear Information System (INIS)

    Song Daojun; Xu Dengyi; Wan Zhaoliang; He Shoulin


    The activities of superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD) were affected remarkably by 60 Co γ-ray irradiation and radiation damage repair inhibitor (Caf, EDTA). SOD, CAT and POD activities showed the similar change pattern in both soybean (sensitive to radiation) and Brassica napus L. (resistant to radiation) seedlings in all treatments. After reaching the maximum value, SOD activity decreased with the increase of doses. CAT activity had the same change pattern as that of SOD in soybean, while with Brassica napus L., CAT activity remained relatively steady from 300 Gy to 1000 Gy. And POD activity increased with the increase of doses. Compared with H 2 O-treatments, CaF, EDAT post-treatments obviously enhanced SOD, CAT and POD activities. With all the treatments, the three enzyme activities were higher in Brassica napus L. than those in soybean seedlings

  16. Phenol degradation catalyzed by a peroxidase mimic constructed through the grafting of heme onto metal-organic frameworks. (United States)

    Jiang, Wei; Yang, Jiebing; Wang, Xinghuo; Han, Haobo; Yang, Yan; Tang, Jun; Li, Quanshun


    The aim of this work was to construct a peroxidase mimic for achieving the phenol degradation through Fenton reaction. The enzyme mimic was synthesized through the conjugation of heme with the amino group of 2-amino-1,4-benzene dicarboxylate in UiO-66-NH 2 (ZrMOF), namely Heme-ZrMOF. Compared to free heme, the composite Heme-ZrMOF exhibited an obviously enhanced ability for phenol degradation with up to 97.3% of phenol removal after 2h. Meanwhile, it could achieve the easy separation of catalyst from the system and the elimination of iron residues in the process of phenol degradation. Finally, the catalyst Heme-ZrMOF was observed to possess good recyclability in the phenol degradation with still 76.2% of phenol removal after 4 cycles. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. Anti-thyroid peroxidase antibody and vitiligo: a controlled study

    Directory of Open Access Journals (Sweden)

    Akhyani Maryam


    Full Text Available Abstract Background Vitiligo is an acquired depigmenting disorder due to destruction of melanocytes. Although many theories have been suggested for its pathogenesis, the role of autoimmunity is the most popular one. The association of vitiligo with autoimmune thyroid diseases and the increased prevalence of autoantibodies including thyroid autoantibodies in vitiligo favor this role. Our objective was to compare the frequency of thyroid peroxidase antibody (anti-TPO in vitiligo patients with healthy subjects in Iran. Methods Ninety-four cases of vitiligo (46 female and 48 male and 96 control subjects (49 female and 47 male were enrolled in this controlled study. Patients with known thyroid disease, history of thyroid surgery and those receiving thyroid medications were not included. The two groups were matched regarding gender and age. The demographic data, symptoms related to thyroid diseases and results of skin and thyroid examinations were recorded in a questionnaire for each subject. Thyroid function tests including free T3, free T4 and TSH-IRMA were performed. Anti-TPO levels were assessed as well. The collected data were analyzed by SPSS version-11 in vitiligo patients and subgroups according to gender, age, extent, and duration of the disease compared with the control group. Results Anti-TPO was detected in 17 (18.1% of patients affected by vitiligo, while this figure was 7 (7.3% in the control group; the difference was significant with p-value The difference of the frequency of anti-TPO was not significant regarding the duration and extent of vitiligo. In addition, there was no significant difference in the levels of free T3, free T4, and TSH in vitiligo patients compared with the control group. Conclusion According to our study, anti-TPO was shown to be significantly more common in vitiligo patients especially in young women, compared with control group. As this antibody is a relatively sensitive and specific marker of autoimmune thyroid

  18. Wired World-Wide Web Interactive Remote Event Display

    Energy Technology Data Exchange (ETDEWEB)

    De Groot, Nicolo


    WIRED (World-Wide Web Interactive Remote Event Display) is a framework, written in the Java{trademark} language, for building High Energy Physics event displays. An event display based on the WIRED framework enables users of a HEP collaboration to visualize and analyze events remotely using ordinary WWW browsers, on any type of machine. In addition, event displays using WIRED may provide the general public with access to the research of high energy physics. The recent introduction of the object-oriented Java{trademark} language enables the transfer of machine independent code across the Internet, to be safely executed by a Java enhanced WWW browser. We have employed this technology to create a remote event display in WWW. The combined Java-WWW technology hence assures a world wide availability of such an event display, an always up-to-date program and a platform independent implementation, which is easy to use and to install.

  19. High performance visual display for HENP detectors

    International Nuclear Information System (INIS)

    McGuigan, Michael; Smith, Gordon; Spiletic, John; Fine, Valeri; Nevski, Pavel


    A high end visual display for High Energy Nuclear Physics (HENP) detectors is necessary because of the sheer size and complexity of the detector. For BNL this display will be of special interest because of STAR and ATLAS. To load, rotate, query, and debug simulation code with a modern detector simply takes too long even on a powerful work station. To visualize the HENP detectors with maximal performance we have developed software with the following characteristics. We develop a visual display of HENP detectors on BNL multiprocessor visualization server at multiple level of detail. We work with general and generic detector framework consistent with ROOT, GAUDI etc, to avoid conflicting with the many graphic development groups associated with specific detectors like STAR and ATLAS. We develop advanced OpenGL features such as transparency and polarized stereoscopy. We enable collaborative viewing of detector and events by directly running the analysis in BNL stereoscopic theatre. We construct enhanced interactive control, including the ability to slice, search and mark areas of the detector. We incorporate the ability to make a high quality still image of a view of the detector and the ability to generate animations and a fly through of the detector and output these to MPEG or VRML models. We develop data compression hardware and software so that remote interactive visualization will be possible among dispersed collaborators. We obtain real time visual display for events accumulated during simulations

  20. You Be the Judge: Display. (United States)

    Koeninger, Jimmy G.

    The instructional package was developed to provide the distributive education teacher-coordinator with visual materials that can be used to supplement existing textbook offerings in the area of display (visual merchandising). Designed for use with 35mm slides of retail store displays, the package allows the student to view the slides of displays…

  1. Displays: Entering a New Dimension (United States)

    Starkman, Neal


    As display technologies prepare to welcome 3-D, the 21st-century classroom will soon bear little resemblance to anything students and teachers have ever seen. In this article, the author presents the latest innovations in the world of digital display technology. These include: (1) Touchlight, an interactive touch screen program that takes a normal…

  2. Software for graphic display systems

    International Nuclear Information System (INIS)

    Karlov, A.A.


    In this paper some aspects of graphic display systems are discussed. The design of a display subroutine library is described, with an example, and graphic dialogue software is considered primarily from the point of view of the programmer who uses a high-level language. (Auth.)

  3. Flexible Bistable Cholesteric Reflective Displays (United States)

    Yang, Deng-Ke


    Cholesteric liquid crystals (ChLCs) exhibit two stable states at zero field condition-the reflecting planar state and the nonreflecting focal conic state. ChLCs are an excellent candidate for inexpensive and rugged electronic books and papers. This paper will review the display cell structure,materials and drive schemes for flexible bistable cholesteric (Ch) reflective displays.


    International Nuclear Information System (INIS)



    This paper discussed the presentation of information in computer-based control rooms. Issues associated with the typical displays currently in use are discussed. It is concluded that these displays should be augmented with new displays designed to better meet the information needs of plant personnel and to minimize the need for interface management tasks (the activities personnel have to do to access and organize the information they need). Several approaches to information design are discussed, specifically addressing: (1) monitoring, detection, and situation assessment; (2) routine task performance; and (3) teamwork, crew coordination, collaborative work

  5. Flat panel display - Impurity doping technology for flat panel displays

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki, Toshiharu [Advanced Technology Planning, Sumitomo Eaton Nova Corporation, SBS Tower 9F, 10-1, Yoga 4-chome, Setagaya-ku, 158-0097 Tokyo (Japan)]. E-mail:


    Features of the flat panel displays (FPDs) such as liquid crystal display (LCD) and organic light emitting diode (OLED) display, etc. using low temperature poly-Si (LTPS) thin film transistors (TFTs) are briefly reviewed comparing with other FPDs. The requirements for fabricating TFTs used for high performance FPDs and system on glass (SoG) are addressed. This paper focuses on the impurity doping technology, which is one of the key technologies together with crystallization by laser annealing, formation of high quality gate insulator and gate-insulator/poly-Si interface. The issues to be solved in impurity doping technology for state of the art and future TFTs are clarified.

  6. Flat panel display - Impurity doping technology for flat panel displays

    International Nuclear Information System (INIS)

    Suzuki, Toshiharu


    Features of the flat panel displays (FPDs) such as liquid crystal display (LCD) and organic light emitting diode (OLED) display, etc. using low temperature poly-Si (LTPS) thin film transistors (TFTs) are briefly reviewed comparing with other FPDs. The requirements for fabricating TFTs used for high performance FPDs and system on glass (SoG) are addressed. This paper focuses on the impurity doping technology, which is one of the key technologies together with crystallization by laser annealing, formation of high quality gate insulator and gate-insulator/poly-Si interface. The issues to be solved in impurity doping technology for state of the art and future TFTs are clarified

  7. Children's Control/Display Stereotypes. (United States)

    Hoffmann, Errol R; Chan, Alan H S; Tai, Judy P C


    Objective The aim of this study was to determine control/display stereotypes for children of a range of ages and development of these stereotypes with age. Background Little is known about control/display stereotypes for children of different ages and the way in which these stereotypes develop with age. This study is part of a program to determine the need to design differentially for these age groups. Method We tested four groups of children with various tasks (age groups 5 to 7, 8 to 10, 11 to 13, 14 to 16), with about 30 in each group. Examples of common tasks were opening a bottle, turning on taps, and allocating numbers to keypads. More complex tasks involved rotating a control to move a display in a requested direction. Results Tasks with which different age groups were familiar showed no effect of age group. Different control/display arrangements generally showed an increase in stereotype strength with age, with dependence on the form of the control/display arrangement. Two-dimensional arrangements, with the control on the same plane as the display, had higher stereotype strength than three-dimensional arrangements for all age groups, suggesting an effect of familiarity with controls and displays with increasing age. Conclusion Children's control/display stereotypes do not differ greatly from those of adults, and hence, design for children older than 5 years of age, for control/display stereotypes, can be the same as that for adult populations. Application When designing devices for children, the relationship between controls and displays can be as for adult populations, for which there are considerable experimental data.

  8. Enhanced performance of a glucose/O(2) biofuel cell assembled with laccase-covalently immobilized three-dimensional macroporous gold film-based biocathode and bacterial surface displayed glucose dehydrogenase-based bioanode. (United States)

    Hou, Chuantao; Yang, Dapeng; Liang, Bo; Liu, Aihua


    The power output and stability of enzyme-based biofuel cells (BFCs) is greatly dependent on the properties of both the biocathode and bioanode, which may be adapted for portable power production. In this paper, a novel highly uniform three-dimensional (3D) macroporous gold (MP-Au) film was prepared by heating the gold "supraspheres", which were synthesized by a bottom-up protein templating approach, and followed by modification of laccase on the MP-Au film by covalent immobilization. The as-prepared laccase/MP-Au biocathode exihibited an onset potential of 0.62 V versus saturated calomel electrode (SCE, or 0.86 V vs NHE, normal hydrogen electrode) toward O2 reduction and a high catalytic current of 0.61 mAcm(-2). On the other hand, mutated glucose dehydrogenase (GDH) surface displayed bacteria (GDH-bacteria) were used to improve the stability of the glucose oxidation at the bioanode. The as-assembled membraneless glucose/O2 fuel cell showed a high power output of 55.8 ± 2.0 μW cm(-2) and open circuit potential of 0.80 V, contributing to the improved electrocatalysis toward O2 reduction at the laccase/MP-Au biocathode. Moreover, the BFC retained 84% of its maximal power density even after continuous operation for 55 h because of the high stability of the bacterial surface displayed GDH mutant toward glucose oxidation. Our findings may be promising for the development of more efficient glucose BFC for portable battery or self-powered device applications.

  9. Sequence and RT-PCR expression analysis of two peroxidases from Arabidopsis thaliana belonging to a novel evolutionary branch of plant peroxidases. (United States)

    Kjaersgård, I V; Jespersen, H M; Rasmussen, S K; Welinder, K G


    cDNA clones encoding two new Arabidopsis thaliana peroxidases, ATP 1a and ATP 2a, have been identified by searching the Arabidopsis database of expressed sequence tags (dbEST). They represent a novel branch of hitherto uncharacterized plant peroxidases which is only 35% identical in amino acid sequence to the well characterized group of basic plant peroxidases represented by the horseradish (Armoracia rusticana) isoperoxidases HRP C, HRP E5 and the similar Arabidopsis isoperoxidases ATP Ca, ATP Cb, and ATP Ea. However ATP 1a is 87% identical in amino acid sequence to a peroxidase encoded by an mRNA isolated from cotton (Gossypium hirsutum). As cotton and Arabidopsis belong to rather diverse families (Malvaceae and Crucifereae, respectively), in contrast with Arabidopsis and horseradish (both Crucifereae), the high degree of sequence identity indicates that this novel type of peroxidase, albeit of unknown function, is likely to be widespread in plant species. The atp 1 and atp 2 types of cDNA sequences were the most redundant among the 28 different isoperoxidases identified among about 200 peroxidase encoding ESTs. Interestingly, 8 out of totally 38 EST sequences coding for ATP 1 showed three identical nucleotide substitutions. This variant form is designated ATP 1b. Similarly, six out of totally 16 EST sequences coding for ATP 2 showed a number of deletions and nucleotide changes. This variant form is designated ATP 2b. The selected EST clones are full-length and contain coding regions of 993 nucleotides for atp 1a, and 984 nucleotides for atp 2a. These regions show 61% DNA sequence identity. The predicted mature proteins ATP 1a, and ATP 2a are 57% identical in sequence and contain the structurally and functionally important residues, characteristic of the plant peroxidase superfamily. However, they do show two differences of importance to peroxidase catalysis: (1) the asparagine residue linked with the active site distal histidine via hydrogen bonding is absent

  10. Versatile protein recognition by the encoded display of multiple chemical elements on a constant macrocyclic scaffold (United States)

    Li, Yizhou; De Luca, Roberto; Cazzamalli, Samuele; Pretto, Francesca; Bajic, Davor; Scheuermann, Jörg; Neri, Dario


    In nature, specific antibodies can be generated as a result of an adaptive selection and expansion of lymphocytes with suitable protein binding properties. We attempted to mimic antibody-antigen recognition by displaying multiple chemical diversity elements on a defined macrocyclic scaffold. Encoding of the displayed combinations was achieved using distinctive DNA tags, resulting in a library size of 35,393,112. Specific binders could be isolated against a variety of proteins, including carbonic anhydrase IX, horseradish peroxidase, tankyrase 1, human serum albumin, alpha-1 acid glycoprotein, calmodulin, prostate-specific antigen and tumour necrosis factor. Similar to antibodies, the encoded display of multiple chemical elements on a constant scaffold enabled practical applications, such as fluorescence microscopy procedures or the selective in vivo delivery of payloads to tumours. Furthermore, the versatile structure of the scaffold facilitated the generation of protein-specific chemical probes, as illustrated by photo-crosslinking.

  11. Transparent Solar Concentrator for Flat Panel Display (United States)

    Yeh, Chia-Hung; Chang, Fuh-Yu; Young, Hong-Tsu; Hsieh, Tsung-Yen; Chang, Chia-Hsiung


    A new concept of the transparent solar concentrator for flat panel display is experimentally demonstrated without adversely affecting the visual effects. The solar concentrator is based on a solar light-guide plate with micro prisms, not only increasing the absorption area of solar energy but also enhancing the conversion efficiency. The incident light is guided by the designed solar light-guide plate according to the total internal reflection (TIR), and converted into electrical power by photovoltaic solar cells. The designed transparent solar concentrator was made and measured with high transparency, namely 94.8%. The developed solar energy system for display can store energy and supply the bias voltage to light on two light-emitting diodes (LEDs) successfully.

  12. Thiol peroxidases mediate specific genome-wide regulation of gene expression in response to hydrogen peroxide (United States)

    Fomenko, Dmitri E.; Koc, Ahmet; Agisheva, Natalia; Jacobsen, Michael; Kaya, Alaattin; Malinouski, Mikalai; Rutherford, Julian C.; Siu, Kam-Leung; Jin, Dong-Yan; Winge, Dennis R.; Gladyshev, Vadim N.


    Hydrogen peroxide is thought to regulate cellular processes by direct oxidation of numerous cellular proteins, whereas antioxidants, most notably thiol peroxidases, are thought to reduce peroxides and inhibit H2O2 response. However, thiol peroxidases have also been implicated in activation of transcription factors and signaling. It remains unclear if these enzymes stimulate or inhibit redox regulation and whether this regulation is widespread or limited to a few cellular components. Herein, we found that Saccharomyces cerevisiae cells lacking all eight thiol peroxidases were viable and withstood redox stresses. They transcriptionally responded to various redox treatments, but were unable to activate and repress gene expression in response to H2O2. Further studies involving redox transcription factors suggested that thiol peroxidases are major regulators of global gene expression in response to H2O2. The data suggest that thiol peroxidases sense and transfer oxidative signals to the signaling proteins and regulate transcription, whereas a direct interaction between H2O2 and other cellular proteins plays a secondary role. PMID:21282621


    Directory of Open Access Journals (Sweden)

    felipe Nael Seixas


    Full Text Available This study evaluated the performance of strips for colorimetric detection of alkaline phosphatase and peroxidase in milk, comparing them with a kit of reagents for alkaline phosphatase and the official methodology for peroxidase. The samples were analyzed at the Laboratory Inspection of Products of Animal Origin, State University of Londrina. For the comparison tests for the detection of alkaline phosphatase four treatments were made by adding different percentages of raw milk (1%, 2%, 5% and 10% in the pasteurized milk, plus two control treatments. Thirty-eight samples triplicate for each treatment were analyzed. To compare the performance of tests for peroxidase 80 pasteurized milk samples were evaluated simultaneously by official methodology and by colorimetric strips. The performance of the alkaline phosphatase were different for the treatments with 1% and 2% of raw milk which had all the strips change color as the reagent kit showed the presence of phosphatase in just 2.63% and 5.26% the cases, respectively for each treatment. The colorimetric strips for alkaline phosphatase are more sensitive for the identification of small quantities compared to the reagent kit. The performance of tests for peroxidase showed no difference. The strips for the detection of peroxidase or alkaline phosphatase were effective and can replace traditional methods.

  14. Purification and characterization of peroxidase from avocado (Persea americana Mill, cv. Hass). (United States)

    Rojas-Reyes, José O; Robles-Olvera, Victor; Carvajal-Zarrabal, Octavio; Castro Matinez, Claudia; Waliszewski, Krzysztof N; Aguilar-Uscanga, María Guadalupe


    Avocado (Persea americana Mill, cv. Hass) fruit ranks tenth in terms of the most important products for Mexico. Avocado products are quite unstable due to the presence of oxidative enzymes such as polyphenol oxidase and peroxidase. The present study is to characterize the activity of purified avocado peroxidase from avocado in order to ascertain the biochemical and kinetic properties and their inhibition conditions. Purification was performed by Sephacryl S 200 HR gel filtration chromatography and its estimated molecular weight was 40 kDa. The zymogram showed an isoelectric point of 4.7. Six substrates were tested in order to ascertain the affinity of the enzyme for these substrates. The purified peroxidase was found to have low Km (0.296 mM) and high catalytic efficiency (2688 mM(-1) s(-1)) using 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid), optimum activity being reached at 51°C, pH 3.8. The addition of dithiothreitol, β-mercaptoethanol, ascorbic acid, sodium azide, L-cysteine and Tween-20 had high inhibitory effects, while metals ions such as Cu(+), Fe(2+) and Mn(2+) had weak inhibitory activity on purified avocado peroxidase. The purified avocado peroxidase exhibits high inhibition (Ki = 0.37 µM) with 1.97 µM n-propyl gallate using ABTS as substrate at 51°C, pH 3.8 for 10 min. © 2013 Society of Chemical Industry.

  15. An updated view on horseradish peroxidases: recombinant production and biotechnological applications. (United States)

    Krainer, Florian W; Glieder, Anton


    Horseradish peroxidase has been the subject of scientific research for centuries. It has been used exhaustively as reporter enzyme in diagnostics and histochemistry and still plays a major role in these applications. Numerous studies have been conducted on the role of horseradish peroxidase in the plant and its catalytic mechanism. However, little progress has been made in its recombinant production. Until now, commercial preparations of horseradish peroxidase are still isolated from plant roots. These preparations are commonly mixtures of various isoenzymes of which only a small fraction has been described so far. The composition of isoenzymes in these mixed isolates is subjected to uncontrollable environmental conditions. Nowadays, horseradish peroxidase regains interest due to its broad applicability in the fields of medicine, life sciences, and biotechnology in cancer therapy, biosensor systems, bioremediation, and biocatalysis. These medically and commercially relevant applications, the recent discovery of new natural isoenzymes with different biochemical properties, as well as the challenges in recombinant production render this enzyme particularly interesting for future biotechnological solutions. Therefore, we reviewed previous studies as well as current developments with biotechnological emphasis on new applications and the major remaining biotechnological challenge-the efficient recombinant production of horseradish peroxidase enzymes.

  16. Peroxidase activity in Raphanus sativus and its relationship with soil heavy metals

    International Nuclear Information System (INIS)

    Alipour, H.; Zare Myvan, H.; Sharifi, M.


    Today heavy metals are important environmental pollutants which generated from human activities and are one of the most important environmental stresses that cause molecular damages to plants through reactive oxygen species formation such as H2O2. Heavy metals are absorbed and accumulated by plants thus are absorbed by human bodies through the food chain. Raphanus sativus is a herbaceous plant within the Brassicaceae family that has different varieties and is used as a food plant in different parts of Iran. Peroxidase is one of the most important enzyme in oxidoreductase super family that can metabolize H2O2. In this research we studied some growth parameters, peroxidase activity and their relationships with heavy metal content and other soil factors in three different populations of radish collected from Sari, Semnan and south of Tehran. After harvesting the plants shoots and roots Peroxidase activity was assayed spectrophotometrically at 470 nm. Our results showed total heavy metal content of shomal 3 station soil and radish plants was higher than other stations, so plants collected from this station had lowest root and shoot lengths, fresh weights, dry weights, protein content and leaf collrophyll content. The peroxidase activity in both leaves and roots of these plants was higher than plants of other stations Therefore our results showed that with increasing heavy metal concentrations in soils peroxidase activity increased.

  17. Relationship between oxidizable fatty acid content and level of antioxidant glutathione peroxidases in marine fish (United States)

    Grim, Jeffrey M.; Hyndman, Kelly A.; Kriska, Tamas; Girotti, Albert W.; Crockett, Elizabeth L.


    SUMMARY Biological membranes can be protected from lipid peroxidation by antioxidant enzymes including catalase (CAT) and selenium-dependent glutathione peroxidases 1 and 4 (GPx1 and GPx4). Unlike GPx1, GPx4 can directly detoxify lipid hydroperoxides in membranes without prior action of phospholipase A2. We hypothesized that (1) GPx4 is enhanced in species that contain elevated levels of highly oxidizable polyunsaturated fatty acids (PUFA) and (2) activities of antioxidant enzymes are prioritized to meet species-specific oxidative stresses. In this study we examined (i) activities of the oxidative enzyme citrate synthase (CS) and antioxidant (CAT, GPx1 and GPx4) enzymes, (ii) GPx4 protein expression, and (iii) phospholipid composition in livers of five species of marine fish (Myxine glutinosa, Petromyzon marinus, Squalus acanthias, Fundulus heteroclitus and Myoxocephalus octodecemspinosus) that contain a range of PUFA. GPx4 activity was, on average, 5.8 times higher in F. heteroclitus and S. acanthias than in the other three marine fish species sampled. Similarly, activities of CAT and GPx1 were highest in S. acanthias and F. heteroclitus, respectively. GPx4 activity for all species correlates with membrane unsaturation, as well as oxidative activity as indicated by CS. These data support our hypothesis that GPx4 level in marine fish is a function, at least in part, of high PUFA content in these animals. GPx1 activity was also correlated with membrane unsaturation, indicating that marine species partition resources among glutathione-dependent defenses for protection from the initial oxidative insult (e.g. H2O2) and to repair damaged lipids within biological membranes. PMID:22031739

  18. Conformation and activity alteration of horseradish peroxidase induced by the interaction with gene carrier polyethyleneimines (United States)

    Huang, Aimin; Wei, Bangzhi; Mo, Junyong; Wang, Yajing; Ma, Lin


    Polyethyleneimine (PEI) has long been considered as "golden standard" for polymeric gene delivery carriers. However the molecular basis of the cytotoxicity of PEI is poorly understood. Little is known about the effects of PEI on the structure and functions of biomacromolecules. In this work, fluorescence, UV-vis absorption, circular dichroism spectroscopy were conducted to investigate the influence of PEI of average molecular weight 25, 10 and 1.8 kDa (denoted as PEI25k, PEI10k and PEI1.8k) on the conformation of horseradish peroxidase (HRP) and its catalytic efficiency. Zeta-potential measurement and isothermal titration calorimetry were used to reveal the mechanism of the interaction between PEIs and HRP. PEIs were found to bind onto the surface of HRP predominantly via hydrophobic interaction and hydrogen bond or van der Waals interaction. The complex formation between HRP and PEI induced a more compact conformation of the enzyme and an increased hydrophobicity of the microenvironment surrounding heme pocket. The conformational change of HRP had little impact on the affinity towards H2O2 and phenol. However, the increase in the non-planarity of porphyrin ring in the heme group led to an increase in the exposure degree of the active center and thus an enhancement of catalytic efficiency of HRP in the presence of high molecular weight PEIs (PEI25k and PEI10k). The polymer size played an important role in PEI-HRP interaction. PEI of low molecular weight (PEI1.8k) was less efficient to alter the conformation and catalytic activity of HRP in aqueous solutions.

  19. Modelling and Display of the Ultraviolet Sky (United States)

    Daniels, J.; Henry, R.; Murthy, J.; Allen, M.; McGlynn, T. A.; Scollick, K.


    A computer program is currently under development to model in 3D - one dimension of which is wavelength - all the known and major speculated sources of ultraviolet (900 A - 3100 A ) radiation over the celestial sphere. The software is being written in Fortran 77 and IDL and currently operates under IRIX (the operating system of the Silicon Graphics Iris Machine); all output models are in FITS format. Models along with display software will become available to the astronomical community. The Ultraviolet Sky Model currently includes the Zodiacal Light, Point Sources of Emission, and the Diffuse Galactic Light. The Ultraviolet Sky Model is currently displayed using SkyView: a package under development at NASA/ GSFC, which allows users to retrieve and display publically available all-sky astronomical survey data (covering many wavebands) over the Internet. We present a demonstration of the SkyView display of the Ultraviolet Model. The modelling is a five year development project: the work illustrated here represents product output at the end of year one. Future work includes enhancements to the current models and incorporation of the following models: Galactic Molecular Hydrogen Fluorescence; Galactic Highly Ionized Atomic Line Emission; Integrated Extragalactic Light; and speculated sources in the intergalactic medium such as Ionized Plasma and radiation from Non-Baryonic Particle Decay. We also present a poster which summarizes the components of the Ultraviolet Sky Model and outlines a further package that will be used to display the Ultraviolet Model. This work is supported by United States Air Force Contract F19628-93-K-0004. Dr J. Daniels is supported with a post-doctoral Fellowship from the Leverhulme Foundation, London, United Kingdom. We are also grateful for the encouragement of Dr Stephen Price (Phillips Laboratory, Hanscomb Air Force Base, MA)

  20. Circular displays: control/display arrangements and stereotype strength with eight different display locations. (United States)

    Chan, Alan H S; Hoffmann, Errol R


    Two experiments are reported that were designed to investigate control/display arrangements having high stereotype strengths when using circular displays. Eight display locations relative to the operator and control were tested with rotational and translational controls situated on different planes according to the Frame of Reference Transformation Tool (FORT) model of Wickens et al. (2010). (Left. No, Right! Development of the Frame of Reference Transformation Tool (FORT), Proceedings of the Human Factors and Ergonomics Society 54th Annual Meeting, 54: 1022-1026). In many cases, there was little effect of display locations, indicating the importance of the Worringham and Beringer (1998. Directional stimulus-response compatibility: a test of three alternative principles. Ergonomics, 41(6), 864-880) Visual Field principle and an extension of this principle for rotary controls (Hoffmann and Chan (2013). The Worringham and Beringer 'visual field' principle for rotary controls. Ergonomics, 56(10), 1620-1624). The initial indicator position (12, 3, 6 and 9 o'clock) had a major effect on control/display stereotype strength for many of the six controls tested. Best display/control arrangements are listed for each of the different control types (rotational and translational) and for the planes on which they are mounted. Data have application where a circular display is used due to limited display panel space and applies to space-craft, robotics operators, hospital equipment and home appliances. Practitioner Summary: Circular displays are often used when there is limited space available on a control panel. Display/control arrangements having high stereotype strength are listed for four initial indicator positions. These arrangements are best for design purposes.

  1. Dye decolorization and detoxification potential of Ca-alginate beads immobilized manganese peroxidase. (United States)

    Bilal, Muhammad; Asgher, Muhammad


    In view of compliance with increasingly stringent environmental legislation, an eco-friendly treatment technology of industrial dyes and effluents is a major environmental challenge in the color industry. In present study, a promising and eco-friendly entrapment approach was adopted to immobilize purified manganese peroxidase (MnP) produced from an indigenous strain of Ganoderma lucidum IBL-05 on Ca-alginate beads. The immobilized MnP was subsequently used for enhanced decolorization and detoxification of textile reactive dyes). MnP isolated from solid-state culture of G. lucidum IBL-05, presented highest immobilization yield (83.9 %) using alginate beads prepared at optimized conditions of 4 % (w/v) sodium alginate, 2 % (w/v) Calcium chloride (CaCl2) and 0.5 mg/ml enzyme concentration. Immobilization of MnP enhanced optimum temperature but caused acidic shift in optimum pH of the enzyme. The immobilized MnP showed optimum activity at pH 4.0 and 60 °C as compared to pH 5.0 and 35 °C for free enzyme. The kinetic parameters K(m) and V(max) of MnP were significantly improved by immobilization. The enhanced catalytic potential of immobilized MnP led to 87.5 %, 82.1 %, 89.4 %, 95.7 % and 83 % decolorization of Sandal-fix Red C4BLN, Sandal-fix Turq Blue GWF, Sandal-fix Foron Blue E2BLN, Sandal-fix Black CKF and Sandal-fix Golden Yellow CRL dyes, respectively. The insolubilized MnP was reusable for 7 repeated cycles in dye color removal. Furthermore, immobilized MnP also caused a significant reduction in biochemical oxygen demand (BOD) (94.61-95.47 %), chemical oxygen demand (COD) (91.18-94.85 %), and total organic carbon (TOC) (89.58-95 %) of aqueous dye solutions. G. lucidum MnP was immobilized in Ca-alginate beads by entrapment method to improve its practical effectiveness. Ca-alginate bound MnP was catalytically more vigorous, thermo-stable, reusable and worked over wider ranges of pH and temperature as compared to its free counterpart. Results of cytotoxicity like

  2. The mitochondrial cytochrome c peroxidase Ccp1 of Saccharomyces cerevisiae is involved in conveying an oxidative stress signal to the transcription factor Pos9 (Skn7). (United States)

    Charizanis, C; Juhnke, H; Krems, B; Entian, K D


    In Saccharomyces cerevisiae two transcription factors, Pos9 (Skn7) and Yap1, are involved in the response to oxidative stress. Fusion of the Pos9 response-regulator domain to the Gal4 DNA-binding domain results in a transcription factor which renders the expression of a GAL1-lacZ reporter gene dependent on oxidative stress. To identify genes which are involved in the oxygen-dependent activation of the Gal4-Pos9 hybrid protein we screened for mutants that failed to induce the heterologous test system upon oxidative stress (fap mutants for factors activating Pos9). We isolated several respiration-deficient and some respiration-competent mutants by this means. We selected for further characterization only those mutants which also displayed an oxidative-stress-sensitive phenotype. One of the respiration-deficient mutants (complementation groupfap6) could be complemented by the ISM1 gene, which encodes mitochondrial isoleucyl tRNA synthetase, suggesting that respiration competence was important for signalling of oxidative stress. In accordance with this notion a rho0 strain and a wild-type strain in which respiration had been blocked (by treatment with antimycin A or with cyanide) also failed to activate Gal4-Pos9 upon imposition of oxidative stress. Another mutant, fap24, which was respiration-competent, could be complemented by CCP1, which encodes the mitochondrial cytochrome c peroxidase. Mitochondrial cytochrome c peroxidase degrades reactive oxygen species within the mitochondria. This suggested a possible sensor function for the enzyme in the oxidative stress response. To test this we used the previously described point mutant ccp1 W191F, which is characterized by a 10(4)-fold decrease in electron flux between cytochrome c and cytochrome c peroxidase. The Ccp1W191F mutant was still capable of activating the Pos9 transcriptional activation domain, suggesting that the signalling function of Ccp1 is independent of electron flux rates.

  3. Color speckle in laser displays (United States)

    Kuroda, Kazuo


    At the beginning of this century, lighting technology has been shifted from discharge lamps, fluorescent lamps and electric bulbs to solid-state lighting. Current solid-state lighting is based on the light emitting diodes (LED) technology, but the laser lighting technology is developing rapidly, such as, laser cinema projectors, laser TVs, laser head-up displays, laser head mounted displays, and laser headlamps for motor vehicles. One of the main issues of laser displays is the reduction of speckle noise1). For the monochromatic laser light, speckle is random interference pattern on the image plane (retina for human observer). For laser displays, RGB (red-green-blue) lasers form speckle patterns independently, which results in random distribution of chromaticity, called color speckle2).

  4. Integrated Display & Environmental Awareness System (United States)

    National Aeronautics and Space Administration — The goal of this project is the development of a head mounted display for use in operations here on Earth and in Space. The technology would provide various means of...

  5. Performance of NCAP projection displays (United States)

    Jones, Philip J.; Tomita, Akira; Wartenberg, Mark


    Prototypes of projection displays based on dispersions of liquid crystal in polymer matrices are beginning to appear. The principle of operation depends on electrically switchable light scattering. They are potentially much brighter than current cathode ray tube (CRT) or twisted nematic liquid crystal (TN LC) cell based displays. Comparisons of efficacy and efficiency show this. The contrast and brightness of such displays depend on a combination of the f- number of the projection system and the scattering characteristics of the light valve. Simplified equations can be derived to show these effects. The degree of scattering of current NCAP formulations is sufficient to produce good contrast projection displays, at convenient voltages, that are around three times brighter than TN LC projectors because of the lack of polarizers in the former.

  6. Interactive editing program using display

    International Nuclear Information System (INIS)

    Lang, I.; Ehsenski, J.; Namsraj, Yu.; Fefilov, B.V.


    A general description is given as well as principal functions are considered of 'DOSE' interactive editor program with a display involved. The program has been elaborated for TRA/1-1001 computer. This program enables one to edit and correct texts in algorithmical languages on a raster display screen as well as to provide perforated tapes for their further usage. 'DOSE' program is regarded as a basic program system for a set of TRA/1 and MINSK-32 computers

  7. A novel membrane-based process to isolate peroxidase from horseradish roots: optimization of operating parameters. (United States)

    Liu, Jianguo; Yang, Bo; Chen, Changzhen


    The optimization of operating parameters for the isolation of peroxidase from horseradish (Armoracia rusticana) roots with ultrafiltration (UF) technology was systemically studied. The effects of UF operating conditions on the transmission of proteins were quantified using the parameter scanning UF. These conditions included solution pH, ionic strength, stirring speed and permeate flux. Under optimized conditions, the purity of horseradish peroxidase (HRP) obtained was greater than 84 % after a two-stage UF process and the recovery of HRP from the feedstock was close to 90 %. The resulting peroxidase product was then analysed by isoelectric focusing, SDS-PAGE and circular dichroism, to confirm its isoelectric point, molecular weight and molecular secondary structure. The effects of calcium ion on HRP specific activities were also experimentally determined.

  8. Musa paradisiaca stem juice as a source of peroxidase and ligninperoxidase. (United States)

    Vernwal, S K; Yadav, R S; Yadav, K D


    Musa paradisiaca stem juice has been shown to contain peroxidase activity of the order of 0.1 enzyme unit/ml. The Km values of this peroxidase for the substrates guaiacol and hydrogen peroxide are 2.4 and 0.28 mM respectively. The pH and temperature optima are 4.5 and 62.5 degrees C respectively. Like other peroxidases, it follows double displacement type mechanism. At low pH, Musa paradisiaca stem juice exhibits ligninperoxidase type activity. The pH optimum for ligninperoxidase type activity is 2.0 and the temperature optimum is 24 degrees C. The Km values for veratryl alcohol and n-propanol are 66 and 78 microM respectively.

  9. Horseradish peroxidase-nanoclay hybrid particles of high functional and colloidal stability. (United States)

    Pavlovic, Marko; Rouster, Paul; Somosi, Zoltan; Szilagyi, Istvan


    Highly stable dispersions of enzyme-clay nanohybrids of excellent horseradish peroxidase activity were developed. Layered double hydroxide nanoclay was synthesized and functionalized with heparin polyelectrolyte to immobilize the horseradish peroxidase enzyme. The formation of a saturated heparin layer on the platelets led to charge inversion of the positively charged bare nanoclay and to highly stable aqueous dispersions. Great affinity of the enzyme to the surface modified platelets resulted in strong horseradish peroxidase adsorption through electrostatic and hydrophobic interactions as well as hydrogen bonding network and prevented enzyme leakage from the obtained material. The enzyme kept its functional integrity upon immobilization and showed excellent activity in decomposition of hydrogen peroxide and oxidation of an aromatic compound in the test reactions. In addition, remarkable long term functional stability of the enzyme-nanoclay hybrid was observed making the developed colloidal system a promising antioxidant candidate in biomedical treatments and industrial processes. Copyright © 2018 Elsevier Inc. All rights reserved.

  10. Screening of postharvest agricultural wastes as alternative sources of peroxidases: characterization and kinetics of a novel peroxidase from lentil ( Lens culinaris L.) stubble. (United States)

    Hidalgo-Cuadrado, Nazaret; Pérez-Galende, Patricia; Manzano, Teresa; De Maria, Cándido Garcia; Shnyrov, Valery L; Roig, Manuel G


    Aqueous crude extracts of a series of plant wastes (agricultural, wild plants, residues from sports activities (grass), ornamental residues (gardens)) from 17 different plant species representative of the typical biodiversity of the Iberian peninsula were investigated as new sources of peroxidases (EC Of these, lentil (Lens culinaris L.) stubble crude extract was seen to provide one of the highest specific peroxidase activities, catalyzing the oxidation of guaiacol in the presence of hydrogen peroxide to tetraguaiacol, and was used for further studies. For the optimum extraction conditions found, the peroxidase activity in this crude extract (110 U mL(-1)) did not vary for at least 15 months when stored at 4 °C (k(inact) = 0.146 year(-1), t(1/2 inact) = 4.75 year), whereas, for comparative purposes, the peroxidase activity (60 U mL(-1)) of horseradish (Armoracia rusticana L.) root crude extract, obtained and stored under the same conditions, showed much faster inactivation kinetics (k(inact) = 2.2 × 10(-3) day(-1), t(1/2 inact) = 315 days). Using guaiacol as an H donor and a universal buffer (see above), all crude extract samples exhibited the highest peroxidase activity in the pH range between 4 and 7. Once semipurified by passing the crude extract through hydrophobic chromatography on phenyl-Sepharose CL-4B, the novel peroxidase (LSP) was characterized as having a purity number (RZ) of 2.5 and three SDS-PAGE electrophoretic bands corresponding to molecular masses of 52, 35, and 18 kDa. The steady-state kinetic study carried out on the H(2)O(2)-mediated oxidation of guaiacol by the catalytic action of this partially purified peroxidase pointed to apparent Michaelian kinetic behavior (K(m)(appH(2)O(2)) = 1.87 mM; V(max)(appH(2)O(2)) = 6.4 mM min(-1); K(m)(app guaicol) = 32 mM; V(max)(app guaicol) = 9.1 mM min(-1)), compatible with the two-substrate ping-pong mechanism generally accepted for peroxidases. Finally, after the effectiveness of the crude

  11. Transcriptome Profiling of Tomato Uncovers an Involvement of Cytochrome P450s and Peroxidases in Stigma Color Formation

    Directory of Open Access Journals (Sweden)

    Yan Zhang


    Full Text Available Stigma is a crucial structure of female reproductive organ in plants. Stigma color is usually regarded as an important trait in variety identification in some species, but the molecular mechanism of stigma color formation remains elusive. Here, we characterized a tomato mutant, yellow stigma (ys, that shows yellow rather than typical green color in the stigma. Analysis of pigment contents revealed that the level of flavonoid naringenin chalcone was increased in the ys stigma, possibly as a result of higher accumulation of p-coumaric acid, suggesting that naringenin chalcone might play a vital role in yellow color control in tomato stigma. To understand the genes and gene networks that regulate tomato stigma color, RNA-sequencing (RNA-Seq analyses were performed to compare the transcriptomes of stigmas between ys mutant and wild-type (WT. We obtained 507 differentially expressed genes, in which, 84 and 423 genes were significantly up-regulated and down-regulated in the ys mutant, respectively. Two cytochrome P450 genes, SlC3H1 and SlC3H2 which encode p-coumarate 3-hydroxylases, and six peroxidase genes were identified to be dramatically inhibited in the yellow stigma. Further bioinformatic and biochemical analyses implied that the repression of the two SlC3Hs and six PODs may indirectly lead to higher naringenin chalcone level through inhibiting lignin biosynthesis, thereby contributing to yellow coloration in tomato stigma. Thus, our data suggest that two SlC3Hs and six PODs are involved in yellow stigma formation. This study provides valuable information for dissecting the molecular mechanism of stigma color control in tomato.Statement: This study reveals that two cytochrome P450s (SlC3H1 and SlC3H2 and six peroxidases potentially regulate the yellow stigma formation by indirectly enhancing biosynthesis of yellow-colored naringenin chalcone in the stigma of tomato.

  12. A peroxidase-dependent apoplastic oxidative burst in cultured Arabidopsis cells functions in MAMP-elicited defense. (United States)

    O'Brien, Jose A; Daudi, Arsalan; Finch, Paul; Butt, Vernon S; Whitelegge, Julian P; Souda, Puneet; Ausubel, Frederick M; Bolwell, G Paul


    Perception by plants of so-called microbe-associated molecular patterns (MAMPs) such as bacterial flagellin, referred to as pattern-triggered immunity, triggers a rapid transient accumulation of reactive oxygen species (ROS). We previously identified two cell wall peroxidases, PRX33 and PRX34, involved in apoplastic hydrogen peroxide (H2O2) production in Arabidopsis (Arabidopsis thaliana). Here, we describe the generation of Arabidopsis tissue culture lines in which the expression of PRX33 and PRX34 is knocked down by antisense expression of a heterologous French bean (Phaseolus vulgaris) peroxidase cDNA construct. Using these tissue culture lines and two inhibitors of ROS generation, azide and diphenylene iodonium, we found that perxoxidases generate about half of the H2O2 that accumulated in response to MAMP treatment and that NADPH oxidases and other sources such as mitochondria account for the remainder of the ROS. Knockdown of PRX33/PRX34 resulted in decreased expression of several MAMP-elicited genes, including MYB51, CYP79B2, and CYP81F2. Similarly, proteomic analysis showed that knockdown of PRX33/PRX34 led to the depletion of various MAMP-elicited defense-related proteins, including the two cysteine-rich peptides PDF2.2 and PDF2.3. Knockdown of PRX33/PRX34 also led to changes in the cell wall proteome, including increases in enzymes involved in cell wall remodeling, which may reflect enhanced cell wall expansion as a consequence of reduced H2O2-mediated cell wall cross-linking. Comparative metabolite profiling of a CaCl2 extract of the PRX33/PRX34 knockdown lines showed significant changes in amino acids, aldehydes, and keto acids but not fatty acids and sugars. Overall, these data suggest that PRX33/PRX34-generated ROS production is involved in the orchestration of pattern-triggered immunity in tissue culture cells.

  13. A polymeric liquid membrane electrode responsive to 3,3',5,5'-tetramethylbenzidine oxidation for sensitive peroxidase/peroxidase mimetic-based potentiometric biosensing. (United States)

    Wang, Xuewei; Yang, Yangang; Li, Long; Sun, Mingshuang; Yin, Haogen; Qin, Wei


    The oxidation of 3,3',5,5'-tetramethylbenzidine (TMB) has great utility in bioanalysis such as peroxidase/peroxidase mimetic-based biosensing. In this paper, the behaviors of TMB oxidation intermediates/products in liquid/liquid biphasic systems have been investigated for the first time. The free radical, charge transfer complex, and diimine species generated by TMB oxidation are all positively charged under acidic and near-neutral conditions. Electron paramagnetic resonance and visible absorbance spectroscopy data demonstrate that these cationic species can be effectively transferred from an aqueous phase into a water-immiscible liquid phase functionalized by an appropriate cation exchanger. Accordingly, sensitive potential responses of TMB oxidation have been obtained on a cation exchanger-doped polymeric liquid membrane electrode under mildly acidic and near-neutral conditions. By using the membrane electrode responsive to TMB oxidations, two sensitive potentiometric biosensing schemes including the peroxidase-labeled sandwich immunoassay and G-quadruplex DNAzyme-based DNA hybridization assay have been developed. The obtained detection limits for the target antigen and DNA are 0.02 ng/mL and 0.1 nM, respectively. Coupled with other advantages such as low cost, high reliability, and ease of miniaturization and integration, the proposed polymeric liquid membrane electrode holds great promise as a facile and efficient transducer for TMB oxidation and related biosensing applications.

  14. Peroxidase activity of the rat blood at prolonged intake of 137Cs

    Directory of Open Access Journals (Sweden)

    Yu. P. Grynevych


    Full Text Available Investigated peroxidase activity of blood white nonlinear rats-males by daily oral administration of 15 kBq 137Cs by chemiluminescence. Discovered oscillatory nature of the changes chemiluminescent indicators peroxi-dase oxidation of blood, the maximum deviation of the control are registered during the 4th and 60th days, and the minimum at the 1st, 7th and 135th days. Recovering kinetic parameters CL does not occur within 135 days of ob-servation (the 90th day of the completion of the introduction of radioactive cesium.

  15. [Isolation and purification of Mn-peroxidase from Azospirillum brasilense Sp245]. (United States)

    Kupriashina, M A; Selivanov, N Iu; Nikitina, V E


    Homogenous Mn-peroxidase of a 26-fold purity grade was isolated from a culture of Azospirillum brasilense Sp245 cultivated on a medium containing 0.1 mM pyrocatechol. The molecular weight of the enzyme is 43 kD as revealed by electrophoresis in SDS-PAAG. It was shown that the use of pyrocatechol and 2,2'-azino-bis(3-ethylbenzotiazoline-6-sulfonate) at concentrations of 0.1 and I mM as inductors increased the Mn-peroxidase activity by a factor of 3.

  16. Illuminant-adaptive color reproduction for mobile display (United States)

    Kim, Jong-Man; Park, Kee-Hyon; Kwon, Oh-Seol; Cho, Yang-Ho; Ha, Yeong-Ho


    This paper proposes an illuminant-adaptive reproduction method using light adaptation and flare conditions for a mobile display. Mobile displays, such as PDAs and cellular phones, are viewed under various lighting conditions. In particular, images displayed in daylight are perceived as quite dark due to the light adaptation of the human visual system, as the luminance of a mobile display is considerably lower than that of an outdoor environment. In addition, flare phenomena decrease the color gamut of a mobile display by increasing the luminance of dark areas and de-saturating the chroma. Therefore, this paper presents an enhancement method composed of lightness enhancement and chroma compensation. First, the ambient light intensity is measured using a lux-sensor, then the flare is calculated based on the reflection ratio of the display device and the ambient light intensity. The relative cone response is nonlinear to the input luminance. This is also changed by the ambient light intensity. Thus, to improve the perceived image, the displayed luminance is enhanced by lightness linearization. In this paper, the image's luminance is transformed by linearization of the response to the input luminance according to the ambient light intensity. Next, the displayed image is compensated according to the physically reduced chroma, resulting from flare phenomena. The reduced chroma value is calculated according to the flare for each intensity. The chroma compensation method to maintain the original image's chroma is applied differently for each hue plane, as the flare affects each hue plane differently. At this time, the enhanced chroma also considers the gamut boundary. Based on experimental observations, the outer luminance-intensity generally ranges from 1,000 lux to 30,000 lux. Thus, in the case of an outdoor environment, i.e. greater than 1,000 lux, this study presents a color reproduction method based on an inverse cone response curve and flare condition. Consequently

  17. Honokiol trimers and dimers via biotransformation catalyzed by Momordica charantia peroxidase: novel and potent α-glucosidase inhibitors. (United States)

    He, Ye; Wang, Xiao-Bing; Fan, Bo-Yi; Kong, Ling-Yi


    Ten honokiol oligomers (1-10), including four novel trimers (1-4) and four novel dimers (5-8), were obtained by means of biotransformation of honokiol catalyzed by Momordica charantia peroxidase (MCP) for the first time. Their structures were established on the basis of spectroscopic methods. The biological results demonstrated that most of the oligomers were capable of inhibiting α-glucosidase with significant abilities, which were one to two orders of magnitude more potent than the substrate, honokiol. In particular, compound 2, the honokiol trimer, displayed the greatest inhibitory activity against α-glucosidase with an IC50 value of 1.38μM. Kinetic and CD studies indicated that 2 inhibited α-glucosidase in a reversible, mixed-type manner and caused conformational changes in the secondary structure of the enzyme protein. These findings suggested that 2 might be exploited as a promising drug candidate for the treatment of diabetes. Copyright © 2013 Elsevier Ltd. All rights reserved.

  18. H2O2 recycling during oxidation of the arylglycerol beta-aryl ether lignin structure by lignin peroxidase and glyoxal oxidase. (United States)

    Hammel, K E; Mozuch, M D; Jensen, K A; Kersten, P J


    Oxidative C alpha-C beta cleavage of the arylglycerol beta-aryl ether lignin model 1-(3,4-dimethoxy-phenyl)-2-phenoxypropane-1,3-diol (I) by Phanerochaete chrysosporium lignin peroxidase in the presence of limiting H2O2 was enhanced 4-5-fold by glyoxal oxidase from the same fungus. Further investigation showed that each C alpha-C beta cleavage reaction released 0.8-0.9 equiv of glycolaldehyde, a glyoxal oxidase substrate. The identification of glycolaldehyde was based on 13C NMR spectrometry of reaction product obtained from beta-, gamma-, and beta,gamma-13C-substituted I, and quantitation was based on an enzymatic NADH-linked assay. The oxidation of glycolaldehyde by glyoxal oxidase yielded 0.9 oxalate and 2.8 H2O2 per reaction, as shown by quantitation of oxalate as 2,3-dihydroxyquinoxaline after derivatization with 1,2-diaminobenzene and by quantitation of H2O2 in coupled spectrophotometric assays with veratryl alcohol and lignin peroxidase. These results suggest that the C alpha-C beta cleavage of I by lignin peroxidase in the presence of glyoxal oxidase should regenerate as many as 3 H2O2. Calculations based on the observed enhancement of LiP-catalyzed C alpha-C beta cleavage by glyoxal oxidase showed that approximately 2 H2O2 were actually regenerated per cleavage of I when both enzymes were present. The cleavage of arylglycerol beta-aryl ether structures by ligninolytic enzymes thus recycles H2O2 to support subsequent cleavage reactions.

  19. Lateralisation of aggressive displays in a tephritid fly (United States)

    Benelli, Giovanni; Donati, Elisa; Romano, Donato; Stefanini, Cesare; Messing, Russell H.; Canale, Angelo


    Lateralisation (i.e. different functional and/or structural specialisations of the left and right sides of the brain) of aggression has been examined in several vertebrate species, while evidence for invertebrates is scarce. In this study, we investigated lateralisation of aggressive displays (boxing with forelegs and wing strikes) in the Mediterranean fruit fly, Ceratitis capitata. We attempted to answer the following questions: (1) do medflies show lateralisation of aggressive displays at the population-level; (2) are there sex differences in lateralisation of aggressive displays; and (3) does lateralisation of aggression enhance fighting success? Results showed left-biased population-level lateralisation of aggressive displays, with no consistent differences among sexes. In both male-male and female-female conflicts, aggressive behaviours performed with left body parts led to greater fighting success than those performed with right body parts. As we found left-biased preferential use of body parts for both wing strikes and boxing, we predicted that the left foreleg/wing is quicker in exploring/striking than the right one. We characterised wing strike and boxing using high-speed videos, calculating mean velocity of aggressive displays. For both sexes, aggressive displays that led to success were faster than unsuccessful ones. However, left wing/legs were not faster than right ones while performing aggressive acts. Further research is needed on proximate causes allowing enhanced fighting success of lateralised aggressive behaviour. This is the first report supporting the adaptive role of lateralisation of aggressive displays in insects.

  20. On-line data display (United States)

    Lang, Sherman Y. T.; Brooks, Martin; Gauthier, Marc; Wein, Marceli


    A data display system for embedded realtime systems has been developed for use as an operator's user interface and debugging tool. The motivation for development of the On-Line Data Display (ODD) have come from several sources. In particular the design reflects the needs of researchers developing an experimental mobile robot within our laboratory. A proliferation of specialized user interfaces revealed a need for a flexible communications and graphical data display system. At the same time the system had to be readily extensible for arbitrary graphical display formats which would be required for data visualization needs of the researchers. The system defines a communication protocol transmitting 'datagrams' between tasks executing on the realtime system and virtual devices displaying the data in a meaningful way on a graphical workstation. The communication protocol multiplexes logical channels on a single data stream. The current implementation consists of a server for the Harmony realtime operating system and an application written for the Macintosh computer. Flexibility requirements resulted in a highly modular server design, and a layered modular object- oriented design for the Macintosh part of the system. Users assign data types to specific channels at run time. Then devices are instantiated by the user and connected to channels to receive datagrams. The current suite of device types do not provide enough functionality for most users' specialized needs. Instead the system design allows the creation of new device types with modest programming effort. The protocol, design and use of the system are discussed.

  1. 75 FR 18056 - Safety Zone; Fireworks Display, Patuxent River, Solomons Island Harbor, MD (United States)


    ... the event, and enhancing public and maritime safety. Basis and Purpose Fireworks displays are... promote public and maritime safety during a fireworks display, and to protect mariners transiting the area...-AA00 Safety Zone; Fireworks Display, Patuxent River, Solomons Island Harbor, MD AGENCY: Coast Guard...

  2. To 'display' or not to 'display'- that is the peptide

    CSIR Research Space (South Africa)

    Crampton, Michael C


    Full Text Available eukaryotic and prokaryotic systems but has mainly focused around phages (Etz et al, 2001), yeast (Kondo and Ueda, 2004) and bacteria (Lee et al 2003). The central variable domain of the FliC protein is dispensable and can be used for the insertion and display...


    Martin, M. D.


    The Interactive Image Display Program (IMDISP) is an interactive image display utility for the IBM Personal Computer (PC, XT and AT) and compatibles. Until recently, efforts to utilize small computer systems for display and analysis of scientific data have been hampered by the lack of sufficient data storage capacity to accomodate large image arrays. Most planetary images, for example, require nearly a megabyte of storage. The recent development of the "CDROM" (Compact Disk Read-Only Memory) storage technology makes possible the storage of up to 680 megabytes of data on a single 4.72-inch disk. IMDISP was developed for use with the CDROM storage system which is currently being evaluated by the Planetary Data System. The latest disks to be produced by the Planetary Data System are a set of three disks containing all of the images of Uranus acquired by the Voyager spacecraft. The images are in both compressed and uncompressed format. IMDISP can read the uncompressed images directly, but special software is provided to decompress the compressed images, which can not be processed directly. IMDISP can also display images stored on floppy or hard disks. A digital image is a picture converted to numerical form so that it can be stored and used in a computer. The image is divided into a matrix of small regions called picture elements, or pixels. The rows and columns of pixels are called "lines" and "samples", respectively. Each pixel has a numerical value, or DN (data number) value, quantifying the darkness or brightness of the image at that spot. In total, each pixel has an address (line number, sample number) and a DN value, which is all that the computer needs for processing. DISPLAY commands allow the IMDISP user to display all or part of an image at various positions on the display screen. The user may also zoom in and out from a point on the image defined by the cursor, and may pan around the image. To enable more or all of the original image to be displayed on the

  4. Thyroid peroxidase antibodies in pregnant women with type 1 diabetes: impact on thyroid function, metabolic control and pregnancy outcome

    DEFF Research Database (Denmark)

    Vestgaard, Marianne; Nielsen, Lene Ringholm; Rasmussen, Åse Krogh


    In pregnant women with type 1 diabetes, we evaluated whether the presence of thyroid peroxidase autoantibodies (anti-TPO) was associated with changes in thyroid function, metabolic control and pregnancy outcome.......In pregnant women with type 1 diabetes, we evaluated whether the presence of thyroid peroxidase autoantibodies (anti-TPO) was associated with changes in thyroid function, metabolic control and pregnancy outcome....

  5. Structure of the Zymomonas mobilis respiratory chain: oxygen affinity of electron transport and the role of cytochrome c peroxidase. (United States)

    Balodite, Elina; Strazdina, Inese; Galinina, Nina; McLean, Samantha; Rutkis, Reinis; Poole, Robert K; Kalnenieks, Uldis


    The genome of the ethanol-producing bacterium Zymomonas mobilis encodes a bd-type terminal oxidase, cytochrome bc1 complex and several c-type cytochromes, yet lacks sequences homologous to any of the known bacterial cytochrome c oxidase genes. Recently, it was suggested that a putative respiratory cytochrome c peroxidase, receiving electrons from the cytochrome bc1 complex via cytochrome c552, might function as a peroxidase and/or an alternative oxidase. The present study was designed to test this hypothesis, by construction of a cytochrome c peroxidase mutant (Zm6-perC), and comparison of its properties with those of a mutant defective in the cytochrome b subunit of the bc1 complex (Zm6-cytB). Disruption of the cytochrome c peroxidase gene (ZZ60192) caused a decrease of the membrane NADH peroxidase activity, impaired the resistance of growing culture to exogenous hydrogen peroxide and hampered aerobic growth. However, this mutation did not affect the activity or oxygen affinity of the respiratory chain, or the kinetics of cytochrome d reduction. Furthermore, the peroxide resistance and membrane NADH peroxidase activity of strain Zm6-cytB had not decreased, but both the oxygen affinity of electron transport and the kinetics of cytochrome d reduction were affected. It is therefore concluded that the cytochrome c peroxidase does not terminate the cytochrome bc1 branch of Z. mobilis, and that it is functioning as a quinol peroxidase. © 2014 The Authors.

  6. A Biocatalytic One-Pot Approach for the Preparation of Lignin Oligomers Using an Oxidase/Peroxidase Cascade Enzyme System

    NARCIS (Netherlands)

    Habib, Mohamed H. M.; Deuss, Peter J.; Loncar, Nikola; Trajkovic, Milos; Fraaije, Marco W.


    Synthetic lignin was prepared biocatalytically in a one-pot, two-step reaction using an oxidase/peroxidase cascade enzyme system. Using eugenol in combination with eugenol oxidase and a peroxidase, lignin-like material was produced. The cascade reaction takes advantage of the ability of the oxidase

  7. Visual Attention to Radar Displays (United States)

    Moray, N.; Richards, M.; Brophy, C.


    A model is described which predicts the allocation of attention to the features of a radar display. It uses the growth of uncertainty and the probability of near collision to call the eye to a feature of the display. The main source of uncertainty is forgetting following a fixation, which is modelled as a two dimensional diffusion process. The model was used to predict information overload in intercept controllers, and preliminary validation obtained by recording eye movements of intercept controllers in simulated and live (practice) interception.

  8. Drag and drop display & builder

    Energy Technology Data Exchange (ETDEWEB)

    Bolshakov, Timofei B.; Petrov, Andrey D.; /Fermilab


    The Drag and Drop (DnD) Display & Builder is a component-oriented system that allows users to create visual representations of data received from data acquisition systems. It is an upgrade of a Synoptic Display mechanism used at Fermilab since 2002. Components can be graphically arranged and logically interconnected in the web-startable Project Builder. Projects can be either lightweight AJAX- and SVG-based web pages, or they can be started as Java applications. The new version was initiated as a response to discussions between the LHC Controls Group and Fermilab.

  9. NIST display colorimeter calibration facility (United States)

    Brown, Steven W.; Ohno, Yoshihiro


    A facility has been developed at the National Institute of Standards and Technology (NIST) to provide calibration services for color-measuring instruments to address the need for improving and certifying the measurement uncertainties of this type of instrument. While NIST has active programs in photometry, flat panel display metrology, and color and appearance measurements, these are the first services offered by NIST tailored to color-measuring instruments for displays. An overview of the facility, the calibration approach, and associated uncertainties are presented. Details of a new tunable colorimetric source and the development of new transfer standard instruments are discussed.

  10. Protein-directed in situ synthesis of platinum nanoparticles with superior peroxidase-like activity, and their use for photometric determination of hydrogen peroxide

    International Nuclear Information System (INIS)

    Chen, Lijian; Wang, Nan; Wang, Xindong; Ai, Shiyun


    Platinum nanoparticles (Pt-NPs) with sizes in the range from 10 to 30 nm were synthesized using protein-directed one-pot reduction. The model globular protein bovine serum albumin (BSA) was exploited as the template, and the resulting BSA/Pt-NPs were studied by transmission electron microscopy, energy dispersive X-ray spectroscopy, and resonance Rayleigh scattering spectroscopy. The modified nanoparticles display a peroxidase-like activity that was exploited in a rapid method for the colorimetric determination of hydrogen peroxide which can be detected in the 50 μM to 3 mM concentration range. The limit of detection is 7.9 μM, and the lowest concentration that can be visually detected is 200 μM. (author)

  11. Peroxidase catalyzed conjugation of peptides, proteins and polysaccharides via endogenous and exogenous phenols.

    NARCIS (Netherlands)

    Oudgenoeg, G.


    The research was directed towards peroxidase mediated cross-linking of proteins and polysaccharides. Two approaches were explored, cross-linking by use of ferulic acid (FA)oand cross-linking by use

  12. Activity of Mn-Oxidizing Peroxidases of Ganoderma lucidum Depending on Cultivation Conditions

    Directory of Open Access Journals (Sweden)

    Jasmina Ćilerdžić


    Full Text Available Trunks and stumps of various deciduous species act as natural habitats for Ganoderma lucidum. The chemical composition of their cell wall affects the development of fungal ligninolytic enzyme system as well as its ability to degrade lignin from the plant cell wall. Additionally, numerous compounds structurally similar to lignin can be degraded by the G. lucidum enzyme system which could take important roles in various biotechnological processes. The laccases, which are the dominant enzymes synthesized by G. lucidum, have been studied more extensively than the Mn-oxidizing peroxidases. Therefore, this study aimed to create the dynamics profile of Mn-oxidizing peroxidases activities in four G. lucidum strains, classifying and determining their properties depending on the cultivation type and plant residue as a carbon source in the medium, as well as to establish whether intraspecific variety exists. The findings suggest that submerged cultivation appeared to be a more appropriate cultivation type for enzyme activities compared with solid-state cultivation, and oak sawdust was a better carbon source than wheat straw. Under the optimum conditions, on day 14, G. lucidum BEOFB 431 was characterized by the highest levels of both Mn-dependent and Mn-independent peroxidase activities (4795.5 and 5170.5 U/L, respectively. Strain, cultivation type, and carbon source were factors that affected the profiles of Mn-oxidizing peroxidases isoenzymes.

  13. Degradation of textile dyes using immobilized lignin peroxidase-like metalloporphines under mild experimental conditions

    Directory of Open Access Journals (Sweden)

    Zucca Paolo


    Full Text Available Abstract Background Synthetic dyes represent a broad and heterogeneous class of durable pollutants, that are released in large amounts by the textile industry. The ability of two immobilized metalloporphines (structurally emulating the ligninolytic peroxidases to bleach six chosen dyes (alizarin red S, phenosafranine, xylenol orange, methylene blue, methyl green, and methyl orange was compared to enzymatic catalysts. To achieve a green and sustainable process, very mild conditions were chosen. Results IPS/MnTSPP was the most promising biomimetic catalyst as it was able to effectively and quickly bleach all tested dyes. Biomimetic catalysis was fully characterized: maximum activity was centered at neutral pH, in the absence of any organic solvent, using hydrogen peroxide as the oxidant. The immobilized metalloporphine kept a large part of its activity during multi-cycle use; however, well-known redox mediators were not able to increase its catalytic activity. IPS/MnTSPP was also more promising for use in industrial applications than its enzymatic counterparts (lignin peroxidase, laccase, manganese peroxidase, and horseradish peroxidase. Conclusions On the whole, the conditions were very mild (standard pressure, room temperature and neutral pH, using no organic solvents, and the most environmental-friendly oxidant and a significant bleaching and partial mineralization of the dyes was achieved in approximately 1 h. Therefore, the process was consistent with large-scale applications. The biomimetic catalyst also had more promising features than the enzymatic catalysts.

  14. Effects of commercial selenium products on glutathione peroxidase activity and semen quality in stud boars (United States)

    The aim of this study was to determine how dietary supplementation of inorganic and organic selenium affects selenium concentration and glutathione peroxidase activity in blood and sperm of sexually mature stud boars. Twenty-four boars of the Large White, Landrace, Pietrain, and Duroc breeds of opt...

  15. Calculated ionisation potentials to determine the oxidation of vanillin precursors by lignin peroxidase.

    NARCIS (Netherlands)

    Have, ten R.; Rietjens, I.M.C.M.; Hartmans, S.; Swarts, H.J.; Field, J.A.


    In view of the biocatalytic production of vanillin, this research focused on the lignin peroxidase (LiP) catalysed oxidation of naturally occurring phenolic derivatives: O-methyl ethers, O-acetyl esters, and O-glucosyl ethers. The ionisation potential (IP) of a series of model compounds was

  16. Molecular Modeling of Peroxidase and Polyphenol Oxidase: Substrate Specificity and Active Site Comparison

    Directory of Open Access Journals (Sweden)

    Lalida Shank


    Full Text Available Peroxidases (POD and polyphenol oxidase (PPO are enzymes that are well known to be involved in the enzymatic browning reaction of fruits and vegetables with different catalytic mechanisms. Both enzymes have some common substrates, but each also has its specific substrates. In our computational study, the amino acid sequence of grape peroxidase (ABX was used for the construction of models employing homology modeling method based on the X-ray structure of cytosolic ascorbate peroxidase from pea (PDB ID:1APX, whereas the model of grape polyphenol oxidase was obtained directly from the available X-ray structure (PDB ID:2P3X. Molecular docking of common substrates of these two enzymes was subsequently studied. It was found that epicatechin and catechin exhibited high affinity with both enzymes, even though POD and PPO have different binding pockets regarding the size and the key amino acids involved in binding. Predicted binding modes of substrates with both enzymes were also compared. The calculated docking interaction energy of trihydroxybenzoic acid related compounds shows high affinity, suggesting specificity and potential use as common inhibitor to grape ascorbate peroxidase and polyphenol oxidase.

  17. Xylem occlusion in Bouvardia flowers : evidence for a role of peroxidase and catechol oxidase

    NARCIS (Netherlands)

    Vaslier, N.; Doorn, van W.G.


    During vase life, Bouvardia flowers show rapid leaf wilting, especially if they are stored dry prior to placement in water. Wilting is due to a blockage in the basal stem end. We investigated the possible role of peroxidase and catechol oxidase in the blockage in cv. van Zijverden flowers, which

  18. Lignin peroxidase isoenzyme: a novel approach to biodegrade the toxic synthetic polymer waste. (United States)

    Khatoon, Nazia; Jamal, Asif; Ali, Muhammad Ishtiaq


    Fungal metabolites are playing an immense role in developing various sustainable waste treatment processes. The present study aimed at production and characterization of fungal lignin peroxidase (EC with a potential to degrade Polyvinyl Chloride. Optimization studies revealed that the maximum enzyme production occurred at a temperature 25°C, pH 5 in the 4th week of the incubation period with fungal strain. Enzyme assay was performed to find out the dominating enzyme in the culture broth. The molecular weight of the enzyme was found to be 46 kDa. Partially purified lignin peroxidase from Phanerocheate chrysosporium was used for the degradation of PVC films. A significant reduction in the weight of PVC film was observed (31%) in shake flask experiment. FTIR spectra of the enzyme-treated plastic film revealed structural changes in the chemical composition, indicating a specific peak at 2943 cm -1 that corresponded to alkenyl C-H stretch. Moreover, deterioration on the surface of PVC films was confirmed by Scanning Electron Microscopy tracked through activity assay for the lignin peroxidase. Extracellular lignin peroxidases from P. chrysosporium play a significant role in the degradation of complex polymeric compounds like PVC.

  19. Glutathione peroxidase activity in the selenium-treated alga Scenedesmus quadricauda

    Czech Academy of Sciences Publication Activity Database

    Vítová, Milada; Bišová, Kateřina; Hlavová, Monika; Zachleder, Vilém; Rucki, M.; Čížková, Mária


    Roč. 102, 1-2 (2011), s. 87-94 ISSN 0166-445X R&D Projects: GA ČR GA525/09/0102 Institutional research plan: CEZ:AV0Z50200510 Keywords : Cell cycle * Enzyme activity * Glutathione peroxidase Subject RIV: EE - Microbiology, Virology Impact factor: 3.761, year: 2011

  20. Horseradish peroxidase-catalyzed cross-linking of feruloylated arabinoxylans with β-casein

    NARCIS (Netherlands)

    Boeriu, C.G.; Oudgenoeg, G.; Spekking, W.T.J.; Berendsen, L.B.J.M.; Vancon, L.; Boumans, H.; Gruppen, H.; Berkel, W.J.H. van; Laane, C.; Voragen, A.G.J.


    Heterologous conjugates of wheat arabinoxylan and β-casein were prepared via enzymatic cross-linking, using sequential addition of the arabinoxylan to a mixture of β-casein, peroxidase, and hydrogen peroxide. The maximal formation of adducts between the β-casein and the feruloylated arabinoxylan was

  1. Nucleotide sequences of two genomic DNAs encoding peroxidase of Arabidopsis thaliana. (United States)

    Intapruk, C; Higashimura, N; Yamamoto, K; Okada, N; Shinmyo, A; Takano, M


    The peroxidase (EC gene of Arabidopsis thaliana was screened from a genomic library using a cDNA encoding a neutral isozyme of horseradish, Armoracia rusticana, peroxidase (HRP) as a probe, and two positive clones were isolated. From the comparison with the sequences of the HRP-encoding genes, we concluded that two clones contained peroxidase-encoding genes, and they were named prxCa and prxEa. Both genes consisted of four exons and three introns; the introns had consensus nucleotides, GT and AG, at the 5' and 3' ends, respectively. The lengths of each putative exon of the prxEa gene were the same as those of the HRP-basic-isozyme-encoding gene, prxC3, and coded for 349 amino acids (aa) with a sequence homology of 89% to that encoded by prxC3. The prxCa gene was very close to the HRP-neutral-isozyme-encoding gene, prxC1b, and coded for 354 aa with 91% homology to that encoded by prxC1b. The aa sequence homology was 64% between the two peroxidases encoded by prxCa and prxEa.

  2. Preferential hydroxylation over epoxidation catalysis by a horseradish peroxidase mutant: a cytochrome P450 mimic. (United States)

    de Visser, Sam P


    Density functional theory calculations are presented on the catalytic properties of a horseradish peroxidase mutant whereby the axial nitrogen atom is replaced by phosphorus. This mutant has never been studied experimentally and only one theoretical report on this system is known (de Visser, S. P. J. Phys. Chem. B 2006, 110, 20759-20761). Thus, a one-atom substitution in horseradish peroxidase changes the properties of the catalytic center of the enzyme to more cytochrome P450-type qualities. In particular, the phosphorus-substituted horseradish peroxidase mutant reacts with substrates via a unique reactivity pattern, whereby alkanes are regioselectively hydroxylated even in the presence of a double bond. Reaction barriers of propene epoxidation and hydroxylation are almost identical to ones observed for a cytochrome P450 catalyst and significantly higher than those obtained for a horseradish peroxidase catalyst. It is shown that the regioselectivity difference is entropy and thermally driven and that the electron-transfer processes that occur during the reaction mechanism follow cytochrome P450-type patterns in the hydroxylation reaction.

  3. Electrochemical determination of hydrogen peroxide using Rhodobacter capsulatus cytochrome c peroxidase at a gold electrode

    NARCIS (Netherlands)

    De Wael, K.; Buschop, H.; Heering, H.A.; De Smet, L.; Van Beeumen, J.; Devreese, B.; Adriaens, A.


    We describe the redox behaviour of horse heart cytochrome c (HHC) and Rhodobacter capsulatus cytochrome c peroxidase (RcCCP) at a gold electrode modified with 4,4?-bipyridyl. RcCCP shows no additional oxidation or reduction peaks compared to the electrochemistry of only HHC, which indicates that it

  4. Tissue Printing to Visualize Polyphenol Oxidase and Peroxidase in Vegetables, Fruits, and Mushrooms (United States)

    Melberg, Amanda R.; Flurkey, William H.; Inlow, Jennifer K.


    A simple tissue-printing procedure to determine the tissue location of the endogenous enzymes polyphenol oxidase and peroxidase in a variety of vegetables, fruits, and mushrooms is described. In tissue printing, cell contents from the surface of a cut section of the tissue are transferred to an adsorptive surface, commonly a nitrocellulose…

  5. In silico molecular modeling and docking studies on the leishmanial tryparedoxin peroxidase

    Directory of Open Access Journals (Sweden)

    Ozal Mutlu


    Full Text Available Leishmaniasis is one of the most common form of neglected parasitic disease that affects about 350 million people worldwide. Leishmanias have a trypanothione mediated hydroperoxide metabolism to eliminate endogenous or exogenous oxidative agents. Both of 2-Cys peroxiredoxin (Prx and glutathione peroxidase type tryparedoxin peroxidase (Px are the terminal enzymes in the trypanothione dependent detoxification system. Therefore absence of trypanothione redox system in mammals and the sensitivity of trypanosomatids against oxidative stress, enzymes of this pathway are drug targets candidates. In this study, 3D structure of tryparedoxin peroxidase (2-Cys peroxiredoxin type from Leishmania donovani (LdTXNPx was described by homology modeling method based on the template of tryparedoxin peroxidase from Crithidia fasciculata and selected compounds were docked to the active site pocket. The quality of the 3D structure of the model was confirmed by various web based validation programs. When compared secondary and tertiary structure of the model, it showed a typical thioredoxin fold containing a central beta-sheet and three alpha-helices. Docking study showed that the selected compound 2 (CID 16073813 interacted with the active site amino acids and binding energy was -118.675 kcal/mol.

  6. Peroxidase-mediated polymerization of 1-naphthol: impact of solution pH and ionic strength. (United States)

    Bhandari, Alok; Xu, Fangxiang; Koch, David E; Hunter, Robert P


    Peroxidase-mediated oxidation has been proposed as a treatment method for naphthol-contaminated water. However, the impact of solution chemistry on naphthol polymerization and removal has not been documented. This research investigated the impact of pH and ionic strength on peroxidase-mediated removal of 1-naphthol in completely mixed batch reactors. The impact of hydrogen peroxide to 1-naphthol ratio and activity of horseradish peroxidase was also studied. Size exclusion chromatography was used to estimate the molecular weight distribution of oligomeric products, and liquid chromatography/mass spectrometry was used to estimate product structure. Naphthol transformation decreased with ionic strength, and substrate removal was lowest at neutral pHs. Solution pH influenced the size and the composition of the oligomeric products. An equimolar ratio of H(2)O(2):naphthol was sufficient for optimal naphthol removal. Polymerization products included naphthoquinones and oligomers derived from two, three, and four naphthol molecules. Our results illustrate the importance of water chemistry when considering a peroxidase-based approach for treatment of naphthol-contaminated waters.

  7. Characterization of glutathione peroxidase diversity in the symbiotic sea anemone Anemonia viridis


    Pey , Alexis; Zamoum , Thamilla; Christen , Richard; Merle , Pierre-Laurent; Furla , Paola


    International audience; Cnidarians living in symbiosis with photosynthetic dinoflagellates (commonly named zooxanthellae) are exposed to high concentrations of reactive oxygen species (ROS) upon illumination. To quench ROS production, both the cnidarian host and zooxanthellae express a full suite of antioxidant enzymes. Studying antioxidative balance is therefore crucial to understanding how symbiotic cnidarians cope with ROS production. We characterized glutathione peroxidases (GPx) in the s...

  8. Strand displacement activated peroxidase activity of hemin for fluorescent DNA sensing. (United States)

    Wang, Quanbo; Xu, Nan; Gui, Zhen; Lei, Jianping; Ju, Huangxian; Yan, Feng


    To efficiently regulate the catalytic activity of the peroxidase mimic hemin, this work designs a double-stranded DNA probe containing an intermolecular dimer of hemin, whose peroxidase activity can be activated by a DNA strand displacement reaction. The double-stranded probe is prepared by annealing two strands of hemin labelled DNA oligonucleotides. Using the fluorescent oxidation product of tyramine by H2O2 as a tracing molecule, the low peroxidase activity of the hemin dimer ensures a low fluorescence background. The strand displacement reaction of the target DNA dissociates the hemin dimer and thus significantly increases the catalytic activity of hemin to produce a large amount of dityramine for fluorescence signal readout. Based on the strand displacement regulated peroxidase activity, a simple and sensitive homogeneous fluorescent DNA sensing method is proposed. The detection can conveniently be carried out in a 96-well plate within 20 min with a detection limit of 0.18 nM. This method shows high specificity, which can effectively distinguish single-base mismatched DNA from perfectly matched target DNA. The DNA strand displacement regulated catalytic activity of hemin has promising application in the determination of various DNA analytes.

  9. Decolorization of direct dyes using peroxidase from raphanus sativus (F04 SL)

    International Nuclear Information System (INIS)

    Bhatti, H.N.; Kalsoom, U.; Habib, A.


    An acidic peroxidase was isolated and partially purified from Raphanus sativus. The purified enzyme was characterized in terms of kinetics and thermodynamic aspects. Finally the enzyme was assessed to see its potential for decolorization of direct dyes. The specific activity of Raphanus sativus peroxidase increased from 44.77 to 65.20 U/mg of protein using 80 % ammonium sulphate precipitation. The optimum pH and temperature of the enzyme was 4 and 55 deg. C respectively. The activation energy of Raphanus sativus peroxidase was 25.44 kJ/mol and average value of Km was 0.25 mM. The activation energy of thermal denaturation of Raphanus sativus peroxidase was 17.79 kJ/mol. It was observed that with an increase in temperature, there was decrease in a half life and enthalpy, which showed that the enzyme was unstable at higher temperature. A maximum decolorization of 97 and 77 % was observed for Solar Blue A and Solar Flavine 5G at pH 4 and temperature 50 deg. C respectively. It was observed that % decolorization of both the dyes increased with an increase in enzyme units and incubation time. H/sub 2/O/sub 2/ dose of 0.8 mM for Solar Blue A and 0.7 mM for Solar Flavine 5G was sufficient for the maximum dye degradation. (author)

  10. A peroxidase gene expressed during early developmental stages of the parasitic plant Orobanche ramosa. (United States)

    González-Verdejo, Clara Isabel; Barandiaran, Xabier; Moreno, Maria Teresa; Cubero, José Ignacio; Di Pietro, Antonio


    Broomrapes (Orobanche spp.) are holoparasitic weeds that cause devastating losses in many economically important crops. The molecular mechanisms that control the early stages of host infection in Orobanche are poorly understood. In the present study, the role of peroxidase has been examined during pre-infection growth and development of O. ramosa, using an in vitro model system. Peroxidase activity was histochemically localized at the tips of actively growing radicles and nascent attachment organs. Addition of exogenous catalase resulted in a significant reduction in the apical growth rate of the radicle. The prx1 gene encoding a putative class III peroxidase was cloned from a cDNA library of O. ramosa and was found to be expressed specifically during the early stages of the parasitic life cycle. The exogenous addition of sucrose resulted in significantly reduced prx1 transcript levels and in a dramatic change in radicle development from polarized apical growth to isotropic growth and the formation of tubercle-like structures. The results indicate an important role of peroxidases during the early parasitic stages of Orobanche.

  11. Structure and organ specificity of an anionic peroxidase from Arabidopsis thaliana cell suspension culture

    DEFF Research Database (Denmark)

    Ostergaard, L; Abelskov, A K; Mattsson, O


    The predominant peroxidase (pI 3.5) (E.C. of an Arabidopsis thaliana cell suspension culture was purified and partially sequenced. Oligonucleotides were designed and a specific probe was obtained. A cDNA clone was isolated from an Arabidopsis cell suspension cDNA library and completely ...

  12. Aqueous synthesis of porous platinum nanotubes at room temperature and their intrinsic peroxidase-like activity. (United States)

    Cai, Kai; Lv, Zhicheng; Chen, Kun; Huang, Liang; Wang, Jing; Shao, Feng; Wang, Yanjun; Han, Heyou


    Platinum nanotubes (PtNTs) exhibiting high porosity were constructed by sacrificing the exterior of tellurium nanowires (TeNWs) and disintegrating the inner part spontaneously in aqueous solution at room temperature, in which the Kirkendall effect may play an important role. The present PtNTs exhibited intrinsic peroxidase-like activity in the presence of H2O2.

  13. Lignin peroxidase mediated biotransformations useful in the biocatalytic production of vanillin

    NARCIS (Netherlands)

    Have, ten R.


    This research concentrates on lignin peroxidase (LiP) mediated biotrans-formations that are useful in producing vanillin.

    In order to obtain this extracellular enzyme, the white-rot fungus Bjerkandera sp. strain BOS55 was cultivated on nitrogen rich

  14. Assessment of Behavior of Rice Root Peroxidase in the Presence of Silver Nanoparticles

    Directory of Open Access Journals (Sweden)



    Full Text Available Background Silver Nanoparticles (AgNPs can change proteins function and structure. The increased production and high surface reactivity of silver nanoparticles, has interested researchers to study the interactions of these particles with biomolecules. Objectives The present study aimed to show the effects of AgNPs on rice plant root peroxidase enzyme and the interaction quality between silver nanoparticles and the enzyme. Materials and Methods Extracted peroxidase enzyme of rice plant root was treated by AgNPs at concentrations of 0, 20, 40, 80, 100mg/L for 2, 7 and 24 hours. The experiment was done with 15 treatments for measuring the peroxidase enzyme activity using the spectrophotometry method at a wavelength of 470. Results Low concentrations of AgNPs and short incubation times can have the maximum positive impact on the peroxidase activity, and in the present study the highest activity was seen at a concentration of 40 mg/L and two hours of incubation time. Conclusions This study suggests that changes of enzyme activity can occur as a result of the effect of silver nanoparticles on enzyme conformation, increase of reactive environment pH, and amount of substrate and enzyme stability.

  15. Evaluation of peroxidases from roots of Cyperus hermaphroditus as enzymatic mechanisms in phenanthrene oxidation

    Energy Technology Data Exchange (ETDEWEB)

    Guerrero Zuniga, A. [Inst. Mexicano del Petroleo, Mexico City (Mexico). Environmental Protection Management Office; Rodriguez Dorantes, A.M. [Lab. Fisiologia Vegetal, Escuela Nacional de Ciencias Biologicas, Mexico City (Mexico). Depto Botanica


    Although phenanthrene is not mutagenic or carcinogenic, it has been shown to be toxic to aquatic organisms. This study evaluated in-vitro phenanthrene oxidation by peroxidases from radical extracts of Cyperus hermaphroditus plants. The characterization of oxidation products of phenanthrene related to the induction of root peroxidases was also examined. Concentrated ethanol stock of phenanthrene solution was added to the mineral solution of each plant container. The total radical biomass was placed in 4.5 ml of an ionic solution to analyze the enzymatic activity of the extracellular peroxidases. The total protein for each experiment was quantified by the Bradford method. Extracellular peroxidases activity was measured using the spectrophotometric method. The amount of radical biomass was quantified as high in the 80 and 120 ppm phenanthrene treatments relative to the control plants. It was suggested that the nature of the Cyperaceae roots combined with the high-octanol water coefficient and a low water solubility for phenanthrene may have facilitated the stabilization of the contaminant towards the roots. The ability of Cyperus hermaphroditus to immobilize phenanthrene through its adhesion was encouraged by the conditions of the hydroponic culture system. The adsorption of phenanthrene was increased with the time of exposure to the contaminant due to the greater total root mass. The study also showed the transformation of phenanthrene by radical extracts of Cyperus hermaphroditus containing guaiacol peroxidases with 12 per cent residual phenanthrene in the in vitro assays. The spectrophotometric analysis confirmed that the enzymatic systems are responsible for the phytotransformation of the pollutant. 9 refs., 2 tabs., 5 figs.

  16. Adaptive aneuploidy protects against thiol peroxidase deficiency by increasing respiration via key mitochondrial proteins. (United States)

    Kaya, Alaattin; Gerashchenko, Maxim V; Seim, Inge; Labarre, Jean; Toledano, Michel B; Gladyshev, Vadim N


    Aerobic respiration is a fundamental energy-generating process; however, there is cost associated with living in an oxygen-rich environment, because partially reduced oxygen species can damage cellular components. Organisms evolved enzymes that alleviate this damage and protect the intracellular milieu, most notably thiol peroxidases, which are abundant and conserved enzymes that mediate hydrogen peroxide signaling and act as the first line of defense against oxidants in nearly all living organisms. Deletion of all eight thiol peroxidase genes in yeast (∆8 strain) is not lethal, but results in slow growth and a high mutation rate. Here we characterized mechanisms that allow yeast cells to survive under conditions of thiol peroxidase deficiency. Two independent ∆8 strains increased mitochondrial content, altered mitochondrial distribution, and became dependent on respiration for growth but they were not hypersensitive to H2O2. In addition, both strains independently acquired a second copy of chromosome XI and increased expression of genes encoded by it. Survival of ∆8 cells was dependent on mitochondrial cytochrome-c peroxidase (CCP1) and UTH1, present on chromosome XI. Coexpression of these genes in ∆8 cells led to the elimination of the extra copy of chromosome XI and improved cell growth, whereas deletion of either gene was lethal. Thus, thiol peroxidase deficiency requires dosage compensation of CCP1 and UTH1 via chromosome XI aneuploidy, wherein these proteins support hydroperoxide removal with the reducing equivalents generated by the electron transport chain. To our knowledge, this is the first evidence of adaptive aneuploidy counteracting oxidative stress.

  17. Display Apple M7649Zm

    CERN Multimedia


    It was Designed for the Power Mac G4. This Apple studio display gives you edge-to-edge distortion-free images. With more than 16.7 million colors and 1,280 x 1,024 dpi resolution, you view brilliant and bright images on this Apple 17-inch monitor.

  18. Information retrieval and display system (United States)

    Groover, J. L.; King, W. L.


    Versatile command-driven data management system offers users, through simplified command language, a means of storing and searching data files, sorting data files into specified orders, performing simple or complex computations, effecting file updates, and printing or displaying output data. Commands are simple to use and flexible enough to meet most data management requirements.

  19. Crystal ball single event display

    International Nuclear Information System (INIS)

    Grosnick, D.; Gibson, A.; Allgower, C.; Alyea, J.; Argonne National Lab., IL


    The Single Event Display (SED) is a routine that is designed to provide information graphically about a triggered event within the Crystal Ball. The SED is written entirely in FORTRAN and uses the CERN-based HICZ graphing package. The primary display shows the amount of energy deposited in each of the NaI crystals on a Mercator-like projection of the crystals. Ten different shades and colors correspond to varying amounts of energy deposited within a crystal. Information about energy clusters is displayed on the crystal map by outlining in red the thirteen (or twelve) crystals contained within a cluster and assigning each cluster a number. Additional information about energy clusters is provided in a series of boxes containing useful data about the energy distribution among the crystals within the cluster. Other information shown on the event display include the event trigger type and data about π o 's and η's formed from pairs of clusters as found by the analyzer. A description of the major features is given, along with some information on how to install the SED into the analyzer

  20. GridOrbit public display

    DEFF Research Database (Denmark)

    Ramos, Juan David Hincapie; Tabard, Aurélien; Bardram, Jakob


    We introduce GridOrbit, a public awareness display that visualizes the activity of a community grid used in a biology laboratory. This community grid executes bioin-formatics algorithms and relies on users to donate CPU cycles to the grid. The goal of GridOrbit is to create a shared awareness about...

  1. Interference Phenomenon with Mobile Displays (United States)

    Trantham, Kenneth


    A simple experiment is presented in which the spacing and geometric pattern of pixels in mobile displays is measured. The technique is based on optical constructive interference. While the experiment is another opportunity to demonstrate wave interference from a grating-like structure, this can also be used to demonstrate concepts of solid state…

  2. Synthetic vision display evaluation studies (United States)

    Regal, David M.; Whittington, David H.


    The goal of this research was to help us understand the display requirements for a synthetic vision system for the High Speed Civil Transport (HSCT). Four experiments were conducted to examine the effects of different levels of perceptual cue complexity in displays used by pilots in a flare and landing task. Increased levels of texture mapping of terrain and runway produced mixed results, including harder but shorter landings and a lower flare initiation altitude. Under higher workload conditions, increased texture resulted in an improvement in performance. An increase in familiar size cues did not result in improved performance. Only a small difference was found between displays using two patterns of high resolution texture mapping. The effects of increased perceptual cue complexity on performance was not as strong as would be predicted from the pilot's subjective reports or from related literature. A description of the role of a synthetic vision system in the High Speed Civil Transport is provide along with a literature review covering applied research related to perceptual cue usage in aircraft displays.

  3. Display Sharing: An Alternative Paradigm (United States)

    Brown, Michael A.


    The current Johnson Space Center (JSC) Mission Control Center (MCC) Video Transport System (VTS) provides flight controllers and management the ability to meld raw video from various sources with telemetry to improve situational awareness. However, maintaining a separate infrastructure for video delivery and integration of video content with data adds significant complexity and cost to the system. When considering alternative architectures for a VTS, the current system's ability to share specific computer displays in their entirety to other locations, such as large projector systems, flight control rooms, and back supporting rooms throughout the facilities and centers must be incorporated into any new architecture. Internet Protocol (IP)-based systems also support video delivery and integration. IP-based systems generally have an advantage in terms of cost and maintainability. Although IP-based systems are versatile, the task of sharing a computer display from one workstation to another can be time consuming for an end-user and inconvenient to administer at a system level. The objective of this paper is to present a prototype display sharing enterprise solution. Display sharing is a system which delivers image sharing across the LAN while simultaneously managing bandwidth, supporting encryption, enabling recovery and resynchronization following a loss of signal, and, minimizing latency. Additional critical elements will include image scaling support, multi -sharing, ease of initial integration and configuration, integration with desktop window managers, collaboration tools, host and recipient controls. This goal of this paper is to summarize the various elements of an IP-based display sharing system that can be used in today's control center environment.

  4. JTEC panel on display technologies in Japan (United States)

    Tannas, Lawrence E., Jr.; Glenn, William E.; Credelle, Thomas; Doane, J. William; Firester, Arthur H.; Thompson, Malcolm


    This report is one in a series of reports that describes research and development efforts in Japan in the area of display technologies. The following are included in this report: flat panel displays (technical findings, liquid crystal display development and production, large flat panel displays (FPD's), electroluminescent displays and plasma panels, infrastructure in Japan's FPD industry, market and projected sales, and new a-Si active matrix liquid crystal display (AMLCD) factory); materials for flat panel displays (liquid crystal materials, and light-emissive display materials); manufacturing and infrastructure of active matrix liquid crystal displays (manufacturing logistics and equipment); passive matrix liquid crystal displays (LCD basics, twisted nematics LCD's, supertwisted nematic LCD's, ferroelectric LCD's, and a comparison of passive matrix LCD technology); active matrix technology (basic active matrix technology, investment environment, amorphous silicon, polysilicon, and commercial products and prototypes); and projection displays (comparison of Japanese and U.S. display research, and technical evaluation of work).

  5. Ruggedized Full-Color Flexible OLED Display

    National Research Council Canada - National Science Library

    Hack, Michael


    .... The team comprised Universal Display Corporation, Princeton University, the University of Southern California, Penn State University, L3 Displays and Vitex Systems, and was led by Universal Display Corporation (PI: Michael Hack...

  6. Heme-coordinated histidine residues form non-specific functional "ferritin-heme" peroxidase system: Possible and partial mechanistic relevance to oxidative stress-mediated pathology in neurodegenerative diseases. (United States)

    Esmaeili, Sajjad; Kooshk, Mohammad Reza Ashrafi; Asghari, Seyyed Mohsen; Khodarahmi, Reza


    Ferritin is a giant protein composed of 24 subunits which is able to sequester up to 4500 atoms of iron. We proposed two kinds of heme binding sites in mammalian ferritins and provided direct evidence for peroxidase activity of heme-ferritin, since there is the possibility that "ferritin-heme" systems display unexpected catalytic behavior like heme-containing enzymes. In the current study, peroxidase activity of heme-bound ferritin was studied using TMB(1), l-DOPA, serotonin, and dopamine, in the presence of H2O2, as oxidant substrate. The catalytic oxidation of TMB was consistent with first-order kinetics with respect to ferritin concentration. Perturbation of the binding affinity and catalytic behavior of heme-bound His-modified ferritin were also documented. We also discuss the importance of the peroxidase-/nitrative-mediated oxidation of vital molecules as well as ferritin-induced catalase inhibition using in vitro experimental system. Uncontrollable "heme-ferritin"-based enzyme activity as well as up-regulation of heme and ferritin may inspire that some oxidative stress-mediated cytotoxic effects in AD-affected cells could be correlated to ferritin-heme interaction and/or ferritin-induced catalase inhibition and describe its contribution as an important causative pathogenesis mechanism in some neurodegenerative disorders. Copyright © 2016 Elsevier B.V. All rights reserved.

  7. Off-line data processing and display for computed tomographic images (EMI brain)

    International Nuclear Information System (INIS)

    Takizawa, Masaomi; Maruyama, Kiyoshi; Yano, Kesato; Takenaka, Eiichi.


    Processing and multi-format display for the CT (EMI) scan data have been tried by using an off-line small computer and an analog memory. Four or six CT images after processing are displayed on the CRT by a small computer with a 16 kilo-words core memory and an analog memory. Multi-format display of the CT image can be selected as follows; multi-slice display, continuative multi-window display, separate multi-window display, and multi-window level display. Electronic zooming for the real size viewing can give magnified CT image with one of displayed images if necessary. Image substraction, edge enhancement, smoothing, non-linear gray scale display, and synthesized image for the plane tomography reconstracted by the normal CT scan data, have been tried by the off-line data processing. A possibility for an effective application of the data base with CT image was obtained by these trials. (auth.)

  8. Smart displays in intelligent environments: a vision for Europe 2007+ (United States)

    Maiser, Eric


    Future electronic systems will create "ambient intelligence": environments that recognise us, applications which can be used intuitively. Displays will always be a key part of such systems, because visual information provides a densely packed fast link to our brain. European researchers and suppliers are global drivers in display innovation - on the other hand Europe is a major influence on the market for display applications. However, today displays are produced in Asia, European research and development is scattered, and lacks both collaboration and a strong production base. That is why adria, a European network for the displays community, has been formed: Its goal is to substantially enhance the standing of the displays industry in Europe by creating a common knowledge base, by generating a common vision for a display future in Europe and by establishing appreciated services for a future association that will serve as a "one-stop-shop" for the community. To effectively start the discussion, a vision paper1 has been compiled including inputs from 95 individuals from 17 European countries. It describes the state displays research and industry are in today and estimates future developments displays will take towards intelligent systems in the next decade and beyond. Recommendations are made to reinforce the displays industry in a sustainable way building on existing strengths in research, as well as in the materials and equipment sectors. The adria network, its roadmapping approach as well as key projections and findings of the vision paper are described here, going beyond the topic of Organic Light Emitting Diodes alone.

  9. Ulex europaeus agglutinin-I binding to dental primary afferent projections in the spinal trigeminal complex combined with double immunolabeling of substance P and GABA elements using peroxidase and colloidal gold. (United States)

    Matthews, M A; Hoffmann, K D; Hernandez, T V


    Ulex europaeus agglutinin I (UEA-I) is a plant lectin with an affinity for L-fucosyl residues in the chains of lactoseries oligosaccharides associated with medium- and smaller-diameter dorsal root ganglion neurons and their axonal processes. These enter Lissauer's tract and terminate within the superficial laminae of the spinal cord overlapping projections known to have a nociceptive function. This implies that the surface coatings of neuronal membranes may have a relationship with functional modalities. The present investigation further examined this concept by studying a neuronal projection with a nociceptive function to determine whether fucosyl-lactoseries residues were incorporated in its primary afferent terminals. Transganglionic transport of horseradish peroxidase (HRP) following injection into tooth pulp chambers was employed to demonstrate dental pulp terminals in the trigeminal spinal complex, while peroxidase and fluorescent tags were used concomitantly to stain for UEA-I. Double immunolabeling for substance P (SP) and gamma-aminobutyric acid (GABA) using peroxidase and colloidal gold allowed a comparison of the distribution of a known excitatory nociceptive transmitter with that of UEA-I binding in specific subnuclei. Synaptic interrelationships between UEA-I positive dental pulp primary afferent inputs and specific inhibitory terminals were also examined. SP immunoreactivity occurred in laminae I and outer lamina II (IIo) of subnucleus caudalis (Vc) and in the ventrolateral and lateral marginal region of the caudal half of subnucleus interpolaris (Vi), including the periobex area in which Vi is slightly overlapped on its lateral aspect by cellular elements of Vc. The adjacent interstitial nucleus (IN) also showed an intense immunoreactivity for this peptide antibody. UEA-I binding displayed a similar distribution pattern in both Vc and Vi, but extended into lamina IIi and the superficial part of Lamina III in Vc. Dental pulp terminals were found to

  10. Tc-cAPX, a cytosolic ascorbate peroxidase of Theobroma cacao L. engaged in the interaction with Moniliophthora perniciosa, the causing agent of witches' broom disease. (United States)

    Camillo, Luciana Rodrigues; Filadelfo, Ciro Ribeiro; Monzani, Paulo Sérgio; Corrêa, Ronan Xavier; Gramacho, Karina Peres; Micheli, Fabienne; Pirovani, Carlos Priminho


    The level of hydrogen peroxide (H2O2) in plants signalizes the induction of several genes, including that of ascorbate peroxidase (APX-EC APX isoenzymes play a central role in the elimination of intracellular H2O2 and contribute to plant responses to diverse stresses. During the infection process in Theobroma cacao by Moniliophthora perniciosa oxidative stress is generated and the APX action recruited from the plant. The present work aimed to characterize the T. cacao APX involved in the molecular interaction of T. cacao-M. perniciosa. The peroxidase activity was analyzed in protein extracts from cocoa plants infected by M. perniciosa and showed the induction of peroxidases like APX in resistant cocoa plants. The cytosolic protein of T. cacao (GenBank: ABR68691.2) was phylogenetically analyzed in relation to other peroxidases from the cocoa genome and eight genes encoding APX proteins with conserved domains were also analyzed. The cDNA from cytosolic APX was cloned in pET28a and the recombinant protein expressed and purified (rTc-cAPX). The secondary structure of the protein was analyzed by Circular Dichroism (CD) displaying high proportion of α-helices when folded. The enzymatic assay shows stable activity using ascorbate and guaiacol as an electron donor for H2O2 reduction. The pH 7.5 is the optimum for enzyme activity. Chromatographic analysis suggests that rTc-cAPX is a homodimer in solution. Results indicate that the rTc-cAPX is correctly folded, stable and biochemically active. The purified rTc-cAPX presented biotechnological potential and is adequate for future structural and functional studies. Copyright © 2013 The Authors. Published by Elsevier Masson SAS.. All rights reserved.

  11. Reconfigurable Auditory-Visual Display (United States)

    Begault, Durand R. (Inventor); Anderson, Mark R. (Inventor); McClain, Bryan (Inventor); Miller, Joel D. (Inventor)


    System and method for visual and audible communication between a central operator and N mobile communicators (N greater than or equal to 2), including an operator transceiver and interface, configured to receive and display, for the operator, visually perceptible and audibly perceptible signals from each of the mobile communicators. The interface (1) presents an audible signal from each communicator as if the audible signal is received from a different location relative to the operator and (2) allows the operator to select, to assign priority to, and to display, the visual signals and the audible signals received from a specified communicator. Each communicator has an associated signal transmitter that is configured to transmit at least one of the visual signals and the audio signal associated with the communicator, where at least one of the signal transmitters includes at least one sensor that senses and transmits a sensor value representing a selected environmental or physiological parameter associated with the communicator.

  12. Game engines and immersive displays (United States)

    Chang, Benjamin; Destefano, Marc


    While virtual reality and digital games share many core technologies, the programming environments, toolkits, and workflows for developing games and VR environments are often distinct. VR toolkits designed for applications in visualization and simulation often have a different feature set or design philosophy than game engines, while popular game engines often lack support for VR hardware. Extending a game engine to support systems such as the CAVE gives developers a unified development environment and the ability to easily port projects, but involves challenges beyond just adding stereo 3D visuals. In this paper we outline the issues involved in adapting a game engine for use with an immersive display system including stereoscopy, tracking, and clustering, and present example implementation details using Unity3D. We discuss application development and workflow approaches including camera management, rendering synchronization, GUI design, and issues specific to Unity3D, and present examples of projects created for a multi-wall, clustered, stereoscopic display.

  13. The virtual environment display system (United States)

    Mcgreevy, Michael W.


    Virtual environment technology is a display and control technology that can surround a person in an interactive computer generated or computer mediated virtual environment. It has evolved at NASA-Ames since 1984 to serve NASA's missions and goals. The exciting potential of this technology, sometimes called Virtual Reality, Artificial Reality, or Cyberspace, has been recognized recently by the popular media, industry, academia, and government organizations. Much research and development will be necessary to bring it to fruition.

  14. Activity and isoenzyme spectrum of peroxidases and dehydrins of some plant species, growing on the shores of lake Baikal, under abiotic stress

    Directory of Open Access Journals (Sweden)

    M.A. Zhivet’ev


    Full Text Available Termostability and optimal pH of weak-associated with plant cell wall and soluble peroxidases was shown to change in relation to natural conditions and season of year. Also the activity of peroxidase was variable during vegetation period. Dehydrine expression was followed by spike of peroxidase activity (and, a priori, an increase of hydrogen peroxide concentration.

  15. Digital Image Processing Overview For Helmet Mounted Displays (United States)

    Parise, Michael J.


    Digital image processing provides a means to manipulate an image and presents a user with a variety of display formats that are not available in the analog image processing environment. When performed in real time and presented on a Helmet Mounted Display, system capability and flexibility are greatly enhanced. The information content of a display can be increased by the addition of real time insets and static windows from secondary sensor sources, near real time 3-D imaging from a single sensor can be achieved, graphical information can be added, and enhancement techniques can be employed. Such increased functionality is generating a considerable amount of interest in the military and commercial markets. This paper discusses some of these image processing techniques and their applications.

  16. TfR Binding Peptide Screened by Phage Display Technology ...

    African Journals Online (AJOL)

    Purpose: To screen an hTfR affinity peptide and investigate its activity in vitro. Methods: hTfR ... Keywords: Peptide, hTfR, Transferrin receptor, Phage display technology, Enhanced green ..... mediated uptake of peptides that bind the human.

  17. Flexible Smart Display with Integrated Graphics Rasterizor using ...

    African Journals Online (AJOL)

    SG-TFTs and other similar technologies can potentially enable fabricating electronics directly on arbitrary substrates. This would further enable integration of embedded intelligence in devices that would enhance the current functionalists of displays. This paper is an effort in this direction as it undertakes a study to design a ...

  18. Advanced Displays and Natural User Interfaces to Support Learning (United States)

    Martin-SanJose, Juan-Fernando; Juan, M. -Carmen; Mollá, Ramón; Vivó, Roberto


    Advanced displays and natural user interfaces (NUI) are a very suitable combination for developing systems to provide an enhanced and richer user experience. This combination can be appropriate in several fields and has not been extensively exploited. One of the fields that this combination is especially suitable for is education. Nowadays,…

  19. Knowledge based development of graphic display systems

    International Nuclear Information System (INIS)

    Woods, D.D.


    Most human factors guidelines on computer display design attempt to ensure that human sensory limits are not strained or that users can potentially access data. While this is a necessary and too often an overlooked step in interface design, it does not address issues about how to use computer displays to aid human performance at domain tasks. This challenge to human factors guidance is particularly acute in complex environments such as nuclear power plants where the goal is more than a useable interface system; the interface must support effective human performance at tasks like situation assessment, fault management, problem solving and planning. Studies of human performance in complex domains reveal that human-machine performance failures can often be linked to problems in information handling - data overload, getting lost, keyhole effects, tunnel vision to name but a few. All of these information handling problems represent manifestations of an inability to find, integrate or interpret the ''right'' data at the ''right'' time, i.e., failures where critical information is not detected among the ambient data load, where critical information is not assembled from data distributed over time or over space; and where critical information is not looked for because of misunderstandings or erroneous assumptions (cf., Woods, 1985). Problems of this kind illustrate that the potential to see, read, or access data does not guarantee successful user information extraction. The result is a need for research and guidance on design for enhanced information extraction in addition to design for data availability

  20. Home Energy Displays: Consumer Adoption and Response

    Energy Technology Data Exchange (ETDEWEB)

    LaMarche, J.; Cheney, K.; Akers, C.; Roth, K.; Sachs, O.


    The focus of this project was to investigate the factors influencing consumer adoption of Home Energy Displays (HEDs) and to evaluate electricity consumption in households with basic HEDs versus enhanced feedback methods - web portals or alerts. We hypothesized that providing flexible and relatable information to users, in addition to a basic HED, would make feedback more effective and achieve persistent energy savings. In Phase I, we conducted three user research studies and found preferences for aesthetically pleasing, easy to understand feedback that is accessible through multiple media and offered free of charge. The deployment of HEDs in 150 households planned for Phase II encountered major recruitment and HED field deployment problems. First, after extensive outreach campaigns to apartment complexes with 760 units, only 8% of building's tenants elected to receive a free HED in their homes as part of the field study. Second, the HED used, a leading market model, had a spectrum of problems, including gateway miscommunications, failure to post to a data-hosting third party, and display malfunctions. In light of these challenges, we are pursuing a modified study investigating the energy savings of a web portal versus alert-based energy feedback instead of a physical HED.

  1. Home Energy Displays. Consumer Adoption and Response

    Energy Technology Data Exchange (ETDEWEB)

    LaMarche, Janelle [Fraunhofer Center for Sustainable Energy Systems, Cambridge, MA (United States); Cheney, K. [Fraunhofer Center for Sustainable Energy Systems, Cambridge, MA (United States); Akers, C. [Fraunhofer Center for Sustainable Energy Systems, Cambridge, MA (United States); Roth, K. [Fraunhofer Center for Sustainable Energy Systems, Cambridge, MA (United States); Sachs, O. [Fraunhofer Center for Sustainable Energy Systems, Cambridge, MA (United States)


    The focus of this project was to investigate the factors influencing consumer adoption of Home Energy Displays (HEDs) and to evaluate electricity consumption in households with basic HEDs versus enhanced feedback methods - web portals or alerts. The team hypothesized that providing flexible and relatable information to users, in addition to a basic HED, would make feedback more effective and achieve persistent energy savings. In Phase I, Fraunhofer conducted three user research studies and found preferences for aesthetically pleasing, easy to understand feedback that is accessible through multiple media and offered free of charge. The deployment of HEDs in 150 households planned for Phase II encountered major recruitment and HED field deployment problems. In light of these challenges, the team is pursuing a modified study investigating the energy savings of a web portal versus alert-based energy feedback instead of a physical HED.

  2. Australian Children's Understanding of Display Rules (United States)

    Choy, Grace


    Cultural display rules govern the manifestation of emotional expressions. In compliance with display rules, the facial expressions displayed (i.e. apparent emotion) may be incongruent with the emotion experienced (i.e. real emotion). This study investigates Australian Caucasian children's understanding of display rules. A sample of 80 four year…

  3. The case for transparent depth display

    NARCIS (Netherlands)

    Kooi, F.L.


    Purpose: The continuing developments in display technology have resulted in the ability to present increasing amounts of data on computer displays. One of the coming break-throughs is generally believed to be the introduction of '3-D displays': displays with a true sense of depth. Though these types

  4. Determining inhibition effects of some aromatic compounds on peroxidase enzyme purified from white and red cabbage

    Energy Technology Data Exchange (ETDEWEB)

    Öztekin, Aykut, E-mail: [Ataturk University, Science Faculty, Department of Chemistry, 25240-Erzurum (Turkey); Agri Ibrahim Cecen University Faculty of Arts and Sciences, Department of Chemistry, 04100-Agri (Turkey); Almaz, Züleyha, E-mail: [Ataturk University, Science Faculty, Department of Chemistry, 25240-Erzurum (Turkey); Mus Alparslan University Faculty of Sciences, Department of Moleculer Biology, 49250-Mus (Turkey); Özdemir, Hasan, E-mail: [Ataturk University, Science Faculty, Department of Chemistry, 25240-Erzurum (Turkey)


    Peroxidases (E.C. catalyze the one electron oxidation of wide range of substrates. They are used in synthesis reaction, removal of peroxide from industrial wastes, clinical biochemistry and immunoassays. In this study, the white cabbage (Brassica Oleracea var. capitata f. alba) and red cabbage (Brassica oleracea L. var. capitata f. rubra) peroxidase enzymes were purified for investigation of inhibitory effect of some aromatic compounds on these enzymes. IC{sub 50} values and Ki constants were calculated for the molecules of 6-Amino nicotinic hydrazide, 6-Amino-5-bromo nicotinic hydrazide, 2-Amino-5-hydroxy benzohydrazide, 4-Amino-3-hydroxy benzohydrazide on purified enzymes and inhibition type of these molecules were determined. (This research was supported by Ataturk University. Project Number: BAP-2015/98).

  5. Expression of a defence-related intercellular barley peroxidase in transgenic tobacco

    DEFF Research Database (Denmark)

    Kristensen, B.K.; Brandt, J.; Bojsen, K.


    genetically, phenotypically and biochemically. The T-DNA was steadily inherited through three generations. The barley peroxidase is expressed and sorted to the intercellular space in the transgenic tobacco plants. The peroxidase can be extracted from the intercellular space in two molecular forms from both...... barley and transgenic tobacco. The tobacco expressed forms are indistinguishable from the barley expressed forms as determined by analytical isoelectric focusing (pI 8.5) and Western-blotting. Staining for N-glycosylation showed that one form only was glycosylated. The N-terminus of purified Prx8 from...... transgenic tobacco was blocked by pyroglutamate, after the removal of which, N-terminal sequencing verified the transit signal-peptide cleavage site deduced from the cDNA sequence. Phenotype comparisons show that the constitutive expression of Prx8 lead to growth retardation. However, an infection assay...

  6. Determining inhibition effects of some aromatic compounds on peroxidase enzyme purified from white and red cabbage (United States)

    Öztekin, Aykut; Almaz, Züleyha; Özdemir, Hasan


    Peroxidases (E.C. catalyze the one electron oxidation of wide range of substrates. They are used in synthesis reaction, removal of peroxide from industrial wastes, clinical biochemistry and immunoassays. In this study, the white cabbage (Brassica Oleracea var. capitata f. alba) and red cabbage (Brassica oleracea L. var. capitata f. rubra) peroxidase enzymes were purified for investigation of inhibitory effect of some aromatic compounds on these enzymes. IC50 values and Ki constants were calculated for the molecules of 6-Amino nicotinic hydrazide, 6-Amino-5-bromo nicotinic hydrazide, 2-Amino-5-hydroxy benzohydrazide, 4-Amino-3-hydroxy benzohydrazide on purified enzymes and inhibition type of these molecules were determined. (This research was supported by Ataturk University. Project Number: BAP-2015/98).

  7. Determining inhibition effects of some aromatic compounds on peroxidase enzyme purified from white and red cabbage

    International Nuclear Information System (INIS)

    Öztekin, Aykut; Almaz, Züleyha; Özdemir, Hasan


    Peroxidases (E.C. catalyze the one electron oxidation of wide range of substrates. They are used in synthesis reaction, removal of peroxide from industrial wastes, clinical biochemistry and immunoassays. In this study, the white cabbage (Brassica Oleracea var. capitata f. alba) and red cabbage (Brassica oleracea L. var. capitata f. rubra) peroxidase enzymes were purified for investigation of inhibitory effect of some aromatic compounds on these enzymes. IC_5_0 values and Ki constants were calculated for the molecules of 6-Amino nicotinic hydrazide, 6-Amino-5-bromo nicotinic hydrazide, 2-Amino-5-hydroxy benzohydrazide, 4-Amino-3-hydroxy benzohydrazide on purified enzymes and inhibition type of these molecules were determined. (This research was supported by Ataturk University. Project Number: BAP-2015/98).

  8. Effect of cadmium on growth, protein content and peroxidase activity in pea plants

    International Nuclear Information System (INIS)

    Bavi, K.; Kholdebarin, B.


    n this study the effects of different cadmium chloride concentrations (5, 10, 20, 50, and 100 mu M) on some physiological and biochemical processes including seed germination, root and shoot fresh and dry weight, protein content and peroxidase activity in peas (Cicer arietinum cv. pars) were investigated. Cadmium did not have any significant effect on the rate of pea seed germination. However, it affected the subsequent growth rate in these plants. Higher cadmium concentrations specially at 50 and 100 mu M reduced plant growth significantly. Leaf chlorosis, wilting and leaf abscission were observed in plants treated with cadmium. Protein content in pea roots reduced significantly in the presence of high cadmium concentrations. Low concentrations of CdCl/sub 2/ resulted in higher peroxidase activity both in roots and shoots of pea plants. (author)

  9. Role of thyroid gland on the peroxidase and iodinating enzymes of submaxillary gland

    International Nuclear Information System (INIS)

    Chandra, T.; Das, R.; Datta, A.G.


    The peroxidase (EC and iodinase (EC activities of rat submaxillary gland were found to be increased after thyroidectomy. The enzyme activities were maximal on the seventh day after operation and then decreased slightly. However, the enzyme activities were still more than 100% even 28 days following operation. Administration of thyroxine (10 μg/100 g body weight) prevented the increase. Puromycin, cycloheximide, and actinomycin D, the inhibitors of protein synthesis, as well as Thiouracil partially abolished the increase of activities. These results suggest that thyroxine acts as a regulator of the iodinase and peroxidase enzyme(s) of submaxillary gland. Iodine 131 was the isotope used in the experiments. (orig./AJ) [de

  10. Activation of glutathione peroxidase via Nrf1 mediates genistein's protection against oxidative endothelial cell injury

    International Nuclear Information System (INIS)

    Hernandez-Montes, Eva; Pollard, Susan E.; Vauzour, David; Jofre-Montseny, Laia; Rota, Cristina; Rimbach, Gerald; Weinberg, Peter D.; Spencer, Jeremy P.E.


    Cellular actions of isoflavones may mediate the beneficial health effects associated with high soy consumption. We have investigated protection by genistein and daidzein against oxidative stress-induced endothelial injury. Genistein but not daidzein protected endothelial cells from damage induced by oxidative stress. This protection was accompanied by decreases in intracellular glutathione levels that could be explained by the generation of glutathionyl conjugates of the oxidised genistein metabolite, 5,7,3',4'-tetrahydroxyisoflavone. Both isoflavones evoked increased protein expression of γ-glutamylcysteine synthetase-heavy subunit (γ-GCS-HS) and increased cytosolic accumulation and nuclear translocation of Nrf2. However, only genistein led to increases in the cytosolic accumulation and nuclear translocation of Nrf1 and the increased expression of and activity of glutathione peroxidase. These results suggest that genistein-induced protective effects depend primarily on the activation of glutathione peroxidase mediated by Nrf1 activation, and not on Nrf2 activation or increases in glutathione synthesis

  11. Horseradish peroxidase embedded in polyacrylamide nanoparticles enables optical detection of reactive oxygen species

    DEFF Research Database (Denmark)

    Poulsen, A.K.; Scharff-Poulsen, Anne Marie; Olsen, L.F.


    We have synthesized and characterized new nanometer-sized polyacrylamide particles containing horseradish peroxidase and fluorescent dyes. Proteins and dyes are encapsulated by radical polymerization in inverse microemulsion. The activity of the encapsulated enzyme has been examined and it mainta......We have synthesized and characterized new nanometer-sized polyacrylamide particles containing horseradish peroxidase and fluorescent dyes. Proteins and dyes are encapsulated by radical polymerization in inverse microemulsion. The activity of the encapsulated enzyme has been examined...... for quantification of hydrogen peroxide and other reactive oxygen species in microenvironments, and we propose that the particles may find use as nanosensors for use in, e.g., living cells. (C) 2007 Elsevier Inc. All rights reserved....

  12. Study on serum thyroid peroxidase antibody levels in autoimmune thyroid disease

    International Nuclear Information System (INIS)

    Zhang Zhixiang; Zheng Lan; Xu Shujin; Guan Jinghua


    Objective: To investigate the clinical significance of changes of serum thyroid peroxidase antibody (TPO-Ab) in patients with hyperthyroidism, hypothyroidism and simple goiter. Methods: Serum TPO-Ab, TMA,TGA and FT 3 , FT 4 , TSH levels were measured with radioimmunoassay(RIA) in 69 patients with hyperthyroidism, 53 patients with hypothyroidism, 45 patients with simple goiter and 20 controls. Results: The positive rate of thyroid peroxidase antibody (TPO-Ab) (82%-92.5%) was higher than that of thyroidglobulim antibody(TGA) (44.2%) and thyroid microsome antibody(TMA) (60.4-69.8%) in all patients with AICD. Conclusion: TPO-Ab could be taken as an important indicator in assessment of treatment and prognosis in patients with auto- immune thyroid diseases. (authors)

  13. Characterization of structure and activity of garlic peroxidase (POX(1B)). (United States)

    El Ichi, Sarra; Miodek, Anna; Sauriat-Dorizon, Hélène; Mahy, Jean-Pierre; Henry, Céline; Marzouki, Mohamed Nejib; Korri-Youssoufi, Hafsa


    Structural characterization and study of the activity of new POX(1B) protein from garlic which has a high peroxidase activity and can be used as a biosensor for the detection of hydrogen peroxide and phenolic compounds were performed and compared with the findings for other heme peroxidases. The structure-function relationship was investigated by analysis of the spectroscopic properties and correlated to the structure determined by a new generation of high-performance hybrid mass spectrometers. The reactivity of the enzyme was analyzed by studies of the redox activity toward various ligands and the reactivity with various substrates. We demonstrated that, in the case of garlic peroxidase, the heme group is pentacoordinated, and has an histidine as a proximal ligand. POX(1B) exhibited a high affinity for hydrogen peroxide as well as various reducing cosubstrates. In addition, high enzyme specificity was demonstrated. The k(cat) and K(M) values were 411 and 400 mM(-1) s(-1) for 3,3',5,5'-tetramethylbenzidine and 2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid), respectively. Furthermore, the reduction of nitro compounds in the presence of POX(1B) was demonstrated by iron(II) nitrosoalkane complex assay. In addition, POX(1B) showed a great potential for application for drug metabolism since its ability to react with 1-nitrohexane in the presence of sodium dithionite was demonstrated by the appearance of a characteristic Soret band at 411 nm. The high catalytic efficiency obtained in the case of the new garlic peroxidase (POX(1B)) is suitable for the monitoring of different analytes and biocatalysis.

  14. Stability and Catalytic Kinetics of Horseradish Peroxidase Confined in Nanoporous SBA-15

    DEFF Research Database (Denmark)

    Ikemoto, Hediki; Chi, Qijin; Ulstrup, Jens


    We have synthesized nanoporous silica, SBA-15 in the 1 m size range with the pore diameter of 7.6 nm. The redox enzyme horseradish peroxidase (HRP) was entrapped in the pores to form nanostructured hybrid materials. The catalytic activity of free and immobilized enzyme was first compared at room...... likely due to different hydrogen bonding of water and increased hydration strength of the protein inside the nanopores....

  15. Fe(III)-TAML activator: a potent peroxidase mimic for chemiluminescent determination of hydrogen peroxide. (United States)

    Vdovenko, Marina M; Demiyanova, Alexandra S; Kopylov, Kirill E; Sakharov, Ivan Yu


    Efforts to replace native peroxidase with its low molecular weight alternatives have stimulated a search for peroxidase mimetics. Herein we describe the oxidation of luminol with hydrogen peroxide catalyzed by commercially available Fe(III)-TAML activator 1a, which was shown to be a more active catalyst than hemin. At Fe(III)-TAML activator 1a use in chemiluminescent assay for H2O2 determination the detection limit value (3σ) of 5×10(-8)M was similar to the detection limit obtained with horseradish peroxidase (1×10(-7)M) and significantly lower than that obtained in the presence of hemin (6×10(-7)M). The linear ranges (R(2)=0.98) of the assay were 6×10(-8)-1×10(-6)M and 6×10(-7)-1×10(-6)M H2O2 for Fe(III)-TAML 1a and hemin, respectively. The CV values for Fe(III)-TAML 1a-based assay measured within the working range varied from 1.0% to 3.7% (n=4), whereas in the case of hemin -5.0% to 9.7% (n=4). Moreover, the sensitivity of Fe(III)-TAML 1a-based method was 56 and 5 times higher than that of hemin- and HRP-based methods, respectively. The obtained results open good perspectives to apply Fe(III)-TAML activator 1a in CL analytical methods instead of hemin, a traditionally used peroxidase mimetic. Copyright © 2014 Elsevier B.V. All rights reserved.

  16. A one-electron oxidation of carcinogenic nonaminoazo dye Sudan I by horseradish peroxidase

    Czech Academy of Sciences Publication Activity Database

    Semanská, M.; Dračínský, Martin; Martínek, V.; Hudeček, J.; Hodek, P.; Frei, E.; Stiborová, M.


    Roč. 29, č. 5 (2008), s. 712-716 ISSN 0172-780X Grant - others:GA MŠk(CZ) 1M0505; GA ČR(CZ) GA203/06/0329 Program:1M Institutional research plan: CEZ:AV0Z40550506 Keywords : carcinogen * Sudan I * peroxidase * NMR spectroscopy * mechanism of oxidation Subject RIV: CC - Organic Chemistry Impact factor: 1.359, year: 2008

  17. V2O5 nanowires with an intrinsic peroxidase-like activity

    NARCIS (Netherlands)

    André, R.; Natálio, F.; Humanes, M.; Leppin, J.; Heinze, K.; Wever, R.; Schröder, H.C.; Müller, W.E.G.; Tremel, W.


    V2O5 nanowires exhibit an intrinsic catalytic activity towards classical peroxidase substrates such as 2,2-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and 3,3,5,5,-tetramethylbenzdine (TMB) in the presence of H2O2. These V2O5 nanowires show an optimum reactivity at a pH of 4.0 and the

  18. Peroxidase production and ligninolytic potentials of fresh water bacteria Raoultella ornithinolytica and Ensifer adhaerens

    Directory of Open Access Journals (Sweden)

    Ayodeji O. Falade


    Full Text Available Interest in novel ligninolytic bacteria has remained topical due to, in part, the maneuverability of the bacterial genome. Conversely, the fungal genome lacks the dexterity for similar maneuverability thus, posing challenges in the fungal enzyme yield optimization process. Some impact of this situation includes the inability to commercialize the bio-catalytic process of lignin degradation by fungi. Consequently, this study assessed some fresh water bacteria isolates for ligninolytic and peroxidase properties through the utilization and degradation of model lignin compounds (guaiacol and veratryl alcohol and the decolourization of selected ligninolytic indicator dyes; Azure B (AZB, Remazol Brilliant Blue R (RBBR and Congo Red (CR. Bacterial strains with appreciable ligninolytic and peroxidase production potentials were identified through 16S rDNA sequence analysis and the nucleotide sequences deposited in the GenBank. About 5 isolates were positive for the degradation of both guaiacol (GA and veratryl alcohol (VA thus, accounting for about 17% of the test isolates. Similarly, AZB, RBBR and CR were respectively decolorized by 3, 2 and 5 bacterial strains thus, accounting for 10%, 7% and 17% of the test isolates. Two of the test bacterial strains were able to decolourize AZB, RBBR and CR respectively and these bacterial strains were identified as Raoultella ornithinolytica OKOH-1 and Ensifer adhaerens NWODO-2 with respective accession numbers as KX640917 and KX640918. Upon quantitation of the peroxidase activities; 5250 ± 0.00 U/L was recorded against Raoultella ornithinolytica OKOH-1 and 5833 ± 0.00 U/L against Ensifer adhaerens NWODO-2. The ligninolytic and dye decolourization properties of Raoultella ornithinolytica OKOH-1 and Ensifer adhaerens NWODO-2 marks for novelty particularly, as dyes with arene substituents were decolourized. Consequently, the potentials for the industrial applicability of these test bacterial strains abound as

  19. The Molecular Mechanism of the Catalase-like Activity in Horseradish Peroxidase. (United States)

    Campomanes, Pablo; Rothlisberger, Ursula; Alfonso-Prieto, Mercedes; Rovira, Carme


    Horseradish peroxidase (HRP) is one of the most relevant peroxidase enzymes, used extensively in immunochemistry and biocatalysis applications. Unlike the closely related catalase enzymes, it exhibits a low activity to disproportionate hydrogen peroxide (H2O2). The origin of this disparity remains unknown due to the lack of atomistic information on the catalase-like reaction in HRP. Using QM(DFT)/MM metadynamics simulations, we uncover the mechanism for reduction of the HRP Compound I intermediate by H2O2 at atomic detail. The reaction begins with a hydrogen atom transfer, forming a peroxyl radical and a Compound II-like species. Reorientation of the peroxyl radical in the active site, concomitant with the transfer of the second hydrogen atom, is the rate-limiting step, with a computed free energy barrier (18.7 kcal/mol, ∼ 6 kcal/mol higher than the one obtained for catalase) in good agreement with experiments. Our simulations reveal the crucial role played by the distal pocket residues in accommodating H2O2, enabling formation of a Compound II-like intermediate, similar to catalases. However, out of the two pathways for Compound II reduction found in catalases, only one is operative in HRP. Moreover, the hydrogen bond network in the distal side of HRP compensates less efficiently than in catalases for the energetic cost required to reorient the peroxyl radical at the rate-determining step. The distal Arg and a water molecule in the "wet" active site of HRP have a substantial impact on the reaction barrier, compared to the "dry" active site in catalase. Therefore, the lower catalase-like efficiency of heme peroxidases compared to catalases can be directly attributed to the different distal pocket architecture, providing hints to engineer peroxidases with a higher rate of H2O2 disproportionation.

  20. A sensitive colorimetric aptasensor based on trivalent peroxidase-mimic DNAzyme and magnetic nanoparticles. (United States)

    Liu, Shuwen; Xu, Naihan; Tan, Chunyan; Fang, Wei; Tan, Ying; Jiang, Yuyang


    In this study, a novel colorimetric aptasensor was prepared by coupling trivalent peroxidase-mimic DNAzyme and magnetic nanoparticles for highly sensitive and selective detection of target proteins. A three G-quadruplex (G4) DNA-hemin complex was employed as the trivalent peroxidase-mimic DNAzyme, in which hemin assisted the G4-DNA to fold into a catalytic conformation and act as an enzyme. The design of the aptasensor includes magnetic nanoparticles (MNPs), complementary DNA (cDNA) modified with biotin, and a label-free single strand DNA (ssDNA) including the aptamer and trivalent peroxidase-mimic DNAzyme. The trivalent DNAzyme, which has the highest catalytic activity among multivalent DNAzymes, catalyzed the H 2 O 2 -mediated oxidation of ABTS. The colorless ABTS was oxidized to produce a blue-green product that can be clearly distinguished by the naked eye. The aptamer and trivalent peroxidase-mimic DNAzyme promote the specificity and sensitivity of this detection method, which can be generalized for other targets by simply replacing the corresponding aptamers. To demonstrate the feasible use of the aptasensor for target detection, a well-known tumor biomarker MUC1 was evaluated as the model target. The limits of detection were determined to be 5.08 and 5.60 nM in a linear range of 50-1000 nM in a buffer solution and 10% serum system, respectively. This colorimetric and label-free aptasensor with excellent sensitivity and strong anti-interference ability has potential application in disease diagnoses, prognosis tracking, and therapeutic evaluation. Copyright © 2018 Elsevier B.V. All rights reserved.

  1. Expression of manganese peroxidase by Lentinula edodes and Lentinula boryana in solid state and submerged system fermentation

    Directory of Open Access Journals (Sweden)



    Full Text Available The production of ethanol from lignocellulosic biomass is referred as a second generation biofuel, whose processing is one of the most promising technologies under development. There are few available studies on the use of enzymes produced by fungi as active for the biodegradation of lignocellulosic biomass. However, the manganese peroxidase (MnP enzyme presents high potential to degrade lignin and the basidiomycetes are the major producers of this oxidase. Thus, this study aimed at evaluating the ability of fungi Lentinula edodes and Lentinula boryana to produce this enzyme when cultivated in submerged fermentation system (SS and also in solid-state fermentation system (SSF containing Eucalyptus benthamii sawdust with or without corn cob meal. In the SS the greatest MnP expression occurred on the 25th day, being of 70 UI.L–1 for L. boryana and of 20 UI.L–1 for L. edodes. In the SSF, the best results were obtained on the 10th day for L. edodes, while for L. boryana it happened between the 20th and the 25th days, despite both species presented values close to 110 UI.L–1. Therefore, the results indicated that the studied fungi express the enzyme of interest and that its production is enhanced when cultivated in solid system.

  2. Involvement of plasma membrane peroxidases and oxylipin pathway in the recovery from phytoplasma disease in apple (Malus domestica). (United States)

    Patui, Sonia; Bertolini, Alberto; Clincon, Luisa; Ermacora, Paolo; Braidot, Enrico; Vianello, Angelo; Zancani, Marco


    Apple trees (Malus domestica Borkh.) may be affected by apple proliferation (AP), caused by 'Candidatus Phytoplasma mali'. Some plants can spontaneously recover from the disease, which implies the disappearance of symptoms through a phenomenon known as recovery. In this article it is shown that NAD(P)H peroxidases of leaf plasma membrane-enriched fractions exhibited a higher activity in samples from both AP-diseased and recovered plants. In addition, an increase in endogenous SA was characteristic of the symptomatic plants, since its content increased in samples obtained from diseased apple trees. In agreement, phenylalanine ammonia lyase (PAL) activity, a key enzyme of the phenylpropanoid pathway, was increased too. Jasmonic acid (JA) increased only during recovery, in a phase subsequent to the pathological state, and in concomitance to a decline of salicylic acid (SA). Oxylipin pathway, responsible for JA synthesis, was not induced during the development of AP-disease, but it appeared to be stimulated when the recovery occurred. Accordingly, lipoxygenase (LOX) activity, detected in plasma membrane-enriched fractions, showed an increase in apple leaves obtained from recovered plants. This enhancement was paralleled by an increase of hydroperoxide lyase (HPL) activity, detected in leaf microsomes, albeit the latter enzyme was activated in either the disease or recovery conditions. Hence, a reciprocal antagonism between SA- and JA-pathways could be suggested as an effective mechanism by which apple plants react to phytoplasma invasions, thereby providing a suitable defense response leading to the establishment of the recovery phenomenon. Copyright © Physiologia Plantarum 2012.

  3. The importance of Arabidopsis glutathione peroxidase 8 for protecting Arabidopsis plant and E. coli cells against oxidative stress. (United States)

    Gaber, Ahmed


    Glutathione peroxidases (GPXs) are major family of the reactive oxygen species (ROS) scavenging enzymes. Recently, database analysis of the Arabidopsis genome revealed a new open-reading frame, thus increasing the total number of AtGPX gene family to eight (AtGPX1-8). The effect of plant hormones like; i. e. salicylic acid (SA), jasmonic acid (JA), abscisic acid (ABA), indoleacetic acid (IAA), and mannitol on the expression of the genes confirm that the AtGPX genes family is regulated by multiple signaling pathways. The survival rate of AtGPX8 knockout plants (KO8) was significantly decreased under heat stress compared with the wild type. Moreover, the content of malondialdehyde (MDA) and protein oxidation was significantly increased in the KO8 plant cells under heat stress. Results indicating that the deficiency of AtGPX8 accelerates the progression of oxidative stress in KO8 plants. On the other hand, the overexpression of AtGPX8 in E. coli cells enhance the growth of the recombinant enzyme on media supplemented with 0.2 mM cumene hydroperoxide, 0.3 mM H 2O 2 or 600 mM NaCl.

  4. Amperometric inhibition biosensors based on horseradish peroxidase and gold sononanoparticles immobilized onto different electrodes for cyanide measurements. (United States)

    Attar, Aisha; Cubillana-Aguilera, Laura; Naranjo-Rodríguez, Ignacio; de Cisneros, José Luis Hidalgo-Hidalgo; Palacios-Santander, José María; Amine, Aziz


    New biosensors based on inhibition for the detection of cyanide and the comparison of the analytical performances of nine enzyme biosensor designs by using three different electrodes: Sonogel-Carbon, glassy carbon and gold electrodes were discussed. Three different horseradish peroxidase immobilization procedures with and without gold sononanoparticles were studied. The amperometric measurements were performed at an applied potential of -0.15V vs. Ag/AgCl in 50mM sodium acetate buffer solution pH=5.0. The apparent kinetic parameters (Kmapp, Vmaxapp) of immobilized HRP were calculated in the absence of inhibitor (cyanide) by using caffeic acid, hydroquinone, and catechol as substrates. The presence of gold sononanoparticles enhanced the electron transfer reaction and improved the analytical performance of the biosensors. The HRP kinetic interactions reveal non-competitive binding of cyanide with an apparent inhibition constant (Ki) of 2.7μM and I50 of 1.3μM. The determination of cyanide can be achieved in a dynamic range of 0.1-58.6μM with a detection limit of 0.03μM which is lower than those reported by previous studies. Hence this biosensing methodology can be used as a new promising approach for detecting cyanide. Copyright © 2014. Published by Elsevier B.V.

  5. The Catalase Activity of Catalase-Peroxidases Is Modulated by Changes in the pKa of the Distal Histidine. (United States)

    Machuqueiro, Miguel; Victor, Bruno; Switala, Jacek; Villanueva, Jacylyn; Rovira, Carme; Fita, Ignacio; Loewen, Peter C


    The unusual Met-Tyr-Trp adduct composed of cross-linked side chains along with an associated mobile Arg is essential for catalase activity in catalase-peroxidases. In addition, acidic residues in the entrance channel, in particular an Asp and a Glu ∼7 and ∼15 Å, respectively, from the heme, significantly enhance catalase activity. The mechanism by which these channel carboxylates influence catalase activity is the focus of this work. Seventeen new variants with fewer and additional acidic residues have been constructed and characterized structurally and for enzymatic activity, revealing that their effect on activity is roughly inversely proportional to their distance from the heme and adduct, suggesting that the electrostatic potential of the heme cavity may be affected. A discrete group of protonable residues are contained within a 15 Å sphere surrounding the heme iron, and a computational analysis reveals that the pK a of the distal His 112 , alone, is modulated within the pH range of catalase activity by the remote acidic residues in a pattern consistent with its protonated form having a key role in the catalase reaction cycle. The electrostatic potential also impacts the catalatic reaction through its influence on the charged status of the Met-Tyr-Trp adduct.

  6. Molecular characterization of the sweet potato peroxidase SWPA4 promoter which responds to abiotic stresses and pathogen infection. (United States)

    Ryu, Sun-Hwa; Kim, Yun-Hee; Kim, Cha Young; Park, Soo-Young; Kwon, Suk-Yoon; Lee, Haeng-Soon; Kwak, Sang-Soo


    Previously, the swpa4 peroxidase gene has been shown to be inducible by a variety of abiotic stresses and pathogenic infections in sweet potato (Ipomoea batatas). To elucidate its regulatory mechanism at the transcriptional level under various stress conditions, we isolated and characterized the promoter region (2374 bp) of swpa4 (referred to as SWPA4). We performed a transient expression assay in tobacco protoplasts with deletions from the 5'-end of SWPA4 promoter fused to the beta-glucuronidase (GUS) reporter gene. The -1408 and -374 bp deletions relative to the transcription start site (+1) showed 8 and 4.5 times higher GUS expression than the cauliflower mosaic virus 35S promoter, respectively. In addition, transgenic tobacco plants expressing GUS under the control of -2374, -1408 or -374 bp region of SWPA4 promoter were generated and studied in various tissues under abiotic stresses and pathogen infection. Gel mobility shift assays revealed that nuclear proteins from sweet potato cultured cells specifically interacted with 60-bp fragment (-178/-118) in -374 bp promoter region. In silico analysis indicated that four kinds of cis-acting regulatory sequences, reactive oxygen species-related element activator protein 1 (AP1), CCAAT/enhancer-binding protein alpha element, ethylene-responsive element (ERE) and heat-shock element, are present in the -60 bp region (-178/-118), suggesting that the -60 bp region might be associated with stress inducibility of the SWPA4 promoter.

  7. The Small Glutathione Peroxidase Mimic 5P May Represent a New Strategy for the Treatment of Liver Cancer. (United States)

    Yin, Juxin; Wang, Bingmei; Zhu, Xuejun; Qu, Xiaonan; Huang, Yi; Lv, Shaowu; Mu, Ying; Luo, Guimin


    Glutathione peroxidase (GPx) is an antioxidant protein containing selenium. Owing to the limitations of native GPx, considerable efforts have been made to develop GPx mimics. Here, a short 5-mer peptides (5P) was synthesized and characterized using matrix-assisted laser desorption ionization time-of-flight mass spectrometry. Enzyme coupled assays were used to evaluate GPx activity. The cell viability and apoptosis of H22 cells were tested, and mice bearing H22 cell-derived tumors were used to determine the effects of 5P on tumor inhibition. In comparison with other enzyme models, 5P provided a suitable substrate with proper catalytic site positions, resulting in enhanced catalytic activity. In our mouse model, 5P showed excellent inhibition of tumor growth and improved immunity. In summary, our findings demonstrated the design and synthesis of the small 5P molecule, which inhibited tumor growth and improved immunity. Notably, 5P could inhibit tumor growth without affecting normal growth. Based on these advantages, the novel mimic may have several clinical applications.

  8. Nuclear Medicine Image Display. Chapter 14

    Energy Technology Data Exchange (ETDEWEB)

    Bergmann, H. [Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna (Austria)


    The final step in a medical imaging procedure is to display the image(s) on a suitable display system where it is presented to the medical specialist for diagnostic interpretation. The display of hard copy images on X ray film or photographic film has largely been replaced today by soft copy image display systems with cathode ray tube (CRT) or liquid crystal display (LCD) monitors as the image rendering device. Soft copy display requires a high quality display monitor and a certain amount of image processing to optimize the image both with respect to the properties of the display device and to some psychophysiological properties of the human visual system. A soft copy display system, therefore, consists of a display workstation providing some basic image processing functions and the display monitor as the intrinsic display device. Display devices of lower quality may be used during intermediate steps of the acquisition and analysis of a patient study. Display monitors with a quality suitable for diagnostic reading by the specialist medical doctor are called primary devices, also known as diagnostic devices. Monitors with lower quality but good enough to be used for positioning, processing of studies, presentation of images in the wards, etc. are referred to as secondary devices or clinical devices. Nuclear medicine images can be adequately displayed even for diagnostic purposes on secondary devices. However, the increasing use of X ray images on which to report jointly with images from nuclear medicine studies, such as those generated by dual modality imaging, notably by positron emission tomography (PET)/computed tomography (CT) and single photon emission computed tomography (SPECT)/CT, requires display devices capable of visualizing high resolution grey scale images at diagnostic quality, i.e. primary display devices. Both grey scale and colour display devices are used, the latter playing an important role in the display of processed nuclear medicine images and

  9. Nuclear Medicine Image Display. Chapter 14

    International Nuclear Information System (INIS)

    Bergmann, H.


    The final step in a medical imaging procedure is to display the image(s) on a suitable display system where it is presented to the medical specialist for diagnostic interpretation. The display of hard copy images on X ray film or photographic film has largely been replaced today by soft copy image display systems with cathode ray tube (CRT) or liquid crystal display (LCD) monitors as the image rendering device. Soft copy display requires a high quality display monitor and a certain amount of image processing to optimize the image both with respect to the properties of the display device and to some psychophysiological properties of the human visual system. A soft copy display system, therefore, consists of a display workstation providing some basic image processing functions and the display monitor as the intrinsic display device. Display devices of lower quality may be used during intermediate steps of the acquisition and analysis of a patient study. Display monitors with a quality suitable for diagnostic reading by the specialist medical doctor are called primary devices, also known as diagnostic devices. Monitors with lower quality but good enough to be used for positioning, processing of studies, presentation of images in the wards, etc. are referred to as secondary devices or clinical devices. Nuclear medicine images can be adequately displayed even for diagnostic purposes on secondary devices. However, the increasing use of X ray images on which to report jointly with images from nuclear medicine studies, such as those generated by dual modality imaging, notably by positron emission tomography (PET)/computed tomography (CT) and single photon emission computed tomography (SPECT)/CT, requires display devices capable of visualizing high resolution grey scale images at diagnostic quality, i.e. primary display devices. Both grey scale and colour display devices are used, the latter playing an important role in the display of processed nuclear medicine images and

  10. Display of nuclear medicine imaging studies

    International Nuclear Information System (INIS)

    Singh, B.; Kataria, S.K.; Samuel, A.M.


    Nuclear medicine imaging studies involve evaluation of a large amount of image data. Digital signal processing techniques have introduced processing algorithms that increase the information content of the display. Nuclear medicine imaging studies require interactive selection of suitable form of display and pre-display processing. Static imaging study requires pre-display processing to detect focal defects. Point operations (histogram modification) along with zoom and capability to display more than one image in one screen is essential. This album mode of display is also applicable to dynamic, MUGA and SPECT data. Isometric display or 3-D graph of the image data is helpful in some cases e.g. point spread function, flood field data. Cine display is used on a sequence of images e.g. dynamic, MUGA and SPECT imaging studies -to assess the spatial movement of tracer with time. Following methods are used at the investigator's discretion for inspection of the 3-D object. 1) Display of orthogonal projections, 2) Display of album of user selected coronal/ sagital/ transverse orthogonal slices, 3) Display of three orthogonal slices through user selected point, 4) Display of a set of orthogonal slices generated in the user-selected volume, 5) Generation and display of 3-D shaded surface. 6) Generation of volume data and display along with the 3-D shaded surface, 7) Side by side display orthogonal slices of two 3-D objects. Displaying a set of two-dimensional slices of a 3-D reconstructed object through shows all the defects but lacks the 3-D perspective. Display of shaded surface lacks the ability to show the embedded defects. Volume display -combining the 3-D surface and gray level volume data is perhaps the best form of display. This report describes these forms of display along with the theory. (author)

  11. In vitro oxidation of indoleacetic acid by soluble auxin-oxidases and peroxidases from maize roots

    International Nuclear Information System (INIS)

    Beffa, R.; Martin, H.V.; Pilet, P.E.


    Soluble auxin-oxidases were extracted from Zea mays L. cv LG11 apical root segments and partially separated from peroxidases (EC by size-exclusion chromatography. Auxin-oxidases were resolved into one main peak corresponding to a molecular mass of 32.5 kilodaltons and a minor peak at 54.5 kilodaltons. Peroxidases were separated into at least four peaks, with molecular masses from 32.5 to 78 kilodaltons. In vitro activity of indoleacetic acid-oxidases was dependent on the presence of MnCl 2 and p-coumaric acid. Compound(s) present in the crude extract and several synthetic auxin transport inhibitors (including 2,3,5-triiodobenzoic acid and N-1-naphthylphthalamic acid) inhibited auxin-oxidase activity, but had no effect on peroxidases. The products resulting from the in vitro enzymatic oxidation of [ 3 H]indoleacetic acid were separated by HPLC and the major metabolite was found to cochromatograph with indol-3yl-methanol

  12. Identification and characterization of a selenium-dependent glutathione peroxidase in Setaria cervi

    International Nuclear Information System (INIS)

    Singh, Anchal; Rathaur, Sushma


    Setaria cervi a bovine filarial parasite secretes selenium glutathione peroxidase during in vitro cultivation. A significant amount of enzyme activity was detected in the somatic extract of different developmental stages of the parasite. Among different stages, microfilariae showed a higher level of selenium glutathione peroxidase activity followed by males then females. However, when the activity was compared in excretory secretory products of these stages males showed higher activity than microfilariae and female worms. The enzyme was purified from female somatic extract using a combination of glutathione agarose and gel filtration chromatography, which migrated as a single band of molecular mass ∼20 kDa. Selenium content of purified enzyme was estimated by atomic absorption spectroscopy and found to be 3.5 ng selenium/μg of protein. Further, inhibition of enzyme activity by potassium cyanide suggested the presence of selenium at the active site of enzyme. This is the first report of identification of selenium glutathione peroxidase from any filarial parasite


    Directory of Open Access Journals (Sweden)



    Full Text Available Mangosteen (Garcinia mangostana L. pericarp is an abundant source of phytochemicals. Blanching prior to further process stabilizes these valuable compounds. In this research, crude peroxidase (POD was extracted from mangosteen peel using Triton X-100. Kinetics of POD inactivation was studied over temperature range of 60- 100°C. The inactivation kinetics followed a monophasic first-order model with k values between 1.93×10-2- 8.14×10-2 min-1. The decreasing trend of k values with increasing temperature indicates a faster inactivation of peroxidase from mangosteen pericarp at higher temperatures. The activation energy (Ea of 35.06 kJ/mol was calculated from the slope of Arrhenius plot. Thermodynamic parameters (∆H, ∆G, ∆S for inactivation of peroxidase at different temperatures (60-100°C were studied in detail. The results of this research will help to design pre-processing conditions of mangosteen pericarp as a source of antioxidants.

  14. Degradation of direct azo dye by Cucurbita pepo free and immobilized peroxidase. (United States)

    Boucherit, Nabila; Abouseoud, Mahmoud; Adour, Lydia


    Enzymatic decolourization of the azo dye, Direct Yellow (DY106) by Cucurbita pepo (courgette) peroxidase (CP) is a complex process, which is greatly affected by pH, temperature, enzyme activity and the concentrations of H2O2 and dye. Courgette peroxidase was extracted and its performance was evaluated by using the free-CP (FCP) and immobilized-CP (ICP) forms in the decolourization of DY106. Immobilization of peroxidase in calcium alginate beads was performed according to a strategy aiming to minimize enzyme leakage and keep its activity at a maximum value by optimizing sodium alginate content, enzyme loading and calcium chloride concentration. The initial conditions at which the highest DY106 decolourization yield was obtained were found at pH 2, temperature 20 degrees C, H2O2 dose 1 mmol/L (FCP) and 100 mmol/L (ICP). The highest decolourization rates were obtained for dye concentrations 50 mg/L (FCP) and 80 mg/L (ICP). Under optimal conditions, the FCP was able to decolorize more than 87% of the dye within 2 min. While with ICP, the decolourization yield was 75% within 15 min. The decolourization and removal of DY106 was proved by UV-Vis analysis. Fourier transform infrared (FT-IR) spectroscopy analysis was also performed on DY106 and enzymatic treatment precipitated byproduct.

  15. Peroxidase Activity in Poplar Inoculated with Compatible and Incompetent Isolates of Paxillus involutus

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    Full Text Available Peroxidase activity of the hybrid poplar Populus×canescens (Ait. Sm. (= P. tremula L. × P. alba L. inoculated with compatible and incompetent isolates of Paxillus involutus (Batsch Fr. was investigated. Screening of the ectomycorrhizal fungal isolates was initiated with exploration of mycelial growth characteristics and mycorrhizal ability in vitro with poplar. Both traits varied within the fungus although they did not seem to be genetically correlated. While isolates SCO1, NAU, and 031 grew faster than others, only isolates MAJ, SCO1, and 031 were able to form ectomycorrhiza with poplar. Isolates MAJ (compatible and NAU (incompetent were subsequently selected for further experiments. Activity of peroxidase, one of the defense-related enzymes, was examined in pure culture and short root components of compatible and incompetent interactions between poplar and P. involutus. Peroxidase activities increased significantly in poplar inoculated with incompetent isolate of the fungus compared to control, while induction of the same enzyme was not detected in compatible associations.

  16. Peroxidase of Brazilian Cerrado grass as an alternative for agro industrial waste treatment

    Directory of Open Access Journals (Sweden)

    Raquel Pinheiro Reis Souza Ramalho


    Full Text Available Decontamination of wastewater continues to be a challenge for society and the scientific community. Despite the availability of various materials for study, enzymes stand out due to their specificity for decomposition and biodegradability for disposal. New sources of enzymes may represent efficient and low-cost alternatives compared to routinely used techniques. In this survey, the peroxidase profile from Echinolaena inflexa fruits was studied for possible applications in the treatment of wastewater. The protein content was found to be 5.33 mg g-1. The optimum reaction conditions were: 50°C, pH 7.5 at 0.1 mol L-1 of phosphate buffer for 15 min. The enzyme was inactivated after 5 min at 94°C and was inhibited when incubated with ascorbic acid at 10 mmol L-1. In tests using phenols and agro industrial waste, the peroxidase was able to oxidase 87.5% of catechol, 67.8% of pyrogallol, 39.1% of resorcinol and still presented 29.1% of the degradation capacity of raw wastewater phenolic compounds. The results showed that the Echinolaena inflexa peroxidase, a new source of enzymes, is a potential alternative to wastewater treatment.

  17. The phylogeny of the mammalian heme peroxidases and the evolution of their diverse functions

    Directory of Open Access Journals (Sweden)

    Ó'Fágáin Ciarán


    Full Text Available Abstract Background The mammalian heme peroxidases (MHPs are a medically important group of enzymes. Included in this group are myeloperoxidase, eosinophil peroxidase, lactoperoxidase, and thyroid peroxidase. These enzymes are associated with such diverse diseases as asthma, Alzheimer's disease and inflammatory vascular disease. Despite much effort to elucidate a clearer understanding of the function of the 4 major groups of this multigene family, we still do not have a clear understanding of their relationships to each other. Results Sufficient signal exists for the resolution of the evolutionary relationships of this family of enzymes. We demonstrate, using a root mean squared deviation statistic, how the removal of the fastest evolving sites aids in the minimisation of the effect of long branch attraction and the generation of a highly supported phylogeny. Based on this phylogeny we have pinpointed the amino acid positions that have most likely contributed to the diverse functions of these enzymes. Many of these residues are in close proximity to sites implicated in protein misfolding, loss of function or disease. Conclusion Our analysis of all available genomic sequence data for the MHPs from all available completed mammalian genomes, involved sophisticated methods of phylogeny reconstruction and data treatment. Our study has (i fully resolved the phylogeny of the MHPs and the subsequent pattern of gene duplication, and (ii, we have detected amino acids under positive selection that have most likely contributed to the observed functional shifts in each type of MHP.

  18. Purification and characterization of novel cationic peroxidases from Asparagus acutifolius L. with biotechnological applications. (United States)

    Guida, Vincenzo; Cantarella, Maria; Chambery, Angela; Mezzacapo, Maria C; Parente, Augusto; Landi, Nicola; Severino, Valeria; Di Maro, Antimo


    Four novel basic peroxidases, named AaP-1, AaP-2, AaP-3, and AaP-4, were purified from Asparagus acutifolius L. seeds by cation-exchange and gel filtration chromatographies. The four proteins showed a similar electrophoretic mobility of 46 kDa while, by MALDI-TOF MS, different Mr values of 42758.3, 41586.9, 42796.3, and 41595.5 were determined for AaP-1, AaP-2, AaP-3, and AaP-4, respectively. N-terminal sequences of AaPs 1-4 up to residue 20 showed a high percentage of identity with the peroxidase from Glycine max. In addition, AaP-1, AaP-2, AaP-3, and AaP-4 were found to be glycoproteins, containing 21.75, 22.27, 25.62, and 18.31 % of carbohydrates, respectively. Peptide mapping and MALDI-TOF MS analysis of AaPs 1-4 showed that the structural differences between AaP-1 and AaP-2 and AaP-3 and AaPs-4 were mainly due to their glycan content. We also demonstrate that AaPs were able to remove phenolic compounds from olive oil mill wastewaters with a higher catalytic efficiency with respect to horseradish peroxidase, thus representing candidate enzymes for potential biotechnological applications in the environmental field.

  19. Arabidopsis peroxidase-catalyzed copolymerization of coniferyl and sinapyl alcohols: kinetics of an endwise process. (United States)

    Demont-Caulet, Nathalie; Lapierre, Catherine; Jouanin, Lise; Baumberger, Stéphanie; Méchin, Valérie


    In order to determine the mechanism of the earlier copolymerization steps of two main lignin precursors, sinapyl (S) alcohol and coniferyl (G) alcohol, microscale in vitro oxidations were carried out with a PRX34 Arabidopsis thaliana peroxidase in the presence of H(2)O(2). This plant peroxidase was found to have an in vitro polymerization activity similar to the commonly used horseradish peroxidase. The selected polymerization conditions lead to a bulk polymerization mechanism when G alcohol was the only phenolic substrate available. In the same conditions, the presence of S alcohol at a 50/50 S/G molar ratio turned this bulk mechanism into an endwise one. A kinetics monitoring (size-exclusion chromatography and liquid chromatography-mass spectrometry) of the different species formed during the first 24h oxidation of the S/G mixture allowed sequencing the bondings responsible for oligomerization. Whereas G homodimers and GS heterodimers exhibit low reactivity, the SS pinoresinol structure act as a nucleating site of the polymerization through an endwise process. This study is particularly relevant to understand the impact of S units on lignin structure in plants and to identify the key step at which this structure is programmed. Copyright © 2010 Elsevier Ltd. All rights reserved.

  20. Study on a hydrogen peroxide biosensor based on horseradish peroxidase/GNPs-thionine/chitosan

    International Nuclear Information System (INIS)

    Kang Xiaobin; Pang Guangchang; Liang Xinyi; Wang Meng; Liu Jing; Zhu Weiming


    Highlights: ► Glutaraldehyde was used as the bridge linking agent to covalently bonded thionine in chitosan, which is more stable and could effectively prevalent leakage of the electronic mediator. ► The effect of GNPs adsorbed HRP was first accurately characterized by bio-layer interferometry using the ForteBio Octer system. ► The application of self-assembly technology increases the biosensor stability. - Abstract: A novel hydrogen peroxide biosensor based on horseradish peroxidase/GNPs-thionine/chitosan has been developed. Gold nanoparticles fixed with horseradish peroxidase were adsorbed on glassy carbon electrode by the chitosan which cross-linked with the electron mediator of horseradish peroxidase as the bridge linking agent. The assembly procedures were monitored by UV–visible spectral scanning, bio-layer interferometry, cyclic voltammetric and alternating current impedance. The chronoamperometry was used to measure hydrogen peroxide. The hydrogen peroxide biosensor linear range of detection is 1 × 10 −7 –1 × 10 −4 mol/L, detection limit up to 5.0 × 10 −8 mol/L. Moreover the stability, reproducibility and selectivity of the biosensor were also studied and the results confirmed that the biosensor exhibit fast response to hydrogen peroxide and possess high sensitivity, good reproducibility and long-term stability.

  1. Quantitative proteomics reveals that peroxidases play key roles in post-flooding recovery in soybean roots. (United States)

    Khan, Mudassar Nawaz; Sakata, Katsumi; Hiraga, Susumu; Komatsu, Setsuko


    Soybean is an important legume crop that exhibits markedly reduced growth and yields under flooding conditions. To unravel the mechanisms involved in recovery after flooding in soybean root, gel-free proteomic analysis was performed. Morphological analysis revealed that growth suppression was more severe with increased flooding duration. Out of a total of 1645 and 1707 identified proteins, 73 and 21 proteins were changed significantly during the recovery stage following 2 and 4 days flooding, respectively. Based on the proteomic, clustering, and in silico protein-protein interaction analyses, six key enzymes were analyzed at the mRNA level. Lipoxygenase 1, which was increased at the protein level during the recovery period, was steadily down-regulated at the mRNA level. The peroxidase superfamily protein continuously increased in abundance during the course of recovery and was up-regulated at the mRNA level. HAD acid phosphatase was decreased at the protein level and down-regulated at the transcript level, while isoflavone reductase and an unknown protein were increased at both the protein and mRNA levels. Consistent with these findings, the enzymatic activity of peroxidase was decreased under flooding stress but increased significantly during the recovery sage. These results suggest that peroxidases might play key roles in post-flooding recovery in soybean roots through the scavenging of toxic radicals.

  2. New fluorimetric assay of horseradish peroxidase using sesamol as substrate and its application to EIA

    Directory of Open Access Journals (Sweden)

    Hidetoshi Arakawa


    Full Text Available Horseradish peroxidase (HRP is generally used as a label enzyme in enzyme immunoassay (EIA. The procedure used for HRP detection in EIA is critical for sensitivity and precision. This paper describes a novel fluorimetric assay for horseradish peroxidase (HRP using sesamol as substrate. The principle of the assay is as follow: sesamol (3,4-methylenedioxy phenol is reacted enzymatically in the presence of hydrogen peroxide to produce dimeric sesamol. The dimer is fluorescent and can be detected sensitively at ex. 347 nm, em. 427 nm.The measurable range of HRP was 1.0×10−18 to 1.0×10−15 mol/assay, with a detection limit of 1.0×10−18 mol/assay. The coefficient of variation (CV, n=8 was examined at each point on the standard curve, with a mean CV percentage of 3.8%. This assay system was applied to thyroid stimulating hormone (TSH EIA using HRP as the label enzyme. Keywords: Sesamol, Fluorescence, Enzyme immunoassay (EIA, Horseradish peroxidase (HRP, Thyroid stimulating hormone (TSH

  3. Not so monofunctional--a case of thermostable Thermobifida fusca catalase with peroxidase activity. (United States)

    Lončar, Nikola; Fraaije, Marco W


    Thermobifida fusca is a mesothermophilic organism known for its ability to degrade plant biomass and other organics, and it was demonstrated that it represents a rich resource of genes encoding for potent enzymes for biocatalysis. The thermostable catalase from T. fusca has been cloned and overexpressed in Escherichia coli with a yield of 400 mg/L. Heat treatment of disrupted cells at 60 °C for 1 h resulted in enzyme preparation of high purity; hence, no chromatography steps are needed for large-scale production. Except for catalyzing the dismutation of hydrogen peroxide, TfuCat was also found to catalyze oxidations of phenolic compounds. The catalase activity was comparable to other described catalases while peroxidase activity was quite remarkable with a k obs of nearly 1000 s(-1) for catechol. Site directed mutagenesis was used to alter the ratio of peroxidase/catalase activity. Resistance to inhibition by classic catalase inhibitors and an apparent melting temperature of 74 °C classifies this enzyme as a robust biocatalyst. As such, it could compete with other commercially available catalases while the relatively high peroxidase activity also offers new biocatalytic possibilities.

  4. Properties of catalase-peroxidase lacking its C-terminal domain

    International Nuclear Information System (INIS)

    Baker, Ruletha D.; Cook, Carma O.; Goodwin, Douglas C.


    Catalase-peroxidases have a two-domain structure. The N-terminal domain contains the bifunctional active site, but the function of the C-terminal domain is unknown. We produced catalase-peroxidase containing only its N-terminal domain (KatG Nterm ). Removal of the C-terminal domain did not result in unexpected changes in secondary structure as evaluated by CD, but KatG Nterm had neither catalase nor peroxidase activity. Partial recovery of both activities was achieved by incubating KatG Nterm with the separately expressed and isolated KatG C-terminal domain. Spectroscopic measurements revealed a shift in heme environment from a mixture of high-spin species (wtKatG) to exclusively hexacoordinate, low-spin (KatG Nterm ). Moreover, a >1000-fold lower k on for CN - binding was observed for KatG Nterm . EPR spectra for KatG Nterm and the results of site-specific substitution of active site histidines suggested that the distal histidine was the sixth ligand. Thus, one important role for the C-terminal domain may be to support the architecture of the active site, preventing heme ligation by this catalytically essential residue

  5. Effects of ageing on peroxidase activity and localization in radish (Raphanus sativus L. seeds

    Directory of Open Access Journals (Sweden)

    A. Scialabba


    Full Text Available Peroxidase activity was assayed in crude extracts of integument, cotyledons and embryo axis of radish seeds, deteriorated under accelerated ageing conditions. Over five days of ageing, in which germination decreased from 100 to 52%, the enzyme activity in integument was higher than that in other seed parts, increasing in the first days of ageing and then decreasing sharply in extremely aged seeds. Polyacrylamide gel electrophoresis analysis showed four peroxidase isoenzymes with MM of 98, 52.5, 32.8 and 29.5 kDa in the embryo axis of unaged seeds, and only the 32.8 and 29.5 kDa MM isoforms in the integument and cotyledons. In these parts of the seed, only the 29.5 kDa MM isoenzyme increased in activity in early days of ageing and decreased thereafter. In the embryo axis, the 29.5 kDa MM isoenzyme activity increased slowly in the first day of ageing, while the 98 and 52.5 kDa MM isoenzyme activities disappeared. A cytochemical localization of peroxidase activity in the various tissues showed that main differences between unaged and extremely aged seeds occurred in the embryo axis.

  6. Study of Horseradish Peroxidase Fixed on Mesoporous Materials as a Chemical Reaction Catalyst (United States)

    Gao, Mengdan; Dai, Rongji


    Nanostructured mesoporous materials is a new type of porous materials, which has been widely used. It has excellent capability in enzymes immobilization, but modification on the chemical bonds of the enzyme reduce the enzymatic activity and rarely used in chemical reactions. The horseradish peroxidase was immobilized on the mesoporous materials with appropriate aperture and its activity and stability was evaluated when catalyzing the nitration reaction of amines and oxidation reaction of thiourea. The optimum mesoporous material to fix the horseradish peroxidase can be obtained by mixing polyoxyethylene - polyoxypropylene-pol, yoxyethylene(P123), 1,3,5-trimethylbenzene(TMB), and tetramethoxysilane (TMOS) at a ratio of 10:1:1, whose surface area and pore volume and pore diameter calculated by BET and BJH model were 402.903m2/g, 1.084cm2/g, 1.084cm2/g respectively. The horseradish peroxidase, immobilized on the mesoporous materials, was applied for catalyzing the nitration reaction of anilines and oxidation reaction of thiourea, produced a high product yield and can be recycled. Thus, it is a strong candidate as a catalysts for oxidation reactions, to be produced at industral scale, due to its high efficiency and low cost.

  7. Chinese hamster ovary cell lysosomes retain pinocytized horseradish peroxidase and in situ-radioiodinated proteins

    International Nuclear Information System (INIS)

    Storrie, B.; Sachdeva, M.; Viers, V.S.


    We used Chinese hamster ovary cells, a cell line of fibroblastic origin, to investigate whether lysosomes are an exocytic compartment. To label lysosomal contents, Chinese hamster ovary cells were incubated with the solute marker horseradish peroxidase. After an 18-h uptake period, horseradish peroxidase was found in lysosomes by cell fractionation in Percoll gradients and by electron microscope cytochemistry. Over a 24-h period, lysosomal horseradish peroxidase was quantitatively retained by Chinese hamster ovary cells and inactivated with a t 1/2 of 6 to 8 h. Lysosomes were radioiodinated in situ by soluble lactoperoxidase internalized over an 18-h uptake period. About 70% of the radioiodine incorporation was pelleted at 100,000 X g under conditions in which greater than 80% of the lysosomal marker enzyme beta-hexosaminidase was released into the supernatant. By one-dimensional electrophoresis, about 18 protein species were present in the lysosomal membrane fraction, with radioiodine incorporation being most pronounced into species of 70,000 to 75,000 daltons. After a 30-min or 2-h chase at 37 degrees C, radioiodine that was incorporated into lysosomal membranes and contents was retained in lysosomes. These observations indicate that lysosomes labeled by fluid-phase pinocytosis are a terminal component of endocytic pathways in fibroblasts

  8. Steroid-Responsive Chronic Schizophreniform Syndrome in the Context of Mildly Increased Antithyroid Peroxidase Antibodies

    Directory of Open Access Journals (Sweden)

    Ludger Tebartz van Elst


    Full Text Available BackgroundSchizophreniform syndromes can be divided into primary forms from polygenic causes or secondary forms due to immunological, epileptiform, monogenic, or degenerative causes. Steroid-responsive encephalopathy associated with autoimmune thyroiditis (SREAT is a secondary immunological form associated with increased thyroid antibodies, such as antithyroid peroxidase antibodies and shows a good response to corticosteroids.Case presentationWe present the case of a 41-year-old woman suffering from a schizophreniform syndrome. Starting at the age of 35, she developed psychotic exacerbations with formal thought disorder, acoustic hallucinations, cenesthopathic experiences, and loss of ego boundaries. At the same time, she began to suffer from chronic sexual delusions and olfactory hallucinations, which did not respond to neuroleptic medication. Her levels of antithyroid peroxidase antibodies were slightly increased, and the blood–brain barrier was disturbed. An electroencephalogram (EEG showed intermittent generalized slowing, and cerebral magnetic resonance imaging (cMRI depicted mild temporolateral atrophy. High-dose corticosteroid treatment led to convincing improvement of attentional performance and the disappearance of delusions and olfactory hallucinations.ConclusionSREAT can mimic typical symptoms of schizophreniform syndromes. The increased titer of antithyroid peroxidase antibodies in combination with the EEG slowing, blood–brain barrier dysfunction, and the cMRI alterations were the basis for suspecting an immunological cause in our patient. Chronic delusions, olfactory hallucinations, and cognitive deficits were successfully treated with corticosteroids. The occurrence of secondary immunological forms of schizophreniform syndromes demonstrates the need for innovative immunosuppressive treatment options.

  9. Purification and characterization of peroxidase from cauliflower (Brassica oleracea L. var. botrytis) buds. (United States)

    Köksal, Ekrem; Gülçin, Ilhami


    Peroxidases (EC; donor: hydrogen peroxide oxidoreductase) are part of a large group of enzymes. In this study, peroxidase, a primer antioxidant enzyme, was purified with 19.3 fold and 0.2% efficiency from cauliflower (Brassica oleracea L.) by ammonium sulphate precipitation, dialysis, CM-Sephadex ion-exchange chromatography and Sephadex G-25 purification steps. The substrate specificity of peroxidase was investigated using 2,2'-azino-bis(3-ethylbenz-thiazoline-6-sulphonic acid) (ABTS), 2-methoxyphenol (guaiacol), 1,2-dihydroxybenzene (catechol), 1,2,3-trihyidroxybenzene (pyrogallol) and 4-methylcatechol. Also, optimum pH, optimum temperature, optimum ionic strength, stable pH, stable temperature, thermal inactivation conditions were determined for guaiacol/H(2)O(2), pyrogallol/H(2)O(2), ABTS/H(2)O(2), catechol/H(2)O(2) and 4-methyl catechol/H(2)O(2) substrate patterns. The molecular weight (M(w)) of this enzyme was found to be 44 kDa by gel filtration chromatography method. Native polyacrylamide gel electrophoresis (PAGE) was performed for isoenzyme determination and a single band was observed. K(m) and V(max) values were calculated from Lineweaver-Burk graph for each substrate patterns.

  10. Phenol remediation by peroxidase from an invasive mesquite: Turning an environmental wound into wisdom. (United States)

    Singh, Savita; Mishra, Ruchi; Sharma, Radhey Shyam; Mishra, Vandana


    The present study examines mesquite (Prosopis juliflora), an invasive species, to yield peroxidase that may reduce hazards of phenolics to living organisms. As low as 0.3U of low-purity mesquite peroxidase (MPx) efficiently remove phenol and chlorophenols (90-92%) compared with Horseradish peroxidase (HRP) (40-60%). MPx shows a very high removal efficiency (40-50%) at a wide range of pH (2-9) and temperature (20-80°C), as opposed to HRP (15-20%). At a high-level of the substrate (2.4mM) and without the addition of PEG, MPx maintains a significant phenolic removal (60-≥92%) and residual activity (∼25%). It proves the superiority of MPx over HRP, which showed insignificant removal (10-12%) under similar conditions, and no residual activity even with PEG addition. The root elongation and plant growth bioassays confirm phenolic detoxification by MPx. Readily availability of mesquite across the countries and easy preparation of MPx from leaves make this tree as a sustainable source for a low-technological solution for phenol remediation. This study is the first step towards converting a biological wound of invasive species into wisdom and strength for protecting the environment from phenol pollution. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. A Novel Colorimetric Immunoassay Utilizing the Peroxidase Mimicking Activity of Magnetic Nanoparticles

    Directory of Open Access Journals (Sweden)

    Hyun Gyu Park


    Full Text Available A simple colorimetric immunoassay system, based on the peroxidase mimicking activity of Fe3O4 magnetic nanoparticles (MNPs, has been developed to detect clinically important antigenic molecules. MNPs with ca. 10 nm in diameter were synthesized and conjugated with specific antibodies against target molecules, such as rotaviruses and breast cancer cells. Conjugation of the MNPs with antibodies (MNP-Abs enabled specific recognition of the corresponding target antigenic molecules through the generation of color signals arising from the colorimetric reaction between the selected peroxidase substrate, 3,3',5,5'-tetramethylbenzidine (TMB and H2O2. Based on the MNP-promoted colorimetric reaction, the target molecules were detected and quantified by measuring absorbance intensities corresponding to the oxidized form of TMB. Owing to the higher stabilities and economic feasibilities of MNPs as compared to horseradish peroxidase (HRP, the new colorimetric system employing MNP-Abs has the potential of serving as a potent immunoassay that should substitute for conventional HRP-based immunoassays. The strategy employed to develop the new methodology has the potential of being extended to the construction of simple diagnostic systems for a variety of biomolecules related to human cancers and infectious diseases, particularly in the realm of point-of-care applications.

  12. The crystal structures of the tryparedoxin-tryparedoxin peroxidase couple unveil the structural determinants of Leishmania detoxification pathway.

    Directory of Open Access Journals (Sweden)

    Annarita Fiorillo

    Full Text Available Leishmaniasis is a neglected disease caused by Leishmania, an intracellular protozoan parasite which possesses a unique thiol metabolism based on trypanothione. Trypanothione is used as a source of electrons by the tryparedoxin/tryparedoxin peroxidase system (TXN/TXNPx to reduce the hydroperoxides produced by macrophages during infection. This detoxification pathway is not only unique to the parasite but is also essential for its survival; therefore, it constitutes a most attractive drug target. Several forms of TXNPx, with very high sequence identity to one another, have been found in Leishmania strains, one of which has been used as a component of a potential anti-leishmanial polyprotein vaccine. The structures of cytosolic TXN and TXNPx from L. major (LmTXN and LmTXNPx offer a unique opportunity to study peroxide reduction in Leishmania parasites at a molecular level, and may provide new tools for multienzyme inhibition-based drug discovery. Structural analyses bring out key structural features to elucidate LmTXN and LmTXNPx function. LmTXN displays an unusual N-terminal α-helix which allows the formation of a stable domain-swapped dimer. In LmTXNPx, crystallized in reducing condition, both the locally unfolded (LU and fully folded (FF conformations, typical of the oxidized and reduced protein respectively, are populated. The structural analysis presented here points to a high flexibility of the loop that includes the peroxidatic cysteine which facilitates Cys52 to form an inter-chain disulfide bond with the resolving cysteine (Cys173, thereby preventing over-oxidation which would inactivate the enzyme. Analysis of the electrostatic surface potentials of both LmTXN and LmTXNPx unveils the structural elements at the basis of functionally relevant interaction between the two proteins. Finally, the structural analysis of TXNPx allows us to identify the position of the epitopes that make the protein antigenic and therefore potentially suitable

  13. LMDS Lightweight Modular Display System. (United States)


    based on standard functions. This means that the cost to produce a particular display function can be met in the most economical fashion and at the same...not mean that the NTDS interface would be eliminated. What is anticipated is the use of ETHERNET at a low level of system interface, ie internal to...GENERATOR dSYMBOL GEN eCOMMUNICATION 3-2 The architecture of the unit’s (fig 3-4) input circuitry is based on a video table look-up ROM. The function

  14. Displaying Annotations for Digitised Globes (United States)

    Gede, Mátyás; Farbinger, Anna


    Thanks to the efforts of the various globe digitising projects, nowadays there are plenty of old globes that can be examined as 3D models on the computer screen. These globes usually contain a lot of interesting details that an average observer would not entirely discover for the first time. The authors developed a website that can display annotations for such digitised globes. These annotations help observers of the globe to discover all the important, interesting details. Annotations consist of a plain text title, a HTML formatted descriptive text and a corresponding polygon and are stored in KML format. The website is powered by the Cesium virtual globe engine.

  15. DP: Parameter Display Page Program

    International Nuclear Information System (INIS)

    Anderson, M.


    The Parameter Display Page program (DP) is a Motif/X11-based program to allow easily configured, dynamic device and process variable monitoring and manipulation in the EPICS environment. DP provides a tabular data format for interactive viewing and manipulation of device and process variable statistics, as well as formatted PostScript output to files and printers. DP understands and operates in two (unfortunately disjoint at this time) namespaces in the EPICS environment ''devices'' and ''process variables''. The higher level namespace of devices includes Composite and Atomic Devices registered via the Device Access server; the lower level (flat) namespace is that of normal Process Variables accessible via Channel Access

  16. Nanobody-Displaying Flagellar Nanotubes. (United States)

    Klein, Ágnes; Kovács, Mátyás; Muskotál, Adél; Jankovics, Hajnalka; Tóth, Balázs; Pósfai, Mihály; Vonderviszt, Ferenc


    In this work we addressed the problem how to fabricate self-assembling tubular nanostructures displaying target recognition functionalities. Bacterial flagellar filaments, composed of thousands of flagellin subunits, were used as scaffolds to display single-domain antibodies (nanobodies) on their surface. As a representative example, an anti-GFP nanobody was successfully inserted into the middle part of flagellin replacing the hypervariable surface-exposed D3 domain. A novel procedure was developed to select appropriate linkers required for functional internal insertion. Linkers of various lengths and conformational properties were chosen from a linker database and they were randomly attached to both ends of an anti-GFP nanobody to facilitate insertion. Functional fusion constructs capable of forming filaments on the surface of flagellin-deficient host cells were selected by magnetic microparticles covered by target GFP molecules and appropriate linkers were identified. TEM studies revealed that short filaments of 2-900 nm were formed on the cell surface. ITC and fluorescent measurements demonstrated that the fusion protein exhibited high binding affinity towards GFP. Our approach allows the development of functionalized flagellar nanotubes against a variety of important target molecules offering potential applications in biosensorics and bio-nanotechnology.

  17. Reactor power peaking information display

    International Nuclear Information System (INIS)

    Book, T.L.; Kochendarfer, R.A.


    This patent describes a system for monitoring operating conditions within a nuclear reactor. The system consists of a method for measuring the operating parameters within the nuclear reactor, including the position of axial power shaping rods and regulating control rod. It also includes a method for determining from the operating parameters the operating limits before a power peaking condition exists within the nuclear reactor, and a method for displaying the operating limits which consists of a visual display permitting the continuous monitoring of the operating conditions within the nuclear reactor as a graph of the shaping rod position vs the regulating rod position having a permissible area and a restricted area. The permissible area is further divided into a recommended operating area for steady state operation and a cursor located on the graph to indicate the present operating condition of the nuclear reactor to allow an operator to view any need for corrective action based on the movement of the cursor out of the recommended operating area and to take any corrective transient action within the permissible area

  18. Optical display for radar sensing (United States)

    Szu, Harold; Hsu, Charles; Willey, Jefferson; Landa, Joseph; Hsieh, Minder; Larsen, Louis V.; Krzywicki, Alan T.; Tran, Binh Q.; Hoekstra, Philip; Dillard, John T.; Krapels, Keith A.; Wardlaw, Michael; Chu, Kai-Dee


    Boltzmann headstone S = kB Log W turns out to be the Rosette stone for Greek physics translation optical display of the microwave sensing hieroglyphics. The LHS is the molecular entropy S measuring the degree of uniformity scattering off the sensing cross sections. The RHS is the inverse relationship (equation) predicting the Planck radiation spectral distribution parameterized by the Kelvin temperature T. Use is made of the conservation energy law of the heat capacity of Reservoir (RV) change T Δ S = -ΔE equals to the internal energy change of black box (bb) subsystem. Moreover, an irreversible thermodynamics Δ S > 0 for collision mixing toward totally larger uniformity of heat death, asserted by Boltzmann, that derived the so-called Maxwell-Boltzmann canonical probability. Given the zero boundary condition black box, Planck solved a discrete standing wave eigenstates (equation). Together with the canonical partition function (equation) an average ensemble average of all possible internal energy yielded the celebrated Planck radiation spectral (equation) where the density of states (equation). In summary, given the multispectral sensing data (equation), we applied Lagrange Constraint Neural Network (LCNN) to solve the Blind Sources Separation (BSS) for a set of equivalent bb target temperatures. From the measurements of specific value, slopes and shapes we can fit a set of Kelvin temperatures T's for each bb targets. As a result, we could apply the analytical continuation for each entropy sources along the temperature-unique Planck spectral curves always toward the RGB color temperature display for any sensing probing frequency.

  19. Simulated monitor display for CCTV

    International Nuclear Information System (INIS)

    Steele, B.J.


    Two computer programs have been developed which generate a two-dimensional graphic perspective of the video output produced by a Closed Circuit Television (CCTV) camera. Both programs were primarily written to produce a graphic display simulating the field-of-view (FOV) of a perimeter assessment system as seen on a CCTV monitor. The original program was developed for use on a Tektronix 4054 desktop computer; however, the usefulness of this graphic display program led to the development of a similar program for a Hewlett-Packard 9845B desktop computer. After entry of various input parameters, such as, camera lens and orientation, the programs automatically calculate and graphically plot the locations of various items, e.g., fences, an assessment zone, running men, and intrusion detection sensors. Numerous special effects can be generated to simulate such things as roads, interior walls, or sides of buildings. Other objects can be digitized and entered into permanent memory similar to the running men. With this type of simulated monitor perspective, proposed camera locations with respect to fences and a particular assessment zone can be rapidly evaluated without the costly time delays and expenditures associated with field evaluation

  20. Thyroid peroxidase antibodies in pregnant women with type 1 diabetes: impact on thyroid function, metabolic control and pregnancy outcome

    DEFF Research Database (Denmark)

    Vestgaard, Marianne; Nielsen, Lene Ringholm; Rasmussen, Åse Krogh


    In pregnant women with type 1 diabetes, we evaluated whether the presence of thyroid peroxidase autoantibodies (anti-TPO) was associated with changes in thyroid function, metabolic control and pregnancy outcome....