WorldWideScience

Sample records for evaluating enzyme cascades

  1. Substrate-driven chemotactic assembly in an enzyme cascade

    Science.gov (United States)

    Zhao, Xi; Palacci, Henri; Yadav, Vinita; Spiering, Michelle M.; Gilson, Michael K.; Butler, Peter J.; Hess, Henry; Benkovic, Stephen J.; Sen, Ayusman

    2018-03-01

    Enzymatic catalysis is essential to cell survival. In many instances, enzymes that participate in reaction cascades have been shown to assemble into metabolons in response to the presence of the substrate for the first enzyme. However, what triggers metabolon formation has remained an open question. Through a combination of theory and experiments, we show that enzymes in a cascade can assemble via chemotaxis. We apply microfluidic and fluorescent spectroscopy techniques to study the coordinated movement of the first four enzymes of the glycolysis cascade: hexokinase, phosphoglucose isomerase, phosphofructokinase and aldolase. We show that each enzyme independently follows its own specific substrate gradient, which in turn is produced by the preceding enzymatic reaction. Furthermore, we find that the chemotactic assembly of enzymes occurs even under cytosolic crowding conditions.

  2. Process Evaluation Tools for Enzymatic Cascades Welcome Message

    DEFF Research Database (Denmark)

    Abu, Rohana

    improvement and implementation. Hence, the goal of this thesis is to evaluate the process concepts in enzymatic cascades in a systematic manner, using tools such as thermodynamic and kinetic analysis. Three relevant case studies have been used to exemplify the approach. In the first case study, thermodynamic......Biocatalysis is attracting significant attention from both academic and industrial scientists due to the excellent capability of enzyme to catalyse selective reactions. Recently, much interest has been shown in the application of enzymatic cascades as a useful tool in organic synthesis......, the kinetics can be controlled in a highly efficient way to achieve a sufficiently favourable conversion to a given target product. This is exemplified in the second case study, in the kinetic modelling of the formation of 2-ketoglutarate from glucoronate, the second case study. This cascade consists of 4...

  3. Exquisite Enzyme-Fenton Biomimetic Catalysts for Hydroxyl Radical Production by Mimicking an Enzyme Cascade.

    Science.gov (United States)

    Zhang, Qi; Chen, Shuo; Wang, Hua; Yu, Hongtao

    2018-03-14

    Hydrogen peroxide (H 2 O 2 ) is a key reactant in the Fenton process. As a byproduct of enzymatic reaction, H 2 O 2 can be obtained via catalytical oxidation of glucose using glucose oxidase in the presence of O 2 . Another oxidation product (gluconic acid) can suitably adjust the microenvironmental pH contributing to the Fe 3+ /Fe 2+ cycle in the Fenton reaction. Enzymes are extremely efficient at catalyzing a variety of reactions with high catalytic activity, substrate specificity, and yields in living organisms. Inspired by the multiple functions of natural multienzyme systems, an exquisite nanozyme-modified α-FeOOH/porous carbon (PC) biomimetic catalyst constructed by in situ growth of glucose oxidase-mimicking Au nanoparticles and crystallization of adsorbed ferric ions within carboxyl into hierarchically PC is developed as an efficient enzyme-Fenton catalyst. The products (H 2 O 2 , ∼4.07 mmol·L -1 ) of the first enzymatic reaction are immediately used as substrates for the second Fenton-like reaction to generate the valuable • OH (∼96.84 μmol·L -1 ), thus mimicking an enzyme cascade pathway. α-FeOOH nanocrystals, attached by C-O-Fe bondings, are encapsulated into the mesoporous PC frameworks, facilitating the electron transfer between α-FeOOH and the PC support and greatly suppressing iron leaching. This study paves a new avenue for designing biomimetic enzyme-based Fenton catalysts mimicking a natural system for • OH production.

  4. Mesoporous silica-encapsulated gold nanoparticles as artificial enzymes for self-activated cascade catalysis.

    Science.gov (United States)

    Lin, Youhui; Li, Zhenhua; Chen, Zhaowei; Ren, Jinsong; Qu, Xiaogang

    2013-04-01

    A significant challenge in chemistry is to create synthetic structures that mimic the complexity and function of natural systems. Here, a self-activated, enzyme-mimetic catalytic cascade has been realized by utilizing expanded mesoporous silica-encapsulated gold nanoparticles (EMSN-AuNPs) as both glucose oxidase- and peroxidase-like artificial enzymes. Specifically, EMSN helps the formation of a high degree of very small and well-dispersed AuNPs, which exhibit an extraordinarily stability and dual enzyme-like activities. Inspired by these unique and attractive properties, we further piece them together into a self-organized artificial cascade reaction, which is usually completed by the oxidase-peroxidase coupled enzyme system. Our finding may pave the way to use matrix as the structural component for the design and development of biomimetic catalysts and to apply enzyme mimics for realizing higher functions. Copyright © 2013 Elsevier Ltd. All rights reserved.

  5. Coupled reactions by coupled enzymes : alcohol to lactone cascade with alcohol dehydrogenase-cyclohexanone monooxygenase fusions

    NARCIS (Netherlands)

    Aalbers, Friso S; Fraaije, Marco W

    2017-01-01

    The combination of redox enzymes for redox-neutral cascade reactions has received increasing appreciation. An example is the combination of an alcohol dehydrogenase (ADH) with a cyclohexanone monooxygenase (CHMO). The ADH can use NADP(+) to oxidize cyclohexanol to form cyclohexanone and NADPH. Both

  6. Cascade catalysis in membranes with enzyme immobilization for multienzymatic conversion of CO2 to methanol

    DEFF Research Database (Denmark)

    Luo, Jianquan; Meyer, Anne S.; Mateiu, Ramona Valentina

    2015-01-01

    .e. by directing membrane fouling formation), without any addition of organic solvent. Such coimmobilization and sequential immobilization systems were examined for the production of methanol from CO2 with formate dehydrogenase (FDH), formaldehyde dehydrogenase (FaldDH) and alcohol dehydrogenase (ADH). Enzyme...... for multi-enzymatic cascade systems, but also reveals the reaction bottleneck and provides possible solutions for the bioconversion of CO2 to methanol....

  7. Synthesis of non-natural carbohydrates from glycerol and aldehydes in a one-pot four-enzyme cascade reaction

    NARCIS (Netherlands)

    Babich, L.; Hartog, L.; Falcicchio, P.; Oost, van der J.

    2011-01-01

    A simple procedure has been developed for the synthesis of enantio- and diastereomerically pure carbohydrate analogues from glycerol and a variety of aldehydes in one pot using a four-enzyme cascade reaction. As a proof of concept of the usefulness of this enzymatic catalytic cascade the naturally

  8. 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.

    2017-01-01

    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

  9. A Cascade of Thermophilic Enzymes As an Approach to the Synthesis of Modified Nucleotides.

    Science.gov (United States)

    Esipov, R S; Abramchik, Yu A; Fateev, I V; Konstantinova, I D; Kostromina, M A; Muravyova, T I; Artemova, K G; Miroshnikov, A I

    2016-01-01

    We propose a new approach for the synthesis of biologically important nucleotides which includes a multi-enzymatic cascade conversion of D -pentoses into purine nucleotides. The approach exploits nucleic acid exchange enzymes from thermophilic microorganisms: ribokinase, phosphoribosylpyrophosphate synthetase, and adenine phosphoribosyltransferase. We cloned the ribokinase gene from Thermus sp . 2.9, as well as two different genes of phosphoribosylpyrophosphate synthetase (PRPP-synthetase) and the adenine phosphoribosyltransferase (APR-transferase) gene from Thermus thermophilus HB27 into the expression vectors, generated high-yield E. coli producer strains, developed methods for the purification of the enzymes, and investigated enzyme substrate specificity. The enzymes were used for the conversion of D -pentoses into 5-phosphates that were further converted into 5-phospho-α- D -pentofuranose 1-pyrophosphates by means of ribokinase and PRPP-synthetases. Target nucleotides were obtained through the condensation of the pyrophosphates with adenine and its derivatives in a reaction catalyzed by APR-transferase. 2-Chloro- and 2-fluoroadenosine monophosphates were synthesized from D -ribose and appropriate heterobases in one pot using a system of thermophilic enzymes in the presence of ATP, ribokinase, PRPP-synthetase, and APR-transferase.

  10. Real-time monitoring of enzyme-free strand displacement cascades by colorimetric assays

    Science.gov (United States)

    Duan, Ruixue; Wang, Boya; Hong, Fan; Zhang, Tianchi; Jia, Yongmei; Huang, Jiayu; Hakeem, Abdul; Liu, Nannan; Lou, Xiaoding; Xia, Fan

    2015-03-01

    The enzyme-free toehold-mediated strand displacement reaction has shown potential for building programmable DNA circuits, biosensors, molecular machines and chemical reaction networks. Here we report a simple colorimetric method using gold nanoparticles as signal generators for the real-time detection of the product of the strand displacement cascade. During the process the assembled gold nanoparticles can be separated, resulting in a color change of the solution. This assay can also be applied in complex mixtures, fetal bovine serum, and to detect single-base mismatches. These results suggest that this method could be of general utility to monitor more complex enzyme-free strand displacement reaction-based programmable systems or for further low-cost diagnostic applications.The enzyme-free toehold-mediated strand displacement reaction has shown potential for building programmable DNA circuits, biosensors, molecular machines and chemical reaction networks. Here we report a simple colorimetric method using gold nanoparticles as signal generators for the real-time detection of the product of the strand displacement cascade. During the process the assembled gold nanoparticles can be separated, resulting in a color change of the solution. This assay can also be applied in complex mixtures, fetal bovine serum, and to detect single-base mismatches. These results suggest that this method could be of general utility to monitor more complex enzyme-free strand displacement reaction-based programmable systems or for further low-cost diagnostic applications. Electronic supplementary information (ESI) available: Experimental procedures and analytical data are provided. See DOI: 10.1039/c5nr00697j

  11. Coordination of gene expression of arachidonic and docosahexaenoic acid cascade enzymes during human brain development and aging.

    Science.gov (United States)

    Ryan, Veronica H; Primiani, Christopher T; Rao, Jagadeesh S; Ahn, Kwangmi; Rapoport, Stanley I; Blanchard, Helene

    2014-01-01

    The polyunsaturated arachidonic and docosahexaenoic acids (AA and DHA) participate in cell membrane synthesis during neurodevelopment, neuroplasticity, and neurotransmission throughout life. Each is metabolized via coupled enzymatic reactions within separate but interacting metabolic cascades. AA and DHA pathway genes are coordinately expressed and underlie cascade interactions during human brain development and aging. The BrainCloud database for human non-pathological prefrontal cortex gene expression was used to quantify postnatal age changes in mRNA expression of 34 genes involved in AA and DHA metabolism. Expression patterns were split into Development (0 to 20 years) and Aging (21 to 78 years) intervals. Expression of genes for cytosolic phospholipases A2 (cPLA2), cyclooxygenases (COX)-1 and -2, and other AA cascade enzymes, correlated closely with age during Development, less so during Aging. Expression of DHA cascade enzymes was less inter-correlated in each period, but often changed in the opposite direction to expression of AA cascade genes. Except for the PLA2G4A (cPLA2 IVA) and PTGS2 (COX-2) genes at 1q25, highly inter-correlated genes were at distant chromosomal loci. Coordinated age-related gene expression during the brain Development and Aging intervals likely underlies coupled changes in enzymes of the AA and DHA cascades and largely occur through distant transcriptional regulation. Healthy brain aging does not show upregulation of PLA2G4 or PTGS2 expression, which was found in Alzheimer's disease.

  12. Coordination of gene expression of arachidonic and docosahexaenoic acid cascade enzymes during human brain development and aging.

    Directory of Open Access Journals (Sweden)

    Veronica H Ryan

    Full Text Available The polyunsaturated arachidonic and docosahexaenoic acids (AA and DHA participate in cell membrane synthesis during neurodevelopment, neuroplasticity, and neurotransmission throughout life. Each is metabolized via coupled enzymatic reactions within separate but interacting metabolic cascades.AA and DHA pathway genes are coordinately expressed and underlie cascade interactions during human brain development and aging.The BrainCloud database for human non-pathological prefrontal cortex gene expression was used to quantify postnatal age changes in mRNA expression of 34 genes involved in AA and DHA metabolism.Expression patterns were split into Development (0 to 20 years and Aging (21 to 78 years intervals. Expression of genes for cytosolic phospholipases A2 (cPLA2, cyclooxygenases (COX-1 and -2, and other AA cascade enzymes, correlated closely with age during Development, less so during Aging. Expression of DHA cascade enzymes was less inter-correlated in each period, but often changed in the opposite direction to expression of AA cascade genes. Except for the PLA2G4A (cPLA2 IVA and PTGS2 (COX-2 genes at 1q25, highly inter-correlated genes were at distant chromosomal loci.Coordinated age-related gene expression during the brain Development and Aging intervals likely underlies coupled changes in enzymes of the AA and DHA cascades and largely occur through distant transcriptional regulation. Healthy brain aging does not show upregulation of PLA2G4 or PTGS2 expression, which was found in Alzheimer's disease.

  13. Combined cross-linked enzyme aggregates of horseradish peroxidase and glucose oxidase for catalyzing cascade chemical reactions.

    Science.gov (United States)

    Nguyen, Le Truc; Yang, Kun-Lin

    2017-05-01

    Cascade reactions involved unstable intermediates are often encountered in biological systems. In this study, we developed combined cross-linked enzyme aggregates (combi-CLEA) to catalyze a cascade reaction which involves unstable hydrogen peroxide as an intermediate. The combi-CLEA contains two enzymes̶ glucose oxidase (GOx) and horseradish peroxidase (HRP) which are cross-linked together as solid aggregates. The first enzyme GOx catalyzes the oxidation of glucose and produces hydrogen peroxide, which is used by the second enzyme HRP to oxidize 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS). The apparent reaction rate of the cascade reaction reaches 10.5±0.5μM/min when the enzyme ratio is 150:1 (GOx:HRP). Interestingly, even in the presence of catalase, an enzyme that quickly decomposes hydrogen peroxide, the reaction rate only decreases by 18.7% to 8.3±0.3μM/min. This result suggests that the intermediate hydrogen peroxide is not decomposed by catalase due to a short diffusion distance between GOx and HRP in the combi-CLEA. Scanning electron microscopy images suggest that combi-CLEA particles are hollow spheres and have an average diameter around 250nm. Because of their size, combi-CLEA particles can be entrapped inside a nylon membrane for detecting glucose by using the cascade reaction. Copyright © 2017 Elsevier Inc. All rights reserved.

  14. Conversion of alcohols to enantiopure amines through dual-enzyme hydrogen-borrowing cascades.

    Science.gov (United States)

    Mutti, Francesco G; Knaus, Tanja; Scrutton, Nigel S; Breuer, Michael; Turner, Nicholas J

    2015-09-25

    α-Chiral amines are key intermediates for the synthesis of a plethora of chemical compounds at industrial scale. We present a biocatalytic hydrogen-borrowing amination of primary and secondary alcohols that allows for the efficient and environmentally benign production of enantiopure amines. The method relies on a combination of two enzymes: an alcohol dehydrogenase (from Aromatoleum sp., Lactobacillus sp., or Bacillus sp.) operating in tandem with an amine dehydrogenase (engineered from Bacillus sp.) to aminate a structurally diverse range of aromatic and aliphatic alcohols, yielding up to 96% conversion and 99% enantiomeric excess. Primary alcohols were aminated with high conversion (up to 99%). This redox self-sufficient cascade possesses high atom efficiency, sourcing nitrogen from ammonium and generating water as the sole by-product. Copyright © 2015, American Association for the Advancement of Science.

  15. Non-complexed four cascade enzyme mixture: simple purification and synergetic co-stabilization.

    Directory of Open Access Journals (Sweden)

    Suwan Myung

    Full Text Available Cell-free biosystems comprised of synthetic enzymatic pathways would be a promising biomanufacturing platform due to several advantages, such as high product yield, fast reaction rate, easy control and access, and so on. However, it was essential to produce (purified enzymes at low costs and stabilize them for a long time so to decrease biocatalyst costs. We studied the stability of the four recombinant enzyme mixtures, all of which originated from thermophilic microorganisms: triosephosphate isomerase (TIM from Thermus thermophiles, fructose bisphosphate aldolase (ALD from Thermotoga maritima, fructose bisphosphatase (FBP from T. maritima, and phosphoglucose isomerase (PGI from Clostridium thermocellum. It was found that TIM and ALD were very stable at evaluated temperature so that they were purified by heat precipitation followed by gradient ammonia sulfate precipitation. In contrast, PGI was not stable enough for heat treatment. In addition, the stability of a low concentration PGI was enhanced by more than 25 times in the presence of 20 mg/L bovine serum albumin or the other three enzymes. At a practical enzyme loading of 1000 U/L for each enzyme, the half-life time of free PGI was prolong to 433 h in the presence of the other three enzymes, resulting in a great increase in the total turn-over number of PGI to 6.2×10(9 mole of product per mole of enzyme. This study clearly suggested that the presence of other proteins had a strong synergetic effect on the stabilization of the thermolabile enzyme PGI due to in vitro macromolecular crowding effect. Also, this result could be used to explain why not all enzymes isolated from thermophilic microorganisms are stable in vitro because of a lack of the macromolecular crowding environment.

  16. Co-immobilization of multiple enzymes by metal coordinated nucleotide hydrogel nanofibers: improved stability and an enzyme cascade for glucose detection.

    Science.gov (United States)

    Liang, Hao; Jiang, Shuhui; Yuan, Qipeng; Li, Guofeng; Wang, Feng; Zhang, Zijie; Liu, Juewen

    2016-03-21

    Preserving enzyme activity and promoting synergistic activity via co-localization of multiple enzymes are key topics in bionanotechnology, materials science, and analytical chemistry. This study reports a facile method for co-immobilizing multiple enzymes in metal coordinated hydrogel nanofibers. Specifically, four types of protein enzymes, including glucose oxidase, Candida rugosa lipase, α-amylase, and horseradish peroxidase, were respectively encapsulated in a gel nanofiber made of Zn(2+) and adenosine monophosphate (AMP) with a simple mixing step. Most enzymes achieved quantitative loading and retained full activity. At the same time, the entrapped enzymes were more stable against temperature variation (by 7.5 °C), protease attack, extreme pH (by 2-fold), and organic solvents. After storing for 15 days, the entrapped enzyme still retained 70% activity while the free enzyme nearly completely lost its activity. Compared to nanoparticles formed with AMP and lanthanide ions, the nanofiber gels allowed much higher enzyme activity. Finally, a highly sensitive and selective biosensor for glucose was prepared using the gel nanofiber to co-immobilize glucose oxidase and horseradish peroxidase for an enzyme cascade system. A detection limit of 0.3 μM glucose with excellent selectivity was achieved. This work indicates that metal coordinated materials using nucleotides are highly useful for interfacing with biomolecules.

  17. Enzymatic conversion of CO2 to CH3OH via reverse dehydrogenase cascade biocatalysis: Quantitative comparison of efficiencies of immobilized enzyme systems

    DEFF Research Database (Denmark)

    Marpani, Fauziah Binti; Pinelo, Manuel; Meyer, Anne S.

    2017-01-01

    A designed biocatalytic cascade system based on reverse enzymatic catalysis by formate dehydrogenase (EC 1.2.1.2), formaldehyde dehydrogenase (EC 1.2.1.46), and alcohol dehydrogenase (EC 1.1.1.1) can convert carbon dioxide (CO2) to methanol (CH3OH) via formation of formic acid (CHOOH......) and formaldehyde (CHOH) during equimolar cofactor oxidation of NADH to NAD+. This reaction is appealing because it represents a double gain: (1) reduction of CO2 and (2) an alternative to fossil fuel based production of CH3OH. The present review evaluates the efficiency of different immobilized enzyme systems...

  18. Intracellular implantation of enzymes in hollow silica nanospheres for protein therapy: cascade system of superoxide dismutase and catalase.

    Science.gov (United States)

    Chang, Feng-Peng; Chen, Yi-Ping; Mou, Chung-Yuan

    2014-11-01

    An approach for enzyme therapeutics is elaborated with cell-implanted nanoreactors that are based on multiple enzymes encapsulated in hollow silica nanospheres (HSNs). The synthesis of HSNs is carried out by silica sol-gel templating of water-in-oil microemulsions so that polyethyleneimine (PEI) modified enzymes in aqueous phase are encapsulated inside the HSNs. PEI-grafted superoxide dismutase (PEI-SOD) and catalase (PEI-CAT) encapsulated in HSNs are prepared with quantitative control of the enzyme loadings. Excellent activities of superoxide dismutation by PEI-SOD@HSN are found and transformation of H2 O2 to water by PEI-CAT@HSN. When PEI-SOD and PEI-CAT are co-encapsulated, cascade transformation of superoxide through hydrogen peroxide to water was facile. Substantial fractions of HSNs exhibit endosome escape to cytosol after their delivery to cells. The production of downstream reactive oxygen species (ROS) and COX-2/p-p38 expression show that co-encapsulated SOD/CAT inside the HSNs renders the highest cell protection against the toxicant N,N'-dimethyl-4,4'-bipyridinium dichloride (paraquat). The rapid cell uptake and strong detoxification effect on superoxide radicals by the SOD/CAT-encapsulated hollow mesoporous silica nanoparticles demonstrate the general concept of implanting catalytic nanoreactors in biological cells with designed functions. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Evaluation of refrigerating and air-conditioning technologies in heat cascading systems under the carbon dioxide emissions constraint: the proposal of the energy cascade balance table

    International Nuclear Information System (INIS)

    Shimazaki, Yoichi

    2003-01-01

    The aim of this study was to evaluate the refrigerating and air-conditioning technologies in cases of introducing both heat cascading systems and thermal recycling systems in industries located around urban areas. It is necessary to introduce heat cascading systems in the industrial sector in Japan to reduce carbon dioxide emissions. The concept of heat cascading is the multi-stage use of thermal energy by temperature level. This paper introduces three energy policies for introducing the heat cascading systems. The author develops an energy cascade model based on linear programming so as to minimize the total system costs with carbon taxes. Five cases are investigated. Carbon dioxide emission constraints result in the enhancement of heat cascading, where high temperature heat is supplied for process heating while low temperature heat is shifted to refrigeration. It was found that increasing the amount of garbage combustion waste heat could reduce electric power for the turbo compression refrigerator by promoting waste heat driven ammonia absorption refrigerator. In addition, this study proposes an energy cascade balance table with respect to the temperature level

  20. Evaluation of pressure tuning of enzymes

    DEFF Research Database (Denmark)

    Naghshineh, Mahsa

    and high energy consumption. Therefore, searching for an environmentally friendly method of pectin extraction is a task for science and industry. Employment of hydrolytic enzymes may represent a green approach to obtain intact pectin polymer. However, the low stability/activity of enzymes, and low polymer...... yield of enzymatic extraction limits the application of enzyme in pectin production. There is evidence that emerging technology of high hydrostatic pressure processing can result in stabilization and activation of some enzymes. Therefore, the use of high hydrostatic pressure in combination with enzyme...... (cellulase/xylanase: 50/0, 50/25, 50/50, 25/50, and 0/50 U/g lime peel) at ambient pressure, 100 and 200 MPa were used to extract pectin from dried lime peel waste. It was found that pressure level, type and concentration of enzyme significantly influenced pectin yield and degree of esterification (DE...

  1. Autonomous molecular cascades for evaluation of cell surfaces

    Science.gov (United States)

    Rudchenko, Maria; Taylor, Steven; Pallavi, Payal; Dechkovskaia, Alesia; Khan, Safana; Butler, Vincent P., Jr.; Rudchenko, Sergei; Stojanovic, Milan N.

    2013-08-01

    Molecular automata are mixtures of molecules that undergo precisely defined structural changes in response to sequential interactions with inputs. Previously studied nucleic acid-based automata include game-playing molecular devices (MAYA automata) and finite-state automata for the analysis of nucleic acids, with the latter inspiring circuits for the analysis of RNA species inside cells. Here, we describe automata based on strand-displacement cascades directed by antibodies that can analyse cells by using their surface markers as inputs. The final output of a molecular automaton that successfully completes its analysis is the presence of a unique molecular tag on the cell surface of a specific subpopulation of lymphocytes within human blood cells.

  2. Evaluation of thermostable enzymes for bioethanol processing

    DEFF Research Database (Denmark)

    Skovgaard, Pernille Anastasia

    of fermentable sugars (glucose) as cellulose is tightly linked to hemicellulose and lignin. Lignocellulose is disrupted during pretreatment, but to degrade cellulose to single sugars, lignocellulolytic enzymes such as cellulases and hemicellulases are needed. Lignocellulolytic enzymes are costly...... for the ioethanol production, but the expenses can be reduced by using thermostable enzymes, which are known for their increased stability and inhibitor olerance. However, the advantage of using thermostable enzymes has not been studied thoroughly and more knowledge is needed for development of bioethanol processes....... Enzymes are added to the bioethanol process after pretreatment. For an efficient sugar and ethanol yield, the solids content of biomass is normally increased, which results in highly viscous slurries that are difficult to mix. Therefore, the first enzymatic challenge is to ensure rapid reduction...

  3. Evaluation of Power Generation Efficiency of Cascade Hydropower Plants: A Case Study

    Directory of Open Access Journals (Sweden)

    Jiahua Wei

    2013-02-01

    Full Text Available Effective utilization of scarce water resources has presented a significant challenge to respond to the needs created by rapid economic growth in China. In this study, the efficiency of the joint operation of the Three Gorges and Gezhouba cascade hydropower plants in terms of power generation was evaluated on the basis of a precise simulation-optimization technique. The joint operation conditions of the Three Gorges and Gezhouba hydropower plants between 2004 and 2010 were utilized in this research in order to investigate the major factors that could affect power output of the cascade complex. The results showed that the current power output of the Three Gorges and Gezhouba cascade complex had already reached around 90% of the maximum theoretical value. Compared to other influencing factors evaluated in this study, the accuracy of hydrological forecasts and flood control levels can have significant impact on the power generating efficiency, whereas the navigation has a minor influence. This research provides a solid quantitative-based methodology to assess the operation efficiency of cascade hydropower plants, and more importantly, proposes potential methods that could improve the operation efficiency of cascade hydropower plants.

  4. Evaluation of liver marker enzymes and biochemical indices of ...

    African Journals Online (AJOL)

    Liver marker enzymes, total protein, amylase and glucose were evaluated in alloxan-induced diabetic wistar rats treated with aqueous extract of Pennisetum purpureum. The liver marker enzymes evaluated were alanine aminotransferase (ALT) and aspartate aminotransferase (AST). Sixteen wistar rats were grouped into ...

  5. Sugar analog synthesis by in vitro biocatalytic cascade: A comparison of alternative enzyme complements for dihydroxyacetone phosphate production as a precursor to rare chiral sugar synthesis.

    Science.gov (United States)

    Hartley, Carol J; French, Nigel G; Scoble, Judith A; Williams, Charlotte C; Churches, Quentin I; Frazer, Andrew R; Taylor, Matthew C; Coia, Greg; Simpson, Gregory; Turner, Nicholas J; Scott, Colin

    2017-01-01

    Carbon-carbon bond formation is one of the most challenging reactions in synthetic organic chemistry, and aldol reactions catalysed by dihydroxyacetone phosphate-dependent aldolases provide a powerful biocatalytic tool for combining C-C bond formation with the generation of two new stereo-centres, with access to all four possible stereoisomers of a compound. Dihydroxyacetone phosphate (DHAP) is unstable so the provision of DHAP for DHAP-dependent aldolases in biocatalytic processes remains complicated. Our research has investigated the efficiency of several different enzymatic cascades for the conversion of glycerol to DHAP, including characterising new candidate enzymes for some of the reaction steps. The most efficient cascade for DHAP production, comprising a one-pot four-enzyme reaction with glycerol kinase, acetate kinase, glycerophosphate oxidase and catalase, was coupled with a DHAP-dependent fructose-1,6-biphosphate aldolase enzyme to demonstrate the production of several rare chiral sugars. The limitation of batch biocatalysis for these reactions and the potential for improvement using kinetic modelling and flow biocatalysis systems is discussed.

  6. Sugar analog synthesis by in vitro biocatalytic cascade: A comparison of alternative enzyme complements for dihydroxyacetone phosphate production as a precursor to rare chiral sugar synthesis.

    Directory of Open Access Journals (Sweden)

    Carol J Hartley

    Full Text Available Carbon-carbon bond formation is one of the most challenging reactions in synthetic organic chemistry, and aldol reactions catalysed by dihydroxyacetone phosphate-dependent aldolases provide a powerful biocatalytic tool for combining C-C bond formation with the generation of two new stereo-centres, with access to all four possible stereoisomers of a compound. Dihydroxyacetone phosphate (DHAP is unstable so the provision of DHAP for DHAP-dependent aldolases in biocatalytic processes remains complicated. Our research has investigated the efficiency of several different enzymatic cascades for the conversion of glycerol to DHAP, including characterising new candidate enzymes for some of the reaction steps. The most efficient cascade for DHAP production, comprising a one-pot four-enzyme reaction with glycerol kinase, acetate kinase, glycerophosphate oxidase and catalase, was coupled with a DHAP-dependent fructose-1,6-biphosphate aldolase enzyme to demonstrate the production of several rare chiral sugars. The limitation of batch biocatalysis for these reactions and the potential for improvement using kinetic modelling and flow biocatalysis systems is discussed.

  7. Enzyme

    Science.gov (United States)

    Enzymes are complex proteins that cause a specific chemical change in all parts of the body. For ... use them. Blood clotting is another example of enzymes at work. Enzymes are needed for all body ...

  8. Reliability Evaluation of Machine Center Components Based on Cascading Failure Analysis

    Science.gov (United States)

    Zhang, Ying-Zhi; Liu, Jin-Tong; Shen, Gui-Xiang; Long, Zhe; Sun, Shu-Guang

    2017-07-01

    In order to rectify the problems that the component reliability model exhibits deviation, and the evaluation result is low due to the overlook of failure propagation in traditional reliability evaluation of machine center components, a new reliability evaluation method based on cascading failure analysis and the failure influenced degree assessment is proposed. A direct graph model of cascading failure among components is established according to cascading failure mechanism analysis and graph theory. The failure influenced degrees of the system components are assessed by the adjacency matrix and its transposition, combined with the Pagerank algorithm. Based on the comprehensive failure probability function and total probability formula, the inherent failure probability function is determined to realize the reliability evaluation of the system components. Finally, the method is applied to a machine center, it shows the following: 1) The reliability evaluation values of the proposed method are at least 2.5% higher than those of the traditional method; 2) The difference between the comprehensive and inherent reliability of the system component presents a positive correlation with the failure influenced degree of the system component, which provides a theoretical basis for reliability allocation of machine center system.

  9. Cascade air stripping: Techno-economic evaluation of a new ground water treatment process

    International Nuclear Information System (INIS)

    Nirmalakhandan, N.; Peace, G.L.; Shanbhag, A.R.; Speece, R.E.

    1992-01-01

    A simple modification of the conventional air-stripping process introduced as cascade air stripping is proposed for efficient and economical removal of semivolatile and low volatility contaminants from ground water. The technical feasibility and economic viability of this process are evaluated using field test results and cost model simulations. The field tests enabled the process model to be verified at various water flow rates ranging from 150 gpm to 400 gpm. The field study also demonstrated the feasibility of the proposed system at a near full-scale level. Cost models were used to compare the proposed process to conventional air stripping and granular-activated carbon adsorption in removing a range of contaminants. This analysis showed that the treatment cost (cents/1,000 gal) of cascade air stripping is about 15% lower than conventional air stripping and about 40% lower than granular-activated carbon adsorption

  10. Evaluation method for the drying performance of enzyme containing formulations

    DEFF Research Database (Denmark)

    Sloth, Jakob; Bach, P.; Jensen, Anker Degn

    2008-01-01

    A method is presented for fast and cheap evaluation of the performance of enzyme containing formulations in terms of preserving the highest enzyme activity during spray drying. The method is based on modeling the kinetics of the thermal inactivation reaction which occurs during the drying process....... Relevant kinetic parameters are determined from differential scanning calorimeter (DSC) experiments and the model is used to simulate the severity of the inactivation reaction for temperatures and moisture levels relevant for spray drying. After conducting experiments and subsequent simulations...... for a number of different formulations it may be deduced which formulation performs best. This is illustrated by a formulation design study where 4 different enzyme containing formulations are evaluated. The method is validated by comparison to pilot scale spray dryer experiments....

  11. One-pot synthesis of GDP-l-fucose by a four-enzyme cascade expressed in Lactococcus lactis.

    Science.gov (United States)

    Li, Ling; Kim, Seul-Ah; Heo, Ji Eun; Kim, Tae-Jip; Seo, Jin-Ho; Han, Nam Soo

    2017-12-20

    GDP-l-fucose is an l-fucose donor to synthesize fucosylated compounds such as human milk oligosaccharides or Lewis antigen. In this study, we used Lactococcus lactis subsp. cremoris NZ9000 to express 4 enzymes, ManB, ManC, Gmd, and WcaG and produced GDP-l-fucose by using one-pot synthesis method with mannose-6-phosphate as substrate and the enzymes as biocatalyst. For preparation of enzyme mixture, 4 genes (manB, manC, gmd, and wcaG) cloned from Escherichia coli were transformed into L. lactis strains using pNZ8008 and the recombinant cell lysates were obtained after cultivation. When mannose-6-phosphate was used as the substrate, the consecutive reactions with ManB, ManC, Gmd, and WcaG resulted in the successful production of GDP-l-fucose (0.13mM). When GDP-d-mannose was used as the substrate, it was entirely converted to GDP-l-fucose (0.2mM; 0.12g/L) via 2 enzymatic reactions mediated by Gmd and WcaG. This is the first report of GDP-l-fucose production by using multiple enzymes expressed in lactic acid bacteria. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. Establishment and evaluation of operation function model for cascade hydropower station

    OpenAIRE

    Chang-ming Ji; Ting Zhou; Hai-tao Huang

    2010-01-01

    Toward solving the actual operation problems of cascade hydropower stations under hydrologic uncertainty, this paper presents the process of extraction of statistical characteristics from long-term optimal cascade operation, and proposes a monthly operation function algorithm for the actual operation of cascade hydropower stations through the identification, processing, and screening of available information during long-term optimal operation. Applying the operation function to the cascade hy...

  13. One pot synthesis of GDP-mannose by a multi-enzyme cascade for enzymatic assembly of lipid-linked oligosaccharides.

    Science.gov (United States)

    Rexer, Thomas F T; Schildbach, Anna; Klapproth, Jan; Schierhorn, Angelika; Mahour, Reza; Pietzsch, Markus; Rapp, Erdmann; Reichl, Udo

    2018-01-01

    Glycosylation of proteins is a key function of the biosynthetic-secretory pathway in the endoplasmic reticulum (ER) and Golgi apparatus. Glycosylated proteins play a crucial role in cell trafficking and signaling, cell-cell adhesion, blood-group antigenicity, and immune response. In addition, the glycosylation of proteins is an important parameter in the optimization of many glycoprotein-based drugs such as monoclonal antibodies. In vitro glycoengineering of proteins requires glycosyltransferases as well as expensive nucleotide sugars. Here, we present a designed pathway consisting of five enzymes, glucokinase (Glk), phosphomannomutase (ManB), mannose-1-phosphate-guanyltransferase (ManC), inorganic pyrophosphatase (PmPpA), and 1-domain polyphosphate kinase 2 (1D-Ppk2) expressed in E. coli for the cell-free production and regeneration of GDP-mannose from mannose and polyphosphate with catalytic amounts of GDP and ADP. It was shown that GDP-mannose is produced at various conditions, that is pH 7-8, temperature 25-35°C and co-factor concentrations of 5-20 mM MgCl 2 . The maximum reaction rate of GDP-mannose achieved was 2.7 μM/min at 30°C and 10 mM MgCl 2 producing 566 nmol GDP-mannose after a reaction time of 240 min. With respect to the initial GDP concentration (0.8 mM) this is equivalent to a yield of 71%. Additionally, the cascade was coupled to purified, transmembrane-deleted Alg1 (ALG1ΔTM), the first mannosyltransferase in the ER-associated lipid-linked oligosaccharide (LLO) assembly. Thereby, in a one-pot reaction, phytanyl-PP-(GlcNAc) 2 -Man 1 was produced with efficient nucleotide sugar regeneration for the first time. Phytanyl-PP-(GlcNAc) 2 -Man 1 can serve as a substrate for the synthesis of LLO for the cell-free in vitro glycosylation of proteins. A high-performance anion exchange chromatography method with UV and conductivity detection (HPAEC-UV/CD) assay was optimized and validated to determine the enzyme kinetics. The established

  14. One pot synthesis of GDP‐mannose by a multi‐enzyme cascade for enzymatic assembly of lipid‐linked oligosaccharides

    Science.gov (United States)

    Schildbach, Anna; Klapproth, Jan; Schierhorn, Angelika; Mahour, Reza; Pietzsch, Markus; Rapp, Erdmann; Reichl, Udo

    2017-01-01

    Abstract Glycosylation of proteins is a key function of the biosynthetic‐secretory pathway in the endoplasmic reticulum (ER) and Golgi apparatus. Glycosylated proteins play a crucial role in cell trafficking and signaling, cell‐cell adhesion, blood‐group antigenicity, and immune response. In addition, the glycosylation of proteins is an important parameter in the optimization of many glycoprotein‐based drugs such as monoclonal antibodies. In vitro glycoengineering of proteins requires glycosyltransferases as well as expensive nucleotide sugars. Here, we present a designed pathway consisting of five enzymes, glucokinase (Glk), phosphomannomutase (ManB), mannose‐1‐phosphate‐guanyltransferase (ManC), inorganic pyrophosphatase (PmPpA), and 1‐domain polyphosphate kinase 2 (1D‐Ppk2) expressed in E. coli for the cell‐free production and regeneration of GDP‐mannose from mannose and polyphosphate with catalytic amounts of GDP and ADP. It was shown that GDP‐mannose is produced at various conditions, that is pH 7–8, temperature 25–35°C and co‐factor concentrations of 5–20 mM MgCl2. The maximum reaction rate of GDP‐mannose achieved was 2.7 μM/min at 30°C and 10 mM MgCl2 producing 566 nmol GDP‐mannose after a reaction time of 240 min. With respect to the initial GDP concentration (0.8 mM) this is equivalent to a yield of 71%. Additionally, the cascade was coupled to purified, transmembrane‐deleted Alg1 (ALG1ΔTM), the first mannosyltransferase in the ER‐associated lipid‐linked oligosaccharide (LLO) assembly. Thereby, in a one‐pot reaction, phytanyl‐PP‐(GlcNAc)2‐Man1 was produced with efficient nucleotide sugar regeneration for the first time. Phytanyl‐PP‐(GlcNAc)2‐Man1 can serve as a substrate for the synthesis of LLO for the cell‐free in vitro glycosylation of proteins. A high‐performance anion exchange chromatography method with UV and conductivity detection (HPAEC‐UV/CD) assay was optimized and

  15. Evaluation of Refrigerating and Air Conditioning Devices in Energy Cascade Systems under the Restriction of Carbon Dioxide Emissions

    Science.gov (United States)

    Shimazaki, Yoichi; Akisawa, Atsushi; Kashiwagi, Takao

    It is necessary to introduce energy cascade systems into the industrial sector in Japan to reduce carbon dioxide emissions. The aim of this study is to evaluate the refrigerating and air conditioning devices in cases of introducing both energy cascade systems and thermal recycling systems in industries located around urban areas. The authors have developed an energy cascade model based on linear programming so as to minimize the total system costs with carbon taxes. Five cases are investigated. Limitation of carbon dioxide emissions results in the enhancement of heat cascading, where high temperature heat is supplied for process heating while low temperature one is shifted to refrigeration. It was found that increasing the amount of garbage combustor waste heat can reduce electric power for the turbo refrigerator by promoting waste heat driven ammonia absorption refrigerator.

  16. The EAL domain protein YciR acts as a trigger enzyme in a c-di-GMP signalling cascade in E. coli biofilm control

    Science.gov (United States)

    Lindenberg, Sandra; Klauck, Gisela; Pesavento, Christina; Klauck, Eberhard; Hengge, Regine

    2013-01-01

    C-di-GMP—which is produced by diguanylate cyclases (DGC) and degraded by specific phosphodiesterases (PDEs)—is a ubiquitous second messenger in bacterial biofilm formation. In Escherichia coli, several DGCs (YegE, YdaM) and PDEs (YhjH, YciR) and the MerR-like transcription factor MlrA regulate the transcription of csgD, which encodes a biofilm regulator essential for producing amyloid curli fibres of the biofilm matrix. Here, we demonstrate that this system operates as a signalling cascade, in which c-di-GMP controlled by the DGC/PDE pair YegE/YhjH (module I) regulates the activity of the YdaM/YciR pair (module II). Via multiple direct interactions, the two module II proteins form a signalling complex with MlrA. YciR acts as a connector between modules I and II and functions as a trigger enzyme: its direct inhibition of the DGC YdaM is relieved when it binds and degrades c-di-GMP generated by module I. As a consequence, YdaM then generates c-di-GMP and—by direct and specific interaction—activates MlrA to stimulate csgD transcription. Trigger enzymes may represent a general principle in local c-di-GMP signalling. PMID:23708798

  17. An Evaluation of Neutron Energy Spectrum Effects in Iron Based on Molecular Dynamics Displacement Cascade Simulations

    International Nuclear Information System (INIS)

    Greenwood, L.R.; Stoller, R.E.

    1998-01-01

    The results of molecular dynamics (MD) displacement cascade simulations in bcc iron have been used to obtain effective cross sections for two measures of primary damage production: (1) the number of surviving point defects expressed as a fraction of the displacements calculated using the standard secondary displacement model of Norgett, Robinson, and Torrens (NRT), and (2) the fraction of the surviving interstitials contained in clusters that formed during the cascade event. Primary knockon atom spectra for iron obtained from the SPECTER code have been used to weight these MD-based damage production cross sections in order to obtain spectrally-averaged values for several locations in commercial fission reactors and materials test reactors. An evaluation of these results indicates that neutron energy spectrum differences between the various enviromnents do not lead to significant differences between the average primary damage formation parameters. In particular, the defect production cross sections obtained for PWR and BWR neutron spectra were not significantly different. The variation of the defect production cross sections as a function of depth into the reactor pressure vessel wall is used as a sample application of the cross sections. A slight difference between the attenuation behavior of the PWR and BWR was noted; this difference could be explained by a subtle difference in the energy dependence of the neutron spectra. Overall, the simulations support the continued use of dpa as a damage correlation parameter

  18. Efficient Production of Enantiopure d-Lysine from l-Lysine by a Two-Enzyme Cascade System

    Directory of Open Access Journals (Sweden)

    Xin Wang

    2016-10-01

    Full Text Available The microbial production of d-lysine has been of great interest as a medicinal raw material. Here, a two-step process for d-lysine production from l-lysine by the successive microbial racemization and asymmetric degradation with lysine racemase and decarboxylase was developed. The whole-cell activities of engineered Escherichia coli expressing racemases from the strains Proteus mirabilis (LYR and Lactobacillus paracasei (AAR were first investigated comparatively. When the strain BL21-LYR with higher racemization activity was employed, l-lysine was rapidly racemized to give dl-lysine, and the d-lysine yield was approximately 48% after 0.5 h. Next, l-lysine was selectively catabolized to generate cadaverine by lysine decarboxylase. The comparative analysis of the decarboxylation activities of resting whole cells, permeabilized cells, and crude enzyme revealed that the crude enzyme was the best biocatalyst for enantiopure d-lysine production. The reaction temperature, pH, metal ion additive, and pyridoxal 5′-phosphate content of this two-step production process were subsequently optimized. Under optimal conditions, 750.7 mmol/L d-lysine was finally obtained from 1710 mmol/L l-lysine after 1 h of racemization reaction and 0.5 h of decarboxylation reaction. d-lysine yield could reach 48.8% with enantiomeric excess (ee ≥ 99%.

  19. Internal Light Source-Driven Photoelectrochemical 3D-rGO/Cellulose Device Based on Cascade DNA Amplification Strategy Integrating Target Analog Chain and DNA Mimic Enzyme.

    Science.gov (United States)

    Lan, Feifei; Liang, Linlin; Zhang, Yan; Li, Li; Ren, Na; Yan, Mei; Ge, Shenguang; Yu, Jinghua

    2017-11-01

    In this work, a chemiluminescence-driven collapsible greeting card-like photoelectrochemical lab-on-paper device (GPECD) with hollow channel was demonstrated, in which target-triggering cascade DNA amplification strategy was ingeniously introduced. The GPECD had the functions of reagents storage and signal collection, and the change of configuration could control fluidic path, reaction time and alterations in electrical connectivity. In addition, three-dimentional reduced graphene oxide affixed Au flower was in situ grown on paper cellulose fiber for achieving excellent conductivity and biocompatibility. The cascade DNA amplification strategy referred to the cyclic formation of target analog chain and its trigger action to hybridization chain reaction (HCR), leading to the formation of numerous hemin/G-quadruplex DNA mimic enzyme with the presence of hemin. Subjected to the catalysis of hemin/G-quadruplex, the strong chemiluminiscence of luminol-H 2 O 2 system was obtained, which then was used as internal light source to excite photoactive materials realizing the simplification of instrument. In this analyzing process, thrombin served as proof-of-concept, and the concentration of target was converted into the DNA signal output by the specific recognition of aptamer-protein and target analog chain recycling. The target analog chain was produced in quantity with the presence of target, which further triggered abundant HCR and introduced hemin/G-quadruplex into the system. The photocurrent signal was obtained after the nitrogen-doped carbon dots sensitized ZnO was stimulated by chemiluminescence. The proposed GPECD exhibited excellent specificity and sensitivity toward thrombin with a detection limit of 16.7 fM. This judiciously engineered GPECD paved a luciferous way for detecting other protein with trace amounts in bioanalysis and clinical biomedicine.

  20. Model for Quantitative Evaluation of Enzyme Replacement Treatment

    Directory of Open Access Journals (Sweden)

    Radeva B.

    2009-12-01

    Full Text Available Gaucher disease is the most frequent lysosomal disorder. Its enzyme replacement treatment was the new progress of modern biotechnology, successfully used in the last years. The evaluation of optimal dose of each patient is important due to health and economical reasons. The enzyme replacement is the most expensive treatment. It must be held continuously and without interruption. Since 2001, the enzyme replacement therapy with Cerezyme*Genzyme was formally introduced in Bulgaria, but after some time it was interrupted for 1-2 months. The dose of the patients was not optimal. The aim of our work is to find a mathematical model for quantitative evaluation of ERT of Gaucher disease. The model applies a kind of software called "Statistika 6" via the input of the individual data of 5-year-old children having the Gaucher disease treated with Cerezyme. The output results of the model gave possibilities for quantitative evaluation of the individual trends in the development of the disease of each child and its correlation. On the basis of this results, we might recommend suitable changes in ERT.

  1. Loop 7 of E2 enzymes: an ancestral conserved functional motif involved in the E2-mediated steps of the ubiquitination cascade.

    Directory of Open Access Journals (Sweden)

    Elena Papaleo

    Full Text Available The ubiquitin (Ub system controls almost every aspect of eukaryotic cell biology. Protein ubiquitination depends on the sequential action of three classes of enzymes (E1, E2 and E3. E2 Ub-conjugating enzymes have a central role in the ubiquitination pathway, interacting with both E1 and E3, and influencing the ultimate fate of the substrates. Several E2s are characterized by an extended acidic insertion in loop 7 (L7, which if mutated is known to impair the proper E2-related functions. In the present contribution, we show that acidic loop is a conserved ancestral motif in E2s, relying on the presence of alternate hydrophobic and acidic residues. Moreover, the dynamic properties of a subset of family 3 E2s, as well as their binary and ternary complexes with Ub and the cognate E3, have been investigated. Here we provide a model of L7 role in the different steps of the ubiquitination cascade of family 3 E2s. The L7 hydrophobic residues turned out to be the main determinant for the stabilization of the E2 inactive conformations by a tight network of interactions in the catalytic cleft. Moreover, phosphorylation is known from previous studies to promote E2 competent conformations for Ub charging, inducing electrostatic repulsion and acting on the L7 acidic residues. Here we show that these active conformations are stabilized by a network of hydrophobic interactions between L7 and L4, the latter being a conserved interface for E3-recruitment in several E2s. In the successive steps, L7 conserved acidic residues also provide an interaction interface for both Ub and the Rbx1 RING subdomain of the cognate E3. Our data therefore suggest a crucial role for L7 of family 3 E2s in all the E2-mediated steps of the ubiquitination cascade. Its different functions are exploited thank to its conserved hydrophobic and acidic residues in a finely orchestrate mechanism.

  2. Evaluating Functional Annotations of Enzymes Using the Gene Ontology.

    Science.gov (United States)

    Holliday, Gemma L; Davidson, Rebecca; Akiva, Eyal; Babbitt, Patricia C

    2017-01-01

    The Gene Ontology (GO) (Ashburner et al., Nat Genet 25(1):25-29, 2000) is a powerful tool in the informatics arsenal of methods for evaluating annotations in a protein dataset. From identifying the nearest well annotated homologue of a protein of interest to predicting where misannotation has occurred to knowing how confident you can be in the annotations assigned to those proteins is critical. In this chapter we explore what makes an enzyme unique and how we can use GO to infer aspects of protein function based on sequence similarity. These can range from identification of misannotation or other errors in a predicted function to accurate function prediction for an enzyme of entirely unknown function. Although GO annotation applies to any gene products, we focus here a describing our approach for hierarchical classification of enzymes in the Structure-Function Linkage Database (SFLD) (Akiva et al., Nucleic Acids Res 42(Database issue):D521-530, 2014) as a guide for informed utilisation of annotation transfer based on GO terms.

  3. Evaluation of diffuse-illumination holographic cinematography in a flutter cascade

    Science.gov (United States)

    Decker, A. J.

    1986-01-01

    Since 1979, the Lewis Research Center has examined holographic cinematography for three-dimensional flow visualization. The Nd:YAG lasers used were Q-switched, double-pulsed, and frequency-doubled, operating at 20 pulses per second. The primary subjects for flow visualization were the shock waves produced in two flutter cascades. Flow visualization was by diffuse-illumination, double-exposure, and holographic interferometry. The performances of the lasers, holography, and diffuse-illumination interferometry are evaluated in single-window wind tunnels. The fringe-contrast factor is used to evaluate the results. The effects of turbulence on shock-wave visualization in a transonic flow are discussed. The depth of field for visualization of a turbulent structure is demonstrated to be a measure of the relative density and scale of that structure. Other items discussed are the holographic emulsion, tests of coherence and polarization, effects of windows and diffusers, hologram bleaching, laser configurations, influence and handling of specular reflections, modes of fringe localization, noise sources, and coherence requirements as a function of the pulse energy. Holography and diffuse illumination interferometry are also reviewed.

  4. Evaluation of Jefferies' level population ratios, and generalization of Seaton's cascade matrix, by a Markov-chain method

    International Nuclear Information System (INIS)

    Kastner, S.O.

    1980-01-01

    Closed expressions are obtained for the conditional probabilities qsub(i)sub(j)sub(,)sub(k) required in evaluating particular ratios of atomic level populations, using a Markov-chain representation of the system of levels. The total transition probability between two arbitrary levels is also evaluated and its relation to population ratios is clarified. It is shown that Seaton's cascade matrix is a subset of the total transition probability matrix. (orig.)

  5. Use of polarization measurements in evaluating cascade contributions to optical excitation functions

    International Nuclear Information System (INIS)

    McConkey, J.W.

    1981-01-01

    Recent developments in theory and experimental measurements of rotational line polarization fractions of diatomic molecules following electron impact are used to show how in some instances cascade free optical excitation functions can be derived without additional measurements of the cascading contribution. The Lyman system of H 2 is presented as an example and some previously conflicting excitation cross-section measurements obtained by different techniques are reconciled

  6. Entropy generation minimization: A practical approach for performance evaluation of temperature cascaded co-generation plants

    KAUST Repository

    Myat, Aung; Thu, Kyaw; Kim, Youngdeuk; Saha, Bidyut Baran; Ng, K. C.

    2012-01-01

    We present a practical tool that employs entropy generation minimization (EGM) approach for an in-depth performance evaluation of a co-generation plant with a temperature-cascaded concept. Co-generation plant produces useful effect production sequentially, i.e., (i) electricity from the micro-turbines, (ii) low pressure steam at 250 °C or about 8-10 bars, (iii) cooling capacity of 4 refrigeration tones (Rtons) and (iv) dehumidification of outdoor air for air conditioned space. The main objective is to configure the most efficient configuration of producing power and heat. We employed entropy generation minimization (EGM) which reflects to minimize the dissipative losses and maximize the cycle efficiency of the individual thermally activated systems. The minimization of dissipative losses or EGM is performed in two steps namely, (i) adjusting heat source temperatures for the heat-fired cycles and (ii) the use of Genetic Algorithm (GA), to seek out the sensitivity of heat transfer areas, flow rates of working fluids, inlet temperatures of heat sources and coolant, etc., over the anticipated range of operation to achieve maximum efficiency. With EGM equipped with GA, we verified that the local minimization of entropy generation individually at each of the heat-activated processes would lead to the maximum efficiency of the system. © 2012.

  7. Entropy generation minimization: A practical approach for performance evaluation of temperature cascaded co-generation plants

    KAUST Repository

    Myat, Aung

    2012-10-01

    We present a practical tool that employs entropy generation minimization (EGM) approach for an in-depth performance evaluation of a co-generation plant with a temperature-cascaded concept. Co-generation plant produces useful effect production sequentially, i.e., (i) electricity from the micro-turbines, (ii) low pressure steam at 250 °C or about 8-10 bars, (iii) cooling capacity of 4 refrigeration tones (Rtons) and (iv) dehumidification of outdoor air for air conditioned space. The main objective is to configure the most efficient configuration of producing power and heat. We employed entropy generation minimization (EGM) which reflects to minimize the dissipative losses and maximize the cycle efficiency of the individual thermally activated systems. The minimization of dissipative losses or EGM is performed in two steps namely, (i) adjusting heat source temperatures for the heat-fired cycles and (ii) the use of Genetic Algorithm (GA), to seek out the sensitivity of heat transfer areas, flow rates of working fluids, inlet temperatures of heat sources and coolant, etc., over the anticipated range of operation to achieve maximum efficiency. With EGM equipped with GA, we verified that the local minimization of entropy generation individually at each of the heat-activated processes would lead to the maximum efficiency of the system. © 2012.

  8. Evaluation of the efficiency of alternative enzyme production technologies

    Energy Technology Data Exchange (ETDEWEB)

    Albaek, M.O.

    2012-03-15

    fermentation technologies for enzyme production were identified in the open literature. Their mass transfer capabilities and their energy efficiencies were evaluated by use of the process model. For each technology the scale-up enzyme production was simulated at industrial scale based on equal mass transfer. The technical feasibility of each technology was assessed based on prior knowledge of successful implementation at industrial scale and mechanical complexity of the fermentation vessel. The airlift reactor was identified as a potential high energy efficiency technology for enzyme production with excellent chances for success. Two different pilot plant configurations of the airlift reactor technology were tested in nine fermentations. The headspace pressure was varied between 0.1 and 1.1 barg and the superficial gas velocity in the airlift riser section was varied between 0.02 and 0.06 m/s. The biological model developed in the stirred tank reactor was shown to apply to the airlift reactor with only small modifications: The mass transfer of oxygen in the airlift reactor was studied and a mass transfer correlation containing the superficial gas velocity and the apparent viscosity of the fermentation broth was shown to describe the experimental data well. The mass transfer rate was approximately 20% lower than the literature data for airlift reactors. Mixing in the pilot scale airlift reactor was also studied. As the mixing time was of the same order of magnitude as the characteristic time for oxygen transfer, mixing could also be limiting the process at that scale. The process model for the airlift reactor was also shown to describe the experimental data well for a range of process conditions. A cost function for oxygen transfer including the equipment cost and running cost for nutrients and electricity was developed for both the stirred tank reactor and the airlift reactor. The cost function was used to identify an optimum range of reactor configuration and process

  9. Landscape evaluation of female black bear habitat effectiveness and capability in the North Cascades, Washington.

    Science.gov (United States)

    William L. Gaines; Andrea L. Lyons; John F. Lehmkuhl; Kenneth J. Raedeke

    2005-01-01

    We used logistic regression to derive scaled resource selection functions (RSFs) for female black bears at two study areas in the North Cascades Mountains. We tested the hypothesis that the influence of roads would result in potential habitat effectiveness (RSFs without the influence of roads) being greater than realized habitat effectiveness (RSFs with roads). Roads...

  10. Cascade-sea : Computer Assisted Curriculum Analysis, Design & Evaluation for Science Education in Africa.

    NARCIS (Netherlands)

    McKenney, Susan; van den Akker, Jan; Maribe, Robert; Gustafson, Kent; Nieveen, Nienke; Plomp, Tjeerd

    1999-01-01

    The CASCADE-SEA program aims to support curriculum development within the context of secondary level science and mathematics education in sub-Saharan Africa. This project focuses on the iterative design of a computer-based curriculum development support system for the creation of classroom

  11. Evaluating trophic cascades as drivers of regime shifts in different ocean ecosystems

    Science.gov (United States)

    Pershing, Andrew J.; Mills, Katherine E.; Record, Nicholas R.; Stamieszkin, Karen; Wurtzell, Katharine V.; Byron, Carrie J.; Fitzpatrick, Dominic; Golet, Walter J.; Koob, Elise

    2015-01-01

    In ecosystems that are strongly structured by predation, reducing top predator abundance can alter several lower trophic levels—a process known as a trophic cascade. A persistent trophic cascade also fits the definition of a regime shift. Such ‘trophic cascade regime shifts' have been reported in a few pelagic marine systems—notably the Black Sea, Baltic Sea and eastern Scotian Shelf—raising the question of how common this phenomenon is in the marine environment. We provide a general methodology for distinguishing top-down and bottom-up effects and apply this methodology to time series from these three ecosystems. We found evidence for top-down forcing in the Black Sea due primarily to gelatinous zooplankton. Changes in the Baltic Sea are primarily bottom-up, strongly structured by salinity, but top-down forcing related to changes in cod abundance also shapes the ecosystem. Changes in the eastern Scotian Shelf that were originally attributed to declines in groundfish are better explained by changes in stratification. Our review suggests that trophic cascade regime shifts are rare in open ocean ecosystems and that their likelihood increases as the residence time of water in the system increases. Our work challenges the assumption that negative correlation between consecutive trophic levels implies top-down forcing.

  12. Coproduction of detergent compatible bacterial enzymes and stain removal evaluation.

    Science.gov (United States)

    Niyonzima, Francois N; More, Sunil S

    2015-10-01

    Most of the detergents that are presently produced contain the detergent compatible enzymes to improve and accelerate the washing performance by removing tough stains. The process is environment friendly as the use of enzymes in the detergent formulation reduces the utilization of toxic detergent constituents. The current trend is to use the detergent compatible enzymes that are active at low and ambient temperature in order to save energy and maintain fabric quality. As the detergent compatible bacterial enzymes are used together in the detergent formulation, it is important to co-produce the detergent enzymes in a single fermentation medium as the enzyme stability is assured, and production cost gets reduced enormously. The review reports on the production, purification, characterization and application of detergent compatible amylases, lipases, and proteases are available. However, there is no specific review or minireview on the concomitant production of detergent compatible amylases, lipases, and proteases. In this minireview, the coproduction of detergent compatible enzymes by bacterial species, enzyme stability towards detergents and detergent components, and stain release analysis were discussed. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. A framework and case studies for evaluation of enzyme ontogeny in children's health risk evaluation.

    Science.gov (United States)

    Ginsberg, Gary; Vulimiri, Suryanarayana V; Lin, Yu-Sheng; Kancherla, Jayaram; Foos, Brenda; Sonawane, Babasaheb

    2017-01-01

    Knowledge of the ontogeny of Phase I and Phase II metabolizing enzymes may be used to inform children's vulnerability based upon likely differences in internal dose from xenobiotic exposure. This might provide a qualitative assessment of toxicokinetic (TK) variability and uncertainty pertinent to early lifestages and help scope a more quantitative physiologically based toxicokinetic (PBTK) assessment. Although much is known regarding the ontogeny of metabolizing systems, this is not commonly utilized in scoping and problem formulation stage of human health risk evaluation. A framework is proposed for introducing this information into problem formulation which combines data on enzyme ontogeny and chemical-specific TK to explore potential child/adult differences in internal dose and whether such metabolic differences may be important factors in risk evaluation. The framework is illustrated with five case study chemicals, including some which are data rich and provide proof of concept, while others are data poor. Case studies for toluene and chlorpyrifos indicate potentially important child/adult TK differences while scoping for acetaminophen suggests enzyme ontogeny is unlikely to increase early-life risks. Scoping for trichloroethylene and aromatic amines indicates numerous ways that enzyme ontogeny may affect internal dose which necessitates further evaluation. PBTK modeling is a critical and feasible next step to further evaluate child-adult differences in internal dose for a number of these chemicals.

  14. Evaluating carbon storage, timber harvest, and habitat possibilities for a Western Cascades (USA) forest landscape.

    Science.gov (United States)

    Kline, Jeffrey D; Harmon, Mark E; Spies, Thomas A; Morzillo, Anita T; Pabst, Robert J; McComb, Brenda C; Schnekenburger, Frank; Olsen, Keith A; Csuti, Blair; Vogeler, Jody C

    2016-10-01

    Forest policymakers and managers have long sought ways to evaluate the capability of forest landscapes to jointly produce timber, habitat, and other ecosystem services in response to forest management. Currently, carbon is of particular interest as policies for increasing carbon storage on federal lands are being proposed. However, a challenge in joint production analysis of forest management is adequately representing ecological conditions and processes that influence joint production relationships. We used simulation models of vegetation structure, forest sector carbon, and potential wildlife habitat to characterize landscape-level joint production possibilities for carbon storage, timber harvest, and habitat for seven wildlife species across a range of forest management regimes. We sought to (1) characterize the general relationships of production possibilities for combinations of carbon storage, timber, and habitat, and (2) identify management variables that most influence joint production relationships. Our 160 000-ha study landscape featured environmental conditions typical of forests in the Western Cascade Mountains of Oregon (USA). Our results indicate that managing forests for carbon storage involves trade-offs among timber harvest and habitat for focal wildlife species, depending on the disturbance interval and utilization intensity followed. Joint production possibilities for wildlife species varied in shape, ranging from competitive to complementary to compound, reflecting niche breadth and habitat component needs of species examined. Managing Pacific Northwest forests to store forest sector carbon can be roughly complementary with habitat for Northern Spotted Owl, Olive-sided Flycatcher, and red tree vole. However, managing forests to increase carbon storage potentially can be competitive with timber production and habitat for Pacific marten, Pileated Woodpecker, and Western Bluebird, depending on the disturbance interval and harvest intensity chosen

  15. Evaluating the Spatial Distribution of Toxic Air Contaminants in Multiple Ecosystem Indicators in the Sierra Nevada-Southern Cascades

    Science.gov (United States)

    Nanus, L.; Simonich, S. L.; Rocchio, J.; Flanagan, C.

    2013-12-01

    Toxic air contaminants originating from agricultural areas of the Central Valley in California threaten vulnerable sensitive receptors including surface water, vegetation, snow, sediments, fish, and amphibians in the Sierra Nevada-Southern Cascades region. The spatial distribution of toxic air contaminants in different ecosystem indicators depends on variation in atmospheric concentrations and deposition, and variation in air toxics accumulation in ecosystems. The spatial distribution of organic air toxics and mercury at over 330 unique sampling locations and sample types over two decades (1990-2009) in the Sierra Nevada-Southern Cascades region were compiled and maps were developed to further understand spatial patterns and linkages between air toxics deposition and ecological effects. Potential ecosystem impacts in the Sierra Nevada-Southern Cascades region include bioaccumulation of air toxics in both aquatic and terrestrial ecosystems, reproductive disruption, and immune suppression. The most sensitive ecological end points in the region that are affected by bioaccumulation of toxic air contaminants are fish. Mercury was detected in all fish and approximately 6% exceeded human consumption thresholds. Organic air toxics were also detected in fish yielding variable spatial patterns. For amphibians, which are sensitive to pesticide exposure and potential immune suppression, increasing trends in current and historic use pesticides are observed from north to south across the region. In other indicators, such as vegetation, pesticide concentrations in lichen increase with increasing elevation. Current and historic use pesticides and mercury were also observed in snowpack at high elevations in the study area. This study shows spatial patterns in toxic air contaminants, evaluates associated risks to sensitive receptors, and identifies data gaps. Future research on atmospheric modeling and information on sources is needed in order to predict which ecosystems are the

  16. The Cascade Mountains revisited: A re-evaluation in light of new lead isotopic data

    International Nuclear Information System (INIS)

    Church, S.E.

    1976-01-01

    Lead isotopic analyses have been repeated using silica gel for several samples from the Cascade Mountains which were previously analyzed by lead sulfide. The improved precision indicates that some of the scatter in the original data was due to thermal fractionation; however, the bulk of the data have not changed significantly. Two-point mixing lines are demonstrated for main cone-satellitic cone pairs from Glacier Peak, Mt. Baker and Mt. Shasta. Comparison with data on oceanic basalts from the Juan de Fuca and Gorda Ridge area indicates that hypothesis of mixing of mid-ocean ridge (MOR) basalt lead and 'alkali basalt-like' lead from the oceanic crust is not tenable. Lead isotope analyses of pre-Astoria Fan sediments from DSDP Leg 18 sites and from the Eocene Tyee Formation indicate that the sedimentary continental detritus from the North American continent has the correct lead isotopic composition to be the continental component necessary to account for the Cascade Mountains lead isotopic array by mixing with Juan de Fuca-Gorda Ridge MOR basalts. However, from recent work on the structure of oceanic trenches by Karig and Sharman (1975), it does not appear that subduction of sediments is the rule. A model of crustal contamination and/or assimilation at the crust/mantle interface is the preferred explanation for the lead isotopic data from the Cascade Mountains. (Auth.)

  17. Evaluation of the efficiency of alternative enzyme production technologies

    DEFF Research Database (Denmark)

    Albæk, Mads Orla

    Enzymes are used in an increasing number of industries. The application of enzymes is extending into the production of lignocellulosic ethanol in processes that economically can compete with fossil fuels. Since lignocellulosic ethanol is based on renewable resources it will have a positive impact...... production of cellulases and hemi-cellulases. The aim of the thesiswas to use modeling tools to identify alternative technologies that have higher energy or raw material efficiency than the current technology. The enzyme production by T. reesei was conducted as an aerobic fed-batch fermentation. The process...... of the uncertainty and sensitivity of the model indicated the biological parameters to be responsible for most of the model uncertainty. A number of alternative fermentation technologies for enzyme production were identified in the open literature. Their mass transfer capabilities and their energy efficiencies were...

  18. Evaluation of Myceliopthora thermophila as an Enzyme Factory for the Production of Thermophilic Cellulolytic Enzymes

    Directory of Open Access Journals (Sweden)

    Leonidas Matsakas

    2015-07-01

    Full Text Available Enzymatic hydrolysis is a key step in bioethanol production. Efficient hydrolysis requires a consortium of different enzymes that are able to hydrolyze cellulose and hemicellulose into fermentable sugars. Myceliopthora thermophila is a promising candidate for the production of thermophilic cellulolytic enzymes, the use of which could reduce the cost of ethanol production. The growth conditions of the fungus were optimized in order to achieve increased secretion of extracellular cellulases. Optimal conditions were found to be 7.0% w/v brewer’s spent grain as the carbon source and 0.4% w/v ammonium sulfate as the nitrogen source. The cellulases obtained were characterized for their optimum activity. The optimum temperature and pH for cellulase activity are 65 °C and pH 5.5, respectively. Studies on thermal inactivation of the crude extract showed that the cellulases of M. thermophila are stable for temperatures up to 60 °C. At this temperature the half-life was found to be as high as 27 h. Enzymatic hydrolysis of cellulose resulted in 31.4% hydrolysis yield at 60 °C after 24 h of incubation. Finally, the recalcitrance constant for cellulose and cellulose pretreated with ionic liquids was calculated to be 5.46 and 2.69, respectively.

  19. Evaluation Of Antibody Elisa, Coproscopy And Serum Enzyme ...

    African Journals Online (AJOL)

    Le titrage avec immunoadsorbant lié à une enzyme (ELISA), la sédimentation fécale et les tests de l'action de l'enzyme du sérum ont été faits sur des échantillons de fèces et de sérum recueillis de 134 bovins (55 positifs et 79 négatifs pour les lésions dues à la douve du foie) lors de l'inspection de viande en Ethiopie.

  20. Evaluation of liver marker enzymes in diabetic subjects in the ...

    African Journals Online (AJOL)

    The activity levels of the liver marker enzymes; Aspartate and Alanine amino transferases (AST and ALT), Alkaline Phosphatase (ALP) and Gamma glutamyltransferase (GGT) in diabetic and non-diabetic subjects within the ages of 25 to 86 were assayed. This study was for two weeks. The results indicated that the plasma ...

  1. Evaluation of design factors for a cascade aerator to enhance the efficiency of an oxidation pond for ferruginous mine drainage.

    Science.gov (United States)

    Oh, Chamteut; Ji, Sangwoo; Cheong, Youngwook; Yim, Giljae; Hong, Ji-Hye

    2016-10-01

    This research focused on the optimum design of a cascade aerator to enhance the efficiency of an oxidation pond in a passive treatment system for remediating ferruginous mine drainage. For this purpose, various aeration experiments with aerators of different drop heights (0-4 m) and formations (types A and B) were executed on mine drainage. Type A simply drops the mine drainage into the oxidation pond while type B sprays the mine drainage and retains it for 8 min in each step. The efficiency enhancement of the oxidation pond was strongly dependent on the increase in pH and DO of the mine drainage discharged into the pond. The water quality improved with the increase in drop height but especially showed better effect with type B. The reasons for this result were attributed to the increase of contact surface and retention time of the mine drainage. The cascade aerator, therefore, should be designed to be as high as possible with the assistance of spraying form and retention time of the mine drainage to maximize the efficiency of the oxidation pond. These effects could be evaluated by calculating required areas of the oxidation pond for 95% of Fe(2+) oxidation.

  2. Learning Cascading

    CERN Document Server

    Covert, Michael

    2015-01-01

    This book is intended for software developers, system architects and analysts, big data project managers, and data scientists who wish to deploy big data solutions using the Cascading framework. You must have a basic understanding of the big data paradigm and should be familiar with Java development techniques.

  3. The real time mass evaluation system as a tool for detection of undeclared cascade operation at GCEPs

    OpenAIRE

    Delbeke, J.F.A.; Howell, J.; Eklund, G.; Peerani, P.; Janssens, W.

    2008-01-01

    Given the flexibility of current cascade designs a real time mass monitoring system is preferred for safeguarding Gas Centrifuge Enrichment Plants. However, if such a system is to be installed in a GCEP it must not impinge on plant operation or be intrusive. Since load cells are already part of the operational process and located outside the cascade hall their exploitation for safeguards purposes is an obvious development. The paper describes, through dynamic simulations, how transients would...

  4. Evaluating correlation between serum liver enzymes and toxocariasis: a case control study

    Directory of Open Access Journals (Sweden)

    Hosein Miladi

    2016-06-01

    Full Text Available Objective: To evaluate the prevalence of toxocariasis in individuals with the normal and abnormal level of liver enzymes. Methods: In this case-control study, the serum samples were collected in the individuals referred to diagnostic laboratories of Arak in Iran. A total of 144 sera with abnormal level of liver enzymes were selected as cases and the same numbers of sera with the normal level of liver enzymes also were selected as controls. The sera were examined for anti-Toxocara IgG. Results: Twelve (4.2% sera contained anti-Toxocara antibody and all of them were in the case group. Although the mean of all liver enzymes was significantly different in the two groups (P < 0.05, statistical test showed no relationship between the level of liver enzymes and toxocariasis. Conclusions: It was concluded that the liver enzyme alteration is not the valid indicator for predicting toxocariasis. Because the kind of liver dysfunction, that is caused by the larvae of Toxocara, is unspecified, and it seems factors such as the number of larvae can play a basic role for the emergence of alterations.

  5. Milk-derived peptide Val-Pro-Pro (VPP) inhibits obesity-induced adipose inflammation via an angiotensin-converting enzyme (ACE) dependent cascade.

    Science.gov (United States)

    Sawada, Yoko; Sakamoto, Yuri; Toh, Mariko; Ohara, Nozomi; Hatanaka, Yuiko; Naka, Ayano; Kishimoto, Yoshimi; Kondo, Kazuo; Iida, Kaoruko

    2015-12-01

    This study aimed to examine the effects of Val-Pro-Pro (VPP), a food-derived peptide with an angiotensin-converting enzyme (ACE) inhibitory property, on obesity-linked insulin resistance, and adipose inflammation in vivo and in vitro. C57BL/6J mice were fed high-fat high-sucrose diet and VPP (0.1% in water) for 4 months. For in vitro analysis, coculture of 3T3-L1 adipocytes overexpressing either ACE (3T3-ACE) or green fluorescent protein (3T3-GFP) and RAW264 macrophages was conducted with VPP. In diet-induced obese mice, VPP improved insulin sensitivity, concomitant with a significant decrease in tumor necrosis factor α (TNF-α) and IL-1β expression in adipose tissue, with a tendency (p = 0.06) toward decreased CC chemokine ligand 5 expression. Additionally, VPP administration inhibited macrophage accumulation and activation in fat tissues. In vitro, VPP attenuated TNF-α mRNA induced by ACE overexpression in 3T3-L1 adipocytes. TNF-α and IL-1β expression decreased following VPP treatment of RAW264 macrophage and 3T3-ACE adipocyte cocultures, but not in RAW264-3T3-GFP adipocyte cocultures. Our data suggest that VPP inhibits adipose inflammation in the interaction between adipocytes and macrophages, acting as an ACE inhibitor, thereby improving obesity-related insulin resistance. Thus, ingestion of VPP may be a viable protective and therapeutic strategy for insulin resistance and obesity-associated adipose inflammation. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Cost evaluation of cellulase enzyme for industrial-scale cellulosic ethanol production based on rigorous Aspen Plus modeling.

    Science.gov (United States)

    Liu, Gang; Zhang, Jian; Bao, Jie

    2016-01-01

    Cost reduction on cellulase enzyme usage has been the central effort in the commercialization of fuel ethanol production from lignocellulose biomass. Therefore, establishing an accurate evaluation method on cellulase enzyme cost is crucially important to support the health development of the future biorefinery industry. Currently, the cellulase cost evaluation methods were complicated and various controversial or even conflict results were presented. To give a reliable evaluation on this important topic, a rigorous analysis based on the Aspen Plus flowsheet simulation in the commercial scale ethanol plant was proposed in this study. The minimum ethanol selling price (MESP) was used as the indicator to show the impacts of varying enzyme supply modes, enzyme prices, process parameters, as well as enzyme loading on the enzyme cost. The results reveal that the enzyme cost drives the cellulosic ethanol price below the minimum profit point when the enzyme is purchased from the current industrial enzyme market. An innovative production of cellulase enzyme such as on-site enzyme production should be explored and tested in the industrial scale to yield an economically sound enzyme supply for the future cellulosic ethanol production.

  7. The Real Time Mass Evaluation System as a tool for the detection of undeclared cascade operation at GCEPs

    NARCIS (Netherlands)

    Delbeke, J.F.A.; Howell, J.; Eklund, G.; Janssens-Maenhout, G.; Peerani, P.; Janssens, W.

    2008-01-01

    Given the flexibility of current cascade designs a real time mass monitoring system is preferred for safeguarding Gas Centrifuge Enrichment Plants. However, if such a system is to be installed in a GCEP it must not impinge on plant operation or be intrusive. Since load cells are already part of the

  8. SELECTIVE EVALUATION OF TWO URINARY ENZYMES (NAG AND AAP BEFORE AND AFTER UNILATERAL SHOCK WAVE LITHOTRIPSY

    Directory of Open Access Journals (Sweden)

    M. R. Nikoobakht

    2006-09-01

    Full Text Available Biological effects extracorporeal shock wave lithotripsy (ESWL is not precisely known. We have evaluated two urinary enzymes activity N-acetyl-B-D-glucosamine (NAG and alanine amino peptidase (AAP before and after unilateral ESWL as markers for renal parenchymal damage. Forty eight patients with kidney stones (mean age 39 who had presented for the first time or at least one year after their previous lithotripsy underwent ESWL. Urinary specimens were collected before and after first, third and seventh days of lithotripsy and NAG, AAP were evaluated. These enzymes displayed the greatest activity 24 hours after ESWL with significant difference compared to the control group, (P < 0.05 versus 0.02. Elevation of urinary enzymes activity correlated with stone size particularly stones larger than 2 cm. These data suggest that there is some tubular and parenchymal damage induced by ESWL that needs time to get improved. The higher urinary enzyme activity in patients with larger stones ( > 2 cm is probably related to injury resulting from passage of smaller stones, produced after lithotripsy of a large stone, and it is suggested that these patients are treated with a safer procedure.

  9. Comprehensive evaluation of SNP identification with the Restriction Enzyme-based Reduced Representation Library (RRL method

    Directory of Open Access Journals (Sweden)

    Du Ye

    2012-02-01

    Full Text Available Abstract Background Restriction Enzyme-based Reduced Representation Library (RRL method represents a relatively feasible and flexible strategy used for Single Nucleotide Polymorphism (SNP identification in different species. It has remarkable advantage of reducing the complexity of the genome by orders of magnitude. However, comprehensive evaluation for actual efficacy of SNP identification by this method is still unavailable. Results In order to evaluate the efficacy of Restriction Enzyme-based RRL method, we selected Tsp 45I enzyme which covers 266 Mb flanking region of the enzyme recognition site according to in silico simulation on human reference genome, then we sequenced YH RRL after Tsp 45I treatment and obtained reads of which 80.8% were mapped to target region with an 20-fold average coverage, about 96.8% of target region was covered by at least one read and 257 K SNPs were identified in the region using SOAPsnp software. Compared with whole genome resequencing data, we observed false discovery rate (FDR of 13.95% and false negative rate (FNR of 25.90%. The concordance rate of homozygote loci was over 99.8%, but that of heterozygote were only 92.56%. Repeat sequences and bases quality were proved to have a great effect on the accuracy of SNP calling, SNPs in recognition sites contributed evidently to the high FNR and the low concordance rate of heterozygote. Our results indicated that repeat masking and high stringent filter criteria could significantly decrease both FDR and FNR. Conclusions This study demonstrates that Restriction Enzyme-based RRL method was effective for SNP identification. The results highlight the important role of bias and the method-derived defects represented in this method and emphasize the special attentions noteworthy.

  10. Evaluation of automated enzyme immunoassays for five anticonvulsants and theophylline adapted to a centrifugal analyzer.

    Science.gov (United States)

    Urquhart, N; Godolphin, W; Campbell, D J

    1979-05-01

    We report a clinical evaluation of the enzyme immunoassay (EMIT) performed with the GEMSAEC centrifugal analyzer as compared to gas-liquid and liquid chromatography for anticonvulsant drugs and theophylline, respectively. A good correlation was obtained for all drugs, although some difficulties were experienced with one lot of reagent for ethosuximide. The analyzer has an economic advantage if many samples are being analyzed for few drugs in each sample.

  11. Multi-approach evaluations of a cascade-Organic Rankine Cycle (C-ORC) system driven by diesel engine waste heat: Part A – Thermodynamic evaluations

    International Nuclear Information System (INIS)

    Shu, Gequn; Yu, Guopeng; Tian, Hua; Wei, Haiqiao; Liang, Xingyu; Huang, Zhiyong

    2016-01-01

    Highlights: • A novel C-ORC system was proposed for recovering waste heat from a diesel engine. • Thermodynamic evaluations were conducted to explore C-ORC’s practical benefits. • C-ORC has significant heat-recovery capacities and efficiency-promotion potential. • Up to 16.0% of engine efficiency can be improved combining with C-ORC. - Abstract: A novel transcritical cascade-Organic Rankine Cycle (C-ORC) system was proposed to recover multi-grade waste heat from a typical heavy-duty diesel engine. The C-ORC comprises of a high-temperature ORC loop (HT-Loop) and a low temperature ORC loop (LT-Loop) to recover waste heat from an engine’s exhaust gas (EG), exhaust gas recirculation (EGR), jacket water (JW) and charge air (CA) in a cascaded pattern. In order to reveal the full performance of the C-ORC system, with due consideration to diesel’s complex practical running conditions, multi-approach evaluations were conducted containing two parts: Part A – thermodynamic evaluations of the energy and exergy aspects and Part B – techno-economic evaluations on costs and benefits aspects. This paper shows the Part A – evaluations of the C-ORC, focusing on indexes including recovered waste heat, net power output, thermal efficiencies and exergy efficiencies. First of all, distributions of the engine’s multi-grade waste heat were studied to reveal the characteristics and utilization potential of waste energy. The comparison and screening of working fluids were carried out next to find the best fluids for the HT-Loop and LT-Loop respectively based on the rated engine condition. Toluene, decane, cyclohexane and D4 were four proper alternatives for the HT-Loop while R143a, R125, R218 and R41 were four proper alternatives for the LT-Loop. Comparisons indicated that toluene and R143a made the perfect match for the C-ORC with the highest net power output (33.9 kW), thermal efficiency (9.9%) and exergy efficiency (39.1%). The rankings of the two groups of

  12. Evaluation of the Activities of Antioxidant Enzyme and Lysosomal Enzymes of the Longissimus dorsi Muscle from Hanwoo (Korean Cattle) in Various Freezing Conditions

    OpenAIRE

    Kang, Sun Moon; Kang, Geunho; Seong, Pil-Nam; Park, Beomyoung; Kim, Donghun; Cho, Soohyun

    2014-01-01

    This study was conducted to evaluate the activities of antioxidant enzyme (glutathione peroxidase (GSH-Px)) and lysosomal enzymes (alpha-glucopyranosidase (AGP) and beta-N-acetyl-glucosaminidase (BNAG)) of the longissimus dorsi (LD) muscle from Hanwoo (Korean cattle) in three freezing conditions. Following freezing at -20, -60, and -196? (liquid nitrogen), LD samples (48 h post-slaughter) were treated as follows: 1) freezing for 14 d, 2) 1 to 4 freeze-thaw cycles (2 d of freezing in each cycl...

  13. Multi-approach evaluations of a cascade-Organic Rankine Cycle (C-ORC) system driven by diesel engine waste heat: Part B-techno-economic evaluations

    International Nuclear Information System (INIS)

    Yu, Guopeng; Shu, Gequn; Tian, Hua; Wei, Haiqiao; Liang, Xingyu

    2016-01-01

    Highlights: • A novel C-ORC system was proposed for recovering waste heat from a diesel engine. • Techno-economic evaluations were conducted to explore C-ORC’s practical benefits. • Toluene and R143a show the best economic performance for two ORC loops in C-ORC. • The best electricity production cost is 0.27 Dollar/kW h under engine conditions. - Abstract: A novel transcritical cascade-Organic Rankine Cycle (C-ORC) system was proposed for recovering multi-grade waste heat from a typical heavy-duty diesel engine. The C-ORC comprises a high temperature ORC loop (HT-Loop) and a low temperature ORC loop (LT-Loop) for recovering waste heat from engine exhaust gas (EG), exhaust gas recirculation (EGR), jacket water (JW) and charge air (CA) in a cascaded pattern. The basic thermodynamic evaluation on energy and exergy aspects were covered in the companion piece-‘Part A-thermodynamic evaluations’, indicating that the proposed C-ORC possesses great heat-recovery capacities and efficiency-promotion potentials. The techno-economic evaluations in Part B of this paper will further explore the performance of the C-ORC system based on costs and benefits in order to reveal its practical benefits. Four techno-economic indexes are mainly focused on: component-to-system cost ratio (CSCR), electricity production cost (EPC), depreciated payback period (DPP) and savings-to-investment ratio (SIR). Under rated engine conditions, working fluids were initially compared to find the most economical fluids for the HT-Loop and the LT-Loop respectively. Results indicated that toluene and R143a still make the perfect match for the C-ORC with the lowest EPC (0.27 Dollar/kW h), DPP (7.8 years) and the highest SIR (1.6). As to component-to-system cost ratio (CSCR), the cost of expanders and heat exchangers together account for more than 3/4 of the total system cost, and the expander of the LT-Loop is the most costly single component. The C-ORC’s techno-economic performance was

  14. Evaluation of the energy efficiency of enzyme fermentation by mechanistic modeling

    DEFF Research Database (Denmark)

    Albaek, Mads O.; Gernaey, Krist V.; Hansen, Morten S.

    2012-01-01

    Modeling biotechnological processes is key to obtaining increased productivity and efficiency. Particularly crucial to successful modeling of such systems is the coupling of the physical transport phenomena and the biological activity in one model. We have applied a model for the expression of ce...... was found. This modeling approach can be used by manufacturers to evaluate the enzyme fermentation process for a range of different process conditions with regard to energy efficiency.......Modeling biotechnological processes is key to obtaining increased productivity and efficiency. Particularly crucial to successful modeling of such systems is the coupling of the physical transport phenomena and the biological activity in one model. We have applied a model for the expression...... of cellulosic enzymes by the filamentous fungus Trichoderma reesei and found excellent agreement with experimental data. The most influential factor was demonstrated to be viscosity and its influence on mass transfer. Not surprisingly, the biological model is also shown to have high influence on the model...

  15. A Sm(II)-mediated cascade approach to Dibenzoindolo[3,2-b]carbazoles : synthesis and evaluation

    OpenAIRE

    Levick, Matthew T.; Grace, Iain; Dai, Sheng-Yao; Kasch, Nicholas; Muryn, Christopher; Lambert, Colin; Turner, Michael L.; Procter, David J.

    2014-01-01

    Previously unstudied dibenzoindolo[3,2-b]carbazoles have been prepared by two-directional, phase tag-assisted synthesis utilizing a connective-Pummerer cyclization and a SmI2-mediated tag cleavage-cyclization cascade. The use of a phase tag allows us to exploit unstable intermediates that would otherwise need to be avoided. The novel materials were characterized by X-ray, cyclic voltammetry, UV-vis spectroscopy, TGA, and DSC. Preliminary studies on the performance of OFET devices are also des...

  16. Abnormal cascading failure spreading on complex networks

    International Nuclear Information System (INIS)

    Wang, Jianwei; Sun, Enhui; Xu, Bo; Li, Peng; Ni, Chengzhang

    2016-01-01

    Applying the mechanism of the preferential selection of the flow destination, we develop a new method to quantify the initial load on an edge, of which the flow is transported along the path with the shortest edge weight between two nodes. Considering the node weight, we propose a cascading model on the edge and investigate cascading dynamics induced by the removal of the edge with the largest load. We perform simulated attacks on four types of constructed networks and two actual networks and observe an interesting and counterintuitive phenomenon of the cascading spreading, i.e., gradually improving the capacity of nodes does not lead to the monotonous increase in the robustness of these networks against cascading failures. The non monotonous behavior of cascading dynamics is well explained by the analysis on a simple graph. We additionally study the effect of the parameter of the node weight on cascading dynamics and evaluate the network robustness by a new metric.

  17. Evaluation of the energy efficiency of enzyme fermentation by mechanistic modeling.

    Science.gov (United States)

    Albaek, Mads O; Gernaey, Krist V; Hansen, Morten S; Stocks, Stuart M

    2012-04-01

    Modeling biotechnological processes is key to obtaining increased productivity and efficiency. Particularly crucial to successful modeling of such systems is the coupling of the physical transport phenomena and the biological activity in one model. We have applied a model for the expression of cellulosic enzymes by the filamentous fungus Trichoderma reesei and found excellent agreement with experimental data. The most influential factor was demonstrated to be viscosity and its influence on mass transfer. Not surprisingly, the biological model is also shown to have high influence on the model prediction. At different rates of agitation and aeration as well as headspace pressure, we can predict the energy efficiency of oxygen transfer, a key process parameter for economical production of industrial enzymes. An inverse relationship between the productivity and energy efficiency of the process was found. This modeling approach can be used by manufacturers to evaluate the enzyme fermentation process for a range of different process conditions with regard to energy efficiency. Copyright © 2011 Wiley Periodicals, Inc.

  18. Evaluation of a UCMK/dCK fusion enzyme for gemcitabine-mediated cytotoxicity

    International Nuclear Information System (INIS)

    Johnson, Adam J.; Brown, Melissa N.; Black, Margaret E.

    2011-01-01

    Highlights: ► Goal was to enhance dFdC cytotoxicity by the creation of a UCMK/dCK fusion enzyme. ► The UCMK/dCK fusion enzyme possesses both native activities. ► The fusion renders cells equally sensitive to dFdC relative to dCK expression alone. ► Dual activities of fusion not sufficient to augment cell dFdC sensitivity in vitro. ► Data may warrant the implementation of UCMK mutagenesis studies. -- Abstract: While gemcitabine (2′-2′-difluoro-2′-deoxycytidine, dFdC) displays wide-ranging antineoplastic activity as a single agent, variable response rates and poor intracellular metabolism often limit its clinical efficacy. In an effort to enhance dFdC cytotoxicity and help normalize response rates, we created a bifunctional fusion enzyme that combines the enzymatic activities of deoxycytidine kinase (dCK) and uridine/cytidine monophosphate kinase (UCMK) in a single polypeptide. Our goal was to evaluate whether the created fusion could induce beneficial, functional changes toward dFdC, expedite dFdC conversion to its active antimetabolites and consequently amplify cell dFdC sensitivity. While kinetic analyses revealed the UCMK/dCK fusion enzyme to possess both native activities, the fusion rendered cells sensitive to the cytotoxic effects of dFdC at the same level as dCK expression alone. These results suggest that increased wild-type UCMK expression does not provide a significant enhancement in dFdC-mediated cytotoxicity and may warrant the implementation of studies aimed at engineering UCMK variants with improved activity toward gemcitabine monophosphate.

  19. Cascade annealing: an overview

    International Nuclear Information System (INIS)

    Doran, D.G.; Schiffgens, J.O.

    1976-04-01

    Concepts and an overview of radiation displacement damage modeling and annealing kinetics are presented. Short-term annealing methodology is described and results of annealing simulations performed on damage cascades generated using the Marlowe and Cascade programs are included. Observations concerning the inconsistencies and inadequacies of current methods are presented along with simulation of high energy cascades and simulation of longer-term annealing

  20. Signaling Cascades: Consequences of Varying Substrate and Phosphatase Levels

    DEFF Research Database (Denmark)

    Feliu, Elisenda; Knudsen, Michael; Wiuf, Carsten Henrik

    2012-01-01

    We study signaling cascades with an arbitrary number of layers of one-site phosphorylation cycles. Such cascades are abundant in nature and integrated parts of many pathways. Based on the Michaelis-Menten model of enzyme kinetics and the law of mass-action, we derive explicit analytic expressions...

  1. Cascade enzymatic reactions for efficient carbon sequestration.

    Science.gov (United States)

    Xia, Shunxiang; Zhao, Xueyan; Frigo-Vaz, Benjamin; Zheng, Wenyun; Kim, Jungbae; Wang, Ping

    2015-04-01

    Thermochemical processes developed for carbon capture and storage (CCS) offer high carbon capture capacities, but are generally hampered by low energy efficiency. Reversible cascade enzyme reactions are examined in this work for energy-efficient carbon sequestration. By integrating the reactions of two key enzymes of RTCA cycle, isocitrate dehydrogenase and aconitase, we demonstrate that intensified carbon capture can be realized through such cascade enzymatic reactions. Experiments show that enhanced thermodynamic driving force for carbon conversion can be attained via pH control under ambient conditions, and that the cascade reactions have the potential to capture 0.5 mol carbon at pH 6 for each mole of substrate applied. Overall it manifests that the carbon capture capacity of biocatalytic reactions, in addition to be energy efficient, can also be ultimately intensified to approach those realized with chemical absorbents such as MEA. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. The Application of Six Sigma Techniques in the Evaluation of Enzyme Measurement Procedures in China.

    Science.gov (United States)

    Zhang, Chuanbao; Zhao, Haijian; Wang, Jing; Zeng, Jie; Wang, Zhiguo

    2015-01-01

    Recently, Six Sigma techniques have been adopted by clinical laboratories to evaluate laboratory performance. Measurement procedures in laboratories can be categorized as "excellent", "good", and "improvement needed" based on sigma (σ) metrics of σ ≥ 6, 3 ≤ σ 1.2 indicates that the trueness of the procedure needs to be improved; 0.8 ≤ QGI ≤ 1.2 indicates that both the precision and trueness of the procedure need to be improved. Fresh frozen sera containing seven enzymes (ALT, ALP, AMY, AST, CK, GGT, and LDH) were sent to 78 clinical laboratories in China. The biases for measurement procedures in each laboratory (Bias) were calculated based on the target values assigned by 18 laboratories performing IFCC (International Federation of Clinical Chemistry and Laboratory medicine) recommended reference methods. The imprecision of each measurement procedure was represented by coefficient variations (CV) calculated based on internal quality control (IQC) data. The σ and QGI values were calculated as follows: σ = (TEa-Bias)/CV; QGI = Bias/(1.5 x CV). TEa is allowable total error for each enzyme derived from biological variation. Our study indicated that 7.9% (6/76, ALP) to 31.0% (18/58, AMY) of the participating laboratories were scored as "excellent" (σ ≥ 6), 21.1% (16/76, ALP) to 41.3% (31/75, CK) of the laboratories were scored as "good" (3 ≤ σ Six Sigma techniques still suggested that approximately 31.1% to 71.0% of the laboratories need to improve their enzyme measurement procedures, either in terms of precision, trueness, or both.

  3. Evaluation, partial characterization and purification of acetylcholine esterase enzyme and antiangiogenic activity from marine sponges

    Directory of Open Access Journals (Sweden)

    Maushmi Shailesh Kumar

    2014-11-01

    Full Text Available Objective: To test three marine sponges Halichondria glabrata Keller, 1891; Spirastrella pachyspira (S. pachyspira Levi, 1958 and Cliona lobata Hancock, 1849 for the presence of the acetylcholinesterase (AChE in both young and developed samples from western coastal area of India. S. pachyspira methanolic extract was selected for anti/pro angiogenic activity. Methods: They were evaluated for AChE activity using Ellman’s assay based on production of yellow colored 5-thio-2-nitrobenzoate. Purification of the enzyme was planned using ammonium sulphate precipitation and characterization by sodium dodecyl sulfate polyacrylamide gel electrophoresis. Chorioallantoic membrane (ChAM assay model was used for angiogenic/ antiangiogenic testing. Results: All the three sponges showed good specific enzyme activity and S. pachyspira contained maximum specific enzyme activity. Sixty percent of ammonium sulphate precipitation of crude protein sample gave single band at 66 kDa corresponding to the true AChE. ChAM assay was performed at 62.5, 125.0 and 250.0 µg/mL. Dosage beyond 250 µg/mL extract showed toxic response with anti angiogenic activity at all the concentrations. Conclusions: AChE activity was detected in all samples. Extract showed good anti-angiogenic response at 62.5 µg/mL. Extract was highly toxic affecting microvasculature of ChAM as well as normal growth and development of the embryo at 500 µg/mL. With further characterization of bioactive compounds from the extract of S. pachyspira, the compounds can be developed for anti tumor activity.

  4. Evaluation of serum angiotension converting enzyme (SACE) as a diagnostic marker for pulmonary embolism

    International Nuclear Information System (INIS)

    Bokhari, S.N.H.; Naeem, M.

    2002-01-01

    Objective: A number of supportive laboratory tests such as ECG, Chest x-ray, ABGs SLDH, SGOT, S. Bilirubin and D-dimer with variable sensitivity and specificity are available to facilitate the clinical diagnosis of acute Pulmonary Embolism (PE). Serum Angiotensin Converting Enzyme (SACE) which is produced mainly by the pulmonary vascular endothelial cells, is found altered during a variety of diffuse lung diseases. This study was designed to evaluate the validity of SACE level as a marker for hypoxic damage to the pulmonary endothelium in PE. Design: A prospective study carried out on forty patients with high clinical suspicion of PE. Besides routine diagnostic tests mentioned above all of them had ventilation Perfusion isotope (v/q) scans (as a diagnostic test) and SACE level checked. Setting: Shaikh Zayed Hospital Lahore. Results: Among forty consecutive patients with age range 25-59 years (mean: 42 Yr). Twenty six patients (65%) with abnormal scans reported as High probability were included in group-A (True Positive), whereas 14(35)% patients having low-probability (suspected or Normal scan were included in group-b, low SACE level (<28iu/l) was found in 19/26 (sensitivity of 73% in group-A (positive Predictive Value: 47%) and 9/14(sensitivity of 64%) in Group-B. Whereas mean levels for both groups were 34.55 and 54.84 respectively. Rise in LDH was pronounced in group A. Only chest x-ray and ECGS were found to be more sensitive for group-A than group-B. Changes in ABGs (type-1 resp. Failure) had low sensitivity. Conclusion: Among clinically suspected cases of PE, fall in SACE level can be used as a sensitive and reliable diagnostic marker as more than 75% of the enzyme in produced in the lungs compared with other enzymes which have extra-pulmonary source. (author)

  5. Evaluation of enzymes inhibition activities of medicinal plant from Burkina Faso.

    Science.gov (United States)

    Bangou, Mindiédiba Jean; Kiendrebeogo, Martin; Meda, Nâg-Tiero Roland; Coulibaly, Ahmed Yacouba; Compaoré, Moussa; Zeba, Boukaré; Millogo-Rasolodimby, Jeanne; Nacoulma, Odile Germaine

    2011-01-15

    The aim of the present study was to evaluate some enzymes inhibitory effects of 11 plant species belonging to 9 families from Burkina Faso. Methanolic extracts were used for their Glutathione-s-transferase (GST), Acetylcholinesterase (AChE), Carboxylesterase (CES) and Xanthine Oxidase (XO) inhibitory activities at final concentration of 100 microg mL(-1). The total phenolics, flavonoids and tannins were also determined spectrophotometrically using Folin-Ciocalteu, AlCl3 and ammonium citrate iron reagents, respectively. Among the 11 species tested, the best inhibitory percentages were found with Euphorbia hirta, Sclerocarya birrea and Scoparia dulcis (inhibition > 40%) followed by Annona senegalensis, Annona squamosa, Polygala arenaria and Ceratotheca sesamoides (inhibition > 25%). The best total phenolic and tannin contents were found with S. birrea with 56.10 mg GAE/100 mg extract and 47.75 mg TAE/100 mg extract, respectively. E hirta presented the higher total flavonoids (9.96 mg QE/100 mg extract). It's was found that Sclerocarya birrea has inhibited all enzymes at more than 30% and this activity is correlated to total tannins contents. Contrary to S. birrea, the enzymatic activities of E. hirta and S. dulcis are correlated to total flavonoids contents. Present findings suggest that the methanolic extracts of those plant species are potential inhibitors of GST, AChE, CES and XO and confirm their traditional uses in the treatment of mental disorders, gout, painful inflammations and cardiovascular diseases.

  6. Mycoparasitism studies of Trichoderma species against three phytopathogenic fungi: evaluation of antagonism and hydrolytic enzyme production.

    Science.gov (United States)

    Qualhato, Thiago Fernandes; Lopes, Fabyano Alvares Cardoso; Steindorff, Andrei Stecca; Brandão, Renata Silva; Jesuino, Rosália Santos Amorim; Ulhoa, Cirano José

    2013-09-01

    Trichoderma spp. are used for biocontrol of several plant pathogens. However, their efficient interaction with the host needs to be accompanied by production of secondary metabolites and cell wall-degrading enzymes. Three parameters were evaluated after interaction between four Trichoderma species and plant-pathogenic fungi: Fusarium solani, Rhizoctonia solani and Sclerotinia sclerotiorum. Trichoderma harzianum and T. asperellum were the most effective antagonists against the pathogens. Most of the Trichoderma species produced toxic volatile metabolites, having significant effects on growth and development of the plant pathogens. When these species were grown in liquid cultures with cell walls from these plant pathogens, they produced and secreted β-1,3-glucanase, NAGAse, chitinase, acid phosphatase, acid proteases and alginate lyase.

  7. Evaluation of an enzyme-linked immunosorbent assay for determination of porcine haptoglobin

    DEFF Research Database (Denmark)

    Petersen, H. H.; Nielsen, J. P.; Jensen, A.L.

    2001-01-01

    An enzyme-linked immunosorbent assay for quantification of haptoglobin in porcine serum was evaluated. Tbe detection limit when expressed as the estimated concentration of a blank sample was 0.0003 mg/ml. The precision of the assay was acceptable with intra-assay coefficients of variation below 4...... % and inter-assay coefficient of variation below 5 % for serum concentrations ranging from 1.0 mg/ml and above. For samples with a concentration below 0.8 mg/ml, the inter-assay coefficient of variation was above 10 %. The assay maintained linearity under dilution. Recovery was proportional. Haemolysis.......2. The maximum allowable analytical imprecision was 2.6 % and the maximum analytical inaccuracy was 9.9 %. The number of samples required to determine, the true haptoglobin value in an individual pig when accounting for the day-to-day fluctuation was 5. In conclusion, the haptoglobin assay was found...

  8. Immunohistochemical evaluation of proliferation, apoptosis and steroidogenic enzymes in the ovary of rats with polycystic ovary.

    Science.gov (United States)

    Lombardi, Leonardo Augusto; Simões, Ricardo Santos; Maganhin, Carla Cristina; Baracat, Maria Cândida Pinheiro; Silva-Sasso, Gisela Rodrigues; Florencio-Silva, Rinaldo; Soares, José Maria; Baracat, Edmund Chada

    2014-07-01

    to evaluate the immunohistochemical expression of proliferative, apoptotic and steroidogenic enzyme markers in the ovaries of rats with polycystic ovary syndrome (PCOS). twenty rats were divided into two groups: GCtrl - estrous phase, and PCOS - with polycystic ovaries. The GCtrl animals were subjected to a lighting period from 7 am to 7 pm, while the animals with PCOS group remained with continuous lighting for 60 days. Subsequently, the animals were anesthetized, the ovaries were removed and fixed in 10% formaldehyde, prior to paraffin embedding. Sections were stained using H.E. or subjected to immunohistochemical methods for the detection of Ki-67, cleaved caspase-3, CYP11A1, CYP17A1 and CYP19A1. The results were analyzed using Student's t-test (p ovaries of rats with PCOS, responsible for the high levels of androgens and estradiol.

  9. Cascading costs: an economic nitrogen cycle.

    Science.gov (United States)

    Moomaw, William R; Birch, Melissa B L

    2005-09-01

    The chemical nitrogen cycle is becoming better characterized in terms of fluxes and reservoirs on a variety of scales. Galloway has demonstrated that reactive nitrogen can cascade through multiple ecosystems causing environmental damage at each stage before being denitrified to N(2). We propose to construct a parallel economic nitrogen cascade (ENC) in which economic impacts of nitrogen fluxes can be estimated by the costs associated with each stage of the chemical cascade. Using economic data for the benefits of damage avoided and costs of mitigation in the Chesapeake Bay basin, we have constructed an economic nitrogen cascade for the region. Since a single ton of nitrogen can cascade through the system, the costs also cascade. Therefore evaluating the benefits of mitigating a ton of reactive nitrogen released needs to consider the damage avoided in all of the ecosystems through which that ton would cascade. The analysis reveals that it is most cost effective to remove a ton of nitrogen coming from combustion since it has the greatest impact on human health and creates cascading damage through the atmospheric, terrestrial, aquatic and coastal ecosystems. We will discuss the implications of this analysis for determining the most cost effective policy option for achieving environmental quality goals.

  10. Angiotensin-I-converting enzyme and gallium scan in noninvasive evaluation of sarcoidosis

    International Nuclear Information System (INIS)

    Nosal, A.; Schleissner, L.A.; Mishkin, F.S.; Lieberman, J.

    1979-01-01

    Angiotensin-converting enzyme assays and gallium-scan results were obtained from 27 patients with biopsy-proven, clinically active sarcoidosis. Twenty-three of these patients had elevated converting enzyme levels, and 22 had positive gallium-scan results. Three of four patients with normal or borderline-elevated levels of angiotensin-converting enzyme also had positive gallium-scan results. Of 156 nonsarcoid patients (pulmonary and other diseases), 27 were found to have elevated serum converting enzyme levels, and 25 of these had negative gallium-scan results. These results indicate that the combination of an assay of angiotensin-converting enzyme and gallium scan increases diagnostic specificity from 83% to 99% without sacrificing sensitivity. It was concluded that the concurrent use of angiotensin-converting enzyme assay and gallium scan is of value in the diagnosis of sarcoidosis

  11. Angiotensin-I-converting enzyme and gallium scan in noninvasive evaluation of sarcoidosis

    Energy Technology Data Exchange (ETDEWEB)

    Nosal, A. (Harbor General Hospital, Torrance, CA); Schleissner, L.A.; Mishkin, F.S.; Lieberman, J.

    1979-03-01

    Angiotensin-converting enzyme assays and gallium-scan results were obtained from 27 patients with biopsy-proven, clinically active sarcoidosis. Twenty-three of these patients had elevated converting enzyme levels, and 22 had positive gallium-scan results. Three of four patients with normal or borderline-elevated levels of angiotensin-converting enzyme also had positive gallium-scan results. Of 156 nonsarcoid patients (pulmonary and other diseases), 27 were found to have elevated serum converting enzyme levels, and 25 of these had negative gallium-scan results. These results indicate that the combination of an assay of angiotensin-converting enzyme and gallium scan increases diagnostic specificity from 83% to 99% without sacrificing sensitivity. It was concluded that the concurrent use of angiotensin-converting enzyme assay and gallium scan is of value in the diagnosis of sarcoidosis.

  12. Evaluation of enzyme immunoassay techniques for diagnosis of the most common intestinal protozoa in fecal samples.

    Science.gov (United States)

    Gaafar, Maha R

    2011-08-01

    This study was designed to evaluate the antigen capture enzyme immunoassays (EIAs) Triage parasite panel and TechLab Entamoeba histolytica II in detecting Giardia intestinalis, Cryptosporidium sp, and Entamoeba histolytica in fecal samples in comparison to microscopy, and in differentiating Entamoeba histolytica from Entamoeba dispar. The Triage EIA was evaluated using 100 stool specimens that were tested by standard ova and parasite examination, including staining with both trichrome and modified acid-fast stains. Differentiation between E. histolytica and E. dispar was performed using TechLab. Microscopic examination revealed that 19% of the samples were positive for Giardia, 4% for Cryptosporidium, and 1% for E. histolytica/E. dispar, and other parasites were found in 5%. By Triage, 23% of the samples were infected with Giardia, 5% with Cryptosporidium, and 2% with E. histolytica/E. dispar. Triage showed a sensitivity of 100% and specificity of 91.5%. The TechLab assay was negative for both samples diagnosed as E. histolytica/E. dispar by Triage, which suggested that they were E. dispar. Both tests showed no cross-reactivity with other intestinal protozoa. These results indicate that antigen detection by EIA has the potential to become a valuable tool, capable of making stool diagnostics more effective. Copyright © 2011 International Society for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

  13. Cascade quantum teleportation

    Institute of Scientific and Technical Information of China (English)

    ZHOU Nan-run; GONG Li-hua; LIU Ye

    2006-01-01

    In this letter a cascade quantum teleportation scheme is proposed. The proposed scheme needs less local quantum operations than those of quantum multi-teleportation. A quantum teleportation scheme based on entanglement swapping is presented and compared with the cascade quantum teleportation scheme. Those two schemes can effectively teleport quantum information and extend the distance of quantum communication.

  14. Mechanisms of cascade collapse

    International Nuclear Information System (INIS)

    Diaz de la Rubia, T.; Smalinskas, K.; Averback, R.S.; Robertson, I.M.; Hseih, H.; Benedek, R.

    1988-12-01

    The spontaneous collapse of energetic displacement cascades in metals into vacancy dislocation loops has been investigated by molecular dynamics (MD) computer simulation and transmission electron microscopy (TEM). Simulations of 5 keV recoil events in Cu and Ni provide the following scenario of cascade collapse: atoms are ejected from the central region of the cascade by replacement collision sequences; the central region subsequently melts; vacancies are driven to the center of the cascade during resolidification where they may collapse into loops. Whether or not collapse occurs depends critically on the melting temperature of the metal and the energy density and total energy in the cascade. Results of TEM are presented in support of this mechanism. 14 refs., 4 figs., 1 tab

  15. Evaluation of the sensor properties of the pH-static enzyme sensor

    NARCIS (Netherlands)

    van der Schoot, B.H.; van der Schoot, Bart H.; Bergveld, Piet

    1990-01-01

    The pH-static enzyme sensor consists of a chemical sensor-actuator system covered with a thin enzyme-entrapping membrane. By the electrochemical generation of protons or hydroxyl ions, pH changes induced by the conversion of a substrate by the enzymatic reaction are compensated. The pH inside the

  16. Evaluation of commercial a-amylase enzyme-linked immunosorbent assy (ELISA) test kits for wheat

    Science.gov (United States)

    a-Amylase enzyme is associated with preharvest sprouting (PHS) and late-maturity a amylase (LMA) in wheat, and reduces wheat and flour quality. Various means have been developed to measure the presence of a-amylase, thereby predicting end-use quality; most are based on enzyme activity. An alternativ...

  17. Evaluation of the effects of enzyme-based liquid chemical stabilizers on subgrade soils

    CSIR Research Space (South Africa)

    Mgangira, Martin B

    2009-07-01

    Full Text Available The purpose of this study was to asses the strength of enzyme treated soil material. Thus the aim of the paper is to present laboratory results on the effects of two enzyme-based liquid chemicals as soil stabilizers. Soil samples were prepared...

  18. Evaluation of the organophosphorus hydrolase enzyme activity in creams and investigation of its stability

    Directory of Open Access Journals (Sweden)

    Mariye Rajaie

    2016-06-01

    Full Text Available The main purpose of this project is investigation of the organophosphorus hydrolase (OPH enzyme activity in water in oil (w/o and oil in water (o/w creams and investigation of the OPH enzyme stability in formulated creams. OPH enzyme was extracted and purified from strain flavobacterium. The w/o and o/w creams were prepared using different formulations. In order to achieve an emulsion with maximum stability, appropriate percentage of the cream components was selected by studying different formulations and the physical and chemical stability of the produced cream were considered. 5Uenzyme/90gcream enzyme was used for each formulation. To measure the enzyme activity in creams, extraction method was used and enzyme activity was determined based on parathion hydrolysis. The thermal stability of OPH in both types of w/o and o/w creams was studied at 4 and 30  °C for various time periods. The average enzyme activity was about 0.0065 U/gcream and 0.018 U/gcream for w/o and o/w creams respectivly. According to the results, the relative activity at 4 °C was reduced to 50% after 26 and 45 days in w/o and o/w creams, respectivly. The results showed that the OPH enzyme activity in o/w cream was 2.6 times more than that of w/o cream, because of the higher hydrophobicity of o/w cream compared to w/o. The OPH enzyme stability in o/w cream was greater in comparison to w/o cream. The OPH enzyme was active for nearly 2 months on o/w creams at 4 °C .

  19. The development and evaluation of airborne in situ N2O and CH4 sampling using a Quantum Cascade Laser Absorption Spectrometer (QCLAS)

    Science.gov (United States)

    Pitt, Joseph; Le Breton, Michael; Allen, Grant; Percival, Carl; Gallagher, Martin; Bauguitte, Stephane; O'Shea, Sebastian; Muller, Jennifer; Zahniser, Mark; Pyle, John; Palmer, Paul

    2016-04-01

    Spectroscopic measurements of atmospheric N2O and CH4 mole fractions were made on board the FAAM (Facility for Airborne Atmospheric Measurements) large Atmospheric Research Aircraft. We evaluate the performance of the mid-IR continuous wave Aerodyne Research Inc. Quantum Cascade Laser Absorption Spectrometer (QCLAS) employed over 17 flights conducted during summer 2014. Two different methods of correcting for the influence of water vapour on the spectroscopic retrievals are compared and evaluated. Test flight data demonstrating the sensitivity of the instrument to changes in cabin pressure is presented, and a new in-flight calibration procedure to account for this issue is described and assessed. Total 1σ uncertainties of 1.81 ppb for CH4 and 0.35 ppb for N2O are derived. We report a mean difference in 1 Hz CH4 mole fraction of 2.05 ppb (1σ = 5.85 ppb) between in-flight measurements made using the QCLAS and simultaneous measurements using a previously characterised Los Gatos Research Fast Greenhouse Gas Analyser (FGGA).

  20. Gaucher disease: MR evaluation of bone marrow features during treatment with enzyme replacement

    International Nuclear Information System (INIS)

    Poll, L.W.; Koch, J.A.; Boerner, D.; Cohnen, M.; Jung, G.; Scherer, A.; Moedder, U.; Niederau, C.

    2001-01-01

    Purpose: Enzyme replacement therapy (ERT) arrests and reverses the hematological and visceral symptoms of adult Gaucher disease, the most frequent lysosomal storage disorder. There are only a few studies available evaluating bone disease during ERT. The aim of this study was to investigate the features of bone marrow (bm) by magnetic resonance imaging (MRI) in these patients during ERT. Materials and Methods: MRI was performed prospectively in thirty adult type I Gaucher patients before and during ERT with a mean follow-up of 3 years. Spin-echo sequences (T 1 /T 2 ) of the lower extremities were obtained and the reconversion (response) or lack of reconversion (non-response) to fatty marrow during treatment was analyzed. The morphological features of bm involvement, a homogeneous or non-homogeneous distribution of bm changes and focal bone lesions surrounded by a rim of reduced signal intensity (SI), were analyzed. Results: Infiltration of bm by Gaucher cells is characterized by a reduction of Sl on both T 1 - and T 2 -weighted sequences. Bone marrow responses were seen in 19 patients (63%) during treatment. Focal bone lesions, surrounded by a rim of reduced Sl, did not respond to ERT and correlated with a non-homogenous distribution of bone involvement and splenectomy. (orig.) [de

  1. In vitro evaluation of total mixed ration supplemented with exogenous fibrolytic enzymes for crossbred cows

    Directory of Open Access Journals (Sweden)

    Pravin Mohan Lunagariya

    2017-03-01

    Full Text Available Aim: The study was conducted to evaluate the levels of exogenous fibrolytic enzymes (EFE on in vitro digestibilities of dry matter (DM and organic matter (OM, total gas production (TGP, metabolizable energy (ME content, and microbial biomass production (MBP. Materials and Methods: The total mixed ration (TMR was prepared using 30% each of sorghum hay and groundnut straw and 40% compound concentrate mixture to meet nutritional requirement of cow (500 kg producing 12 kg fat corrected milk. The EFE was incorporated at 0, 40, 60, 80, 100, 120, 140, 160, 180, 200, 220, 240, 260, 280, 300, 320, 340, 360, 380, and 400 mg/kg TMR. The TMR substrates with different levels of EFE were in vitro incubated to ascertain their effect on digestibility, gas production, and nutritive values. Results: The significantly (p<0.05 higher and optimum in vitro digestibilities of DM (63.03% and OM (63.62% as well as TGP (72.35 ml/500 mg TMR were observed at supplementation of 240 mg EFE/kg TMR, while ME (7.16 MJ/kg DM and MBP (97.63 mg/500 mg TMR were also better. Conclusion: The incorporation of EFE at 240 mg/kg TMR resulted significantly (p<0.05 higher and optimum in vitro digestibilities of DM and OM. The TGP, ME, and MBP were also better. The levels of EFE 240 mg/kg TMR were found suitable for further in vivo study in crossbred cows.

  2. The Evaluation of Angiotensin-Converting Enzyme Inhibitors in Renal Elimination with Selected Molecular Descriptors

    Directory of Open Access Journals (Sweden)

    Trbojevic Jovana

    2017-06-01

    Full Text Available Angiotensin-converting enzyme (ACE inhibitors modulate the function of the renin-angiotensin-aldosterone system, and they are commonly prescribed antihypertensive drugs especially in patients with renal failure. In this study, the relationships between several molecular properties of eight ACE inhibitors (enalapril, quinapril, fosinopril, ramipril, benazepril, perindopril, moexipril, trandolapril and their renal elimination data, from relevant literature, were investigated. The ’molecular descriptors of the ACE inhibitors, which included aqueous solubility data (logS; an electronic descriptor, polar surface area (PSA;, a constitutional parameter, molecular mass (Mr; and a geometric descriptor, volume value (Vol, as well as lipophilicity descriptors (logP values, were calculated using different software packages. Simple linear regression analysis showed the best correlation between renal elimination data and lipophilicity descriptor AClogP values (R2 = 0.5742. In the next stage of the study, multiple linear regression was applied to assess a higher correlation between the ACE inhibitors’ renal elimination data and lipophilicity, AClogP, with one additional descriptor as an independent variable. Good correlations were established between renal elimination data from the literature and the AClogP lipophilicity descriptor using the constitutional parameter (molecular mass (R2 = 0.7425 or the geometric descriptor (volume value (R2 = 0.7224 as an independent variable. The application of computed molecular descriptors in evaluating drug elimination is of great importance in drug research.

  3. Evaluation and comparison of radio-, fluorescence, and enzyme-linked immunoassays for serum thyroxine

    International Nuclear Information System (INIS)

    Kaplan, L.A.; Gau, N.; Fearn, J.; Steain, E.A.; Chen, I.W.; Maxon, H.; Volle, C.

    1981-01-01

    We have compared three analytical systems for the measurement of serum thyroxine: enzyme-linked immunoassay (EIA), fluorescent immunoassay (FIA) and a radioimmunoassay (RIA). These were evaluated with respect to their precision, accuracy, analytical sensitivity and sample throughput. The RIA is more sensitive than the EIA (10 μg/L vs. 35 μg/L). Both systems have excellent precision (X=86 μg/L, C.V.sub(RIA)=C.V.sub(EIA)=4.6 percent). Both the EIA and RIA demonstrate good accuracy with recovery of between 97-98 percent of added thyroxine. The FIA has an apparent sensitiviity between that of the RIA and EIA (25 μg/L), but a precision consistently lower than the other two systems (C.V. =7.4 percent, X=86 μg/L). Patients' results by RIA compared well with those from EIA (r=0.91,P 0.05). Although not fully automated, the EIA performed on the Abbott ABA-100 analyzer has a sample throughput equal to the automated RIA system (Micromedic, Concept 4)

  4. Evaluation of an enzyme-linked immunoelectrotransfer blot test for the confirmatory serodiagnosis of human toxocariasis

    Directory of Open Access Journals (Sweden)

    William H Roldán

    2009-05-01

    Full Text Available To improve the serodiagnosis of human toxocariasis, a sensitive and specific enzyme-linked immunoelectrotransfer blot (EITB-IgG test was developed and evaluated using Toxocara canislarvae excretory-secretory antigens for detecting anti-Toxocara IgG antibodies. The EITB-IgG profile of toxocariasis was characterized by comparing 27 sera from patients with toxocariasis, 110 sera from healthy subjects and 186 sera from patients with other helminth diseases (ascariasis, ancylostomiasis, trichuriasis, enterobiasis, strongyloidiasis, hymenolepiasis, diphyllobothriasis, taeniasis, cysticercosis, hydatidosis and fascioliasis. Antigenic bands of 24, 28, 30, 35, 56, 117, 136 and 152 kDa were predominantly recognized in sera from all patients with toxocariasis. However, only bands of 24-35 kDa were highly specific for Toxocara infection (98.3%, whereas other antigenic bands observed displayed cross-reactivity. Additionally, when the results of the EITB-IgG test were compared to those of the ELISA-IgG test, a 100% concordance was observed for positive results in human toxocariasis cases. The concordance for negative results between the two tests for healthy subjects and patients with other helminth diseases were 96.3% and 53.7%, respectively, showing that the EITB-IgG test has a higher specificity than ELISA. In conclusion, the EITB-IgG test is a very useful tool to confirm the serological diagnosis of human toxocariasis.

  5. Evaluation of two automated enzyme-immunoassays for detection of thermophilic campylobacters in faecal samples from cattle and swine

    DEFF Research Database (Denmark)

    Hoorfar, Jeffrey; Nielsen, E.M.; Stryhn, H.

    1999-01-01

    We evaluated the performance of two enzyme-immunoassays (EIA) for the detection of naturally occurring, thermophilic Campylobacter spp. found in faecal samples from cattle (n = 21 and n = 26) and swine (n = 43) relative to the standard culture method, and also assuming that none of the tests...

  6. Evaluation of the Optimal Reaction Conditions for the Methanolysis and Ethanolysis of Castor Oil Catalyzed by Immobilized Enzymes

    DEFF Research Database (Denmark)

    Andrade, Thalles Allan; Al-Kabalawi, Ibrahim; Errico, Massimiliano

    This study aims to compare the efficiency of the transesterification of castor oil with methanol and ethanol as part of the biodiesel production, using immobilized enzyme Lipozyme IM as catalyst. Different reaction conditions were evaluated and optimized, including the reaction temperature, alcohol...

  7. Evaluation of Staphylococcus aureus DNA aptamer by enzyme-linked aptamer assay and isothermal titration calorimetry.

    Science.gov (United States)

    Bayraç, Ceren; Öktem, Hüseyin Avni

    2017-02-01

    To monitor the specificity of Staphylococcus aureus aptamer (SA-31) against its target cell, we used enzyme-linked aptamer assay. In the presence of target cell, horseradish peroxidase-conjugated streptavidin bound to biotin-labeled SA-31 showed specific binding to S  aureus among 3 different bacteria with limit of detection of 10 3 colony-forming unit per milliliter. The apparent K a was 1.39 μM -1  ± 0.3 μM -1 . The binding of SA-31 to membrane proteins extracted from cell surface was characterized using isothermal titration calorimetry, and the effect of changes in binding temperature and salt concentrations of binding buffer was evaluated based on thermodynamic parameters (K a , ΔH, and ΔG). Since binding of aptamer to its targets solely depends on its 3-dimensional structure under experimental conditions used in selection process, the change in temperature and ion concentration changed the affinity of SA-31 to its target on surface of bacteria. At 4°C, SA-31 did not show an affinity to its target with poor heat change upon injection of membrane fraction to aptamer solution. However, the apparent association constants of SA-31 slightly varied from K a  = 1.56 μM -1  ± 0.69 μM -1 at 25°C to K a  = 1.03 μM -1  ± 0.9 μM -1 at 37°C. At spontaneously occurring exothermic binding reactions, affinities of S aureus aptamer to its target were also 9.44 μM -1  ± 0.38 μM -1 at 50mM, 1.60 μM -1  ± 0.11 μM -1 at 137mM, and 3.28 μM -1  ± 0.46 μM -1 at 200 mM of salt concentration. In this study, it was demonstrated that enzyme-linked aptamer assay and isothermal titration calorimetry were useful tools for studying the fundamental binding mechanism between a DNA aptamer and its target on the outer surface of S aureus. Copyright © 2016 John Wiley & Sons, Ltd.

  8. Evaluation of Correlation between Pretest Probability for Clostridium difficile Infection and Clostridium difficile Enzyme Immunoassay Results.

    Science.gov (United States)

    Kwon, Jennie H; Reske, Kimberly A; Hink, Tiffany; Burnham, C A; Dubberke, Erik R

    2017-02-01

    The objective of this study was to evaluate the clinical characteristics and outcomes of hospitalized patients tested for Clostridium difficile and determine the correlation between pretest probability for C. difficile infection (CDI) and assay results. Patients with testing ordered for C. difficile were enrolled and assigned a high, medium, or low pretest probability of CDI based on clinical evaluation, laboratory, and imaging results. Stool was tested for C. difficile by toxin enzyme immunoassay (EIA) and toxigenic culture (TC). Chi-square analyses and the log rank test were utilized. Among the 111 patients enrolled, stool samples from nine were TC positive and four were EIA positive. Sixty-one (55%) patients had clinically significant diarrhea, 19 (17%) patients did not, and clinically significant diarrhea could not be determined for 31 (28%) patients. Seventy-two (65%) patients were assessed as having a low pretest probability of having CDI, 34 (31%) as having a medium probability, and 5 (5%) as having a high probability. None of the patients with low pretest probabilities had a positive EIA, but four were TC positive. None of the seven patients with a positive TC but a negative index EIA developed CDI within 30 days after the index test or died within 90 days after the index toxin EIA date. Pretest probability for CDI should be considered prior to ordering C. difficile testing and must be taken into account when interpreting test results. CDI is a clinical diagnosis supported by laboratory data, and the detection of toxigenic C. difficile in stool does not necessarily confirm the diagnosis of CDI. Copyright © 2017 American Society for Microbiology.

  9. Evaluation of a Hypocrea jecorina Enzyme Preparation for Hydrolysis of Tifton 85 Bermudagrass

    Science.gov (United States)

    Ximenes, E. A.; Brandon, S. K.; Doran-Peterson, J.

    Tifton 85 bermudagrass, developed at the ARS-USDA in Tifton, GA, is grown on over ten million acres in the USA for hay and forage. Of the bermudagrass cultivars, Tifton 85 exhibits improved digestibility because the ratio of ether- to ester-linked phenolic acids has been lowered using traditional plant breeding techniques. A previously developed pressurized batch hot water (PBHW) method was used to treat Tifton 85 bermudagrass for enzymatic hydrolysis. Native grass (untreated) and PBHW-pretreated material were compared as substrates for fungal cultivation to produce enzymes. Cellulase activity, measured via the filter paper assay, was higher for fungi cultivated on PBHW-pretreated grass, whereas the other nine enzyme assays produced higher activities for the untreated grass. Ferulic acid and vanillin levels increased significantly for the enzyme preparations produced using PBHW-pretreated grass and the release of these phenolic compounds may have contributed to the observed reduction in enzyme activities. Culture supernatant from Tifton 85 bermudagrass-grown fungi were combined with two commercial enzyme preparations and the enzyme activity profiles are reported. The amount of reducing sugar liberated by the enzyme mixture from Hypocrea jecorina (after 192 h incubation with untreated bermudagrass) individually or in combination with feruloyl esterase was 72.1 and 84.8%, respectively, of the commercial cellulase preparation analyzed under the same conditions.

  10. Noise propagation in two-step series MAPK cascade.

    Directory of Open Access Journals (Sweden)

    Venkata Dhananjaneyulu

    Full Text Available Series MAPK enzymatic cascades, ubiquitously found in signaling networks, act as signal amplifiers and play a key role in processing information during signal transduction in cells. In activated cascades, cell-to-cell variability or noise is bound to occur and thereby strongly affects the cellular response. Commonly used linearization method (LM applied to Langevin type stochastic model of the MAPK cascade fails to accurately predict intrinsic noise propagation in the cascade. We prove this by using extensive stochastic simulations for various ranges of biochemical parameters. This failure is due to the fact that the LM ignores the nonlinear effects on the noise. However, LM provides a good estimate of the extrinsic noise propagation. We show that the correct estimate of intrinsic noise propagation in signaling networks that contain at least one enzymatic step can be obtained only through stochastic simulations. Noise propagation in the cascade depends on the underlying biochemical parameters which are often unavailable. Based on a combination of global sensitivity analysis (GSA and stochastic simulations, we developed a systematic methodology to characterize noise propagation in the cascade. GSA predicts that noise propagation in MAPK cascade is sensitive to the total number of upstream enzyme molecules and the total number of molecules of the two substrates involved in the cascade. We argue that the general systematic approach proposed and demonstrated on MAPK cascade must accompany noise propagation studies in biological networks.

  11. Cascade Chaotic System With Applications.

    Science.gov (United States)

    Zhou, Yicong; Hua, Zhongyun; Pun, Chi-Man; Chen, C L Philip

    2015-09-01

    Chaotic maps are widely used in different applications. Motivated by the cascade structure in electronic circuits, this paper introduces a general chaotic framework called the cascade chaotic system (CCS). Using two 1-D chaotic maps as seed maps, CCS is able to generate a huge number of new chaotic maps. Examples and evaluations show the CCS's robustness. Compared with corresponding seed maps, newly generated chaotic maps are more unpredictable and have better chaotic performance, more parameters, and complex chaotic properties. To investigate applications of CCS, we introduce a pseudo-random number generator (PRNG) and a data encryption system using a chaotic map generated by CCS. Simulation and analysis demonstrate that the proposed PRNG has high quality of randomness and that the data encryption system is able to protect different types of data with a high-security level.

  12. Fabrication and optimisation of optical biosensor using alcohol oxidase enzyme to evaluate detection of formaldehyde

    Science.gov (United States)

    Rachim, A.; Sari, A. P.; Nurlely, Fauzia, V.

    2017-07-01

    In this study, a new and simple biosensor base on alcohol oxidase (AOX)-enzyme for detecting formaldehyde in aqueous solutions has been successfully fabricated. The alcohol oxidase (AOX) enzyme was immobilized on poly-n-butyl acrylic-co-N-acryloxysuccinimide (nBA-NAS) membrane containing chromoionophore. The chemical reaction between AOX and formaldehyde generates a colour change of chromoionophore detected by optical absorbance measured in UV Vis. This paper focuses on the concentration optimization of buffer phosphate solution, response time, the quantity of enzyme and the measurement of the detection range of biosensors. The result shows that the optimum concentration and pH of buffer phosphate solution is 0.05 M and pH 7, respectively. The optimum response time is 3 min, the optimum unit of enzyme for biosensor is 1 unit/sample and the detection range of biosensor is 0.264 mM with R2 = 0.9421.

  13. An evaluation on elastase enzyme activity in gingival crevicular fluid in periodontitis

    Directory of Open Access Journals (Sweden)

    Qujeq D

    2003-08-01

    Full Text Available Statement of Problem: Changes in protein levels, host calls enzymes and inflammatory mediators in gingival"ncrevicular Fluid (GCF are considered as diagnostic indicators of Periodontitis."nPurpose: he aim of the present study was to measure the elastase enzyme activity in gingival crevicular Fluid"namong patients with periodontitis."nMaterial and Methods: In this study, 52 periodontitis patients (experimental group and 51 healthy subjects"nwithout any gingival inflammatio (control group were participated. Subjects of the periodontitis group"nshowed pockets of 4-5 mm depth without gingival enlargement and recession or pockets of 1-2 mm depth"nwith gingival recession. For enzyme activity measurement, lOOu,! of gingival fluid of each sample was mixed"nwith lOOu! of enzyme substrate on the tube. The mixture was incubated at 34°c for lh with a buffer solution"nof 1ml volume and absorbance was read at 410nm with spectrophotometer. The enzyme activity differences"nbetween two groups were analyzed by student t test."nResults: The elastase enzyme activity in gingival crevicular fluid in subjects with periodontium destruction"nand control subjects was 153±11.3 and 52.7±10.4 enzyme unit in ml per minute, respectively. The difference"nbetween groups was statistically significant (PO.05."nConclusion: Based on the findings of this study, the measurement of elastae enzyme activity could be a useful"nindication of tissue changes that may ultimately manifest clinically as periodontitis.

  14. Conjugation of cascades

    International Nuclear Information System (INIS)

    San Martin, Jesus; Rodriguez-Perez, Daniel

    2009-01-01

    Presented in this work are some results relative to sequences found in the logistic equation bifurcation diagram, which is the unimodal quadratic map prototype. All of the different saddle-node bifurcation cascades, associated with every last appearance p-periodic orbit (p=3,4,5,...), can also be generated from the very Feigenbaum cascade. In this way it is evidenced the relationship between both cascades. The orbits of every saddle-node bifurcation cascade, mentioned above, are located in different chaotic bands, and this determines a sequence of orbits converging to every band-merging Misiurewicz point. In turn, these accumulation points form a sequence whose accumulation point is the Myrberg-Feigenbaum point. It is also proven that the first appearance orbits in the n-chaotic band converge to the same point as the last appearance orbits of the (n + 1)-chaotic band. The symbolic sequences of band-merging Misiurewicz points are computed for any window.

  15. Evaluating the cascading impacts of sea level rise and coastal flooding on emergency response spatial accessibility in Lower Manhattan, New York City

    Science.gov (United States)

    Yin, Jie; Yu, Dapeng; Lin, Ning; Wilby, Robert L.

    2017-12-01

    This paper describes a scenario-based approach for evaluating the cascading impacts of sea level rise (SLR) and coastal flooding on emergency responses. The analysis is applied to Lower Manhattan, New York City, considering FEMA's 100- and 500-year flood scenarios and New York City Panel on Climate Change (NPCC2)'s high-end SLR projections for the 2050s and 2080s, using the current situation as the baseline scenario. Service areas for different response timeframes (3-, 5- and 8-min) and various traffic conditions are simulated for three major emergency responders (i.e. New York Police Department (NYPD), Fire Department, New York (FDNY) and Emergency Medical Service (EMS)) under normal and flood scenarios. The modelling suggests that coastal flooding together with SLR could result in proportionate but non-linear impacts on emergency services at the city scale, and the performance of operational responses is largely determined by the positioning of emergency facilities and the functioning of traffic networks. Overall, emergency service accessibility to the city is primarily determined by traffic flow speed. However, the situation is expected to be further aggravated during coastal flooding, with is set to increase in frequency and magnitude due to SLR.

  16. Evaluation of alcohol dehydrogenase and aldehyde dehydrogenase enzymes as bi-enzymatic anodes in a membraneless ethanol microfluidic fuel cell

    Science.gov (United States)

    Galindo-de-la-Rosa, J.; Arjona, N.; Arriaga, L. G.; Ledesma-García, J.; Guerra-Balcázar, M.

    2015-12-01

    Alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (AldH) enzymes were immobilized by covalent binding and used as the anode in a bi-enzymatic membraneless ethanol hybrid microfluidic fuel cell. The purpose of using both enzymes was to optimize the ethanol electro-oxidation reaction (EOR) by using ADH toward its direct oxidation and AldH for the oxidation of aldehydes as by-products of the EOR. For this reason, three enzymatic bioanode configurations were evaluated according with the location of enzymes: combined, vertical and horizontally separated. In the combined configuration, a current density of 16.3 mA cm-2, a voltage of 1.14 V and a power density of 7.02 mW cm-2 were obtained. When enzymes were separately placed in a horizontal and vertical position the ocp drops to 0.94 V and to 0.68 V, respectively. The current density also falls to values of 13.63 and 5.05 mA cm-2. The decrease of cell performance of bioanodes with separated enzymes compared with the combined bioanode was of 31.7% and 86.87% for the horizontal and the vertical array.

  17. Immunohistochemical evaluation of proliferation, apoptosis and steroidogenic enzymes in the ovary of rats with polycystic ovary

    Directory of Open Access Journals (Sweden)

    Leonardo Augusto Lombardi

    2014-07-01

    Full Text Available Objective: to evaluate the immunohistochemical expression of proliferative, apoptotic and steroidogenic enzyme markers in the ovaries of rats with polycystic ovary syndrome (PCOS. Methods: twenty rats were divided into two groups: GCtrl - estrous phase, and PCOS - with polycystic ovaries. The GCtrl animals were subjected to a lighting period from 7 am to 7 pm, while the animals with PCOS group remained with continuous lighting for 60 days. Subsequently, the animals were anesthetized, the ovaries were removed and fixed in 10% formaldehyde, prior to paraffin embedding. Sections were stained using H.E. or subjected to immunohistochemical methods for the detection of Ki-67, cleaved caspase-3, CYP11A1, CYP17A1 and CYP19A1. The results were analyzed using Student's t-test (p < 0,05. Results: morphological results showed evidence of interstitial cells originating from the inner theca cells of degenerating ovarian cysts in PCOS. Immunoexpression of Ki-67 was higher in the granulosa cells in GCtrl, and the theca interna cells in PCOS, while cleaved caspase-3 was higher in granulosa cells of ovarian cysts from PCOS and in the theca interna cells of GCtrl. Immunoreactivity of CYP11A1 in the theca interna, granulosa and interstitial cells was similar between the two groups, while CYP17A1 and CYP19A1 were higher in the granulosa and interstitial cells in the PCOS group. Conclusion: the results indicate that the interstitial cells are derived from the theca interna and that enzymatic changes occur in the theca interna and interstitial cells in ovaries of rats with PCOS, responsible for the high levels of androgens and estradiol.

  18. Learning optimal embedded cascades.

    Science.gov (United States)

    Saberian, Mohammad Javad; Vasconcelos, Nuno

    2012-10-01

    The problem of automatic and optimal design of embedded object detector cascades is considered. Two main challenges are identified: optimization of the cascade configuration and optimization of individual cascade stages, so as to achieve the best tradeoff between classification accuracy and speed, under a detection rate constraint. Two novel boosting algorithms are proposed to address these problems. The first, RCBoost, formulates boosting as a constrained optimization problem which is solved with a barrier penalty method. The constraint is the target detection rate, which is met at all iterations of the boosting process. This enables the design of embedded cascades of known configuration without extensive cross validation or heuristics. The second, ECBoost, searches over cascade configurations to achieve the optimal tradeoff between classification risk and speed. The two algorithms are combined into an overall boosting procedure, RCECBoost, which optimizes both the cascade configuration and its stages under a detection rate constraint, in a fully automated manner. Extensive experiments in face, car, pedestrian, and panda detection show that the resulting detectors achieve an accuracy versus speed tradeoff superior to those of previous methods.

  19. A label-free ultrasensitive fluorescence detection of viable Salmonella enteritidis using enzyme-induced cascade two-stage toehold strand-displacement-driven assembly of G-quadruplex DNA.

    Science.gov (United States)

    Zhang, Peng; Liu, Hui; Ma, Suzhen; Men, Shuai; Li, Qingzhou; Yang, Xin; Wang, Hongning; Zhang, Anyun

    2016-06-15

    The harm of Salmonella enteritidis (S. enteritidis ) to public health mainly by contaminating fresh food and water emphasizes the urgent need for rapid detection techniques to help control the spread of the pathogen. In this assay, an newly designed capture probe complex that contained specific S. enteritidis-aptamer and hybridized signal target sequence was used for viable S. enteritidis recognition directly. In the presence of the target S. enteritidis, single-stranded target sequences were liberated and initiated the replication-cleavage reaction, producing numerous G-quadruplex structures with a linker on the 3'-end. And then, the sensing system took innovative advantage of quadratic linker-induced strand-displacement for the first time to release target sequence in succession, leading to the cyclic reuse of the target sequences and cascade signal amplification, thereby achieving the successive production of G-quadruplex structures. The fluorescent dye, N-Methyl mesoporphyrin IX, binded to these G-quadruplex structures and generated significantly enhanced fluorescent signals to achieve highly sensitive detection of S. enteritidis down to 60 CFU/mL with a linear range from 10(2) to 10(7)CFU/mL. By coupling the cascade two-stage target sequences-recyclable toehold strand-displacement with aptamer-based target recognition successfully, it is the first report on a novel non-label, modification-free and DNA extraction-free ultrasensitive fluorescence biosensor for detecting viable S. enteritidis directly, which can discriminate from dead S. enteritidis. Copyright © 2016 Elsevier B.V. All rights reserved.

  20. Evaluation of the efficiency and utility of recombinant enzyme-free seamless DNA cloning methods

    Directory of Open Access Journals (Sweden)

    Ken Motohashi

    2017-03-01

    Full Text Available Simple and low-cost recombinant enzyme-free seamless DNA cloning methods have recently become available. In vivo Escherichia coli cloning (iVEC can directly transform a mixture of insert and vector DNA fragments into E. coli, which are ligated by endogenous homologous recombination activity in the cells. Seamless ligation cloning extract (SLiCE cloning uses the endogenous recombination activity of E. coli cellular extracts in vitro to ligate insert and vector DNA fragments. An evaluation of the efficiency and utility of these methods is important in deciding the adoption of a seamless cloning method as a useful tool. In this study, both seamless cloning methods incorporated inserting DNA fragments into linearized DNA vectors through short (15–39 bp end homology regions. However, colony formation was 30–60-fold higher with SLiCE cloning in end homology regions between 15 and 29 bp than with the iVEC method using DH5α competent cells. E. coli AQ3625 strains, which harbor a sbcA gene mutation that activates the RecE homologous recombination pathway, can be used to efficiently ligate insert and vector DNA fragments with short-end homology regions in vivo. Using AQ3625 competent cells in the iVEC method improved the rate of colony formation, but the efficiency and accuracy of SLiCE cloning were still higher. In addition, the efficiency of seamless cloning methods depends on the intrinsic competency of E. coli cells. The competency of chemically competent AQ3625 cells was lower than that of competent DH5α cells, in all cases of chemically competent cell preparations using the three different methods. Moreover, SLiCE cloning permits the use of both homemade and commercially available competent cells because it can use general E. coli recA− strains such as DH5α as host cells for transformation. Therefore, between the two methods, SLiCE cloning provides both higher efficiency and better utility than the iVEC method for seamless DNA plasmid

  1. Positional information generated by spatially distributed signaling cascades.

    Directory of Open Access Journals (Sweden)

    Javier Muñoz-García

    2009-03-01

    Full Text Available The temporal and stationary behavior of protein modification cascades has been extensively studied, yet little is known about the spatial aspects of signal propagation. We have previously shown that the spatial separation of opposing enzymes, such as a kinase and a phosphatase, creates signaling activity gradients. Here we show under what conditions signals stall in the space or robustly propagate through spatially distributed signaling cascades. Robust signal propagation results in activity gradients with long plateaus, which abruptly decay at successive spatial locations. We derive an approximate analytical solution that relates the maximal amplitude and propagation length of each activation profile with the cascade level, protein diffusivity, and the ratio of the opposing enzyme activities. The control of the spatial signal propagation appears to be very different from the control of transient temporal responses for spatially homogenous cascades. For spatially distributed cascades where activating and deactivating enzymes operate far from saturation, the ratio of the opposing enzyme activities is shown to be a key parameter controlling signal propagation. The signaling gradients characteristic for robust signal propagation exemplify a pattern formation mechanism that generates precise spatial guidance for multiple cellular processes and conveys information about the cell size to the nucleus.

  2. Multicentric Evaluation of New Commercial Enzyme Immunoassays for the Detection of Immunoglobulin M and Total Antibodies against Hepatitis A Virus▿

    Science.gov (United States)

    Arcangeletti, M. C.; Dussaix, E.; Ferraglia, F.; Roque-Afonso, A. M.; Graube, A.; Chezzi, C.

    2011-01-01

    A multicentric clinical study was conducted on representative sera from 1,738 European and U.S. subjects for the evaluation of new anti-hepatitis A virus enzyme immunoassays from Bio-Rad Laboratories. Comparison with reference DiaSorin S.p.A. tests confirmed the good performance of Bio-Rad assays (99.85% and 99.47% overall agreement in detecting total antibodies and IgM, respectively). PMID:21653739

  3. Biochemical evaluation of a parsley tyrosine decarboxylase results in a novel 4-hydroxyphenylacetaldehyde synthase enzyme.

    Science.gov (United States)

    Torrens-Spence, Michael P; Gillaspy, Glenda; Zhao, Bingyu; Harich, Kim; White, Robert H; Li, Jianyong

    2012-02-10

    Plant aromatic amino acid decarboxylases (AAADs) are effectively indistinguishable from plant aromatic acetaldehyde syntheses (AASs) through primary sequence comparison. Spectroscopic analyses of several characterized AASs and AAADs were performed to look for absorbance spectral identifiers. Although this limited survey proved inconclusive, the resulting work enabled the reevaluation of several characterized plant AAS and AAAD enzymes. Upon completion, a previously reported parsley AAAD protein was demonstrated to have AAS activity. Substrate specificity tests demonstrate that this novel AAS enzyme has a unique substrate specificity towards tyrosine (km 0.46mM) and dopa (km 1.40mM). Metabolite analysis established the abundance of tyrosine and absence of dopa in parsley extracts. Such analysis indicates that tyrosine is likely to be the sole physiological substrate. The resulting information suggests that this gene is responsible for the in vivo production of 4-hydroxyphenylacetaldehyde (4-HPAA). This is the first reported case of an AAS enzyme utilizing tyrosine as a primary substrate and the first report of a single enzyme capable of producing 4-HPAA from tyrosine. Copyright © 2012 Elsevier Inc. All rights reserved.

  4. Evaluation of eight enzyme immunoassays for detection of immunoglobulin G against Helicobacter pylori

    NARCIS (Netherlands)

    Thijs, JC; Kleibeuker, JH; vanZwet, AA; Berrelkamp, RJP; Meijer, B.C

    Eight commercial enzyme-linked immunosorbent assays (ELISAs) were used to test sera taken from 102 patients in whom Helicobacter pylori infection status had been determined by means of biopsy culture, PCR, histology, and urease production and by C-13 urea breath test. By those means, 61 patients had

  5. Thermophilic Campylobacter spp. in turkey samples: evaluation of two automated enzyme immunoassays and conventional microbiological techniques

    DEFF Research Database (Denmark)

    Borck, Birgitte; Stryhn, H.; Ersboll, A.K.

    2002-01-01

    Aims: To determine the sensitivity and specificity of two automated enzyme immunoassays (EIA), EiaFoss and Minividas, and a conventional microbiological culture technique for detecting thermophilic Campylobacter spp. in turkey samples. Methods and Results: A total of 286 samples (faecal, meat...

  6. Cascade Organic Solar Cells

    KAUST Repository

    Schlenker, Cody W.

    2011-09-27

    We demonstrate planar organic solar cells consisting of a series of complementary donor materials with cascading exciton energies, incorporated in the following structure: glass/indium-tin-oxide/donor cascade/C 60/bathocuproine/Al. Using a tetracene layer grown in a descending energy cascade on 5,6-diphenyl-tetracene and capped with 5,6,11,12-tetraphenyl- tetracene, where the accessibility of the π-system in each material is expected to influence the rate of parasitic carrier leakage and charge recombination at the donor/acceptor interface, we observe an increase in open circuit voltage (Voc) of approximately 40% (corresponding to a change of +200 mV) compared to that of a single tetracene donor. Little change is observed in other parameters such as fill factor and short circuit current density (FF = 0.50 ± 0.02 and Jsc = 2.55 ± 0.23 mA/cm2) compared to those of the control tetracene-C60 solar cells (FF = 0.54 ± 0.02 and Jsc = 2.86 ± 0.23 mA/cm2). We demonstrate that this cascade architecture is effective in reducing losses due to polaron pair recombination at donor-acceptor interfaces, while enhancing spectral coverage, resulting in a substantial increase in the power conversion efficiency for cascade organic photovoltaic cells compared to tetracene and pentacene based devices with a single donor layer. © 2011 American Chemical Society.

  7. Energy cascades in Canada

    Energy Technology Data Exchange (ETDEWEB)

    Hayden, A. C.; Brown, T. D.

    1979-03-15

    Combining energy uses in a cascade can result in significant overall reductions in fuel requirements. The simplest applications for a cascade are in the recovery of waste heat from existing processes using special boilers or turbines. Specific applications of more-complex energy cascades for Canada are discussed. A combined-cycle plant at a chemical refinery in Ontario is world leader in energy efficiency. Total-energy systems for commercial buildings, such as one installed in a school in Western Canada, offer attractive energy and operating cost benefits. A cogeneration plant proposed for the National Capital Region, generating electricity as well as steam for district heating, allows the use of a low-grade fossil fuel (coal), greatly improves energy-transformation efficiency, and also utilizes an effectively renewable resource (municipal garbage). Despite the widespread availability of equipment and technology of energy cascades, the sale of steam and electricity across plant boundaries presents a barrier. More widespread use of cascades will require increased cooperation among industry, electric utilities and the various levels of government if Canada is to realize the high levels of energy efficiency potential available.

  8. Cascade Organic Solar Cells

    KAUST Repository

    Schlenker, Cody W.; Barlier, Vincent S.; Chin, Stephanie W.; Whited, Matthew T.; McAnally, R. Eric; Forrest, Stephen R.; Thompson, Mark E.

    2011-01-01

    We demonstrate planar organic solar cells consisting of a series of complementary donor materials with cascading exciton energies, incorporated in the following structure: glass/indium-tin-oxide/donor cascade/C 60/bathocuproine/Al. Using a tetracene layer grown in a descending energy cascade on 5,6-diphenyl-tetracene and capped with 5,6,11,12-tetraphenyl- tetracene, where the accessibility of the π-system in each material is expected to influence the rate of parasitic carrier leakage and charge recombination at the donor/acceptor interface, we observe an increase in open circuit voltage (Voc) of approximately 40% (corresponding to a change of +200 mV) compared to that of a single tetracene donor. Little change is observed in other parameters such as fill factor and short circuit current density (FF = 0.50 ± 0.02 and Jsc = 2.55 ± 0.23 mA/cm2) compared to those of the control tetracene-C60 solar cells (FF = 0.54 ± 0.02 and Jsc = 2.86 ± 0.23 mA/cm2). We demonstrate that this cascade architecture is effective in reducing losses due to polaron pair recombination at donor-acceptor interfaces, while enhancing spectral coverage, resulting in a substantial increase in the power conversion efficiency for cascade organic photovoltaic cells compared to tetracene and pentacene based devices with a single donor layer. © 2011 American Chemical Society.

  9. Simulation of concentration spikes in cascades

    International Nuclear Information System (INIS)

    Wood, H.G.

    2006-01-01

    Research has been conducted to investigate the maximum possible enrichment that might be temporarily achieved in a facility that is producing enriched uranium for fuel for nuclear power reactors. The purpose is to provide information to evaluate if uranium enrichment facilities are producing 235 U enriched within declared limits appropriate for power reactors or if the facilities are actually producing more highly enriched uranium. The correlation between feed rate and separation factor in a gas centrifuge cascade shows that as flow decreases, the separation factor increases, thereby, creating small amounts of higher enriched uranium than would be found under optimum design operating conditions. The research uses a number of cascade enrichment programs to model the phenomenon and determine the maximum enrichment possible during the time transient of a gas centrifuge cascade. During cascade start-up, the flow through the centrifuges begins at lower than centrifuge design stage flow rates. Steady-state cascade models have been used to study the maximum 235 U concentrations that would be predicted in the cascade. These calculations should produce an upper bound of product concentrations expected during the transient phase of start-up. Due to the fact that there are different ways in which to start a cascade, several methods are used to determine the maximum enrichment during the time transient. Model cascades were created for gas centrifuges with several product to .feed assay separation factors. With this information, the models were defined and the equilibrium programs were used to determine the maximum enrichment level during the time transient. The calculations predict in a cascade with separation factor 1.254 designed to produce enriched uranium for the purpose of supplying reactor fuel, it would not be unreasonable to see some 235 U in the range of 12-15%. Higher assays produced during the start-up period might lead inspectors to believe the cascade is being

  10. Evaluation of Macerating Pectinase Enzyme Activity under Various Temperature, pH and Ethanol Regimes

    Directory of Open Access Journals (Sweden)

    Andrew G. Reynolds

    2018-02-01

    Full Text Available The polygalacturonase (PGU, hemicellulase (mannanase and protease enzyme activities in commercial macerating, pectinase-enzyme preparations commonly used by wineries in Ontario (Scottzyme Color X and Color Pro were measured under various simulated process conditions (temperature, pH, and ethanol concentration. Treatments included three temperatures (15, 20 and 30 °C; pH = 3.0, 3.5, 4.0 and 5.0; ethanol = 0%, four pH levels (3.0, 3.5, 4.0 and 5.0; temperature = 15, 20, 30 and 50 °C; ethanol = 0%, and four ethanol concentrations ((2.5, 5, 7.5 and 10%; temperature = 20 °C and pH = 3.5. Polygalacturonase enzyme activity in Color X increased linearly with temperature at all pH levels, and increased with pH at all temperature regimes. Polygalacturonase activity decreased with increasing ethanol. Color X mannanase activity increased with temperatures between 15 and 40 °C, and decreased with increased pH between 3.0 and 5.0. Response of mannanase to ethanol was cubic with a sharp decrease between 8 and 10% ethanol. Protease activity increased linearly with temperatures between 20 and 40 °C. These data suggest that the PGU, mannanase and protease components in these enzyme products provide sufficient activities within the ranges of pH, temperature, and ethanol common during the initial stages of red wine fermentations, although low must temperatures (<20 °C and presence of ethanol would likely lead to sub-optimal enzyme activities.

  11. Hadron cascades produced by electromagnetic cascades

    International Nuclear Information System (INIS)

    Nelson, W.R.; Jenkins, T.M.; Ranft, J.

    1986-12-01

    A method for calculating high energy hadron cascades induced by multi-GeV electron and photon beams is described. Using the EGS4 computer program, high energy photons in the EM shower are allowed to interact hadronically according to the vector meson dominance (VMD) model, facilitated by a Monte Carlo version of the dual multistring fragmentation model which is used in the hadron cascade code FLUKA. The results of this calculation compare very favorably with experimental data on hadron production in photon-proton collisions and on the hadron production by electron beams on targets (i.e., yields in secondary particle beam lines). Electron beam induced hadron star density contours are also presented and are compared with those produced by proton beams. This FLUKA-EGS4 coupling technique could find use in the design of secondary beams, in the determination high energy hadron source terms for shielding purposes, and in the estimation of induced radioactivity in targets, collimators and beam dumps

  12. The role of enzyme and substrate concentration in the evaluation of serum angiotensin converting enzyme (ACE) inhibition by enalaprilat in vitro.

    Science.gov (United States)

    Weisser, K; Schloos, J

    1991-10-09

    The relationship between serum angiotensin converting enzyme (ACE) activity and concentration of the ACE inhibitor enalaprilat was determined in vitro in the presence of different concentrations (S = 4-200 mM) of the substrate Hip-Gly-Gly. From Henderson plots, a competitive tight-binding relationship between enalaprilat and serum ACE was found yielding a value of approximately 5 nM for serum ACE concentration (Et) and an inhibition constant (Ki) for enalaprilat of approximately 0.1 nM. A plot of reaction velocity (Vi) versus total inhibitor concentration (It) exhibited a non-parallel shift of the inhibition curve to the right with increasing S. This was reflected by apparent Hill coefficients greater than 1 when the commonly used inhibitory sigmoid concentration-effect model (Emax model) was applied to the data. Slopes greater than 1 were obviously due to discrepancies between the free inhibitor concentration (If) present in the assay and It plotted on the abscissa and could, therefore, be indicators of tight-binding conditions. Thus, the sigmoid Emax model leads to an overestimation of Ki. Therefore, a modification of the inhibitory sigmoid Emax model (called "Emax tight model") was applied, which accounts for the depletion of If by binding, refers to It and allows estimation of the parameters Et and IC50f (free concentration of inhibitor when 50% inhibition occurs) using non-linear regression analysis. This model could describe the non-symmetrical shape of the inhibition curves and the results for Ki and Et correlated very well with those derived from the Henderson plots. The latter findings confirm that the degree of ACE inhibition measured in vitro is, in fact, dependent on the concentration of substrate and enzyme present in the assay. This is of importance not only for the correct evaluation of Ki but also for the interpretation of the time course of serum ACE inhibition measured ex vivo. The non-linear model has some advantages over the linear Henderson

  13. Evaluation of the protein concentration in enzymes via the determination of sulphur by TXRF

    International Nuclear Information System (INIS)

    Mertens, M.; Rittmeyer, C.; Kolbesen, B.O.

    2000-01-01

    Total reflection x-ray fluorescence spectrometry (TXRF) offers many advantages for the identification of trace elements in biological samples like enzymes, tissues or plants. Without any preliminary treatment elements may be determined with high accuracy especially transition metals like Fe, Ni, Cu, Mo and the alkaline earth metal Ca. A further aspect of the investigation of enzymes is the simple and simultaneous determination of light elements. Especially sulphur is of interest. The element sulphur exists mainly in the two amino, acids methionine and cysteine as well as in iron-sulphur clusters and may be used for an easy and simultaneous calculation of the protein concentration. Hence the quantitative determination of sulphur by TXRF allows a cross-check regarding of the conventional quantitative determination of protein concentration by, for example, the Lowry method. On the basis of three enzymes of different origins and molecular weights the presentation will show the influence of the bio-organic matrix and different buffer media on element determination by TXRF. As is already known the influence of the matrix on the detection of light elements is stronger than on transition metals. It can be discussed whether layer thickness and layer effects of the drying residues (characterization by SEM and thickness profilometer (ALPHA-step)) and / or self absorption effects as well as the excitation are of significance. The results indicate that with enzymes of low molecular weight a reliable determination of sulphur is possible whereas those with higher molecular weights gave poorer results on account of the matrix effects described. (author)

  14. Empirical evaluation of a virtual laboratory approach to teach lactate dehydrogenase enzyme kinetics.

    Science.gov (United States)

    Booth, Christine; Cheluvappa, Rajkumar; Bellinson, Zack; Maguire, Danni; Zimitat, Craig; Abraham, Joyce; Eri, Rajaraman

    2016-06-01

    Personalised instruction is increasingly recognised as crucial for efficacious learning today. Our seminal work delineates and elaborates on the principles, development and implementation of a specially-designed adaptive, virtual laboratory. We strived to teach laboratory skills associated with lactate dehydrogenase (LDH) enzyme kinetics to 2nd-year biochemistry students using our adaptive learning platform. Pertinent specific aims were to:(1)design/implement a web-based lesson to teach lactate dehydrogenase(LDH) enzyme kinetics to 2nd-year biochemistry students(2)determine its efficacious in improving students' comprehension of enzyme kinetics(3)assess their perception of its usefulness/manageability(vLab versus Conventional Tutorial). Our tools were designed using HTML5 technology. We hosted the program on an adaptive e-learning platform (AeLP). Provisions were made to interactively impart informed laboratory skills associated with measuring LDH enzyme kinetics. A series of e-learning methods were created. Tutorials were generated for interactive teaching and assessment. The learning outcomes herein were on par with that from a conventional classroom tutorial. Student feedback showed that the majority of students found the vLab learning experience "valuable"; and the vLab format/interface "well-designed". However, there were a few technical issues with the 1st roll-out of the platform. Our pioneering effort resulted in productive learning with the vLab, with parity with that from a conventional tutorial. Our contingent discussion emphasises not only the cornerstone advantages, but also the shortcomings of the AeLP method utilised. We conclude with an astute analysis of possible extensions and applications of our methodology.

  15. Comparative evaluation of Bacillus licheniformis 5A5 and Aloe variegata milk-clotting enzymes

    Directory of Open Access Journals (Sweden)

    S. A. Ahmed

    2012-03-01

    Full Text Available The properties of a milk clotting enzyme (MCE produced by bacteria (Bacillus licheniformis 5A5 were investigated and compared to those of rennet extracted from a plant (Aloe variegata. Production of MCE by B. licheniformis 5A5 was better in static than in shaken cultures. Maximum activity (98.3 and 160.3 U/ml of clotting was obtained at 75ºC and 80ºC with bacterial and plant rennet, respectively. In the absence of substrate, the clotting activity of Aloe MCE was found to be less sensitive to heat inactivation up to 80ºC for 75 min, retaining 63.8% of its activity, while bacterial MCE was completely inhibited. CaCl2 stimulated milk clotting activity (MCA up to 2% and 1.5% for bacterial and plant enzymes. NaCl inhibited MCA for both enzymes, even at low concentration (1%. Plant MCE was more sensitive to NaCl at 3% concentration it retained 30.2% of its activity, whereas bacterial MCE retained 64.1%. Increasing skim milk concentration caused a significant increase in MCA up to 6% for both enzymes. Mn2+ stimulated the activity of bacterial and plant enzymes to 158.6 and 177.9%, respectively. EDTA and PMSF increased the activity of plant MCE by 34.4 and 41.1%, respectively, which is higher than those for the bacterial MCE (19.1 and 20.9%. Some natural materials activated MCE, the highest activation of bacterial MCE (128.1% was obtained in the presence of Fenugreek (with acid extraction. However Lupine Giza 1 (with neutral extraction gave the highest activation of plant MCE (137.9%. All extracts from Neem plant increased MCA at range from 105.6% to 136.4%. Plant MCE exhibited much better stability when stored at room temperature (25-30ºC for 30 days, retaining 51.2% of its activity. Bacterial MCE was highly stabile when stored under freezing (-18ºC, retaining 100% of its activity after 30 days. Moreover, bacterial MCE was highly tolerant to repeated freezing and thawing without loss of activity for 8 months.

  16. Acyl-CoA hydrolysis by the high molecular weight protein 1 subunit of yersiniabactin synthetase: Mutational evidence for a cascade of four acyl-enzyme intermediates during hydrolytic editing

    OpenAIRE

    Suo, Zucai; Chen, Huawei; Walsh, Christopher T.

    2000-01-01

    Yersiniabactin (Ybt) synthetase is a three-subunit, 17-domain [7 domains in high molecular weight protein (HMWP)2, 9 in HMWP1, and 1 in YbtE] enzyme producing the virulence-conferring siderophore yersiniabactin in Yersinia pestis. The 350-kDa HMWP1 subunit contains a polyketide synthase module (KS-AT-MT2-KR-ACP) and a nonribosomal peptide synthetase module (Cy3-MT3-PCP3-TE). The full-length HMWP1 was heterologously overexpressed in Escherichia coli and purified...

  17. Cascade reactor: introduction

    International Nuclear Information System (INIS)

    Pitts, J.H.

    1985-01-01

    Cascade is a concept for an ultrasafe, highly efficient, easily built reactor to convert inertial-confinement fusion energy into electrical power. The Cascade design includes a rotating double-cone-shaped chamber in which a moving, 1-m-thick ceramic granular blanket is held against the reactor wall by centrifugal action. The granular material absorbs energy from the fusion reactions. Accomplishments this year associated with Cascade included improvements to simplify chamber design and lower activation. The authors switched from a steel chamber wall to one made from silicon-carbide (SiC) panels held in compression by SiC-fiber/Al-composite tendons that gird the chamber both circumferentially and axially. The authors studies a number of heat-exchanger designs and selected a gravity-flow cascade design with a vacuum on the primary side. This design allows granules leaving the chamber to be transported to the heat exchangers using their own peripheral speed. The granules transfer their thermal energy and return to the chamber gravitationally: no vacuum locks or conveyors are needed

  18. Stability of cascade search

    Energy Technology Data Exchange (ETDEWEB)

    Fomenko, Tatiana N [M. V. Lomonosov Moscow State University, Faculty of Computational Mathematics and Cybernetics, Moscow (Russian Federation)

    2010-10-22

    We find sufficient conditions on a searching multi-cascade for a modification of the set of limit points of the cascade that satisfy an assessing inequality for the distance from each of these points to the initial point to be small, provided that the modifications of the initial point and the initial set-valued functionals or maps used to construct the multi-cascade are small. Using this result, we prove the stability (in the above sense) of the cascade search for the set of common pre-images of a closed subspace under the action of n set-valued maps, n{>=}1 (in particular, for the set of common roots of these maps and for the set of their coincidences). For n=2 we obtain generalizations of some results of A. V. Arutyunov; the very statement of the problem comes from a recent paper of his devoted to the study of the stability of the subset of coincidences of a Lipschitz map and a covering map.

  19. Hadronic cascade processes

    International Nuclear Information System (INIS)

    Ilgenfritz, E.M.; Kripfganz, J.; Moehring, H.J.

    1977-01-01

    The analytical treatment of hadronic decay cascades within the framework of the statistical bootstrap model is demonstrated on the basis of a simple variant. Selected problems for a more comprehensive formulation of the model such as angular momentum conservation, quantum statistical effects, and the immediate applicability to particle production processes at high energies are discussed in detail

  20. Integrated Broadband Quantum Cascade Laser

    Science.gov (United States)

    Mansour, Kamjou (Inventor); Soibel, Alexander (Inventor)

    2016-01-01

    A broadband, integrated quantum cascade laser is disclosed, comprising ridge waveguide quantum cascade lasers formed by applying standard semiconductor process techniques to a monolithic structure of alternating layers of claddings and active region layers. The resulting ridge waveguide quantum cascade lasers may be individually controlled by independent voltage potentials, resulting in control of the overall spectrum of the integrated quantum cascade laser source. Other embodiments are described and claimed.

  1. Evaluation of coagulation parameters and liver enzymes among alcohol drinkers in Port Harcourt, Nigeria

    Directory of Open Access Journals (Sweden)

    Adias TC

    2013-06-01

    Full Text Available Teddy Charles Adias,1 Everton Egerton,2 Osaro Erhabor3 1Bayelsa College of Health Technology, Bayelsa State, Nigeria; 2Department of Medical Laboratory Science, Rivers State University of Science and Technology, Port Harcourt, Nigeria; 3Faculty of Medical Laboratory Science, Department of Haematology and Transfusion Medicine, Usmanu Danfodiyo University, Sokoto, Nigeria Abstract: Alcohol is a major contributor to the global burden of disease, disability, and death in high, middle, and low-income countries. Harmful use of alcohol is one of the main factors contributing to premature deaths and avoidable disease burden worldwide and has a major impact on public health. The aim of this present cross-sectional study was to investigate the effect of alcohol consumption on coagulation parameters and liver enzymes of subjects in Port Harcourt, Nigeria. Two hundred adults consisting of 120 alcohol dependent subjects and 80 age, gender-matched nondrinkers aged 25–65 years (mean age 45.25 ± 11.50 years were enrolled in this study. Of the 120 chronic alcohol drinkers, 37 were dependent on local dry gin, while 83 were dependent on other alcoholic beverages. The mean values of the liver enzymes, aspartate aminotransferase and gamma glutamyl transferase, were significantly higher (P = 0.002 and P = 0.02 respectively among the chronic alcohol consumers compared with their nondrinker counterparts. Although the value of alanine aminotransferase was higher in the chronic drinkers, it did not reveal any significant difference (P = 0.11. The coagulation parameters, prothrombin time and activated partial thromboplastin time were investigated among chronic drinkers and nondrinkers. The mean value of prothrombin time and activated partial thromboplastin time was significantly higher in the chronic alcohol drinkers compared to the nondrinkers (P = 0.04 and P = 0.02 respectively. We observed a positive and significant correlation between values of liver enzymes, serum

  2. Evaluation of the Inhibition of Carbohydrate Hydrolyzing Enzymes, the Antioxidant Activity, and the Polyphenolic Content of Citrus limetta Peel Extract

    Directory of Open Access Journals (Sweden)

    Eduardo Padilla-Camberos

    2014-01-01

    Full Text Available Type 2 diabetes mellitus is one of the most frequent causes of death in Mexico, characterized by chronic hyperglycemia. One alternative strategy for this metabolic abnormality is inhibiting the enzymes responsible for the metabolism of carbohydrates. We evaluated whether the aqueous Citrus limetta peel extract could inhibit the metabolism of carbohydrates. We found that this extract inhibited primarily the enzyme α-amylase by 49.6% at a concentration of 20 mg/mL and to a lesser extent the enzyme α-glucosidase with an inhibition of 28.2% at the same concentration. This inhibition is likely due to the high polyphenol content in the Citrus limetta peel (19.1 mg GAE/g. Antioxidant activity of the Citrus limetta peel demonstrated dose-dependent antioxidant activity, varying from 6.5% at 1.125 mg/mL to 42.5% at 20 mg/mL. The study of these polyphenolic compounds having both antihyperglycemic and antioxidant activities may provide a new approach to the management of type 2 diabetes mellitus.

  3. Ontogenetic role of angiontensin-converting enzyme in rats: thirst and sodium appetite evaluation.

    Science.gov (United States)

    Mecawi, André S; Araujo, Iracema G; Rocha, Fábio F; Coimbra, Terezila M; Antunes-Rodrigues, José; Reis, Luís C

    2010-01-12

    We investigated the influence of captopril (an angiotensin converting enzyme inhibitor) treatment during pregnancy and lactation period on hydromineral balance of the male adult offspring, particularly, concerning thirst and sodium appetite. We did not observe significant alterations in basal hydromineral (water intake, 0.3M NaCl intake, volume and sodium urinary concentration) or cardiovascular parameters in adult male rats perinatally treated with captopril compared to controls. However, male offspring rats that perinatally exposed to captopril showed a significant attenuation in water intake induced by osmotic stimulation, extracellular dehydration and beta-adrenergic stimulation. Moreover, captopril treatment during perinatal period decreased the salt appetite induced by sodium depletion. This treatment also attenuated thirst and sodium appetite aroused during inhibition of peripheral angiotensin II generation raised by low concentration of captopril in the adult offspring. Interestingly, perinatal exposure to captopril did not alter water or salt intake induced by i.c.v. administration of angiotensin I or angiotensin II. These results showed that chronic inhibition of angiotensin converting enzyme during pregnancy and lactation modifies the regulation of induced thirst and sodium appetite in adulthood.

  4. Empirical evaluation of inhibitory product, substrate, and enzyme effects during the enzymatic saccharification of lignocellulosic biomass.

    Science.gov (United States)

    Smith, Benjamin T; Knutsen, Jeffrey S; Davis, Robert H

    2010-05-01

    The cellulose hydrolysis kinetics during batch enzymatic saccharification are typified by a rapid initial rate that subsequently decays, resulting in incomplete conversion. Previous studies suggest that changes associated with the solution, substrate, or enzymes may be responsible. In this work, kinetic experiments were conducted to determine the relative magnitude of these effects. Pretreated corn stover (PCS) was used as a lignocellulosic substrate likely to be found in a commercial saccharification process, while Avicel and Kraft lignin were used to create model substrates. Glucose inhibition was observed by spiking the reaction slurry with glucose during initial-rate experiments. Increasing the glucose concentration from 7 to 48 g/L reduced the cellulose conversion rate by 94%. When product sugars were removed using ultrafiltration with a 10 kDa membrane, the glucose-based conversion increased by 9.5%. Reductions in substrate reactivity with conversion were compared directly by saccharifying PCS and Avicel substrates that had been pre-reacted to different conversions. Reaction of substrate with a pre-conversion of 40% resulted in about 40% reduction in the initial rate of saccharification, relative to fresh substrate with identical cellulose concentration. Overall, glucose inhibition and reduced substrate reactivity appear to be dominant factors, whereas minimal reductions of enzyme activity were observed.

  5. A focused fragment library targeting the antibiotic resistance enzyme - Oxacillinase-48: Synthesis, structural evaluation and inhibitor design.

    Science.gov (United States)

    Akhter, Sundus; Lund, Bjarte Aarmo; Ismael, Aya; Langer, Manuel; Isaksson, Johan; Christopeit, Tony; Leiros, Hanna-Kirsti S; Bayer, Annette

    2018-02-10

    β-Lactam antibiotics are of utmost importance when treating bacterial infections in the medical community. However, currently their utility is threatened by the emergence and spread of β-lactam resistance. The most prevalent resistance mechanism to β-lactam antibiotics is expression of β-lactamase enzymes. One way to overcome resistance caused by β-lactamases, is the development of β-lactamase inhibitors and today several β-lactamase inhibitors e.g. avibactam, are approved in the clinic. Our focus is the oxacillinase-48 (OXA-48), an enzyme reported to spread rapidly across the world and commonly identified in Escherichia coli and Klebsiella pneumoniae. To guide inhibitor design, we used diversely substituted 3-aryl and 3-heteroaryl benzoic acids to probe the active site of OXA-48 for useful enzyme-inhibitor interactions. In the presented study, a focused fragment library containing 49 3-substituted benzoic acid derivatives were synthesised and biochemically characterized. Based on crystallographic data from 33 fragment-enzyme complexes, the fragments could be classified into R 1 or R 2 binders by their overall binding conformation in relation to the binding of the R 1 and R 2 side groups of imipenem. Moreover, binding interactions attractive for future inhibitor design were found and their usefulness explored by the rational design and evaluation of merged inhibitors from orthogonally binding fragments. The best inhibitors among the resulting 3,5-disubstituted benzoic acids showed inhibitory potential in the low micromolar range (IC 50  = 2.9 μM). For these inhibitors, the complex X-ray structures revealed non-covalent binding to Arg250, Arg214 and Tyr211 in the active site and the interactions observed with the mono-substituted fragments were also identified in the merged structures. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

  6. Preparation and evaluation of a coumarin library towards the inhibitory activity of the enzyme gGAPDH from Trypanosoma cruzi

    Energy Technology Data Exchange (ETDEWEB)

    Alvim Junior, Joel; Dias, Ricardo L.A.; Correa, Arlene G. [Universidade Federal de Sao Carlos, SP (Brazil). Dept. de Quimica]. E-mail: agcorrea@power.ufscar.br; Castilho, Marcelo S.; Oliva, Glaucius [Sao Paulo Univ., Sao Carlos, SP (Brazil). Inst. de Fisica

    2005-07-15

    Chagas' disease, caused by Trypanosoma cruzi, is endemic in 15 countries in Latin America. In this work a library of 38 coumarins was prepared in solution phase and evaluated against T. cruzi glycolytic enzyme glyceraldehyde-3-phosphate-dehydrogenase (gGAPDH). The synthetic route was based on the Knoevenagel condensation of different 2-hydroxybenzaldehydes with Meldrum's acid or diethyl malonate, followed by O-alkylation and/or transesterification reactions. Among the prepared coumarins, the best values obtained to inhibit 50% of the enzymatic activity range from 80 to 130 {mu}M. (author)

  7. Preparation and evaluation of a coumarin library towards the inhibitory activity of the enzyme gGAPDH from Trypanosoma cruzi

    International Nuclear Information System (INIS)

    Alvim Junior, Joel; Dias, Ricardo L.A.; Correa, Arlene G.; Castilho, Marcelo S.; Oliva, Glaucius

    2005-01-01

    Chagas' disease, caused by Trypanosoma cruzi, is endemic in 15 countries in Latin America. In this work a library of 38 coumarins was prepared in solution phase and evaluated against T. cruzi glycolytic enzyme glyceraldehyde-3-phosphate-dehydrogenase (gGAPDH). The synthetic route was based on the Knoevenagel condensation of different 2-hydroxybenzaldehydes with Meldrum's acid or diethyl malonate, followed by O-alkylation and/or transesterification reactions. Among the prepared coumarins, the best values obtained to inhibit 50% of the enzymatic activity range from 80 to 130 μM. (author)

  8. Evaluation of immunofluorescence microscopy and enzyme-linked immunosorbent assay in detection of Cryptosporidium and Giardia infections in asymptomatic dogs

    DEFF Research Database (Denmark)

    Rimhanen-Finne, R.; Enemark, Heidi L.; Kolehmainen, J.

    2007-01-01

    The performance of immunofluorescence microscopy (IF) and enzyme-linked immunosorbent assay (ELISA) in canine feces was evaluated. IF and Cryptosporidium ELISA detected 10(5) oocysts/g, while the detection limit for Giardia ELISA was 10(4) cysts/g. The Cryptosporidium ELISA showed 94% specificity...... zoonotic character of Cryptosporidium and Giardia infections in 150 asymptomatic Finnish dogs from the Helsinki area were studied. The overall proportion of dogs positive for Cryptosporidium was 5% (7/150) and that for Giardia 5% (8/150). In dogs...

  9. Evaluation of a covalent mix-enzyme linked immunosorbent assay for screening of Salmonella antibodies in pig serum

    DEFF Research Database (Denmark)

    Chow, E.Y.W.; Wu, J.T.Y.; Jauho, E.S.

    2004-01-01

    In this study, a commercial Salmonella covalent mix-enzyme linked immunosorbent assay (ELISA) for serological detection of Salmonella infection in swine was evaluated by comparing it with the conventional fecal culture method and inter-laboratory proficiency testing, using a panel of sera tested.......9% tested negative. The interlaboratory comparison study found a kappa value of 0.9 between our laboratory (using an automated system) and the manufacturer laboratory (using the manual method). Comparison of ELISA results from all 5 participating laboratories showed very good to excellent agreement, between...

  10. Interrelation of structure and operational states in cascading failure of overloading lines in power grids

    Science.gov (United States)

    Xue, Fei; Bompard, Ettore; Huang, Tao; Jiang, Lin; Lu, Shaofeng; Zhu, Huaiying

    2017-09-01

    As the modern power system is expected to develop to a more intelligent and efficient version, i.e. the smart grid, or to be the central backbone of energy internet for free energy interactions, security concerns related to cascading failures have been raised with consideration of catastrophic results. The researches of topological analysis based on complex networks have made great contributions in revealing structural vulnerabilities of power grids including cascading failure analysis. However, existing literature with inappropriate assumptions in modeling still cannot distinguish the effects between the structure and operational state to give meaningful guidance for system operation. This paper is to reveal the interrelation between network structure and operational states in cascading failure and give quantitative evaluation by integrating both perspectives. For structure analysis, cascading paths will be identified by extended betweenness and quantitatively described by cascading drop and cascading gradient. Furthermore, the operational state for cascading paths will be described by loading level. Then, the risk of cascading failure along a specific cascading path can be quantitatively evaluated considering these two factors. The maximum cascading gradient of all possible cascading paths can be used as an overall metric to evaluate the entire power grid for its features related to cascading failure. The proposed method is tested and verified on IEEE30-bus system and IEEE118-bus system, simulation evidences presented in this paper suggests that the proposed model can identify the structural causes for cascading failure and is promising to give meaningful guidance for the protection of system operation in the future.

  11. Disaster Mythology and Availability Cascades

    Directory of Open Access Journals (Sweden)

    Lisa Grow Sun

    2013-04-01

    Full Text Available Sociological research conducted in the aftermath of natural disasters has uncovered a number of “disaster myths” – widely shared misconceptions about typical post-disaster human behavior. This paper discusses the possibility that perpetuation of disaster mythology reflects an “availability cascade,” defined in prior scholarship as a “self-reinforcing process of collective belief formation by which an expressed perception triggers a chain reaction that gives the perception increasing plausibility through its rising availability in public discourse.” (Kuran and Sunstein 1999. Framing the spread of disaster mythology as an availability cascade suggests that certain tools may be useful in halting the myths’ continued perpetuation. These tools include changing the legal and social incentives of so-called “availability entrepreneurs” – those principally responsible for beginning and perpetuating the cascade, as well as insulating decision-makers from political pressures generated by the availability cascade. This paper evaluates the potential effectiveness of these and other solutions for countering disaster mythology. Las investigaciones sociológicas realizadas tras los desastres naturales han hecho evidentes una serie de “mitos del desastre”, conceptos erróneos ampliamente compartidos sobre el comportamiento humano típico tras un desastre. Este artículo analiza la posibilidad de que la perpetuación de los mitos del desastre refleje una “cascada de disponibilidad”, definida en estudios anteriores como un “proceso de auto-refuerzo de la formación de una creencia colectiva, a través del que una percepción expresada produce una reacción en cadena que hace que la percepción sea cada vez más verosímil, a través de una mayor presencia en el discurso público” (Kuran y Sunstein 1999. Enmarcar la propagación de los mitos del desastre como una cascada de disponibilidad sugiere que ciertas herramientas pueden ser

  12. Pancreatic Enzymes

    Science.gov (United States)

    ... Contact Us DONATE NOW GENERAL DONATION PURPLESTRIDE Pancreatic enzymes Home Facing Pancreatic Cancer Living with Pancreatic Cancer ... and see a registered dietitian. What are pancreatic enzymes? Pancreatic enzymes help break down fats, proteins and ...

  13. Information cascade on networks

    Science.gov (United States)

    Hisakado, Masato; Mori, Shintaro

    2016-05-01

    In this paper, we discuss a voting model by considering three different kinds of networks: a random graph, the Barabási-Albert (BA) model, and a fitness model. A voting model represents the way in which public perceptions are conveyed to voters. Our voting model is constructed by using two types of voters-herders and independents-and two candidates. Independents conduct voting based on their fundamental values; on the other hand, herders base their voting on the number of previous votes. Hence, herders vote for the majority candidates and obtain information relating to previous votes from their networks. We discuss the difference between the phases on which the networks depend. Two kinds of phase transitions, an information cascade transition and a super-normal transition, were identified. The first of these is a transition between a state in which most voters make the correct choices and a state in which most of them are wrong. The second is a transition of convergence speed. The information cascade transition prevails when herder effects are stronger than the super-normal transition. In the BA and fitness models, the critical point of the information cascade transition is the same as that of the random network model. However, the critical point of the super-normal transition disappears when these two models are used. In conclusion, the influence of networks is shown to only affect the convergence speed and not the information cascade transition. We are therefore able to conclude that the influence of hubs on voters' perceptions is limited.

  14. Cascade ICF power reactor

    International Nuclear Information System (INIS)

    Hogan, W.J.; Pitts, J.H.

    1986-01-01

    The double-cone-shaped Cascade reaction chamber rotates at 50 rpm to keep a blanket of ceramic granules in place against the wall as they slide from the poles to the exit slots at the equator. The 1 m-thick blanket consists of layers of carbon, beryllium oxide, and lithium aluminate granules about 1 mm in diameter. The x rays and debris are stopped in the carbon granules; the neutrons are multiplied and moderated in the BeO and breed tritium in the LiAlO 2 . The chamber wall is made up of SiO tiles held in compression by a network of composite SiC/Al tendons. Cascade operates at a 5 Hz pulse rate with 300 MJ in each pulse. The temperature in the blanket reaches 1600 K on the inner surface and 1350 K at the outer edge. The granules are automatically thrown into three separate vacuum heat exchangers where they give up their energy to high pressure helium. The helium is used in a Brayton cycle to obtain a thermal-to-electric conversion efficiency of 55%. Studies have been done on neutron activation, debris recovery, vaporization and recondensation of blanket material, tritium control and recovery, fire safety, and cost. These studies indicate that Cascade appears to be a promising ICF reactor candidate from all standpoints. At the 1000 MWe size, electricity could be made for about the same cost as in a future fission reactor

  15. Evaluation Of Antioxidant Enzymes, Copper, Zinc And Selenium In Preterm And Full Term Neonates

    International Nuclear Information System (INIS)

    Moawad, A.T.; Mohamed, A.A.; EL Shafie, A.I.

    2011-01-01

    Although oxidative stress-related disease like bronchopulmonary dysplasia, respiratory distress syndrome and retinopathy mostly affect neonates with extremely low birth weight, healthy preterm might also be at risk of oxidative damages. Zinc (Zn), copper (Cu) and selenium (Se) are essential trace elements for metabolism, growth, neurological and immunological function. Trace elements are considered the essential components or cofactors in the antioxidant system especially glutathione peroxidase (GSHPx) and superoxide dismutase (SOD) enzymes. The current study was conducted on 60 neonates divided into two groups; the first group consisted of 30 healthy preterm neonates (14 males and 16 females) with mean gestational age of 34.5±0.3 weeks and mean birth weight of 1742.25 ± 130.11. The second group consisted of 30 full term neonates with mean gestational age of 39.1±0.81 weeks and mean birth weight of 3210±150.25 g. All the neonates were breast fed without any other supplementation to avoid any change in trace elements concentrations. Furthermore, all neonates were subjected to full history thorough clinical examination and laboratory investigation including determinations of plasma levels of Zn, Cu and Se using atomic absorption spectrophotometer. The erythrocyte levels of GSHPx and SOD enzymes were measured. The data revealed that plasma levels of Cu and Zn were significantly decreased in premature neonates than full term subjects but plasma level of Se showed non-significant difference between the premature and full term infants. The erythrocyte levels of GSHPx and SOD were significantly decreased in preterm than full term infants. There were no correlations between erythrocytes levels of GSHPx and the serum levels of Zn, Cu and Se in both preterm or term subjects, while SOD was significantly correlated with plasma levels of Cu and Zn, and no correlation with plasma level of Se was observed. According to the obtained results, it could be concluded that the

  16. Evaluation of gastrointestinal bacterial population for the production of holocellulose enzymes for biomass deconstruction.

    Science.gov (United States)

    Asem, Dhaneshwaree; Leo, Vincent Vineeth; Passari, Ajit Kumar; Tonsing, Mary Vanlalhruaii; Joshi, J Beslin; Uthandi, Sivakumar; Hashem, Abeer; Abd Allah, Elsayed Fathi; Singh, Bhim Pratap

    2017-01-01

    The gastrointestinal (GI) habitat of ruminant and non-ruminant animals sustains a vast ensemble of microbes that are capable of utilizing lignocellulosic plant biomass. In this study, an indigenous swine (Zovawk) and a domesticated goat (Black Bengal) were investigated to isolate bacteria having plant biomass degrading enzymes. After screening and enzymatic quantification of eighty-one obtained bacterial isolates, Serratia rubidaea strain DBT4 and Aneurinibacillus aneurinilyticus strain DBT87 were revealed as the most potent strains, showing both cellulase and xylanase production. A biomass utilization study showed that submerged fermentation (SmF) of D2 (alkaline pretreated pulpy biomass) using strain DBT4 resulted in the most efficient biomass deconstruction with maximum xylanase (11.98 U/mL) and FPase (0.5 U/mL) activities (55°C, pH 8). The present study demonstrated that bacterial strains residing in the gastrointestinal region of non-ruminant swine are a promising source for lignocellulose degrading microorganisms that could be used for biomass conversion.

  17. Evaluation of gastrointestinal bacterial population for the production of holocellulose enzymes for biomass deconstruction.

    Directory of Open Access Journals (Sweden)

    Dhaneshwaree Asem

    Full Text Available The gastrointestinal (GI habitat of ruminant and non-ruminant animals sustains a vast ensemble of microbes that are capable of utilizing lignocellulosic plant biomass. In this study, an indigenous swine (Zovawk and a domesticated goat (Black Bengal were investigated to isolate bacteria having plant biomass degrading enzymes. After screening and enzymatic quantification of eighty-one obtained bacterial isolates, Serratia rubidaea strain DBT4 and Aneurinibacillus aneurinilyticus strain DBT87 were revealed as the most potent strains, showing both cellulase and xylanase production. A biomass utilization study showed that submerged fermentation (SmF of D2 (alkaline pretreated pulpy biomass using strain DBT4 resulted in the most efficient biomass deconstruction with maximum xylanase (11.98 U/mL and FPase (0.5 U/mL activities (55°C, pH 8. The present study demonstrated that bacterial strains residing in the gastrointestinal region of non-ruminant swine are a promising source for lignocellulose degrading microorganisms that could be used for biomass conversion.

  18. Comparative evaluation of oxidative enzyme activities during adventitious rooting in the cuttings of grapevine rootstocks.

    Science.gov (United States)

    Kose, Cafer; Erdal, Serkan; Kaya, Ozkan; Atici, Okkeş

    2011-03-15

    This study investigated changes in peroxidase (POX) and polyphenol oxidase (PPO) activities through adventitious rooting in hardwood cuttings of grapevine rootstocks. Three grapevine rootstocks with different propensity to produce adventitious roots were selected: recalcitrant (Ramsey), non-recalcitrant (Rupestris du Lot) and intermediate (99R) cultivars. The averages of root number at 65 days were 96 in Lot, 76 in 99R and 30 in Ramsey. Both enzyme activities characteristically increased before adventitious rooting, regardless of rooting ability of the rootstocks, and then decreased. POX activity increased in Ramsey cuttings at 22 days, in Lot and 99R cuttings at 14 days after planting, and then decreased gradually until 51 days. The highest POX activity was determined in Ramsey rootstock with the highest rooting ability and the lowest activity was determined in the rootstocks with the lowest rooting ability. PPO activity gradually increased in Ramsey rootstock cuttings from 10 days to 22 days, in Lot and 99R cuttings at 14 days, and then decreased until 51 days. A significant correlation was identified between high POX activity and adventitious rooting capability in rootstocks, but the same result was not determined with PPO activity. A recalcitrant rooting variety cannot increase POX activity sufficiently before rooting. Therefore applications that could increase POX activity in stem cuttings during rooting may facilitate increased rooting in such rootstocks. Copyright © 2011 Society of Chemical Industry.

  19. Evaluation of electrochemiluminescene immunoassay and enzyme-linked immunosorbent assay for serum HBsAb detection

    International Nuclear Information System (INIS)

    Ma Caiyun; Jiang Li; Ge Gaoxia; Zhang Xiaojie

    2005-01-01

    Electrochemiluminescene immunoassay (ECLIA) and enzyme-linked immunosorbent (ELISA) were used to detect the different concentrations of serum HBsAb, in order to compare the results of ECLIA and ELISA. The result showed that intra-assay coefficient of variation of ECLIA was about 0.95% for high value, 1.13% for mean values and 2.63% for low value, while that of ELISA was about 5.76%, 12.8% and 15.9%, respectively. The interassay coefficient of ECLIA was about 4.03% for high values, 4.93% for mean values and 7.34% for low values, while that of ELISA was about 10.1%, 19.6% and 25.2%, respectively. The analytical sensitivity of ECLIA was about 4.0IU/L, while that of ELISA is about 19.0IU/L. Only in 3 samples, the results measured by ECLIA and ELISA were different (ECLIA: positive; ELISA: negative) among 165 samples. It is concluded that the met hod of ECLIA is more efficient than ELISA for detection of HBsAb in serum. (authors)

  20. Direct immunofluorescence and enzyme-linked immunosorbent assays for evaluating chlorinated hydrocarbon degrading bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Brigmon, R.L.; Franck, M.M.; Brey, J.; Fliermans, C.B. [Westinghouse Savannah River, Aiken, SC (United States). Environmental Biotechnology Section; Scott, D.; Lanclos, K. [Medical Coll. of Georgia, Augusta, GA (United States)

    1997-06-01

    Immunological procedures were developed to enumerate chlorinated hydrocarbon degrading bacteria. Polyclonal antibodies (Pabs) were produced by immunizing New Zealand white rabbits against 18 contaminant-degrading bacteria. These included methanotrophic and chlorobenzene (CB) degrading species. An enzyme-linked immunosorbent assay (ELISA) was used to test for specificity and sensitivity of the Pabs. Direct fluorescent antibodies (DFAs) were developed with these Pabs against select methanotrophic bacteria isolated from a trichloroethylene (TCE) contaminated landfill at the Savannah River Site (SRS) and cultures from the American Type Culture Collection (ATCC). Analysis of cross reactivity testing data showed some of the Pabs to be group specific while others were species specific. The threshold of sensitivity for the ELISA is 105 bacteria cells/ml. The DFA can detect as few as one bacterium per ml after concentration. Results from the DFA and ELISA techniques for enumeration of methanotrophic bacteria in groundwater were higher but not significantly different (P < 0.05) compared to indirect microbiological techniques such as MPN. These methods provide useful information on in situ community structure and function for bioremediation applications within 1--4 hours of sampling.

  1. Evaluation of endogenous nitric oxide synthesis in congenital urea cycle enzyme defects.

    Science.gov (United States)

    Nagasaka, Hironori; Tsukahara, Hirokazu; Yorifuji, Tohru; Miida, Takashi; Murayama, Kei; Tsuruoka, Tomoko; Takatani, Tomozumi; Kanazawa, Masaki; Kobayashi, Kunihiko; Okano, Yoshiyuki; Takayanagi, Masaki

    2009-03-01

    Nitric oxide (NO) is synthesized from arginine and O(2) by nitric oxide synthase (NOS). Citrulline, which is formed as a by-product of the NOS reaction, can be recycled to arginine by the 2 enzymes acting in the urea cycle: argininosuccinate synthetase (ASS) and argininosuccinate lyase (ASL). Although the complete urea cycle is expressed only in the liver, ASS and ASL are expressed in other organs including the kidney and vascular endothelium. To examine possible alterations of the NO pathway in urea cycle defects, we measured plasma concentrations of arginine and citrulline and serum concentrations of nitrite/nitrate (NOx(-), stable NO metabolites) and asymmetric dimethylarginine (ADMA, an endogenous NOS inhibitor) in patients with congenital urea cycle disorders of 3 types: ornithine transcarbamylase (OTC) deficiency, ASS deficiency, and ASL deficiency. All were receiving oral arginine replacement at the time of this study. The same parameters were also measured in healthy subjects, who participated as controls. The OTC-deficient patients had significantly high NOx(-) and nonsignificantly high ADMA concentrations. Their NOx(-) was significantly positively correlated with arginine. The ASS-deficient patients had significantly low NOx(-) and significantly high ADMA concentrations. The ASL-deficient patients had normal NOx(-) and nonsignificantly high ADMA concentrations. In ASS-deficient and ASL-deficient patients, the NOx(-) was significantly inversely correlated with citrulline. These results suggest that NO synthesis is enhanced in OTC-deficient patients while receiving arginine but that NO synthesis remains low in ASS-deficient patients despite receiving arginine. They also suggest that endogenous NO synthesis is negatively affected by citrulline and ADMA in ASS-deficient and ASL-deficient patients. Although the molecular mechanisms remain poorly understood, we infer that the NO pathway might play a role in the pathophysiology related to congenital urea cycle

  2. Trophic cascades of bottom-up and top-down forcing on nutrients and plankton in the Kattegat, evaluated by modelling

    DEFF Research Database (Denmark)

    Petersen, Marcell Elo; Maar, Marie; Larsen, Janus

    2017-01-01

    The aim of the study was to investigate the relative importance of bottom-up and top-down forcing on trophic cascades in the pelagic food-web and the implications for water quality indicators (summer phytoplankton biomass and winter nutrients) in relation to management. The 3D ecological model....... On annual basis, the system was more bottom-up than top-down controlled. Microzooplankton was found to play an important role in the pelagic food web as mediator of nutrient and energy fluxes. This study demonstrated that the best scenario for improved water quality was a combined reduction in nutrient...

  3. Proximity does not contribute to activity enhancement in the glucose oxidase-horseradish peroxidase cascade

    Science.gov (United States)

    Zhang, Yifei; Tsitkov, Stanislav; Hess, Henry

    2016-12-01

    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.

  4. Evaluation of the Optimal Reaction Conditions for the Methanolysis and Ethanolysis of Castor Oil Catalyzed by Immobilized Enzymes

    DEFF Research Database (Denmark)

    Andrade, Thalles Allan; Al-Kabalawi, Ibrahim F.; Errico, Massimiliano

    :1 methanol-to-oil molar ratio, 5 wt% of enzymes, 7.5 wt% of water, 50 wt% n-hexane, at 50 °C. The fatty acid methyl esters content was 96.8 % and 1.0 % FFA. Regarding the reactions with ethanol, 98.0 % fatty acid ethyl ester was obtained and 1.3 % FFA, when the reaction was carried out at 60 °C, 4:1 ethanol......As an alternative to the use of chemical catalysts, immobilized enzyme Lipozyme 435 was evaluated as catalyst for biodiesel production, comparing its efficiency in the castor oil transesterification with methanol and ethanol. Different reaction conditions were assessed and optimized, including...... the reaction temperature (35 – 60 °C), alcohol-to-oil molar ratio (from 3:1 to 6:1), amount of catalyst (from 3 to 15 wt% by weight of oil), addition of water (0 – 15 wt%), and use of n-hexane as a solvent (0 – 75 wt%). For the transesterification with methanol, the optimal reaction conditions were 3...

  5. Evaluation of a magnetic particles-based chemiluminescence enzyme immunoassay for Golgi protein 73 in human serum.

    Science.gov (United States)

    Liu, Xiangyi; Wan, Xiaohua; Lu, Sheng; Zhang, Lijun; Yu, Shaohua; Lu, Xinxin

    2015-05-20

    Golgi protein 73 (GP73) is regarded as a potential serum biomarker for early diagnosis of hepatocellular carcinoma (HCC). We developed a rapid magnetic particles-based chemiluminescence enzyme immunoassay (MPs-CLEIA) for the determination of serum GP73. Fluorescein isothiocyanate (FITC) and alkaline phosphatase (ALP) were used to label 2 different monoclonal antibodies to GP73. Serum GP73 was captured with labeled antibodies and formed a sandwiched immunoreaction. The magnetic particles (MPs) coated with anti-FITC antibody were used as a means of separation of the GP73 protein from other serum proteins. After adding the enzyme substrate solution, the relative light unit (RLU) was measured. A MPs-CLEIA for serum GP73 was established and evaluated. The RLU was directly proportional to the concentration of GP73. The method linearity was 5-600 μg/l. Limit of the blank was 2.19 μg/l. The intra- and inter-assay imprecision was 73-0.89), and the sensitivity and specificity, with cut-off value of 115.6 μg/l, were 75.4% and 92.1%, respectively. The proposed method demonstrates an acceptable performance for quantifying serum GP73. This assay could be appropriate for routine use in clinical laboratories. Copyright © 2015 Elsevier B.V. All rights reserved.

  6. Cascading Corruption News

    DEFF Research Database (Denmark)

    Damgaard, Mads

    2018-01-01

    Through a content analysis of 8,800 news items and six months of front pages in three Brazilian newspapers, all dealing with corruption and political transgression, this article documents the remarkable skew of media attention to corruption scandals. The bias is examined as an information...... phenomenon, arising from systemic and commercial factors of Brazil’s news media: An information cascade of news on corruption formed, destabilizing the governing coalition and legitimizing the impeachment process of Dilma Rousseff. As this process gained momentum, questions of accountability were disregarded...

  7. Cascading Corruption News

    DEFF Research Database (Denmark)

    Damgaard, Mads

    2018-01-01

    Through a content analysis of 8,800 news items and six months of front pages in three Brazilian newspapers, all dealing with corruption and political transgression, this article documents the remarkable skew of media attention to corruption scandals. The bias is examined as an information...... phenomenon, arising from systemic and commercial factors of Brazil’s news media: An information cascade of news on corruption formed, destabilizing the governing coalition and legitimizing the impeachment process of Dilma Rousseff. As this process gained momentum, questions of accountability were disregarded...... by the media, with harmful effects on democracy....

  8. Evaluation of an enzyme-linked immunosorbent assay (ELISA) for the serological diagnosis of sarcoptic mange in dogs.

    Science.gov (United States)

    Lower, K S; Medleau, L M; Hnilica, K; Bigler, B

    2001-12-01

    Canine scabies is a challenging disease to diagnose because sarcoptic mites are hard to find on skin scrapings. The purpose of this study was to evaluate a serologic enzyme-linked immunosorbent assay (ELISA) as an aid in the diagnosis of canine scabies. In addition, serum samples were obtained post treatment to determine the duration and persistence of circulating scabies antibodies after resolution of natural infection. Nineteen dogs diagnosed with sarcoptic mange and 38 control dogs were tested. Sixteen scabies-infested dogs showed positive pretreatment ELISA results (84.2% sensitivity). Thirty-four control dogs showed negative ELISA results (89.5% specificity). In the 11 scabies dogs from which multiple post treatment serum samples were obtained, detectable antibodies were not present 1 month after treatment in four cases, but were present for 1-4.5 months post treatment in seven dogs. Our results suggest that this scabies ELISA test is useful in the diagnosis of canine scabies.

  9. Evaluation of Two Commercial Enzyme-Linked Immunosorbent Assay Kits for the Detection of Human Circulating Metrnl.

    Science.gov (United States)

    Zheng, Si-Li; Li, Zhi-Yong; Zhang, Zheng; Wang, Dong-Sheng; Xu, Jian; Miao, Chao-Yu

    2018-04-01

    Metrnl is a newly discovered secreted protein with neurotrophic activity and metabolic effect, while in earlier studies its circulating level in human was not explored. We evaluated two commercial enzyme-linked immunosorbent assay kits (DY7867-05, R&D Systems and SK00478-02, Aviscera Bioscience) for the detection of human circulating Metrnl. The DY7867-05 kit showed superiority over the SK00478-02 kit since it generated better curve fitting degree, smaller variation among tests, higher inter-assay reproducibility and better specificity, and could effectively detect human Metrnl in six types of blood samples. Subsequent analysis was performed using the DY7867-05 kit. Sample storage conditions were investigated. No gender difference in circulating Metrnl levels was found, while people with newly diagnosed type 2 diabetes mellitus (T2DM) had significantly lower Metrnl levels compared to the healthy controls.

  10. Performance evaluation of enzyme immunoassay for voriconazole therapeutic drug monitoring with automated clinical chemistry analyzers

    Directory of Open Access Journals (Sweden)

    Yongbum Jeon

    2017-08-01

    Full Text Available Objective: Voriconazole is a triazole antifungal developed for the treatment of fungal infectious disease, and the clinical utility of its therapeutic drug monitoring has been evaluated. Recently, a new assay for analyzing the serum voriconazole concentration with an automated clinical chemistry analyzer was developed. We evaluated the performance of the new assay based on standardized protocols. Methods: The analytical performance of the assay was evaluated according to its precision, trueness by recovery, limit of quantitation, linearity, and correlation with results from liquid chromatography-tandem mass spectrometry (LC-MS/MS. The evaluation was performed with the same protocol on two different routine chemistry analyzers. All evaluations were performed according to CLSI Guidelines EP15, EP17, EP6, and EP9 [1–4]. Results: Coefficients of variation for within-run and between-day imprecision were 3.2–5.1% and 1.5–3.0%, respectively, on the two different analyzers for pooled serum samples. The recovery rates were in the range of 95.4–102.2%. The limit of blank was 0.0049 μg/mL, and the limit of detection of the samples was 0.0266–0.0376 μg/mL. The percent recovery at three LoQ levels were 67.9–74.6% for 0.50 μg/mL, 75.5–80.2% for 0.60 μg/mL, and 89.9–96.6% for 0.70 μg/mL. A linear relationship was demonstrated between 0.5 μg/mL and 16.0 μg/mL (R2=0.9995–0.9998. The assay correlated well with LC-MS/MS results (R2=0.9739–0.9828. Conclusions: The assay showed acceptable precision, trueness, linearity, and limit of quantification, and correlated well with LC-MS/MS. Therefore, its analytical performance is satisfactory for monitoring the drug concentration of voriconazole. Keywords: Voriconazole, Antifungal agents, Therapeutic drug monitoring

  11. Performance evaluation of enzyme immunoassay for voriconazole therapeutic drug monitoring with automated clinical chemistry analyzers.

    Science.gov (United States)

    Jeon, Yongbum; Han, Minje; Han, Eun Young; Lee, Kyunghoon; Song, Junghan; Song, Sang Hoon

    2017-08-01

    Voriconazole is a triazole antifungal developed for the treatment of fungal infectious disease, and the clinical utility of its therapeutic drug monitoring has been evaluated. Recently, a new assay for analyzing the serum voriconazole concentration with an automated clinical chemistry analyzer was developed. We evaluated the performance of the new assay based on standardized protocols. The analytical performance of the assay was evaluated according to its precision, trueness by recovery, limit of quantitation, linearity, and correlation with results from liquid chromatography-tandem mass spectrometry (LC-MS/MS). The evaluation was performed with the same protocol on two different routine chemistry analyzers. All evaluations were performed according to CLSI Guidelines EP15, EP17, EP6, and EP9 [1-4]. Coefficients of variation for within-run and between-day imprecision were 3.2-5.1% and 1.5-3.0%, respectively, on the two different analyzers for pooled serum samples. The recovery rates were in the range of 95.4-102.2%. The limit of blank was 0.0049 μg/mL, and the limit of detection of the samples was 0.0266-0.0376 μg/mL. The percent recovery at three LoQ levels were 67.9-74.6% for 0.50 μg/mL, 75.5-80.2% for 0.60 μg/mL, and 89.9-96.6% for 0.70 μg/mL. A linear relationship was demonstrated between 0.5 μg/mL and 16.0 μg/mL ( R 2 =0.9995-0.9998). The assay correlated well with LC-MS/MS results ( R 2 =0.9739-0.9828). The assay showed acceptable precision, trueness, linearity, and limit of quantification, and correlated well with LC-MS/MS. Therefore, its analytical performance is satisfactory for monitoring the drug concentration of voriconazole.

  12. Comparison of a neutralization enzyme immunoassay and an enzyme-linked immunosorbent assay for evaluation of immune status of children vaccinated for mumps.

    Science.gov (United States)

    Harmsen, T; Jongerius, M C; van der Zwan, C W; Plantinga, A D; Kraaijeveld, C A; Berbers, G A

    1992-01-01

    A 50% neutralization enzyme immunoassay (N50-EIA) was compared with an indirect enzyme-linked immunosorbent assay (ELISA) for determining mumps virus antibodies in three consecutive serum samples from 138 children vaccinated with a live mumps vaccine at the age (in years) of 1.5. By the N50-EIA, most (132 of 138) preserum samples did not show neutralizing activity. Eight to 12 weeks after vaccination, 17 of the children were still negative, but only 7 remained so after 2.5 years, resulting in a seroconversion rate of 125 of 132 (95%). Over the same period, the neutralization geometric mean titer rose from 3.6 to 9.9. By an indirect ELISA, 128 of 138 preserum samples were found negative. The early and late postvaccination sera of 8 children were ELISA negative, resulting in a seroconversion rate of 120 of 128 (94%). Only two children remained seronegative by both methods. Seven of the late postvaccination serum samples yielded noncorresponding results, reflecting 95% correlation between both methods. Due to cross-reactivity with parainfluenza viruses, the ELISA proved to be less specific, but on the other hand, it showed a greater sensitivity than the N50-EIA. PMID:1500523

  13. EFSA Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids (CEF); Scientific Opinion on Flavouring Group Evaluation 309 (FGE.309): Sodium Diacetate

    DEFF Research Database (Denmark)

    Larsen, John Christian; Nørby, Karin Kristiane; Beltoft, Vibe Meister

    The Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids of the European Food Safety Authority was requested to evaluate sodium diacetate [FL-no: 16.073] in the Flavouring Group Evaluation 309, using the Procedure in Commission Regulation (EC) No 1565/2000. However, although...

  14. Cascade Error Projection Learning Algorithm

    Science.gov (United States)

    Duong, T. A.; Stubberud, A. R.; Daud, T.

    1995-01-01

    A detailed mathematical analysis is presented for a new learning algorithm termed cascade error projection (CEP) and a general learning frame work. This frame work can be used to obtain the cascade correlation learning algorithm by choosing a particular set of parameters.

  15. Criticality safety study of shutdown diffusion cascade coolers

    International Nuclear Information System (INIS)

    Paschal, L.S.; Basoglu, B.; Bentley, C.L.; Dunn, M.E.

    1996-01-01

    Gaseous diffusion plants use cascade coolers in the production of highly enriched uranium (HEU) to remove heat from the enriched stream of UF 6 . The cascade coolers operate like shell and tube heat exchangers with the UF 6 on the shell side and Freon on the tube side. Recirculating cooling water (RCW) in condensers is used to cool the Freon. A criticality safety analysis was previously performed for cascade coolers during normal operation. The purpose of this paper is to evaluate several different hypothetical accidents regarding RCW ingress into the cooler to determine whether criticality safety concerns exist

  16. Evaluation of coal combustion byproducts as soil liming materials - their influence on soil pH and enzyme activities

    Energy Technology Data Exchange (ETDEWEB)

    McCarty, G W; Siddaramappa, R; Wright, R J; Codling, E E; Gao, G

    1994-03-01

    To evaluate coal combustion byproducts as liming materials and address issues related to soil quality, the authors compared the influence of different amounts of four combustion byproducts (fly ash and bed ash from a fluidized bed combustion furnace, lime-injected multistage burner residue, and spray dryer residue) and CaCO[sub 3] on soil pH and activities of urease, phosphatase, arylsulfatase, and dehydrogenase in an acidic soil. Studies comparing the influence of the combustion byproducts and CaCO[sub 3] on soil pH showed that on weight basis of application, substantial differences were observed in the ability of these materials to influence soil pH but that such differences decreased markedly after the data were transformed to a CaCO[sub 3] equivalent basis of application. Analysis of covariance for these transformed data indicated that whereas the liming abilities of fly ash and CaCO[sub 3] were not significantly different when compared on the CaCO[sub 3] equivalent basis, those of bed ash, multistage burner residue, and spray dryer residue were less than that of CaCO[sub 3]. Studies comparing the influence of the byproducts and CaCO[sub 3] on soil enzyme activities showed that the effect of these liming materials on the enzyme activities studied was largely due to their influence on soil pH. These studies showed that the combustion byproducts tested functioned as soil liming materials in a manner similar to that of CaCO[sub 3] and seemed to have little adverse effect on soil quality.

  17. Interband cascade lasers

    International Nuclear Information System (INIS)

    Vurgaftman, I; Meyer, J R; Canedy, C L; Kim, C S; Bewley, W W; Merritt, C D; Abell, J; Weih, R; Kamp, M; Kim, M; Höfling, S

    2015-01-01

    We review the current status of interband cascade lasers (ICLs) emitting in the midwave infrared (IR). The ICL may be considered the hybrid of a conventional diode laser that generates photons via electron–hole recombination, and an intersubband-based quantum cascade laser (QCL) that stacks multiple stages for enhanced current efficiency. Following a brief historical overview, we discuss theoretical aspects of the active region and core designs, growth by molecular beam epitaxy, and the processing of broad-area, narrow-ridge, and distributed feedback (DFB) devices. We then review the experimental performance of pulsed broad area ICLs, as well as the continuous-wave (cw) characteristics of narrow ridges having good beam quality and DFBs producing output in a single spectral mode. Because the threshold drive powers are far lower than those of QCLs throughout the λ = 3–6 µm spectral band, ICLs are increasingly viewed as the laser of choice for mid-IR laser spectroscopy applications that do not require high output power but need to be hand-portable and/or battery operated. Demonstrated ICL performance characteristics to date include threshold current densities as low as 106 A cm −2 at room temperature (RT), cw threshold drive powers as low as 29 mW at RT, maximum cw operating temperatures as high as 118 °C, maximum cw output powers exceeding 400 mW at RT, maximum cw wallplug efficiencies as high as 18% at RT, maximum cw single-mode output powers as high as 55 mW at RT, and single-mode output at λ = 5.2 µm with a cw drive power of only 138 mW at RT. (topical review)

  18. Cascading Generative Adversarial Networks for Targeted

    KAUST Repository

    Hamdi, Abdullah

    2018-01-01

    Abundance of labelled data played a crucial role in the recent developments in computer vision, but that faces problems like scalability and transferability to the wild. One alternative approach is to utilize the data without labels, i.e. unsupervised learning, in learning valuable information and put it in use to tackle vision problems. Generative Adversarial Networks (GANs) have gained momentum for their ability to model image distributions in unsupervised manner. They learn to emulate the training set and that enables sampling from that domain and using the knowledge learned for useful applications. Several methods proposed enhancing GANs, including regularizing the loss with some feature matching. We seek to push GANs beyond the data in the training and try to explore unseen territory in the image manifold. We first propose a new regularizer for GAN based on K-Nearest Neighbor (K-NN) selective feature matching to a target set Y in high-level feature space, during the adversarial training of GAN on the base set X, and we call this novel model K-GAN. We show that minimizing the added term follows from cross-entropy minimization between the distributions of GAN and set Y. Then, we introduce a cascaded framework for GANs that try to address the task of imagining a new distribution that combines the base set X and target set Y by cascading sampling GANs with translation GANs, and we dub the cascade of such GANs as the Imaginative Adversarial Network (IAN). Several cascades are trained on a collected dataset Zoo-Faces and generated innovative samples are shown, including from K-GAN cascade. We conduct an objective and subjective evaluation for different IAN setups in the addressed task of generating innovative samples and we show the effect of regularizing GAN on different scores. We conclude with some useful applications for these IANs, like multi-domain manifold traversing.

  19. Cascading Generative Adversarial Networks for Targeted

    KAUST Repository

    Hamdi, Abdullah

    2018-04-09

    Abundance of labelled data played a crucial role in the recent developments in computer vision, but that faces problems like scalability and transferability to the wild. One alternative approach is to utilize the data without labels, i.e. unsupervised learning, in learning valuable information and put it in use to tackle vision problems. Generative Adversarial Networks (GANs) have gained momentum for their ability to model image distributions in unsupervised manner. They learn to emulate the training set and that enables sampling from that domain and using the knowledge learned for useful applications. Several methods proposed enhancing GANs, including regularizing the loss with some feature matching. We seek to push GANs beyond the data in the training and try to explore unseen territory in the image manifold. We first propose a new regularizer for GAN based on K-Nearest Neighbor (K-NN) selective feature matching to a target set Y in high-level feature space, during the adversarial training of GAN on the base set X, and we call this novel model K-GAN. We show that minimizing the added term follows from cross-entropy minimization between the distributions of GAN and set Y. Then, we introduce a cascaded framework for GANs that try to address the task of imagining a new distribution that combines the base set X and target set Y by cascading sampling GANs with translation GANs, and we dub the cascade of such GANs as the Imaginative Adversarial Network (IAN). Several cascades are trained on a collected dataset Zoo-Faces and generated innovative samples are shown, including from K-GAN cascade. We conduct an objective and subjective evaluation for different IAN setups in the addressed task of generating innovative samples and we show the effect of regularizing GAN on different scores. We conclude with some useful applications for these IANs, like multi-domain manifold traversing.

  20. Watching Individual Enzymes at Work

    Science.gov (United States)

    Blank, Kerstin; Rocha, Susana; De Cremer, Gert; Roeffaers, Maarten B. J.; Uji-i, Hiroshi; Hofkens, Johan

    Single-molecule fluorescence experiments are a powerful tool to analyze reaction mechanisms of enzymes. Because of their unique potential to detect heterogeneities in space and time, they have provided unprecedented insights into the nature and mechanisms of conformational changes related to the catalytic reaction. The most important finding from experiments with single enzymes is the generally observed phenomenon that the catalytic rate constants fluctuate over time (dynamic disorder). These fluctuations originate from conformational changes occurring on time scales, which are similar to or slower than that of the catalytic reaction. Here, we summarize experiments with enzymes that show dynamic disorder and introduce new experimental strategies showing how single-molecule fluorescence experiments can be applied to address other open questions in medical and industrial enzymology, such as enzyme inactivation processes, reactant transfer in cascade reactions, and the mechanisms of interfacial catalysis.

  1. [Evaluation of the Performance of Two Kinds of Anti-TP Enzyme-Linked Immunosorbent Assay].

    Science.gov (United States)

    Gao, Nan; Huang, Li-Qin; Wang, Rui; Jia, Jun-Jie; Wu, Shuo; Zhang, Jing; Ge, Hong-Wei

    2018-06-01

    To evaluate the accuracy and precision of 2 kinds of anti-treponema pallidum (anti-TP) ELISA reagents in our laboratory for detecting the anti-TP in voluntary blood donors, so as to provide the data support for use of ELISA reagents after introduction of chemiluminescene immunoassay (CLIA). The route detection of anti-TP was performed by using 2 kinds of ELISA reagents, then 546 responsive positive samples detected by anti-TP ELISA were collected, and the infections status of samples confirmed by treponema pallidum particle agglutination (TPPA) test was identified. The confirmed results of responsive samples detected by 2 kinds of anti-TP ELISA reagents were compared, the accuracy of 2 kinds of anti-TP ELISA reagents was analyzed by drawing ROC and comparing area under curve (AUC), and precision of 2 kinds of anti-TP ELISA reagents was compared by statistical analysis of quality control data from 7.1 2016 to 6.30 2017. There were no statistical difference in confirmed positive rate of responsive samples and weak positive samples between 2 kinds of anti-TP ELISA reagents. The responsive samples detected by 2 kinds of anti-TP ELISA reagents accounted for 85.53%(467/546) of all responsive samples, the positive rate confirmed by TPPA test was 82.87%. 44 responsive samples detected by anti-TP ELISA reagent A and 35 responsive samples detected by anti-TP ELISA reagent B were confirmed to be negative by TPPA test. Comparison of AUC showed that the accuracy of 2 kinds of anti-TP ELISA reagents was more high, the difference between 2 reagents was not statistically significant. The coefficient of variation (CV) of anti-TP ELISA reagent A and B was 14.98% and 18.04% respectively, which met the precision requirement of ELISA test. The accuracy and precision of 2 kinds of anti-TP ELISA reagents used in our laboratory are similar, and using any one of anti-TP ELISA reagents all can satisfy the requirements of blood screening.

  2. Evaluation of an enzyme linked immunosorbent assay kit for the detection of Babesia bovis antibodies in cattle in Argentina

    Energy Technology Data Exchange (ETDEWEB)

    Echaide, S; Echaide, I E; Mangold, A J; Lugaresi, C I; Guglielmone, A A [Estacion Experimental Agropecuaria, Instituto Nacional de Tecnologia Agropecuaria, Rafaela, Santa Fe (Argentina); Gaido, A B [Estacion Experimental Agropecuaria Salta, Salta (Argentina)

    1998-11-01

    An enzyme linked immunosorbent assay (ELISA) for the detection of antibodies to Babesia bovis was evaluated by using sera of 874 cattle carrying B. bovis antibodies, 700 sera of uninfected cattle, and 357 sera from calves from 16 herds subjected to different B. bovis inoculation rates. The seropositive/ seronegative cut-off point set as double the mean percent positivity of negative cattle sera (= 16%). The sensitivity of the ELISA (four trials) ranged from 97.1% to 100% and the specificity (three trials) varied from 92.0% to 97.0%. The agreement between ELISA and immunofluorescent antibody test was {>=} 90.0% in 18 of 23 evaluations and it ranged from 86.0% to 88.0% in the remainder. The correlation coefficient between percentage of sera positive to ELISA and IFA test in 16 herds was 0.9958 (P<0.001). The ELISA has the advantages of a high sensitivity, objectivity and capacity to test large number of samples in short period of time and could replace the IFA test specially for epidemiological studies. (author) 11 refs, 1 fig., 2 tabs

  3. Development and evaluation of a Sarcocystis neurona-specific IgM capture enzyme-linked immunosorbent assay.

    Science.gov (United States)

    Murphy, J E; Marsh, A E; Reed, S M; Meadows, C; Bolten, K; Saville, W J A

    2006-01-01

    Equine protozoal myeloencephalitis (EPM) is a serious neurologic disease of horses caused primarily by the protozoal parasite Sarcocystis neurona. Currently available antemortem diagnostic testing has low specificity. The hypothesis of this study was that serum and cerebrospinal fluid (CSF) of horses experimentally challenged with S neurona would have an increased S neurona-specific IgM (Sn-IgM) concentration after infection, as determined by an IgM capture enzyme linked immunoassay (ELISA). The ELISA was based on the S neurona low molecular weight protein SNUCD-1 antigen and the monoclonal antibody 2G5 labeled with horseradish peroxidase. The test was evaluated using serum and CSF from 12 horses experimentally infected with 1.5 million S neurona sporocysts and 16 horses experimentally infected with varying doses (100 to 100,000) of S neurona sporocysts, for which results of histopathologic examination of the central nervous system were available. For horses challenged with 1.5 million sporocysts, there was a significant increase in serum Sn-IgM concentrations compared with values before infection at weeks 2-6 after inoculation (P neurona, there were significant increases in serum Sn-IgM concentration at various points in time after inoculation, depending on the challenge dose (P < .01). In addition, there was a significant increase between the CSF Sn-IgM concentrations before and after inoculation (P < .0001). These results support further evaluation of the assay as a diagnostic test during the acute phase of EPM.

  4. Evaluation of an enzyme linked immunosorbent assay kit for the detection of Babesia bovis antibodies in cattle in Argentina

    International Nuclear Information System (INIS)

    Echaide, S.; Echaide, I.E.; Mangold, A.J.; Lugaresi, C.I.; Guglielmone, A.A.; Gaido, A.B.

    1998-01-01

    An enzyme linked immunosorbent assay (ELISA) for the detection of antibodies to Babesia bovis was evaluated by using sera of 874 cattle carrying B. bovis antibodies, 700 sera of uninfected cattle, and 357 sera from calves from 16 herds subjected to different B. bovis inoculation rates. The seropositive/ seronegative cut-off point set as double the mean percent positivity of negative cattle sera (= 16%). The sensitivity of the ELISA (four trials) ranged from 97.1% to 100% and the specificity (three trials) varied from 92.0% to 97.0%. The agreement between ELISA and immunofluorescent antibody test was ≥ 90.0% in 18 of 23 evaluations and it ranged from 86.0% to 88.0% in the remainder. The correlation coefficient between percentage of sera positive to ELISA and IFA test in 16 herds was 0.9958 (P<0.001). The ELISA has the advantages of a high sensitivity, objectivity and capacity to test large number of samples in short period of time and could replace the IFA test specially for epidemiological studies. (author)

  5. Efficiency of three buffers for extracting B-glucosidase enzyme in different soil orders: Evaluating the role of soil organic matter

    Directory of Open Access Journals (Sweden)

    Viviana Gutiérrez

    2017-01-01

    Full Text Available The objective of this research was to evaluate extraction methods for β - glucosidases comparing three buffer solutions (MUB, acetate, and maleate at different incubation times (0.5 h to 10 h and in three different soil orders (Mollisols, Andisols and Ultisols. Seven acidic soils were evaluated, showing differences in pH, OM, and clay contents. To evaluate the effect of OM as enzymes source, one soil of each order was treated to partially remove its OM and then the enzyme assay was performed. When using MUB and maleate buffers the highest (32 and 31 μg - p NP g - soil - 1 h - 1 in average , respec tively were found, and the latter was significantly (p < 0.050 correlated with the soil clay content. The activity obtained with acetate buffer was much lower ( 3 8.2 μg - p NP g - soil - 1 h - 1 in average . The use of MUB buffer with 1 h of incubation is suggested as extraction method, showing good reproducibility and allowing to express higher enzyme potential for soil comparisons. For the Andisol and Ultisol, the enzyme activity significantly decreased with the OM removal (% indicating that OM is the major sourc e of the measured β - glucosidase activity, while a different trend was observed for the Mollisol, in which the mineral fraction (mainly 2:1 type clay appears to be involved in the increased enzyme activity displayed after the initial OM removal.

  6. EFSA CEF Panel (EFSA Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids), 2013. Scientific Opinion on Flavouring Group Evaluation 76, Revision 1 (FGE.76Rev1)

    OpenAIRE

    Beltoft, Vibe Meister; Binderup, Mona-Lise; Frandsen, Henrik Lauritz; Lund, Pia; Nørby, Karin Kristiane

    2013-01-01

    The Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids of the European Food Safety Authority was requested to consider evaluations of flavouring substances assessed since 2000 by the Joint FAO/WHO Expert Committee on Food Additives (JECFA), and to decide whether further evaluation is necessary, as laid down in Commission Regulation (EC) No 1565/2000. The present opinion concerns a group of 26 sulphur-containing heterocyclic compounds evaluated by the JECFA at the 59th m...

  7. Murine Efficacy and Pharmacokinetic Evaluation of the Flaviviral NS5 Capping Enzyme 2-Thioxothiazolidin-4-One Inhibitor BG-323.

    Science.gov (United States)

    Bullard, Kristen M; Gullberg, Rebekah C; Soltani, Elnaz; Steel, J Jordan; Geiss, Brian J; Keenan, Susan M

    2015-01-01

    Arthropod-borne flavivirus infection continues to cause significant morbidity and mortality worldwide. Identification of drug targets and novel antiflaviviral compounds to treat these diseases has become a global health imperative. A previous screen of 235,456 commercially available small molecules identified the 2-thioxothiazolidin-4-one family of compounds as inhibitors of the flaviviral NS5 capping enzyme, a promising target for antiviral drug development. Rational drug design methodologies enabled identification of lead compound BG-323 from this series. We have shown previously that BG-323 potently inhibits NS5 capping enzyme activity, displays antiviral effects in dengue virus replicon assays and inhibits growth of West Nile and yellow fever viruses with low cytotoxicity in vitro. In this study we further characterized BG-323's antiviral activity in vitro and in vivo. We found that BG-323 was able to reduce replication of WNV (NY99) and Powassan viruses in culture, and we were unable to force resistance into WNV (Kunjin) in long-term culture experiments. We then evaluated the antiviral activity of BG-323 in a murine model. Mice were challenged with WNV NY99 and administered BG-323 or mock by IP inoculation immediately post challenge and twice daily thereafter. Mice were bled and viremia was quantified on day three. No significant differences in viremia were observed between BG-323-treated and control groups and clinical scores indicated both BG-323-treated and control mice developed signs of illness on approximately the same day post challenge. To determine whether differences in in vitro and in vivo efficacy were due to unfavorable pharmacokinetic properties of BG-323, we conducted a pharmacokinetic evaluation of this small molecule. Insights from pharmacokinetic studies indicate that BG-323 is cell permeable, has a low efflux ratio and does not significantly inhibit two common cytochrome P450 (CYP P450) isoforms thus suggesting this molecule may be less

  8. Murine Efficacy and Pharmacokinetic Evaluation of the Flaviviral NS5 Capping Enzyme 2-Thioxothiazolidin-4-One Inhibitor BG-323.

    Directory of Open Access Journals (Sweden)

    Kristen M Bullard

    Full Text Available Arthropod-borne flavivirus infection continues to cause significant morbidity and mortality worldwide. Identification of drug targets and novel antiflaviviral compounds to treat these diseases has become a global health imperative. A previous screen of 235,456 commercially available small molecules identified the 2-thioxothiazolidin-4-one family of compounds as inhibitors of the flaviviral NS5 capping enzyme, a promising target for antiviral drug development. Rational drug design methodologies enabled identification of lead compound BG-323 from this series. We have shown previously that BG-323 potently inhibits NS5 capping enzyme activity, displays antiviral effects in dengue virus replicon assays and inhibits growth of West Nile and yellow fever viruses with low cytotoxicity in vitro. In this study we further characterized BG-323's antiviral activity in vitro and in vivo. We found that BG-323 was able to reduce replication of WNV (NY99 and Powassan viruses in culture, and we were unable to force resistance into WNV (Kunjin in long-term culture experiments. We then evaluated the antiviral activity of BG-323 in a murine model. Mice were challenged with WNV NY99 and administered BG-323 or mock by IP inoculation immediately post challenge and twice daily thereafter. Mice were bled and viremia was quantified on day three. No significant differences in viremia were observed between BG-323-treated and control groups and clinical scores indicated both BG-323-treated and control mice developed signs of illness on approximately the same day post challenge. To determine whether differences in in vitro and in vivo efficacy were due to unfavorable pharmacokinetic properties of BG-323, we conducted a pharmacokinetic evaluation of this small molecule. Insights from pharmacokinetic studies indicate that BG-323 is cell permeable, has a low efflux ratio and does not significantly inhibit two common cytochrome P450 (CYP P450 isoforms thus suggesting this molecule

  9. Inferring network structure from cascades

    Science.gov (United States)

    Ghonge, Sushrut; Vural, Dervis Can

    2017-07-01

    Many physical, biological, and social phenomena can be described by cascades taking place on a network. Often, the activity can be empirically observed, but not the underlying network of interactions. In this paper we offer three topological methods to infer the structure of any directed network given a set of cascade arrival times. Our formulas hold for a very general class of models where the activation probability of a node is a generic function of its degree and the number of its active neighbors. We report high success rates for synthetic and real networks, for several different cascade models.

  10. Simultaneous measurement of two enzyme activities using infrared spectroscopy: A comparative evaluation of PARAFAC, TUCKER and N-PLS modeling

    DEFF Research Database (Denmark)

    Baum, Andreas; Hansen, Per Waaben; Meyer, Anne S.

    2013-01-01

    multiway methods, namely PARAFAC, TUCKER3 and N-PLS, to establish simultaneous enzyme activity assays for pectin lyase and pectin methyl esterase. Correlation coefficients Rpred2 for prediction test sets are 0.48, 0.96 and 0.96 for pectin lyase and 0.70, 0.89 and 0.89 for pectin methyl esterase......Enzymes are used in many processes to release fermentable sugars for green production of biofuel, or the refinery of biomass for extraction of functional food ingredients such as pectin or prebiotic oligosaccharides. The complex biomasses may, however, require a multitude of specific enzymes which...... are active on specific substrates generating a multitude of products. In this paper we use the plant polymer, pectin, to present a method to quantify enzyme activity of two pectolytic enzymes by monitoring their superimposed spectral evolutions simultaneously. The data is analyzed by three chemometric...

  11. Enzyme Informatics

    Science.gov (United States)

    Alderson, Rosanna G.; Ferrari, Luna De; Mavridis, Lazaros; McDonagh, James L.; Mitchell, John B. O.; Nath, Neetika

    2012-01-01

    Over the last 50 years, sequencing, structural biology and bioinformatics have completely revolutionised biomolecular science, with millions of sequences and tens of thousands of three dimensional structures becoming available. The bioinformatics of enzymes is well served by, mostly free, online databases. BRENDA describes the chemistry, substrate specificity, kinetics, preparation and biological sources of enzymes, while KEGG is valuable for understanding enzymes and metabolic pathways. EzCatDB, SFLD and MACiE are key repositories for data on the chemical mechanisms by which enzymes operate. At the current rate of genome sequencing and manual annotation, human curation will never finish the functional annotation of the ever-expanding list of known enzymes. Hence there is an increasing need for automated annotation, though it is not yet widespread for enzyme data. In contrast, functional ontologies such as the Gene Ontology already profit from automation. Despite our growing understanding of enzyme structure and dynamics, we are only beginning to be able to design novel enzymes. One can now begin to trace the functional evolution of enzymes using phylogenetics. The ability of enzymes to perform secondary functions, albeit relatively inefficiently, gives clues as to how enzyme function evolves. Substrate promiscuity in enzymes is one example of imperfect specificity in protein-ligand interactions. Similarly, most drugs bind to more than one protein target. This may sometimes result in helpful polypharmacology as a drug modulates plural targets, but also often leads to adverse side-effects. Many cheminformatics approaches can be used to model the interactions between druglike molecules and proteins in silico. We can even use quantum chemical techniques like DFT and QM/MM to compute the structural and energetic course of enzyme catalysed chemical reaction mechanisms, including a full description of bond making and breaking. PMID:23116471

  12. Evaluation and selection of Bacillus species based on enzyme production, antimicrobial activity and biofilm synthesis as direct-fed microbials candidates for poultry

    Directory of Open Access Journals (Sweden)

    Juan D Latorre

    2016-10-01

    Full Text Available Social concern about misuse of antibiotics as growth promoters (AGP and generation of multidrug-resistant bacteria have restricted the dietary inclusion of antibiotics in livestock feed in several countries. Direct-fed microbials (DFM are one of the multiple alternatives commonly evaluated as substitutes of AGP. Sporeformer bacteria from the genus Bacillus have been extensively investigated because of their extraordinary properties to form highly-resistant endospores, production of antimicrobial compounds and synthesize different exogenous enzymes. The purpose of the present study was to evaluate and select Bacillus spp. from environmental and poultry sources as DFM candidates, considering their enzyme production profile, biofilm synthesis capacity and pathogen-inhibition activity. Thirty one Bacillus isolates were screened for in vitro relative enzyme activity of amylase, protease, lipase and phytase using a selective media for each enzyme, with 3/31 strains selected as superior enzyme producers. These three isolates were identified as B. subtilis (1/3, and B. amyloliquefaciens (2/3 based on biochemical tests and 16S rRNA sequence analysis. For evaluation of biofilm synthesis, the generation of an adherent crystal violet-stained ring was determined in polypropylene tubes, resulting in 11/31 strains showing a strong biofilm formation. Moreover, all Bacillus strains were evaluated for growth inhibition activity against Salmonella enterica serovar Enteritidis (26/31, Escherichia coli (28/31 and Clostridioides difficile (29/31. Additionally, in previous in vitro and in vivo studies, these selected Bacillus strains have shown to be resistant to different biochemical conditions of the gastrointestinal tract of poultry. Results of the present study suggest that the selection and consumption of Bacillus-DFM, producing a variable set of enzymes and antimicrobial compounds may contribute to enhanced performance through improving nutrient digestibility

  13. DNA-Based Enzyme Reactors and Systems

    Directory of Open Access Journals (Sweden)

    Veikko Linko

    2016-07-01

    Full Text Available During recent years, the possibility to create custom biocompatible nanoshapes using DNA as a building material has rapidly emerged. Further, these rationally designed DNA structures could be exploited in positioning pivotal molecules, such as enzymes, with nanometer-level precision. This feature could be used in the fabrication of artificial biochemical machinery that is able to mimic the complex reactions found in living cells. Currently, DNA-enzyme hybrids can be used to control (multi-enzyme cascade reactions and to regulate the enzyme functions and the reaction pathways. Moreover, sophisticated DNA structures can be utilized in encapsulating active enzymes and delivering the molecular cargo into cells. In this review, we focus on the latest enzyme systems based on novel DNA nanostructures: enzyme reactors, regulatory devices and carriers that can find uses in various biotechnological and nanomedical applications.

  14. Evaluation of a competitive enzyme-linked immunosorbent assay for measurements of soluble HLA-G protein

    DEFF Research Database (Denmark)

    Rasmussen, M; Dahl, M; Buus, S

    2014-01-01

    . We report a novel method, a competitive immunoassay, for measuring HLA-G5/sHLA-G1 in biological fluids. The sHLA-G immunoassay is based upon a competitive enzyme-linked immunosorbent assay (ELISA) principle. It includes a recombinant sHLA-G1 protein in complex with β2-microglobulin and a peptide...... as a standard, biotinylated recombinant sHLA-G1 as an indicator, and the MEM-G/9 anti-HLA-G monoclonal antibody (mAb) as the capture antibody. The specificity and sensitivity of the assay were evaluated. Testing with different recombinant HLA class I proteins and different anti-HLA class I mAbs showed....../ml. An intra-assay coefficient of variation (CV) of 15.5% at 88 ng/ml and an inter-assay CV of 23.1% at 39 ng/ml were determined. An assay based on the competitive sHLA-G ELISA may be important for measurements of sHLA-G proteins in several conditions: assisted reproduction, organ transplantation, cancer...

  15. [Fundamental evaluation of apolipoprotein B-48 by chemiluminescence enzyme immunoassay--identification of apolipoprotein B-48 with immunoblotting].

    Science.gov (United States)

    Sato, Itsuko; Fujioka, Yoshio; Hayashi, Fujio; Mukai, Masahiko; Kawano, Seiji; Ishikawa, Yuichi; Yamashita, Shizuya; Kumagai, Shunichi

    2007-06-01

    Apolipoprotein B-48 (apo B-48) is a constituent of chylomicrons and chylomicron remnants, and its fasting concentration has been reported to be a marker of postprandial hyperlipidemia, which is thought to be a risk factor of atherosclerosis. We evaluated the serum apo B-48 concentrations by chemiluminescence enzyme immunoassay (CLEIA), which was recently introduced as Lumipulse f fully automated immunosaasy analyzer by Fujirebio Inc (Tokyo, Japan), and performed immunoblotting on agarose gel electrophoresis with anti-apo B-48 antibody. Apo B-48 assay was intra-assay reproducible (CVs: 1.9-3.1%) and inter-assay reproducible (CVs: 2.2-4.4%). The assay range for apo B-48 was from 0.2 to 40.0 microg/ml. The effects of interfering substances such as free/conjugated birirubin, hemoglobin, Intrafat, ascorbic acid and rheumatoid factor were negligible. For storage, it was preferable to freeze, and to avoid frozen-thaw process as much as possible. Anti-apo B-48 antibody was reactive over a wide range from origin to the position of very-low-density lipoproteins in immunoblotting after agarose gel electrophoresis. Apo B-48 measurement by CLEIA was feasible to clinical use for the assessment of lipoprotein metabolism.

  16. Development of an LC-MS based enzyme activity assay for MurC: application to evaluation of inhibitors and kinetic analysis.

    Science.gov (United States)

    Deng, Gejing; Gu, Rong-Fang; Marmor, Stephen; Fisher, Stewart L; Jahic, Haris; Sanyal, Gautam

    2004-06-29

    An enzyme activity assay, based on mass spectrometric (MS) detection of specific reaction product following HPLC separation, has been developed to evaluate pharmaceutical hits identified from primary high throughput screening (HTS) against target enzyme Escherichia coli UDP-N-acetyl-muramyl-L-alanine ligase (MurC), an essential enzyme in the bacterial peptidoglycan biosynthetic pathway, and to study the kinetics of the enzyme. A comparative analysis of this new liquid chromatographic-MS (LC-MS) based assay with a conventional spectrophotometric Malachite Green (MG) assay, which detects phosphate produced in the reaction, was performed. The results demonstrated that the LC-MS assay, which determines specific ligase activity of MurC, offers several advantages including a lower background (0.2% versus 26%), higher sensitivity (> or = 10 fold), lower limit of quantitation (LOQ) (0.02 microM versus 1 microM) and wider linear dynamic range (> or = 4 fold) than the MG assay. Good precision for the LC-MS assay was demonstrated by the low intraday and interday coefficient of variation (CV) values (3 and 6%, respectively). The LC-MS assay, free of the artifacts often seen in the Malachite Green assay, offers a valuable secondary assay for hit evaluation in which the false positives from the primary high throughput screening can be eliminated. In addition, the applicability of this assay to the study of enzyme kinetics has also been demonstrated. Copyright 2004 Elsevier B.V.

  17. Cascade energy amplifier

    International Nuclear Information System (INIS)

    Barzilov, A.P.; Gulevich, A.V.; Kukharchuk, O.F.

    2000-01-01

    The technical problem of long-life fission product and minor actinide incineration and production of plutonium fuel in the prospective nuclear systems will arise at significant scales of nuclear power industry development. Subcritical nuclear reactors driven by extemal neutron sources (energy amplifiers) are considered as incinerators of toxicity of complete nuclear industry. In the frames of this concept, the subcritical reactor part consisting of two coupled blanket regions (inner fast neutron spectrum core and outer thermal core) driven by extemal neutron source is discussed. Two types of source are studied: spallation target and 14-MeV fusion bum of micropellets. Liquid metal Pb-Bi is considered as target material and coolant of inner fast core. Thermal core is a heavy-water subcritical reactor of the Candu-type. The fast core is protected from thermal neutrons influence with the boron shield. All reactor technologies used in this concept are tested during years of operation and commercially available. Thus, the cascade energy amplifiers have a set of advantages in comparison with traditional concepts: in energy production, in transmutation efficiency, and in economics. (authors)

  18. Evaluation of herb-drug interaction of a polyherbal Ayurvedic formulation through high throughput cytochrome P450 enzyme inhibition assay.

    Science.gov (United States)

    Pandit, Subrata; Kanjilal, Satyajyoti; Awasthi, Anshumali; Chaudhary, Anika; Banerjee, Dipankar; Bhatt, B N; Narwaria, Avinash; Singh, Rahul; Dutta, Kakoli; Jaggi, Manu; Singh, Anu T; Sharma, Neena; Katiyar, Chandra Kant

    2017-02-02

    Arishtas are Ayurvedic formulation made with decoction of herbs. Arjunarishta formulation is being used in Ayurveda for cardio-protective activity. Ashwagandharishta formulation possesses antioxidant, anti-atherosclerotic and anti-stress properties. Ridayarishta, a novel empirical formulation was prepared using combination of selected ingredients from these two formulations to support healthy heart functions and to reduce stress. Aim of the Study was to investigate herb-drug interaction (HDI) of Ridayarishta formulation through human hepatic cytochrome P450 (CYP450) enzyme inhibition assay. Ridayarishta formulation was phyto-chemically standardized against arjunolic acid, arjunetin, berberine, piperine, resveratrol and withaferin-A using high performance thin layer chromatography (HPTLC) analysis. The formulation was standardized with respect to ethanol by gas chromatographic (GC) analysis. HDI was evaluated with Ridayarishta formulation and amlodipine besilate, atenolol, atorvastatin, metformin, glipizide glimepiride cocktail using high throughput CYP450 enzyme inhibition assay; against CYP1A2, 2C19, 2D6 and 3A4 isozymes. Contents of arjunolic acid, arjunetin, berberine, piperine, resveratrol and withaferin-A in Ridayarishta formulation were found to be 1.76±0.12, 1.51±0.09, 1.85±0.05, 3.2±0.12, 1.21±0.08, and 2.16±0.09ppm, respectively. Quantity of ethanol in Ridayarishta was found to be 7.95±0.023% (V/V). Ridayarishta showed significantly higher (Pdrugs showed significantly (P<0.001and P<0.01) less or negligible HDI. Ridayarishta formulation alone and cocktail with amlodipine besilate, atenolol, atorvastatin, metformin, glipizide, glimepiride had negligible or insignificant effect on CYP450 inhibition. It may be concluded that consumption of Ridayarishta along with selective cardio protective, antihypertensive and anti-diabetic conventional medicine is safe with negligible or without any significant CYP450 (CYP1A2, 2C19, 2D6 and 3A4) inhibition mediated

  19. Ultrarelativistic cascades and strangeness production

    Energy Technology Data Exchange (ETDEWEB)

    Kahana, D.E. [State Univ. of New York, Stony Brook, NY (United States). Dept. of Physics; Kahana, S.H. [Brookhaven National Lab., Upton, NY (United States). Physics Dept.

    1998-08-24

    A two-phase cascade code, LUCIFER II, developed for the treatment of ultra high energy-ion-ion collisions is applied to the production of strangeness at SPS energies {radical}(s)=17-20. This simulation is able to simultaneously describe both hard processes such as Drell-Yan and slower, soft processes such as the production of light mesons by separating the dynamics into two steps, a fast cascade involving only the nucleons in the original colliding relativistic ions followed, after an appropriate delay, by a normal multiscattering of the resulting excited baryons and mesons produced virtually in the first step. No energy loss can take place in the short time interval over which the first cascade takes place. The chief result is a reconciliation of the important Drell-Yan measurements with the apparent success of standard cascades to describe the nucleon stopping and meson production in heavy-ion experiments at the CERN SPS. (orig.) 26 refs.

  20. Ultrarelativistic cascades and strangeness production

    International Nuclear Information System (INIS)

    Kahana, D.E.; Kahana, S.H.

    1998-01-01

    A two-phase cascade code, LUCIFER II, developed for the treatment of ultra high energy-ion-ion collisions is applied to the production of strangeness at SPS energies √(s)=17-20. This simulation is able to simultaneously describe both hard processes such as Drell-Yan and slower, soft processes such as the production of light mesons by separating the dynamics into two steps, a fast cascade involving only the nucleons in the original colliding relativistic ions followed, after an appropriate delay, by a normal multiscattering of the resulting excited baryons and mesons produced virtually in the first step. No energy loss can take place in the short time interval over which the first cascade takes place. The chief result is a reconciliation of the important Drell-Yan measurements with the apparent success of standard cascades to describe the nucleon stopping and meson production in heavy-ion experiments at the CERN SPS. (orig.)

  1. Ultrarelativistic cascades and strangeness production

    International Nuclear Information System (INIS)

    Kahana, D.E.; Kahana, S.H.

    1998-02-01

    A two phase cascade, LUCIFER II, developed for the treatment of ultra high energy Ion-Ion collisions is applied to the production of strangeness at SPS energies. This simulation is able to simultaneously describe both hard processes such as Drell-Yan and slower, soft processes such as the production of light mesons by separating the dynamics into two steps, a fast cascade involving only the nucleons in the original colliding relativistic ions followed, after an appropriate delay, by a normal multiscattering of the resulting excited baryons and mesons produced virtually in the first step. No energy loss can take place in the short time interval over which the first cascade takes place. The chief result is a reconciliation of the important Drell-Yan measurements with the apparent success of standard cascades to describe the nucleon stopping and meson production in heavy ion experiments at the CERN SPS

  2. Cascade redox flow battery systems

    Science.gov (United States)

    Horne, Craig R.; Kinoshita, Kim; Hickey, Darren B.; Sha, Jay E.; Bose, Deepak

    2014-07-22

    A reduction/oxidation ("redox") flow battery system includes a series of electrochemical cells arranged in a cascade, whereby liquid electrolyte reacts in a first electrochemical cell (or group of cells) before being directed into a second cell (or group of cells) where it reacts before being directed to subsequent cells. The cascade includes 2 to n stages, each stage having one or more electrochemical cells. During a charge reaction, electrolyte entering a first stage will have a lower state-of-charge than electrolyte entering the nth stage. In some embodiments, cell components and/or characteristics may be configured based on a state-of-charge of electrolytes expected at each cascade stage. Such engineered cascades provide redox flow battery systems with higher energy efficiency over a broader range of current density than prior art arrangements.

  3. Evaluation of three enzyme-linked immunosorbent assays for sarcoptic mange diagnosis and assessment in the Iberian ibex, Capra pyrenaica.

    Science.gov (United States)

    Ráez-Bravo, Arián; Granados, José Enrique; Serrano, Emmanuel; Dellamaria, Debora; Casais, Rosa; Rossi, Luca; Puigdemont, Anna; Cano-Manuel, Francisco Javier; Fandos, Paulino; Pérez, Jesús María; Espinosa, José; Soriguer, Ramón Casimiro; Citterio, Carlo; López-Olvera, Jorge Ramón

    2016-10-21

    Sarcoptic mange is a contagious skin disease caused by the mite Sarcoptes scabiei, affecting different mammalian species worldwide including the Iberian ibex (Capra pyrenaica), in which mortalities over 90 % of the population have been reported. No efficient diagnostic methods are available for this disease, particularly when there are low mite numbers and mild or no clinical signs. In this study, three enzyme-linked immunosorbent assays (ELISA) developed for dog (ELISA A), Cantabrian chamois (Rupicapra pyrenaica parva) (ELISA B) and Alpine chamois (Rupicapra rupicapra) (ELISA C), were evaluated to detect specific antibodies (IgG) to sarcoptic mange in Iberian ibex sera. Serum samples from 131 Iberian ibexes (86 healthy and 45 scabietic) were collected from 2005 to 2012 in the Sierra Nevada Natural and National Parks (southern Spain). Based on visual inspection, ibexes were classified into one of three categories, namely healthy (without scabietic compatible lesions), mildly affected (skin lesions over less than 50 % of the body surface) and severely affected (skin lesions over more than 50 % of the body surface). The optimal cut-off point, specificity, sensitivity and the area under the curve (AUC) were calculated, and the agreement between tests was determined. Moreover, differences in the optical density (OD) related to scabies severity have been evaluated for the best test. ELISA C showed better performance than the two other tests, reaching higher values of sensitivity (93.0 %) and specificity (93.5 %) against the visual estimation of the percentage of affected skin, chosen as the gold standard. Significantly higher concentrations of specific antibodies were observed with this test in the mildly and severely infested ibexes than in healthy ones. Our results revealed that ELISA C was an optimal test to diagnose sarcoptic mange in the Iberian ibex. Further studies characterizing immune response during the course of the disease, including spontaneous or drug

  4. Stochastic background of atmospheric cascades

    International Nuclear Information System (INIS)

    Wilk, G.; Wlodarczyk, Z.

    1993-01-01

    Fluctuations in the atmospheric cascades developing during the propagation of very high energy cosmic rays through the atmosphere are investigated using stochastic branching model of pure birth process with immigration. In particular, we show that the multiplicity distributions of secondaries emerging from gamma families are much narrower than those resulting from hadronic families. We argue that the strong intermittent like behaviour found recently in atmospheric families results from the fluctuations in the cascades themselves and are insensitive to the details of elementary interactions

  5. Computation of inverse magnetic cascades

    International Nuclear Information System (INIS)

    Montgomery, D.

    1981-10-01

    Inverse cascades of magnetic quantities for turbulent incompressible magnetohydrodynamics are reviewed, for two and three dimensions. The theory is extended to the Strauss equations, a description intermediate between two and three dimensions appropriate to tokamak magnetofluids. Consideration of the absolute equilibrium Gibbs ensemble for the system leads to a prediction of an inverse cascade of magnetic helicity, which may manifest itself as a major disruption. An agenda for computational investigation of this conjecture is proposed

  6. EFSA CEF Panel (EFSA Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids), 2013. Scientific Opinion on Flavouring Group Evaluation 21, Revision 4 (FGE.21Rev4)

    DEFF Research Database (Denmark)

    Beltoft, Vibe Meister; Binderup, Mona-Lise; Frandsen, Henrik Lauritz

    The Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids of the European Food Safety Authority was requested to evaluate 59 flavouring substances in the Flavouring Group Evaluation 21, Revision 4, using the Procedure in Commission Regulation (EC) No 1565/2000. This revision...... of these flavouring substances, the specifications for the materials of commerce have also been considered. Adequate specifications including complete purity criteria and identity for the materials of commerce have been provided for all 41 candidate substances...

  7. Bluetongue virus: comparative evaluation of enzyme-linked immunosorbent assay, immunodiffusion, and serum neutralization for detection of viral antibodies.

    OpenAIRE

    Poli, G; Stott, J; Liu, Y S; Manning, J S

    1982-01-01

    Comparative studies on the detection of bovine serum immunoglobulin G antibodies to bluetongue virus with an enzyme-linked immunosorbent assay, an immunodiffusion method, and a serum neutralization assay demonstrated complete concordance between the enzyme-linked immunosorbent assay and the serum neutralization assay results. However, the immunodiffusion method failed to detect bluetongue virus antibody in a substantial number of sera found to possess bluetongue virus immunoglobulin G with th...

  8. Evaluation of the C6 Lyme Enzyme Immunoassay for the Diagnosis of Lyme Disease in Children and Adolescents.

    Science.gov (United States)

    Lipsett, Susan C; Branda, John A; McAdam, Alexander J; Vernacchio, Louis; Gordon, Caroline D; Gordon, Catherine R; Nigrovic, Lise E

    2016-10-01

    The commercially-available C6 Lyme enzyme immunoassay (EIA) has been approved to replace the standard whole-cell sonicate EIA as a first-tier test for the diagnosis of Lyme disease and has been suggested as a stand-alone diagnostic. However, the C6 EIA has not been extensively studied in pediatric patients undergoing evaluation for Lyme disease. We collected discarded serum samples from children and adolescents (aged ≤21 years) undergoing conventional 2-tiered testing for Lyme disease at a single hospital-based clinical laboratory located in an area endemic for Lyme disease. We performed a C6 EIA on all collected specimens, followed by a supplemental immunoblot if the C6 EIA result was positive but the whole-cell sonicate EIA result was negative. We defined a case of Lyme disease as either a clinician-diagnosed erythema migrans lesion or a positive standard 2-tiered serologic result in a patient with symptoms compatible with Lyme disease. We then compared the performance of the C6 EIA alone and as a first-tier test followed by immunoblot, with that of standard 2-tiered serology for the diagnosis of Lyme disease. Of the 944 specimens collected, 114 (12%) were from patients with Lyme disease. The C6 EIA alone had sensitivity similar to that of standard 2-tiered testing (79.8% vs 81.6% for standard 2-tiered testing; P = .71) with slightly lower specificity (94.2% vs 98.8% 2; P Lyme disease, the C6 EIA could guide initial clinical decision making, although a supplemental immunoblot should still be performed. © The Author 2016. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail journals.permissions@oup.com.

  9. Evaluation of the highly sensitive chemiluminescent enzyme immunoassay "Lumipulse HBsAg-HQ" for hepatitis B virus screening.

    Science.gov (United States)

    Deguchi, Matsuo; Kagita, Masanori; Yoshioka, Nori; Tsukamoto, Hiroko; Takao, Miyuki; Tahara, Kazuko; Maeda, Ikuhiro; Hidaka, Yoh; Yamauchi, Satoshi; Kaneko, Atsushi; Miyakoshi, Hideo; Isomura, Mitsuo

    2017-10-06

    Ongoing efforts in the development of HBsAg detection kits are focused on improving sensitivity and specificity. The purpose of this study was to evaluate an improved, highly sensitive quantitative assay, "Lumipulse HBsAg-HQ", a chemiluminescent enzyme immunoassay designed for a fully automated instrument, the "Lumipulse G1200". Serum samples for reproducibility, dilution, correlation, sensitivity, and specificity studies were obtained from patients at the Osaka University Hospital. Seroconversion and sensitivity panels were purchased from a commercial vender. Subtype, sensitivity panels, and HBsAg recombinant proteins with one or two amino acid substitutions were prepared in-house. The coefficients of variation for the low, medium, and high concentration samples ranged from 1.93 to 2.55%. The HBsAg-HQ reagent for dilution testing showed good linearity in the 0.005-150 HBsAg IU/mL range and no prozone phenomenon. All 102 HBV carrier samples were positive by HBsAg-HQ, while other commercial reagents showed one or more to be negative. In the seroconversion panel, the 14-day blood sample was positive. The sensitivity against HBsAg-HQ "ad" and "ay" subtypes was 0.025 ng/mL. Comparisons among the HBsAg-HQ, HISCL, and Architect HBsAg reagents were performed using the Bland-Altman plot. Specificity for 1000 seronegative individuals was 99.7%. HBsAg-HQ detected 29 positive serum among 12 231 routinely obtained serum samples, which showed concentrations of 0.005-0.05 HBsAg IU/mL. According to these results, the Lumipulse HBsAg-HQ assay, with a highly sensitive limit of detection of 0.005 IU/mL, may facilitate the development of a better management strategy for a considerable proportion of infected patients. © 2017 Wiley Periodicals, Inc.

  10. A separation-integrated cascade reaction to overcome thermodynamic limitations in rare-sugar synthesis.

    Science.gov (United States)

    Wagner, Nina; Bosshart, Andreas; Failmezger, Jurek; Bechtold, Matthias; Panke, Sven

    2015-03-27

    Enzyme cascades combining epimerization and isomerization steps offer an attractive route for the generic production of rare sugars starting from accessible bulk sugars but suffer from the unfavorable position of the thermodynamic equilibrium, thus reducing the yield and requiring complex work-up procedures to separate pure product from the reaction mixture. Presented herein is the integration of a multienzyme cascade reaction with continuous chromatography, realized as simulated moving bed chromatography, to overcome the intrinsic yield limitation. Efficient production of D-psicose from sucrose in a three-step cascade reaction using invertase, D-xylose isomerase, and D-tagatose epimerase, via the intermediates D-glucose and D-fructose, is described. This set-up allowed the production of pure psicose (99.9%) with very high yields (89%) and high enzyme efficiency (300 g of D-psicose per g of enzyme). © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Exercise-induced serum enzyme elevations confounding the evaluation of investigational drug toxicity. Report of two cases in a vaccine trial.

    Science.gov (United States)

    Johnson, Casey; Monath, Thomas P; Kanesa-Thasan, Niranjan; Mathis, Danell; Miller, Chuck; Shapiro, Seth; Nichols, Richard; McCarthy, Karen; Deary, Alison; Bedford, Philip

    2005-01-01

    Two subjects developed marked elevations in creatine kinase and other serum enzymes associated with mild myalgia during a randomized, double-blind, controlled Phase 1 clinical trial of an investigational live, attenuated vaccine against West Nile virus (ChimeriVax-WN02). One subject had received ChimeriVax-WN02 while the other subject was enrolled in an active control group and received licensed yellow fever 17D vaccine (YF-VAX). Subsequently, the clinical trial was interrupted, and an investigation was begun to evaluate the enzyme abnormalities. As daily serum samples were collected for determination of quantitative viremia, it was possible to define the enzyme elevations with precision and to relate these elevations to physical activity of the subjects, symptoms, and virological and serological measurements. Evaluation of both subjects clearly showed that skeletal muscle injury, and not cardiac or hepatic dysfunction, was responsible for the biochemical abnormalities. This investigation also implicated strenuous exercise as the cause of the apparent muscle injury rather than the study vaccines. As a result of this experience, subjects engaged in future early-stage trials of these live, attenuated viral vaccines will be advised not to engage in contact sports or new or enhanced exercise regimens for which they are not trained or conditioned. The inclusion of placebo control arm (in lieu of or addition to an active vaccine control) will also be useful in differentiating causally related serum enzyme elevations.

  12. Simultaneous measurement of two enzyme activities using infrared spectroscopy: A comparative evaluation of PARAFAC, TUCKER and N-PLS modeling.

    Science.gov (United States)

    Baum, Andreas; Hansen, Per Waaben; Meyer, Anne S; Mikkelsen, Jørn Dalgaard

    2013-08-06

    Enzymes are used in many processes to release fermentable sugars for green production of biofuel, or the refinery of biomass for extraction of functional food ingredients such as pectin or prebiotic oligosaccharides. The complex biomasses may, however, require a multitude of specific enzymes which are active on specific substrates generating a multitude of products. In this paper we use the plant polymer, pectin, to present a method to quantify enzyme activity of two pectolytic enzymes by monitoring their superimposed spectral evolutions simultaneously. The data is analyzed by three chemometric multiway methods, namely PARAFAC, TUCKER3 and N-PLS, to establish simultaneous enzyme activity assays for pectin lyase and pectin methyl esterase. Correlation coefficients Rpred(2) for prediction test sets are 0.48, 0.96 and 0.96 for pectin lyase and 0.70, 0.89 and 0.89 for pectin methyl esterase, respectively. The retrieved models are compared and prediction test sets show that especially TUCKER3 performs well, even in comparison to the supervised regression method N-PLS. Copyright © 2013 Elsevier B.V. All rights reserved.

  13. Time structure of cascade showers

    International Nuclear Information System (INIS)

    Nakatsuka, Takao

    1984-01-01

    Interesting results have been reported on the time structure of the electromagnetic components of air showers which have been obtained by using recent fast electronic circuit technology. However, these analyses and explanations seem not very persuasive. One of the reasons is that there is not satisfactory theoretical calculation yet to explain the delay of electromagnetic components in cascade processes which are the object of direct observation. Therefore, Monte Carlo calculation was attempted for examining the relationship between the altitude at which high energy γ-ray is generated up in the air and the time structure of cascade showers at the level of observation. The investigation of a dominant factor over the delay of electromagnetic components indicated that the delay due to the multiple scattering of electrons was essential. The author used the analytical solution found by himself of C. N. Yang's equation for the study on the delay due to multiple scattering. The results were as follows: The average delay time and the spread of distribution of electromagnetic cascades were approximately in linear relationship with the mass of a material having passed in a thin uniform medium; the rise time of arrival time distribution for electromagnetic cascade showers was very steep under the condition that they were generated up in the air and observed on the ground; the subpeaks delayed by tens of ns in arrival time may sometimes appear due to the perturbation in electromagnetic cascade processes. (Wakatsuki, Y.)

  14. Evaluation of reaction mechanisms and the kinetic parameters for the transesterification of castor oil by liquid enzymes

    DEFF Research Database (Denmark)

    Andrade, Thalles Allan; Errico, Massimiliano; Christensen, Knud Villy

    2017-01-01

    of the transesterification of castor oil with methanol using the enzyme Eversa® Transform as catalyst were investigated. Reactions were carried out for 8 hours at 35 °C with: an alcohol-to-oil molar ratio equal to 6:1, a 5 wt% of liquid enzyme solution and addition of 5 wt% of water by weight of castor oil. From...... methanolysis rates of glycerides obtained, indicated that transesterification dominates over hydrolysis. The mechanism among the four models proposed that gave the best fit could be simplified, eliminating the kinetic parameters with negligible effects on the reaction rates. This model was able to fit...

  15. Thermometric enzyme linked immunosorbent assay in continuous flow system: optimization and evaluation using human serum albumin as a model system.

    Science.gov (United States)

    Borrebaeck, C; Börjeson, J; Mattiasson, B

    1978-06-15

    Thermometric enzyme-linked immunosorbent assay (TELISA) is described. After the procedure of optimization, human serum albumin was assayed using anti-human serum albumin bound to Sepharose CL 4-B in the enzyme thermistor unit and catalase as label on the free antigen. The model system was used for assays down to 10(-13)M and the preparation of immobilized antibodies was used repeatedly up to 100 times. Comparative studies of the TELISA technique with bromocresol green, immunoturbidimetric and rocket immunoelectrophoretic methods were carried out and showed that TELISA could be used as an alternative method.

  16. Rescuing Ecosystems from Extinction Cascades

    Science.gov (United States)

    Sahasrabudhe, Sagar; Motter, Adilson

    2010-03-01

    Food web perturbations stemming from climate change, overexploitation, invasive species, and natural disasters often cause an initial loss of species that results in a cascade of secondary extinctions. Using a predictive modeling framework, here we will present a systematic network-based approach to reduce the number of secondary extinctions. We will show that the extinction of one species can often be compensated by the concurrent removal of a second specific species, which is a counter-intuitive effect not previously tested in complex food webs. These compensatory perturbations frequently involve long-range interactions that are not a priori evident from local predator-prey relationships. Strikingly, in numerous cases even the early removal of a species that would eventually be extinct by the cascade is found to significantly reduce the number of cascading extinctions. Other nondestructive interventions based on partial removals and growth suppression and/or mortality increase are shown to sometimes prevent all secondary extinctions.

  17. A novel bi-enzyme electrochemical biosensor for selective and sensitive determination of methyl salicylate.

    Science.gov (United States)

    Fang, Yi; Umasankar, Yogeswaran; Ramasamy, Ramaraja P

    2016-07-15

    An amperometric sensor based on a bi-enzyme modified electrode was fabricated to detect methyl salicylate, a volatile organic compound released by pathogen-infected plants via systemic response. The detection is based on cascadic conversion reactions that result in an amperometric electrochemical signal. The bi-enzyme electrode is made of alcohol oxidase and horseradish peroxidase enzymes immobilized on to a carbon nanotube matrix through a molecular tethering method. Methyl salicylate undergoes hydrolysis to form methanol, which is consumed by alcohol oxidase to form formaldehyde while simultaneously reducing oxygen to hydrogen peroxide. The hydrogen peroxide will be further reduced to water by horseradish peroxidase, which results in an amperometric signal via direct electron transfer. The bi-enzyme biosensor was evaluated by cyclic voltammetry and constant potential amperometry using hydrolyzed methyl salicylate as the analyte. The sensitivity of the bi-enzyme biosensor as determined by cyclic voltammetry and constant potential amperometry were 112.37 and 282.82μAcm(-2)mM(-1) respectively, and the corresponding limits of detection were 22.95 and 0.98μM respectively. Constant potential amperometry was also used to evaluate durability, repeatability and interference from other compounds. Wintergreen oil was used for real sample study to establish the application of the bi-enzyme sensor for selective determination of plant pathogen infections. Copyright © 2016 Elsevier B.V. All rights reserved.

  18. Multicountry Prospective Clinical Evaluation of Two Enzyme-Linked Immunosorbent Assays and Two Rapid Diagnostic Tests for Diagnosing Dengue Fever

    Science.gov (United States)

    Dauner, Allison L.; Valks, Andrea; Forshey, Brett M.; Long, Kanya C.; Thaisomboonsuk, Butsaya; Sierra, Gloria; Picos, Victor; Talmage, Sara; Morrison, Amy C.; Halsey, Eric S.; Comach, Guillermo; Yasuda, Chadwick; Loeffelholz, Michael; Jarman, Richard G.; Fernandez, Stefan; An, Ung Sam; Kochel, Tadeusz J.; Jasper, Louis E.; Wu, Shuenn-Jue L.

    2015-01-01

    We evaluated four dengue diagnostic devices from Alere, including the SD Bioline Dengue Duo (nonstructural [NS] 1 Ag and IgG/IgM), the Panbio Dengue Duo Cassette (IgM/IgG) rapid diagnostic tests (RDTs), and the Panbio dengue IgM and IgG capture enzyme-linked immunosorbent assays (ELISAs) in a prospective, controlled, multicenter study in Peru, Venezuela, Cambodia, and the United States, using samples from 1,021 febrile individuals. Archived, well-characterized samples from an additional 135 febrile individuals from Thailand were also used. Reference testing was performed on all samples using an algorithm involving virus isolation, in-house IgM and IgG capture ELISAs, and plaque reduction neutralization tests (PRNT) to determine the infection status of the individual. The primary endpoints were the clinical sensitivities and specificities of these devices. The SD Bioline Dengue Duo had an overall sensitivity of 87.3% (95% confidence interval [CI], 84.1 to 90.2%) and specificity of 86.8% (95% CI, 83.9 to 89.3%) during the first 14 days post-symptom onset (p.s.o.). The Panbio Dengue Duo Cassette demonstrated a sensitivity of 92.1% (87.8 to 95.2%) and specificity of 62.2% (54.5 to 69.5%) during days 4 to 14 p.s.o. The Panbio IgM capture ELISA had a sensitivity of 87.6% (82.7 to 91.4%) and specificity of 88.1% (82.2 to 92.6%) during days 4 to 14 p.s.o. Finally, the Panbio IgG capture ELISA had a sensitivity of 69.6% (62.1 to 76.4%) and a specificity of 88.4% (82.6 to 92.8%) during days 4 to 14 p.s.o. for identification of secondary dengue infections. This multicountry prospective study resulted in reliable real-world performance data that will facilitate data-driven laboratory test choices for managing patient care during dengue outbreaks. PMID:25588659

  19. Evaluation of a competitive enzyme-linked immunosorbent assay for measurements of soluble HLA-G protein.

    Science.gov (United States)

    Rasmussen, M; Dahl, M; Buus, S; Djurisic, S; Ohlsson, J; Hviid, T V F

    2014-08-01

    The human leukocyte antigen (HLA) class Ib molecule, HLA-G, has gained increased attention because of its assumed important role in immune regulation. The HLA-G protein exists in several soluble isoforms. Most important are the actively secreted HLA-G5 full-length isoform generated by alternative splicing retaining intron 4 with a premature stop codon, and the cleavage of full-length membrane-bound HLA-G1 from the cell surface, so-called soluble HLA-G1 (sHLA-G1). A specific and sensitive immunoassay for measurements of soluble HLA-G is mandatory for conceivable routine testing and research projects. We report a novel method, a competitive immunoassay, for measuring HLA-G5/sHLA-G1 in biological fluids. The sHLA-G immunoassay is based upon a competitive enzyme-linked immunosorbent assay (ELISA) principle. It includes a recombinant sHLA-G1 protein in complex with β2-microglobulin and a peptide as a standard, biotinylated recombinant sHLA-G1 as an indicator, and the MEM-G/9 anti-HLA-G monoclonal antibody (mAb) as the capture antibody. The specificity and sensitivity of the assay were evaluated. Testing with different recombinant HLA class I proteins and different anti-HLA class I mAbs showed that the sHLA-G immunoassay was highly specific. Optimal combinations of competitor sHLA-G1 and capture mAb concentrations were determined. Two versions of the assay were tested. One with a relatively wide dynamic range from 3.1 to 100.0 ng/ml, and another more sensitive version ranging from 1.6 to 12.5 ng/ml. An intra-assay coefficient of variation (CV) of 15.5% at 88 ng/ml and an inter-assay CV of 23.1% at 39 ng/ml were determined. An assay based on the competitive sHLA-G ELISA may be important for measurements of sHLA-G proteins in several conditions: assisted reproduction, organ transplantation, cancer, and certain pregnancy complications, both in research studies and possibly in the future also for clinical routine use. © 2014 John Wiley & Sons A/S. Published by John Wiley

  20. Quadrotor trajectory tracking using PID cascade control

    Science.gov (United States)

    Idres, M.; Mustapha, O.; Okasha, M.

    2017-12-01

    Quadrotors have been applied to collect information for traffic, weather monitoring, surveillance and aerial photography. In order to accomplish their mission, quadrotors have to follow specific trajectories. This paper presents proportional-integral-derivative (PID) cascade control of a quadrotor for path tracking problem when velocity and acceleration are small. It is based on near hover controller for small attitude angles. The integral of time-weighted absolute error (ITAE) criterion is used to determine the PID gains as a function of quadrotor modeling parameters. The controller is evaluated in three-dimensional environment in Simulink. Overall, the tracking performance is found to be excellent for small velocity condition.

  1. Evaluation of the microparticle enzyme immunoassay Abbott IMx Select Chlamydia and the importance of urethral site sampling to detect Chlamydia trachomatis in women.

    OpenAIRE

    Brokenshire, M K; Say, P J; van Vonno, A H; Wong, C

    1997-01-01

    OBJECTIVE: To evaluate the commercial microparticle enzyme immunoassay (MEIA), Abbott IMx Select Chlamydia, for the detection of Chlamydia trachomatis in women and to compare its performance with endocervical cell culture. Also, to determine whether sampling the urethral site is an important part of chlamydial diagnosis in women. SETTING: The Auckland, Manukau, and Waitakere Sexual Health Clinics, Auckland, New Zealand and the Department of Clinical Microbiology, Auckland Hospital, Auckland, ...

  2. EVALUATION OF AN ENZYME-LINKED IMMUNOSORBENT ASSAY FOR BIOLOGICAL MONITORING OF 3-PHENOXYBENZOIC ACID IN URINE

    Science.gov (United States)

    Abstract describes the development of an enzyme-linked immunosorbent assay (ELISA) method for monitoring 2,4-dichlorophenoxyacetic acid (2,4-D exposures). The ELISA is compared with a gas chromatograhy/mass spectrometry procedure. ELISA method development steps and comparative ...

  3. Node vulnerability of water distribution networks under cascading failures

    International Nuclear Information System (INIS)

    Shuang, Qing; Zhang, Mingyuan; Yuan, Yongbo

    2014-01-01

    Water distribution networks (WDNs) are important in modern lifeline system. Its stability and reliability are critical for guaranteeing high living quality and continuous operation of urban functions. The aim of this paper is to evaluate the nodal vulnerability of WDNs under cascading failures. Vulnerability is defined to analyze the effects of the consequent failures. A cascading failure is a step-by-step process which is quantitatively investigated by numerical simulation with intentional attack. Monitored pressures in different nodes and flows in different pipes have been used to estimate the network topological structure and the consequences of nodal failure. Based on the connectivity loss of topological structure, the nodal vulnerability has been evaluated. A load variation function is established to record the nodal failure reason and describe the relative differences between the load and the capacity. The proposed method is validated by an illustrative example. The results revealed that the network vulnerability should be evaluated with the consideration of hydraulic analysis and network topology. In the case study, 70.59% of the node failures trigger the cascading failures with different failure processes. It is shown that the cascading failures result in severe consequences in WDNs. - Highlights: • The aim of this paper is to evaluate the nodal vulnerability of water distribution networks under cascading failures. • Monitored pressures and flows have been used to estimate the network topological structure and the consequences of nodal failure. • Based on the connectivity loss of topological structure, the nodal vulnerability has been evaluated. • A load variation function is established to record the failure reason and describe the relative differences between load and capacity. • The results show that 70.59% of the node failures trigger the cascading failures with different failure processes

  4. Metabolic enzyme activities of abyssal and hadal fishes: pressure effects and a re-evaluation of depth-related changes

    Science.gov (United States)

    Gerringer, M. E.; Drazen, J. C.; Yancey, P. H.

    2017-07-01

    Metabolic enzyme activities of muscle tissue have been useful and widely-applied indicators of whole animal metabolic capacity, particularly in inaccessible systems such as the deep sea. Previous studies have been conducted at atmospheric pressure, regardless of organism habitat depth. However, maximum reaction rates of some of these enzymes are pressure dependent, complicating the use of metabolic enzyme activities as proxies of metabolic rates. Here, we show pressure-related rate changes in lactate and malate dehydrogenase (LDH, MDH) and pyruvate kinase (PK) in six fish species (2 hadal, 2 abyssal, 2 shallow). LDH maximal reaction rates decreased with pressure for the two shallow species, but, in contrast to previous findings, it increased for the four deep species, suggesting evolutionary changes in LDH reaction volumes. MDH maximal reaction rates increased with pressure in all species (up to 51±10% at 60 MPa), including the tide pool snailfish, Liparis florae (activity increase at 60 MPa 44±9%), suggesting an inherent negative volume change of the reaction. PK was inhibited by pressure in all species tested, including the hadal liparids (up to 34±3% at 60 MPa), suggesting a positive volume change during the reaction. The addition of 400 mM TMAO counteracted this inhibition at both 0.5 and 2.0 mM ADP concentrations for the hadal liparid, Notoliparis kermadecensis. We revisit depth-related trends in metabolic enzyme activities according to these pressure-related rate changes and new data from seven abyssal and hadal species from the Kermadec and Mariana trenches. Results show that, with abyssal and hadal species, pressure-related rate changes are another variable to be considered in the use of enzyme activities as proxies for metabolic rate, in addition to factors such as temperature and body mass. Intraspecific increases in tricarboxylic acid cycle enzymes with depth of capture, independent of body mass, in two hadal snailfishes suggest improved nutritional

  5. Multiplicity distributions in QCD cascades

    International Nuclear Information System (INIS)

    Gustafson, G.

    1992-03-01

    Multiplicity distributions for hadrons and for jets are studied in QCD parton cascades. The colour dipole formalism is used and earlier results in the double log approximation are generalized to include terms which are suppressed by colour factors or factors of ln s. The result is a set of coupled differential equations, together with appropriate boundary conditions

  6. EFSA EFSA Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids (CEF); Scientific Opinion on Flavouring Group Evaluation 304 (FGE.304): Five carboxamides from chemical group 30

    DEFF Research Database (Denmark)

    Larsen, John Christian; Nørby, Karin Kristiane; Beltoft, Vibe Meister

    The Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids of the European Food Safety Authority was requested to evaluate five flavouring substances in the Flavouring Group Evaluation 304, using the Procedure in Commission Regulation (EC) No 1565/2000. None of the substances...... data are required. Besides the safety assessment of these flavouring substances, the specifications for the materials of commerce have also been considered. Specifications including complete purity criteria and identity for the materials of commerce have been provided for all five candidate substances....

  7. EFSA Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids (CEF) ; Scientific Opinion on Flavouring Group Evaluation 305 (FGE.305): L - Methionylglycine of chemical group 34

    DEFF Research Database (Denmark)

    Beltoft, Vibe Meister; Binderup, Mona-Lise; Frandsen, Henrik Lauritz

    use in foods that are not heated or intended to be heated. Besides the safety assessment of the flavouring substance, the specifications for the material of commerce have also been considered. Adequate specifications including complete purity criteria and identity for the material of commerce have......The Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids of the European Food Safety Authority was requested to evaluate one flavouring substance, the dipeptide L-methionylglycine [FL-no: 17.037], in the Flavouring Group Evaluation 305, using the Procedure in Commission...... been provided for the candidate substance. © European Food Safety Authority, 2013...

  8. EFSA CEF Panel (EFSA Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids), 2013. Scientific Opinion on Flavouring Group Evaluation 24, Revision 2 (FGE.24Rev2)

    DEFF Research Database (Denmark)

    Beltoft, Vibe Meister; Binderup, Mona-Lise; Frandsen, Henrik Lauritz

    The Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids of the European Food Safety Authority was requested to evaluate 24 flavouring substances in the Flavouring Group Evaluation 24, Revision 2, using the Procedure in Commission Regulation (EC) No 1565/2000. This revision...... the safety assessment of these flavouring substances, the specifications for the materials of commerce have also been considered. Adequate specifications including complete purity criteria and identity for the materials of commerce have been provided for all 24 candidate substances....

  9. EFSA CEF Panel (EFSA Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids), 2013. Scientific Opinion on Flavouring Group Evaluation 21, Revision 4 (FGE.21Rev4)

    OpenAIRE

    Beltoft, Vibe Meister; Binderup, Mona-Lise; Frandsen, Henrik Lauritz; Lund, Pia; Nørby, Karin Kristiane

    2013-01-01

    The Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids of the European Food Safety Authority was requested to evaluate 59 flavouring substances in the Flavouring Group Evaluation 21, Revision 4, using the Procedure in Commission Regulation (EC) No 1565/2000. This revision is made due to the inclusion of the assessment of new toxicity data on one supporting substance 5,6-dihydro-2,4,6-tris(2-methylpropyl)-4H-1,3,5-dithiazine [FL-no: 15.113], which is considered to be str...

  10. A new crystal form of Aspergillus oryzae catechol oxidase and evaluation of copper site structures in coupled binuclear copper enzymes.

    Science.gov (United States)

    Penttinen, Leena; Rutanen, Chiara; Saloheimo, Markku; Kruus, Kristiina; Rouvinen, Juha; Hakulinen, Nina

    2018-01-01

    Coupled binuclear copper (CBC) enzymes have a conserved type 3 copper site that binds molecular oxygen to oxidize various mono- and diphenolic compounds. In this study, we found a new crystal form of catechol oxidase from Aspergillus oryzae (AoCO4) and solved two new structures from two different crystals at 1.8-Å and at 2.5-Å resolutions. These structures showed different copper site forms (met/deoxy and deoxy) and also differed from the copper site observed in the previously solved structure of AoCO4. We also analysed the electron density maps of all of the 56 CBC enzyme structures available in the protein data bank (PDB) and found that many of the published structures have vague copper sites. Some of the copper sites were then re-refined to find a better fit to the observed electron density. General problems in the refinement of metalloproteins and metal centres are discussed.

  11. A new crystal form of Aspergillus oryzae catechol oxidase and evaluation of copper site structures in coupled binuclear copper enzymes.

    Directory of Open Access Journals (Sweden)

    Leena Penttinen

    Full Text Available Coupled binuclear copper (CBC enzymes have a conserved type 3 copper site that binds molecular oxygen to oxidize various mono- and diphenolic compounds. In this study, we found a new crystal form of catechol oxidase from Aspergillus oryzae (AoCO4 and solved two new structures from two different crystals at 1.8-Å and at 2.5-Å resolutions. These structures showed different copper site forms (met/deoxy and deoxy and also differed from the copper site observed in the previously solved structure of AoCO4. We also analysed the electron density maps of all of the 56 CBC enzyme structures available in the protein data bank (PDB and found that many of the published structures have vague copper sites. Some of the copper sites were then re-refined to find a better fit to the observed electron density. General problems in the refinement of metalloproteins and metal centres are discussed.

  12. A comparison of methods for cascade prediction

    OpenAIRE

    Guo, Ruocheng; Shakarian, Paulo

    2016-01-01

    Information cascades exist in a wide variety of platforms on Internet. A very important real-world problem is to identify which information cascades can go viral. A system addressing this problem can be used in a variety of applications including public health, marketing and counter-terrorism. As a cascade can be considered as compound of the social network and the time series. However, in related literature where methods for solving the cascade prediction problem were proposed, the experimen...

  13. Computer simulation of displacement cascades in copper

    International Nuclear Information System (INIS)

    Heinisch, H.L.

    1983-06-01

    More than 500 displacement cascades in copper have been generated with the computer simulation code MARLOWE over an energy range pertinent to both fission and fusion neutron spectra. Three-dimensional graphical depictions of selected cascades, as well as quantitative analysis of cascade shapes and sizes and defect densities, illustrate cascade behavior as a function of energy. With increasing energy, the transition from production of single compact damage regions to widely spaced multiple damage regions is clearly demonstrated

  14. Gelation of high-methoxy pectin by enzymic de-esterification in the presence of calcium ions: a preliminary evaluation.

    Science.gov (United States)

    O'Brien, Aileen B; Philp, Kevin; Morris, Edwin R

    2009-09-28

    Cohesive gels have been obtained by de-esterification of 1.0wt% high-methoxy citrus pectin (degree of esterification approximately 68%) in the presence of Ca(2+) cations, using a commercial preparation (NovoShape) of fungal methyl esterase cloned from Aspergillus aculeatus. A convenient rate of network formation (gelation within approximately 30min) was achieved at an enzyme concentration of 0.2 PEU/g pectin. At a Ca(2+)-concentration of 40mM and incubation temperature of 20 degrees C, severe syneresis (>7% of sample mass) was observed, but release of fluid decreased with decreasing concentration of Ca(2+) and increasing temperature of incubation, becoming undetectable for 10mM Ca(2+) at 30 degrees C. Under these conditions, progressive development of solid-like character (storage modulus, G') was observed during 160min of enzymic de-esterification, and the mechanical spectrum recorded at the end of the incubation period had the form typical of a biopolymer gel. On subsequent heating to 70 degrees C, dissociation of the gel network (sigmoidal reduction in G' and G'') was observed. At or above the midpoint temperature of this melting process ( approximately 50 degrees C), there was no indication of gel formation on enzymic de-esterification (at 50 or 60 degrees C). At lower temperatures (20, 30 and 40 degrees C), the rate of gelation (assessed visually) showed no systematic increase as the incubation temperature was increased towards the temperature-optimum of the enzyme ( approximately 50 degrees C). This unexpected behaviour is attributed to competition between faster de-esterification and slower formation of Ca(2+)-induced 'egg-box' junctions.

  15. Dynamics robustness of cascading systems.

    Directory of Open Access Journals (Sweden)

    Jonathan T Young

    2017-03-01

    Full Text Available A most important property of biochemical systems is robustness. Static robustness, e.g., homeostasis, is the insensitivity of a state against perturbations, whereas dynamics robustness, e.g., homeorhesis, is the insensitivity of a dynamic process. In contrast to the extensively studied static robustness, dynamics robustness, i.e., how a system creates an invariant temporal profile against perturbations, is little explored despite transient dynamics being crucial for cellular fates and are reported to be robust experimentally. For example, the duration of a stimulus elicits different phenotypic responses, and signaling networks process and encode temporal information. Hence, robustness in time courses will be necessary for functional biochemical networks. Based on dynamical systems theory, we uncovered a general mechanism to achieve dynamics robustness. Using a three-stage linear signaling cascade as an example, we found that the temporal profiles and response duration post-stimulus is robust to perturbations against certain parameters. Then analyzing the linearized model, we elucidated the criteria of when signaling cascades will display dynamics robustness. We found that changes in the upstream modules are masked in the cascade, and that the response duration is mainly controlled by the rate-limiting module and organization of the cascade's kinetics. Specifically, we found two necessary conditions for dynamics robustness in signaling cascades: 1 Constraint on the rate-limiting process: The phosphatase activity in the perturbed module is not the slowest. 2 Constraints on the initial conditions: The kinase activity needs to be fast enough such that each module is saturated even with fast phosphatase activity and upstream changes are attenuated. We discussed the relevance of such robustness to several biological examples and the validity of the above conditions therein. Given the applicability of dynamics robustness to a variety of systems, it

  16. Evaluation of simultaneous binding of Chromomycin A3 to the multiple sites of DNA by the new restriction enzyme assay.

    Science.gov (United States)

    Murase, Hirotaka; Noguchi, Tomoharu; Sasaki, Shigeki

    2018-06-01

    Chromomycin A3 (CMA3) is an aureolic acid-type antitumor antibiotic. CMA3 forms dimeric complexes with divalent cations, such as Mg 2+ , which strongly binds to the GC rich sequence of DNA to inhibit DNA replication and transcription. In this study, the binding property of CMA3 to the DNA sequence containing multiple GC-rich binding sites was investigated by measuring the protection from hydrolysis by the restriction enzymes, AccII and Fnu4HI, for the center of the CGCG site and the 5'-GC↓GGC site, respectively. In contrast to the standard DNase I footprinting method, the DNA substrates are fully hydrolyzed by the restriction enzymes, therefore, the full protection of DNA at all the cleavable sites indicates that CMA3 simultaneously binds to all the binding sites. The restriction enzyme assay has suggested that CMA3 has a high tendency to bind the successive CGCG sites and the CGG repeat. Copyright © 2018 Elsevier Ltd. All rights reserved.

  17. Cascaded Bragg scattering in fiber optics.

    Science.gov (United States)

    Xu, Y Q; Erkintalo, M; Genty, G; Murdoch, S G

    2013-01-15

    We report on a theoretical and experimental study of cascaded Bragg scattering in fiber optics. We show that the usual energy-momentum conservation of Bragg scattering can be considerably relaxed via cascade-induced phase-matching. Experimentally we demonstrate frequency translation over six- and 11-fold cascades, in excellent agreement with derived phase-matching conditions.

  18. Cascade Distiller System Performance Testing Interim Results

    Science.gov (United States)

    Callahan, Michael R.; Pensinger, Stuart; Sargusingh, Miriam J.

    2014-01-01

    The Cascade Distillation System (CDS) is a rotary distillation system with potential for greater reliability and lower energy costs than existing distillation systems. Based upon the results of the 2009 distillation comparison test (DCT) and recommendations of the expert panel, the Advanced Exploration Systems (AES) Water Recovery Project (WRP) project advanced the technology by increasing reliability of the system through redesign of bearing assemblies and improved rotor dynamics. In addition, the project improved the CDS power efficiency by optimizing the thermoelectric heat pump (TeHP) and heat exchanger design. Testing at the NASA-JSC Advanced Exploration System Water Laboratory (AES Water Lab) using a prototype Cascade Distillation Subsystem (CDS) wastewater processor (Honeywell d International, Torrance, Calif.) with test support equipment and control system developed by Johnson Space Center was performed to evaluate performance of the system with the upgrades as compared to previous system performance. The system was challenged with Solution 1 from the NASA Exploration Life Support (ELS) distillation comparison testing performed in 2009. Solution 1 consisted of a mixed stream containing human-generated urine and humidity condensate. A secondary objective of this testing is to evaluate the performance of the CDS as compared to the state of the art Distillation Assembly (DA) used in the ISS Urine Processor Assembly (UPA). This was done by challenging the system with ISS analog waste streams. This paper details the results of the AES WRP CDS performance testing.

  19. Influence of a history of arterial hypertension and pretreatment blood pressure on the effect of angiotensin converting enzyme inhibition after acute myocardial infarction. Trandolapril Cardiac Evaluation Study

    DEFF Research Database (Denmark)

    Gustafsson, F; Køber, L; Torp-Pedersen, C

    1998-01-01

    OBJECTIVE: To evaluate the influence of a history of arterial hypertension and the level of pretreatment blood pressure on the efficacy of the angiotensin converting enzyme (ACE) inhibitor trandolapril on mortality and morbidity in patients with acute myocardial infarction (AMI) and left...... ventricular dysfunction. METHODS: Data from the Trandolapril Cardiac Event study, in which 1749 patients with an enzyme verified AMI and echocardiographic evidence of left ventricular dysfunction were randomized in a double-blind manner to treatment with trandolapril or placebo, were retrospectively analysed....... Follow up time was 24-50 months (mean 26 months). RESULTS: Four hundred patients (23%) had a history of arterial hypertension. A total of 173 (43%) patients with a history of hypertension died during follow up versus 500 (37%) patients in the normotensive group. Treatment with trandolapril...

  20. Annealing simulation of cascade damage using MARLOWE-DAIQUIRI codes

    International Nuclear Information System (INIS)

    Muroga, Takeo

    1984-01-01

    The localization effect of the defects generated by the cascade damage on the properties of solids was studied by using a computer code. The code is based on the two-body collision approximation method and the Monte Carlo method. The MARLOWE and DAIQUIRI codes were partly improved to fit the present calculation of the annealing of cascade damage. The purpose of this study is to investigate the behavior of defects under the simulated reactive and irradiation condition. Calculation was made for alpha iron (BCC), and the threshold energy was set at 40 eV. The temperature dependence of annealing and the growth of a cluster were studied. The overlapping effect of cascade was studied. At first, the extreme case of overlapping was studied, then the practical cases were estimated by interpolation. The state of overlapping of cascade corresponded to the irradiation speed. The interaction between cascade and dislocations was studied, and the calculation of the annealing of primary knock-out atoms (PKA) in alpha iron was performed. At low temperature, the effect of dislocations was large, but the growth of vacancy was not seen. At high temperature, the effect of dislocations was small. The evaluation of the simulation of various ion irradiation and the growth efficiency of defects were performed. (Kato, T.)

  1. The temporal development of collision cascades in the binary collision approximation

    International Nuclear Information System (INIS)

    Robinson, M.T.

    1989-07-01

    A modified binary collision approximation (BCA) was developed to allow explicit evaluation of the times at which projectiles in a collision cascade reach significant points in their trajectories, without altering the ''event-driven'' character of the model. The modified BCA was used to study the temporal development of cascades in copper and gold, initiated by primary atoms of up to 10 keV initial kinetic energy. Cascades generated with time-ordered collisions show fewer ''distant'' Frenkel pairs than do cascades generated with velocity-ordered collisions. In the former, the slower projectiles tend to move in less-damaged crystal than they do in the latter. The effect is larger in Au than in Cu and increases with primary energy. As an approach to cascade nonlinearities, cascades were generated in which stopped cascade atoms were allowed to be redisplaced in later encounters. There were many more redisplacements in time-ordered cascades than in velocity-ordered ones. Because of the additional stopping introduced by the redisplacement events, the cascades in which they were allowed had fewer defects than occurred otherwise. This effect also was larger in Au than in Cu and larger at high energies although most of the redisplacement encounters involved only low-energy particles. 13 refs., 5 figs., 4 tabs

  2. Evaluation of Organic Matter Removal Efficiency and Microbial Enzyme Activity in Vertical-Flow Constructed Wetland Systems

    Directory of Open Access Journals (Sweden)

    Qiaoling Xu

    2016-09-01

    Full Text Available In this study, enzyme activities and their relationships to organics purification were investigated in three different vertical flow constructed wetlands, namely system A (planting Pennisetum sinese Roxb, system B (planting Pennisetum purpureum Schum., and system C (no plant. These three wetland systems were fed with simulation domestic sewage at an influent flow rate of 20 cm/day. The results showed that the final removal efficiency of Chemical Oxygen Demand (COD in these three systems was 87%, 85% and 63%, respectively. Planting Pennisetum sinese Roxb and Pennisetum purpureum Schum. could improve the amount of adsorption and interception for organic matter in the substrate, and the amount of interception of organic matter in planting the Pennisetum sinese Roxb system was higher than that in planting the Pennisetum purpureum Schum. system. The activities of enzymes (urease, phosphatase and cellulase in systems A and B were higher than those in system C, and these enzyme activities in the top layer (0–30 cm were significantly higher than in the other layers. The correlations between the activities of urease, phosphatase, cellulase and the COD removal rates were R = 0.815, 0.961 and 0.973, respectively. It suggests that using Pennisetum sinese Roxb and Pennisetum purpureum Schum. as wetland plants could promote organics removal, and the activities of urease, phosphatase and cellulase in those three systems were important indicators for COD purification from wastewater. In addition, 0–30 cm was the main function layer. This study could provide a theoretical basis for COD removal in the wetland system and supply new plant materials for selection.

  3. Carbon dioxide/methanol conversion cycle based on cascade enzymatic reactions supported on superparamagnetic nanoparticles

    Directory of Open Access Journals (Sweden)

    CATERINA G.C. MARQUES NETTO

    2017-10-01

    Full Text Available ABSTRACT The conversion of carbon dioxide into important industrial feedstock is a subject of growing interest in modern society. A possible way to achieve this goal is by carrying out the CO2/methanol cascade reaction, allowing the recycle of CO2 using either chemical catalysts or enzymes. Efficient and selective reactions can be performed by enzymes; however, due to their low stability, immobilization protocols are required to improve their performance. The cascade reaction to reduce carbon dioxide into methanol has been explored by the authors, using, sequentially, alcohol dehydrogenase (ADH, formaldehyde dehydrogenase (FalDH, and formate dehydrogenase (FDH, powered by NAD+/NADH and glutamate dehydrogenase (GDH as the co-enzyme regenerating system. All the enzymes have been immobilized on functionalized magnetite nanoparticles, and their reactions investigated separately in order to establish the best performance conditions. Although the stepwise scheme led to only 2.3% yield of methanol per NADH; in a batch system under CO2 pressure, the combination of the four immobilized enzymes increased the methanol yield by 64 fold. The studies indicated a successful regeneration of NADH in situ, envisaging a real possibility of using immobilized enzymes to perform the cascade CO2-methanol reaction.

  4. Atom-atom collision cascades localization

    International Nuclear Information System (INIS)

    Kirsanov, V.V.

    1980-01-01

    The presence of an impurity and thermal vibration influence on the atom-atom collision cascade development is analysed by the computer simulation method (the modificated dynamic model). It is discovered that the relatively low energetic cascades are localized with the temperature increase of an irradiated crystal. On the basis of the given effect the mechanism of splitting of the high energetic cascades into subcascades is proposed. It accounts for two factors: the primary knocked atom energy and the irradiated crystal temperature. Introduction of an impurity also localizes the cascades independently from the impurity atom mass. The cascades localization leads to intensification of the process of annealing in the cascades and reduction of the post-cascade vacancy cluster sizes. (author)

  5. Cascade reactor: granule fabrication processes

    International Nuclear Information System (INIS)

    Erlandson, O.D.; Winkler, E.O.; Maya, I.; Pitts, J.H.

    1985-01-01

    A key feature of Cascade is the granular blanket. Of the many blanket material options open to Cascade, fabrication of Li 2 O granules was felt to offer the greatest challenge. The authors explored available methods for initial Li 2 O granule fabrication. They identified three cost-effective processes for fabricating Li 2 O granules: the VSM drop-melt furnace process, which is based on melting and spheroidizing irregularly shaped Li 2 O feed granules; the LiOH process, which spheroidizes liquefied LiOH and uses GA Technologies' sphere-forming procedures; and the Li 2 CO 3 sol-gel process, used for making spherical fuel particles for the high-temperature gas-cooled reactor (HTGR). Each process is described below

  6. Bankruptcy cascades in interbank markets.

    Directory of Open Access Journals (Sweden)

    Gabriele Tedeschi

    Full Text Available We study a credit network and, in particular, an interbank system with an agent-based model. To understand the relationship between business cycles and cascades of bankruptcies, we model a three-sector economy with goods, credit and interbank market. In the interbank market, the participating banks share the risk of bad debits, which may potentially spread a bank's liquidity problems through the network of banks. Our agent-based model sheds light on the correlation between bankruptcy cascades and the endogenous economic cycle of booms and recessions. It also demonstrates the serious trade-off between, on the one hand, reducing risks of individual banks by sharing them and, on the other hand, creating systemic risks through credit-related interlinkages of banks. As a result of our study, the dynamics underlying the meltdown of financial markets in 2008 becomes much better understandable.

  7. Evaluation of 90-day Repeated Dose Oral Toxicity, Glycometabolism, Learning and Memory Ability, and Related Enzyme of Chromium Malate Supplementation in Sprague-Dawley Rats.

    Science.gov (United States)

    Feng, Weiwei; Wu, Huiyu; Li, Qian; Zhou, Zhaoxiang; Chen, Yao; Zhao, Ting; Feng, Yun; Mao, Guanghua; Li, Fang; Yang, Liuqing; Wu, Xiangyang

    2015-11-01

    Our previous study showed that chromium malate improved the regulation of blood glucose in mice with alloxan-induced diabetes. The present study was designed to evaluate the 90-day oral toxicity of chromium malate in Sprague-Dawley rats. The present study inspected the effect of chromium malate on glycometabolism, glycometabolism-related enzymes, lipid metabolism, and learning and memory ability in metabolically healthy Sprague-Dawley rats. The results showed that all rats survived and pathological, toxic, feces, and urine changes were not observed. Chromium malate did not cause measurable damage on liver, brain, and kidney. The fasting blood glucose, serum insulin, insulin resistance index, C-peptide, hepatic glycogen, glucose-6-phosphate dehydrogenase, glucokinase, total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, and triglyceride levels of normal rats in chromium malate groups had no significant change when compared with control group and chromium picolinate group under physiologically relevant conditions. The serum and organ content of Cr in chromium malate groups had no significant change compared with control group. No significant changes were found in morris water maze test and superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and true choline esterase (TChE) activity. The results indicated that supplementation with chromium malate did not cause measurable toxicity and has no obvious effect on glycometabolism and related enzymes, learning and memory ability, and related enzymes and lipid metabolism of female and male rats. The results of this study suggest that chromium malate is safe for human consumption.

  8. Evaluation of antioxidant potential, enzyme inhibition activity and phenolic profile of Lathyrus cicera and Lathyrus digitatus: Potential sources of bioactive compounds for the food industry.

    Science.gov (United States)

    Llorent-Martínez, E J; Ortega-Barrales, P; Zengin, G; Mocan, A; Simirgiotis, M J; Ceylan, R; Uysal, S; Aktumsek, A

    2017-09-01

    The genus Lathyrus has great importance in terms of food and agricultural areas. In this study, the in vitro antioxidant activity (phosphomolybdenum, DPPH, ABTS, FRAP, CUPRAC and metal chelating) and enzyme inhibitory activity evaluation (acetylcholinesterase, butyrylcholinesterase, α-amylase and α-glucosidase) of L. cicera and L. digitatus were investigated, as well as their phytochemical profiles. The screening of the main phytochemical compounds in aerial parts of L. cicera and L. digitatus was carried out by high-performance liquid chromatography with electrospray ionization mass spectrometric detection (HPLC-ESI-MS n ), observing that flavonoids represent the highest percentage of identified compounds, with abundance of tri- and tetra-glycosilated flavonoids, including acylated ones, especially in L. cicera. Generally, L. digitatus exhibited stronger antioxidant and enzyme inhibitory activities in correlation with its higher level of phenolics. The high number of phenolic compounds and the results of the antioxidant and enzyme assays suggest that these plants may be further used as sources of bioactive compounds, and for the preparation of new nutraceuticals. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Clinical evaluation of chitotriosidase enzyme activity in Gaucher and Niemann Pick A/B diseases: A retrospective study from India.

    Science.gov (United States)

    Kadali, Srilatha; Kolusu, Anusha; Sunkara, Satish; Gummadi, Maheshwar Reddy; Undamatla, Jayanthi

    2016-06-01

    Plasma chitotriosidase originates from activated macrophages and is reported to be elevated in many Lysosomal Storage Disorders. Measurement of this enzyme activity has been an available tool for monitoring therapy of Gaucher disease. The degree of elevation of chitotriosidase is useful for differential diagnosis of Gaucher disease and Niemann Pick A/B. However the potential utility of this chitotriosidase assay depends on the frequency of deficient chitotriosidase activity in a particular population. We therefore aim to study the clinical utility of this assay Gaucher and Niemann Pick A/B diseases in the backdrop of chitotriosidase deficiency in our population. The study comprises 173 patients with clinical suspicion of either Gaucher disease (n=108) or Niemann Pick A/B (n=65) and 92 healthy controls. The plasma samples of controls, Gaucher disease, and Niemann Pick A/B showed chitotriosidase deficiency of 12%, 25% and 27% respectively. The degree of elevation of chitotriosidase in Gaucher disease and Niemann Pick A/B patients is 40-326 (11,325.7±6395.4nmol/h/ml) and 7-22 folds (1192.5±463.0nmol/h/ml) respectively. In view of these findings of distinguishable fold elevation of chitotriosidase in Gaucher disease or Niemann Pick A/B, it can be a potential surrogate differential diagnostic marker for these groups of diseases, except in the patients in whom this enzyme is deficient. Copyright © 2016 Elsevier B.V. All rights reserved.

  10. Paper sludge (PS) to bioethanol: Evaluation of virgin and recycle mill sludge for low enzyme, high-solids fermentation.

    Science.gov (United States)

    Boshoff, Sonja; Gottumukkala, Lalitha Devi; van Rensburg, Eugéne; Görgens, Johann

    2016-03-01

    Paper sludge (PS) from the paper and pulp industry consists primarily of cellulose and ash and has significant potential for ethanol production. Thirty-seven PS samples from 11 South African paper and pulp mills exhibited large variation in chemical composition and resulting ethanol production. Simultaneous saccharification and fermentation (SSF) of PS in fed-batch culture was investigated at high solid loadings and low enzyme dosages. Water holding capacity and viscosity of the PS influenced ethanol production at elevated solid loadings of PS. High viscosity of PS from virgin pulp mills restricted the solid loading to 18% (w/w) at an enzyme dosage of 20 FPU/gram dry PS (gdPS), whereas an optimal solid loading of 27% (w/w) was achieved with corrugated recycle mill PS at 11 FPU/gdPS. Ethanol concentration and yield of virgin pulp and corrugated recycle PS were 34.2g/L at 66.9% and 45.5 g/L at 78.2%, respectively. Copyright © 2015 Elsevier Ltd. All rights reserved.

  11. Re-evaluating the kinetics of ATP hydrolysis during initiation of DNA sliding by Type III restriction enzymes.

    Science.gov (United States)

    Tóth, Júlia; Bollins, Jack; Szczelkun, Mark D

    2015-12-15

    DNA cleavage by the Type III restriction enzymes requires long-range protein communication between recognition sites facilitated by thermally-driven 1D diffusion. This 'DNA sliding' is initiated by hydrolysis of multiple ATPs catalysed by a helicase-like domain. Two distinct ATPase phases were observed using short oligoduplex substrates; the rapid consumption of ∼10 ATPs coupled to a protein conformation switch followed by a slower phase, the duration of which was dictated by the rate of dissociation from the recognition site. Here, we show that the second ATPase phase is both variable and only observable when DNA ends are proximal to the recognition site. On DNA with sites more distant from the ends, a single ATPase phase coupled to the conformation switch was observed and subsequent site dissociation required little or no further ATP hydrolysis. The overall DNA dissociation kinetics (encompassing site release, DNA sliding and escape via a DNA end) were not influenced by the second phase. Although the data simplifies the ATP hydrolysis scheme for Type III restriction enzymes, questions remain as to why multiple ATPs are hydrolysed to prepare for DNA sliding. © The Author(s) 2015. Published by Oxford University Press on behalf of Nucleic Acids Research.

  12. Lens Coupled Quantum Cascade Laser

    Science.gov (United States)

    Hu, Qing (Inventor); Lee, Alan Wei Min (Inventor)

    2013-01-01

    Terahertz quantum cascade (QC) devices are disclosed that can operate, e.g., in a range of about 1 THz to about 10 THz. In some embodiments, QC lasers are disclosed in which an optical element (e.g., a lens) is coupled to an output facet of the laser's active region to enhance coupling of the lasing radiation from the active region to an external environment. In other embodiments, terahertz amplifier and tunable terahertz QC lasers are disclosed.

  13. An algebraic approach to signaling cascades with N layers

    DEFF Research Database (Denmark)

    Feliu, Elisenda; Knudsen, Michael; Andersen, Lars Nørvang

    2012-01-01

    Posttranslational modification of proteins is key in transmission of signals in cells. Many signaling pathways contain several layers of modification cycles that mediate and change the signal through the pathway. Here, we study a simple signaling cascade consisting of n layers of modification cyc...... state for any given total amounts of substrates and enzymes.We demonstrate that many steady-state concentrations are related through rational functions that can be found recursively. For example, stimulus-response curves arise as inverse functions to explicit rational functions. We show...

  14. In vitro and in vivo evaluations of a radioiodinated thymidine phosphorylase inhibitor as a tumor diagnostic agent for angiogenic enzyme imaging

    International Nuclear Information System (INIS)

    Akizawa, Hiromichi; Zhao, Songji; Takahashi, Masayuki; Nishijima, Ken-ichi; Kuge, Yuji; Tamaki, Nagara; Seki, Koh-ichi; Ohkura, Kazue

    2010-01-01

    Introduction: The expression of thymidine phosphorylase (TP) is closely associated with angiogenesis, tumor invasiveness and activation of antitumor agents. We evaluated radioiodinated 5-iodo-6-[(2-iminoimidazolidinyl)methyl]uracil ([ 125 I]IIMU) having high TP-inhibitory potency as the new radiotracer for SPECT targeting of TP expression in tumors. Methods: The characteristics of the radioiodinated TP inhibitor IIMU were determined by evaluating the uptake by tumor cells in vitro and by biodistribution studies in vivo. The distribution of the radiotracer and the extent of TP-specific uptake by tumors were evaluated by a counting method in tumor-bearing mice. Results: The in vitro uptake of radiolabeled IIMU by A431 cells along with high TP expressions was attributed to the binding of the radiotracer to its target enzyme, i.e., TP. In vivo distribution of the radiotracer in A431 tumor-bearing mice revealed tumor/blood and tumor/muscle activity uptake ratios of 36 and 106, respectively, at 3 h after the radiotracer injection. On using low TP-expressing tumors and TP blocking studies as controls, minor TP-specific accumulation of the radiotracer was detected in these studies. Conclusion: According to the binding of radioiodinated IIMU to the angiogenic enzyme TP, it can be concluded that radioiodinated IIMU might be suitable as a SPECT tracer for tumor imaging.

  15. EFSA CEF Panel (EFSA Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids), 2013. Scientific Opinion on Flavouring Group Evaluation 76, Revision 1 (FGE.76Rev1)

    DEFF Research Database (Denmark)

    Beltoft, Vibe Meister; Binderup, Mona-Lise; Frandsen, Henrik Lauritz

    The Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids of the European Food Safety Authority was requested to consider evaluations of flavouring substances assessed since 2000 by the Joint FAO/WHO Expert Committee on Food Additives (JECFA), and to decide whether further...... by Industry for use as a flavouring substance in Europe and will therefore not be considered any further. The substances were evaluated through a stepwise approach that integrates information on structure-activity relationships, intake from current uses, toxicological threshold of concern, and available data...... as flavouring substances, as these substances could not be evaluated because of concern with respect to genotoxicity. Besides the safety assessment of these flavouring substances, the specifications for the materials of commerce have also been considered and for all 26 substances, the information is adequate....

  16. Evaluation of a commercially available enzyme-linked immunosorbent assay for the diagnosis of canine sarcoptic mange.

    Science.gov (United States)

    Curtis, C F

    2001-02-24

    This study was designed to assess the accuracy of a commercial enzyme-linked immunosorbent assay for the diagnosis of canine scabies. Serum samples from 37 dogs were examined blind; 12 had sarcoptic mange confirmed by the identification of mites in skin scrapings, 12 were atopic (with positive intradermal reactions to one or more aeroallergens, including Dermatophagoides farinae), and 13 were healthy dogs with no history of skin disease. Optical density values of more than 0.16 were considered positive, 0.145 to 0.16 were considered questionable and less than 0.145 were considered negative. Ten of the 12 dogs with scabies were positive, all 12 atopic dogs were negative, and 11 of the 13 healthy dogs were negative and two were questionable.

  17. Mycoparasitism studies of Trichoderma harzianum against Sclerotinia sclerotiorum: evaluation of antagonism and expression of cell wall-degrading enzymes genes.

    Science.gov (United States)

    Troian, Rogério Fraga; Steindorff, Andrei Stecca; Ramada, Marcelo Henrique Soller; Arruda, Walquiria; Ulhoa, Cirano José

    2014-10-01

    Trichoderma spp. are known for their biocontrol activity against several plant pathogens. A specific isolate of Trichoderma harzianum, 303/02, has the potential to inhibit the growth of Sclerotinia sclerotiorum, an important agent involved in several crop diseases. In this study, the interaction between T. harzianum 303/02 and mycelia, sclerotia and apothecia of S. sclerotiorum was studied by scanning electron microscopy. RT-qPCR was used to examine the expression of 11 genes potentially involved in biocontrol. T. harzianum 303/02 parasitizes S. sclerotiorum by forming branches that coil around the hyphae. The fungus multiplied abundantly at the sclerotia and apothecia surface, forming a dense mycelium that penetrated the inner surface of these structures. The levels of gene expression varied according to the type of structure with which T. harzianum was interacting. The data also showed the presence of synergistic action between the cell-wall degrading enzymes.

  18. Identification of N-glycosylation in prolyl endoprotease from Aspergillus niger and evaluation of the enzyme for its possible application in proteomics.

    Science.gov (United States)

    Sebela, Marek; Rehulka, Pavel; Kábrt, Jaromír; Rehulková, Helena; Ozdian, Tomás; Raus, Martin; Franc, Vojtech; Chmelík, Josef

    2009-11-01

    An acidic prolyl endoprotease from Aspergillus niger was isolated from the commercial product Brewers Clarex to evaluate its possible application in proteomics. The chromatographic purification yielded a single protein band in sodium dodecyl sulfate polyacrylamide gel electrophoresis providing an apparent molecular mass of 63 kDa and a broad peak (m/z 58,061) in linear matrix-assisted laser desorption/ionization (MALDI) time-of-flight (TOF) mass spectrometry (MS) indicating the glycoprotein nature of the enzyme. Indeed, a colorimetric assessment with phenol and sulfuric acid showed the presence of neutral sugars (9% of weight). The subsequent treatment with N-glycosidase F released a variety of high-mannose type N-glycans, which were successfully detected using MALDI-TOF MS. MALDI-TOF/TOF tandem MS analysis of glycopeptides from a tryptic digest of prolyl endoprotease unraveled the identity of the N-glycosylation site in the primary structure. The data obtained also show that the enzyme is present in its processed form, i.e. without putative signal and propeptide parts. Spectrophotometric measurements demonstrated optimal activity at pH 4.0-4.5 and also high thermostability for the cleavage at the C-terminal part of proline residues. In-solution digestion of standard proteins (12-200 kDa) allowed to evaluate the cleavage specificity. The enzyme acts upon proline and alanine residues, but there is an additional minor cleavage at some other residues like Gly, Leu, Arg, Ser and Tyr. The digestion of a honeybee peptide comprising six proline residues (apidaecin 1A) led to the detection of specific peptides terminated by proline as it was confirmed by MALDI postsource decay analysis. Copyright 2009 John Wiley & Sons, Ltd.

  19. Thermodynamics of Enzyme-Catalyzed Reactions Database

    Science.gov (United States)

    SRD 74 Thermodynamics of Enzyme-Catalyzed Reactions Database (Web, free access)   The Thermodynamics of Enzyme-Catalyzed Reactions Database contains thermodynamic data on enzyme-catalyzed reactions that have been recently published in the Journal of Physical and Chemical Reference Data (JPCRD). For each reaction the following information is provided: the reference for the data, the reaction studied, the name of the enzyme used and its Enzyme Commission number, the method of measurement, the data and an evaluation thereof.

  20. Quaternary Magmatism in the Cascades - Geologic Perspectives

    Science.gov (United States)

    Hildreth, Wes

    2007-01-01

    uniquely qualified to present this synthesis. During more than three decades of volcanological studies, he has carried out comprehensive investigations of Mount Adams, Mount Baker, the Three Sisters, and the Simcoe Mountains Volcanic Field. He also brings a broad experience in other volcanic arcs, having conducted integrated field and laboratory investigations at several major volcanic centers in the Andes and the Aleutian arcs. His expertise and perspective have been further enhanced by in-depth petrologic studies of caldera environments, primarily in Long Valley, California, and Yellowstone. On the basis of all these field and laboratory investigations and exhaustive literature searches, he has published three definitive petrologic syntheses addressing the passage and transformation of basaltic magmas from their mantle sources through the crust to form the many types of volcanic manifestations at the Earth's surface. A major strength of this Professional Paper is that it adheres to data first and foremost, and only then correlates these data with relevant theories. Petrological and geophysical interpretation is left to the later sections of the volume, and even there is never allowed to stray from the pertinent databases. Hildreth's interpretations are not just idle speculations, but are carefully reasoned inferences firmly based on his thorough evaluation of the observational geological data. Professional Paper 1744 should not be skimmed lightly, in the hope that the salient points will quickly rub off. Instead, every section, indeed every paragraph, presents scholarly observations and insightful interpretations that demand careful and thoughtful study. This volume will influence and guide the course of Cascade investigations for decades to come.

  1. The relationship between collisional phase defect distribution and cascade collapse efficiency

    International Nuclear Information System (INIS)

    Morishita, K.; Heinisch, H.L.; Ishino, S.; Sekimura, N.

    1994-01-01

    Defect distributions after the collisional phase of cascade damage processes were calculated using the computer simulation code MARLOWE, which is based on the binary collision approximation. The densities of vacant sites were evaluated in defect-dense regions at the end of the collisional phase in simulated ion irradiations of several pure metals (Au, Ag, Cu, Ni, Fe, Mo and W). The vacancy density distributions were compared to the measured cascade collapse efficiencies obtained from low-dose ion irradiations of thin foils reported in the literature to identify the minimum or ''critical'' values of the vacancy densities during the collisional phase corresponding to cascade collapse. The critical densities are generally independent of the cascade energy in the same metal. The relationships between physical properties of the target elements and the critical densities are discussed within the framework of the cascade thermal spike model. ((orig.))

  2. EFSA Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids (CEF); Scientific Opinion on Flavouring Group Evaluation 310 (FGE.310): Rebaudioside A from chemical group 30

    DEFF Research Database (Denmark)

    Larsen, John Christian; Nørby, Karin Kristiane; Beltoft, Vibe Meister

    The Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids of the European Food Safety Authority was requested to evaluate rebaudioside A [FL-no: 16.113], a steviol glycoside. The substance was not considered to have genotoxic potential. Since a comprehensive and adequate...... toxicological database, including human studies, is available for steviol glycosides, the Panel based its evaluation of rebaudioside A on a comparison of the ADI of 4 mg/kg bw, expressed as steviol, established by EFSA, with the estimated dietary exposure figures based on the MSDI and mTAMDI approaches....... The Panel concluded that rebaudioside A [FL-no: 16.113] would not give rise to safety concerns at the estimated level of intake arising from its use as flavouring substance....

  3. Parameters for measurement of oxidative stress in diabetes mellitus: applicability of enzyme-linked immunosorbent assay for clinical evaluation.

    Science.gov (United States)

    Noiri, Eisei; Tsukahara, Hirokazu

    2005-05-01

    Investigations of the mechanisms involved in the onset and progression of diabetes have recently confronted the role of reactive oxygen species (ROS) and oxidative stress. Prolonged exposure to hyperglycemic conditions induces nonenzymatic glycation of protein via the so-called Maillard reaction, resulting in Schiff-base products and Amadori products that engender ROS production. These processes initiate and exacerbate micro- and macrovascular complications in diabetes. Increased oxidative stress is induced by excessive ROS production and inadequate antioxidant defenses. Recently, oxidative stress status markers have been associated directly with the severity and prognosis of diabetes. To examine oxidative stress, reliable and high-throughput methods are needed to examine large numbers of clinical samples. The emerging availability of enzyme-linked immunosorbent assay (ELISA) for oxidative stress status markers allows its application to assessment of various pathophysiologic conditions, including diabetes. This review outlines the recent achievements of ELISA application for clinical studies elucidating oxidative stress. It introduces the potential applicability of ELISA for investigating oxidative stress in diabetes.

  4. Ion-implantation dense cascade data

    International Nuclear Information System (INIS)

    Winterbon, K.B.

    1983-04-01

    A tabulation is given of data useful in estimating various aspects of ion-implantation cascades in the nuclear stopping regime, particularly with respect to nonlinearity of the cascade at high energy densities. The tabulation is restricted to self-ion implantation. Besides power-cross-section cascade dimensions, various material properties are included. Scaling of derived quantities with input data is noted, so one is not limited to the values assumed by the author

  5. A non-conventional isotope separation cascade without any mixing: net cascade

    International Nuclear Information System (INIS)

    Zeng Shi; Jiang Dongjun; Ying Zhengen

    2012-01-01

    A component has different concentrations in the incoming flows at a confluent point in all existing isotope separations cascades for multi-component isotope separation and mixing is inevitable, which results in deterioration of separation performance of the separation cascade. However, realization of no-mixing at a confluent point is impossible with a conventional cascade. A non-conventional isotope separation cascade, net cascade, is found to be able to realize no mixings for all components at confluent points, and its concept is further developed here. No-mixing is fulfilled by requiring symmetrical separation of two specified key components at every stage, and the procedure of realizing no-mixing is presented in detail. Some properties of net cascade are investigated preliminarily, and the results demonstrated the no-mixing property is indeed realized. Net cascade is the only separation cascade that so far possesses the no-mixing property. (authors)

  6. Contingency Analysis of Cascading Line Outage Events

    Energy Technology Data Exchange (ETDEWEB)

    Thomas L Baldwin; Magdy S Tawfik; Miles McQueen

    2011-03-01

    As the US power systems continue to increase in size and complexity, including the growth of smart grids, larger blackouts due to cascading outages become more likely. Grid congestion is often associated with a cascading collapse leading to a major blackout. Such a collapse is characterized by a self-sustaining sequence of line outages followed by a topology breakup of the network. This paper addresses the implementation and testing of a process for N-k contingency analysis and sequential cascading outage simulation in order to identify potential cascading modes. A modeling approach described in this paper offers a unique capability to identify initiating events that may lead to cascading outages. It predicts the development of cascading events by identifying and visualizing potential cascading tiers. The proposed approach was implemented using a 328-bus simplified SERC power system network. The results of the study indicate that initiating events and possible cascading chains may be identified, ranked and visualized. This approach may be used to improve the reliability of a transmission grid and reduce its vulnerability to cascading outages.

  7. Final Project Report - Coupled Biogeochemical Process Evaluation for Conceptualizing Trichloriethylene Co-Metabolism: Co-Metabolic Enzyme Activity Probes and Modeling Co-Metabolism and Attenuation

    Energy Technology Data Exchange (ETDEWEB)

    Starr, Robert C; Orr, Brennon R; Lee, M Hope; Delwiche, Mark

    2010-02-26

    Trichloroethene (TCE) (also known as trichloroethylene) is a common contaminant in groundwater. TCE is regulated in drinking water at a concentration of 5 µg/L, and a small mass of TCE has the potential to contaminant large volumes of water. The physical and chemical characteristics of TCE allow it to migrate quickly in most subsurface environments, and thus large plumes of contaminated groundwater can form from a single release. The migration and persistence of TCE in groundwater can be limited by biodegradation. TCE can be biodegraded via different processes under either anaerobic or aerobic conditions. Anaerobic biodegradation is widely recognized, but aerobic degradation is less well recognized. Under aerobic conditions, TCE can be oxidized to non hazardous conditions via cometabolic pathways. This study applied enzyme activity probes to demonstrate that cometabolic degradation of TCE occurs in aerobic groundwater at several locations, used laboratory microcosm studies to determine aerobic degradation rates, and extrapolated lab-measured rates to in situ rates based on concentrations of microorganisms with active enzymes involved in cometabolic TCE degradation. Microcosms were constructed using basalt chips that were inoculated with microorganisms to groundwater at the Idaho National Laboratory Test Area North TCE plume by filling a set of Flow-Through In Situ Reactors (FTISRs) with chips and placing the FTISRs into the open interval of a well for several months. A parametric study was performed to evaluate predicted degradation rates and concentration trends using a competitive inhibition kinetic model, which accounts for competition for enzyme active sites by both a growth substrate and a cometabolic substrate. The competitive inhibition kinetic expression was programmed for use in the RT3D reactive transport package. Simulations of TCE plume evolution using both competitive inhibition kinetics and first order decay were performed.

  8. Evaluation of the Effects of Mitragyna speciosa Alkaloid Extract on Cytochrome P450 Enzymes Using a High Throughput Assay

    Directory of Open Access Journals (Sweden)

    Raja Elina Raja Aziddin

    2011-08-01

    Full Text Available The extract from Mitragyna speciosa has been widely used as an opium substitute, mainly due to its morphine-like pharmacological effects. This study investigated the effects of M. speciosa alkaloid extract (MSE on human recombinant cytochrome P450 (CYP enzyme activities using a modified Crespi method. As compared with the liquid chromatography-mass spectrometry method, this method has shown to be a fast and cost-effective way to perform CYP inhibition studies. The results indicated that MSE has the most potent inhibitory effect on CYP3A4 and CYP2D6, with apparent half-maximal inhibitory concentration (IC50 values of 0.78 µg/mL and 0.636 µg/mL, respectively. In addition, moderate inhibition was observed for CYP1A2, with an IC50 of 39 µg/mL, and weak inhibition was detected for CYP2C19. The IC50 of CYP2C19 could not be determined, however, because inhibition was < 50%. Competitive inhibition was found for the MSE-treated CYP2D6 inhibition assay, whereas non-competitive inhibition was shown in inhibition assays using CYP3A4, CYP1A2 and CYP2C19. Quinidine (CYP2D6, ketoconazole (CYP3A4, tranylcypromine (CYP2C19 and furafylline (CYP1A2 were used as positive controls throughout the experiments. This study shows that MSE may contribute to an herb-drug interaction if administered concomitantly with drugs that are substrates for CYP3A4, CYP2D6 and CYP1A2.

  9. Use of enzymes for the evaluation of treated straw under special consideration of the influence of gamma irradiation

    International Nuclear Information System (INIS)

    Nehring, K.; Friedel, K.

    1982-01-01

    In order to utilise the nutrients in straw as much as possible a large variety of methods has been developed in the last few years. The following methods of straw treatment were considered: (1) use of chemicals with an alkaline effect, (2) defibration with alkaline prehydrolysis, (3) steam-pressure-extraction method, (4) γ irradiation, and (5) treatment with whit rot fungi. After straw treatment with alkalis there is practically no change in the composition of the straw. Enzymatic methods of investigation particulary the cellulase method, showed distinct relations between in vivo digestibility and 'digestibility' in the cellulase method. With the help of regression analysis equations were developed with which the in vivo values can be calculated. The defibration method primarily changed the structure of the material, which resulted in better accessibility to the influence of enzymes. Up to DOM values of 70 % the activity of cellulase decomposed the majority of carbohydrates. With the steam-pressure-extraction method the disintegration of the morphologic structure was achieved at a temperature of approximately 180 0 C and subsequent rapid relaxation ('explosion process') so that solubility values of approximately 70 % could be achieved with the cellulase method, too. The effect of γ-rays depended to a high degree on the intensity of the treatment. In various materials such as wood, straw or green forage the treatment effect starts at the same intensity of radiation of more than 0.1 MGy and then increases proportionally to the applied radiation energy. Above all, the highly polymeric carbohydrates are split, partly down to their monomeric components which can be further decomposed with cellulase. The treatment with fungi resulted in a considerable decrease of the lignin content and in the increase of the DOM values. The various methods of treatment must be valued differently as to their processes; the cellulase method seems to reveal a new possibility of relative

  10. A Semisupervised Cascade Classification Algorithm

    Directory of Open Access Journals (Sweden)

    Stamatis Karlos

    2016-01-01

    Full Text Available Classification is one of the most important tasks of data mining techniques, which have been adopted by several modern applications. The shortage of enough labeled data in the majority of these applications has shifted the interest towards using semisupervised methods. Under such schemes, the use of collected unlabeled data combined with a clearly smaller set of labeled examples leads to similar or even better classification accuracy against supervised algorithms, which use labeled examples exclusively during the training phase. A novel approach for increasing semisupervised classification using Cascade Classifier technique is presented in this paper. The main characteristic of Cascade Classifier strategy is the use of a base classifier for increasing the feature space by adding either the predicted class or the probability class distribution of the initial data. The classifier of the second level is supplied with the new dataset and extracts the decision for each instance. In this work, a self-trained NB∇C4.5 classifier algorithm is presented, which combines the characteristics of Naive Bayes as a base classifier and the speed of C4.5 for final classification. We performed an in-depth comparison with other well-known semisupervised classification methods on standard benchmark datasets and we finally reached to the point that the presented technique has better accuracy in most cases.

  11. The critical care cascade: a systems approach.

    Science.gov (United States)

    Ghosh, Rishi; Pepe, Paul

    2009-08-01

    To emphasize the evolving body of evidence that supports the need for a more seamless and interconnected continuum of patient care for a growing compendium of critical care conditions, starting in the prehospital and emergency department (ED) phases of management and continuing through ICU and rehabilitation services. The care of critically ill and injured patients has become increasingly complex. It now has been demonstrated that, for a number of such critical care conditions, optimal management not only relies heavily on the talents of highly coordinated, multidisciplinary teams, but it also may require shared responsibilities across a continuum of longitudinal care involving numerous specialties and departments. This continuum usually needs to begin in the prehospital and ED settings with management extending through specialized in-hospital diagnostic and interventional suites to traditional ICU and rehabilitation programs. In recent years, examples of these conditions have included the development of systems of care for trauma, cardiac arrest, myocardial infarction, stroke, sepsis syndromes, toxicology and other critical illnesses. Although the widespread implementation of such multidisciplinary, multispecialty critical care cascades of care has been achieved most commonly in trauma care, current healthcare delivery systems generally tend to employ compartmentalized organization for the majority of other critical care patients. Accordingly, optimal systematic care often breaks down in the management of these complex patients due to barriers such as lack of interoperable communication between teams, disjointed transfers between services, unnecessary time-consuming, re-evaluations and transitional pauses in time-dependent circumstances, deficiencies in cross-disciplinary education and quality assurance loops, and significant variability in patient care practices. Such barriers can lead to adverse outcomes in this fragile patient population. This article discusses

  12. Evaluation of metabolic enzymes in response to Excel Mera 71, a glyphosate-based herbicide, and recovery pattern in freshwater teleostean fishes.

    Science.gov (United States)

    Samanta, Palas; Pal, Sandipan; Mukherjee, Aloke Kumar; Ghosh, Apurba Ratan

    2014-01-01

    Metabolic enzymes such as alanine aminotransferase (ALT), aspartate aminotransferase (AST), and alkaline phosphatase (ALP) were evaluated in Indian teleostean fishes, namely, Anabas testudineus (Bloch) and Heteropneustes fossilis (Bloch), for an exposure to 30 days of Excel Mera 71 (17.2 mg/L), a glyphosate formulation, and subsequent depuration under Liv.52, a plant extract at a dose of 187.5 mg/d/250 L for the same period in the same tissues under laboratory condition. ALT activity was significantly increased (PExcel Mera 71 caused alterations in the metabolic enzymatic activities in fish tissues and AST showed the highest alteration in both the fishes, while lowest in ALP and ALT in A. testudineus and H. fossilis, respectively. During depuration under Liv.52, all the enzyme activities came down towards the control condition which indicated the compensatory response by the fish against this herbicidal stress and it was in the following order: AST>ALT>ALP, in A. testudineus, while H. fossilis showed the following trend: ALT>AST>ALP. Therefore, these parameters could be used as indicators of herbicidal pollution in aquatic organisms and were recommended for environmental monitoring for investigating the mechanism involved in the recovery pattern.

  13. Evaluation of Leishmania (Leishmania chagasi strains isolated from dogs originating from two visceral leishmaniasis-endemic areas in Brazil using multilocus enzyme electrophoresis

    Directory of Open Access Journals (Sweden)

    Carlos Eduardo Ribeiro Coutinho

    2011-10-01

    Full Text Available INTRODUCTION: Domestic dogs are the most important reservoir in the peridomestic transmission cycle of Leishmania (Leishmania chagasi. The genetic variability of subpopulations of this parasite circulating in dogs has not been thoroughly analyzed in Brazil, even though this knowledge has important implications in the clinical-epidemiological context. METHODS: The objective of this study was to evaluate and compare the phenotypic variability of 153 L. chagasi strains isolated from dogs originating from the municipalities of Rio de Janeiro (n = 57 and Belo Horizonte (n = 96, where the disease is endemic. Strains isolated only from intact skin were selected and analyzed by multilocus enzyme electrophoresis using nine enzyme systems (6PG, GPI, NH1 and NH2, G6P, PGM, MDH, ME, and IDHNADP. RESULTS: The electrophoretic profile was identical for all isolates analyzed and was the same as that of the L. chagasi reference strain (MHOM/BR/74/PP75. Phenetic analysis showed a similarity index of one for all strains, with the isolates sharing 100% of the characteristics analyzed. CONCLUSIONS: The results demonstrate that the L. chagasi populations circulating in dogs from Rio de Janeiro and Belo Horizonte belong to a single zymodeme.

  14. Functional evaluation of carbohydrate-centred glycoclusters by enzyme-linked lectin assay: ligands for concanavalin A.

    Science.gov (United States)

    Köhn, Maja; Benito, Juan M; Ortiz Mellet, Carmen; Lindhorst, Thisbe K; García Fernández, José M

    2004-06-07

    The affinities of the mannose-specific lectin concanavalin A (Con A) towards D-glucose-centred mannosyl clusters differing in the anomeric configuration of the monosaccharide core, nature of the bridging functional groups and valency, have been measured by a competitive enzyme-linked lectin assay. Pentavalent thioether-linked ligands (5 and 7) were prepared by radical addition of 2,3,4,6-tetra-O-acetyl-1-thio-alpha-D-mannopyranose to the corresponding penta-O-allyl-alpha- or -beta-D-glucopyranose, followed by deacetylation. The distinct reactivity of the anomeric position in the D-glucose scaffold was exploited in the preparation of a tetravalent cluster (10) that keeps a reactive aglyconic group for further manipulation, including incorporation of a reporter group or attachment to a solid support. Hydroboration of the double bonds in the penta-O-allyl-alpha-D-glucopyranose derivative and replacement of the hydroxy groups with amine moieties gave a suitable precursor for the preparation of pentavalent and 15-valent mannosides through the thiourea-bridging reaction (17 and 20, respectively). The diastereomeric 1-thiomannose-coated clusters 5 and 7 were demonstrated to be potent ligands for Con A, with IC(50) values for the inhibition of the Con A-yeast mannan association indicative of 6.4- and 5.5-fold increases in binding affinity (valency-corrected values), respectively, relative to the value for methyl alpha-D-mannopyranoside. The tetravalent cluster 10 exhibited a valency-corrected relative lectin-binding potency virtually identical to that of the homologous pentavalent mannoside 7. In sharp contrast, replacement of the 1-thiomannose wedges of 5 with alpha-D-mannopyranosylthioureido units (17) virtually abolished any multivalent or statistic effects, with a dramatic decrease of binding affinity. The 15-valent ligand 20, possessing classical O-glycosidic linkages, exhibited a twofold increase in lectin affinity relative to the penta-O-(thioglycoside) 5; it is

  15. Evaluation of guppy (Poecilia reticulata Peters) immunization against Tetrahymena sp. by enzyme-linked immunosorbent assay (ELISA).

    Science.gov (United States)

    Sharon, Galit; Nath, Pulak R; Isakov, Noah; Zilberg, Dina

    2014-09-15

    Analysis of the effectiveness of guppy (Poecilia reticulata Peters) immunization based on measurements of antibody (Ab) titers suffers from a shortage of reagents that can detect guppy antibodies (Abs). To overcome this problem, we immunized mice with different preparations of guppy immunoglobulins (Igs) and used the mouse antisera to develop a quantitative enzyme-linked immunosorbent assay (ELISA). The most efficient immunogen for mouse immunization was guppy Igs adsorbed on protein A/G beads. Antisera from mice boosted with this immunoglobulin (Ig) preparation were highly specific and contained high Ab titers. They immunoreacted in a Western blot with Ig heavy and light chains from guppy serum, and Ig heavy chain from guppy whole-body homogenate. The mouse anti-guppy Ig was applied in an ELISA aimed at comparing the efficiency of different routes of guppy immunization against Tetrahymena: (i) anal intubation with sonicated Tetrahymena (40,000 Tetrahymena/fish in a total volume of 10 μL) mixed with domperidon, deoxycholic acid and free amino acids (valine, leucine, isoleucine, phenylalanine and tryptophan), or (ii) intraperitoneal (i.p.) injection of sonicated Tetrahymena in complete Freund's adjuvant (15,000 Tetrahymena/fish in total a volume of 20 μL). Negative control fish were anally intubated with the intubation mixture without Tetrahymena, or untreated. ELISA measurement of anti-Tetrahymena Ab titer revealed a significantly higher level of Abs in i.p.-immunized guppies, compared to the anally intubated and control fish. In addition, the efficiency of immunization was tested by monitoring guppy mortality following (i) i.p. challenge with Tetrahymena (900 Tetrahymena/fish) or (ii) cold stress followed by immersion in water containing 10,000 Tetrahymena/mL. Fish mortality on day 14 post-Tetrahymena infection by i.p. injection exceeded 50% in the control and anally intubated fish, compared to 31% in i.p.-immunized fish. Immunization did not protect from

  16. Evaluation of the potential allergenicity of the enzyme microbial transglutaminase using the 2001 FAO/WHO Decision Tree

    DEFF Research Database (Denmark)

    Pedersen, Mona H.; Hansen, Tine K.; Sten, Eva

    2004-01-01

    All novel proteins must be assessed for their potential allergenicity before they are introduced into the food market. One method to achieve this is the 2001 FAO/WHO Decision Tree recommended for evaluation of proteins from genetically modified organisms (GMOs). It was the aim of this study...... to investigate the allergenicity of microbial transglutaminase (m-TG) from Streptoverticillium mobaraense. Amino acid sequence similarity to known allergens, pepsin resistance, and detection of protein binding to specific serum immunoglobulin E (IgE) (RAST) have been evaluated as recommended by the decision tree...... meets the requirements of the decision tree. However, there is a match at the five contiguous amino acid level to the major codfish allergen Gad c1. The potential cross reactivity between m-TG and Gad c1 was investigated in RAST using sera from 25 documented cod-allergic patients and an extract of raw...

  17. Design concept of Hydro cascade control system

    International Nuclear Information System (INIS)

    Fustik, Vangel; Kiteva, Nevenka

    2006-01-01

    In this paper a design concept of the comple hydro cascade scheme is presented with the design parameters of the main technical features. The cascade control system architecture is designed considering up-to-date communication and information technology. The control algorithm is based on Pond Level Control and Economic Load Allocation concepts.

  18. Centrifugal separator cascade connected in zigzag manner

    International Nuclear Information System (INIS)

    Kai, Tsunetoshi; Inoue, Yoshiya; Oya, Akio; Nagakura, Masaaki.

    1974-01-01

    Object: To effectively accommodate centrifugal separators of the entire cascade within the available space in a plant by freely selecting perpendicular direction of connection of the centrifugal separator. Structure: Centrifugal separators are connected in zigzag fashion by using a single header for each stage so that in a rectangular shape the entire cascade is arranged. (Kamimura, M.)

  19. Cascaded impedance networks for NPC inverter

    DEFF Research Database (Denmark)

    Li, Ding; Gao, Feng; Loh, Poh Chiang

    2010-01-01

    they are subject to the renewable sources. To date, three distinct types of impedance networks can be summarized for implementing a hybrid source impedance network, which can in principle be combined and cascaded before connected to a NPC inverter by proposed two ways. The resulting cascaded impedance network NPC...

  20. Bienzymatic sensor based on the use of redox enzymes and chitosan-MWCNT nanocomposite. Evaluation of total phenolic content in plant extracts

    International Nuclear Information System (INIS)

    Diaconu, M.; Litescu, S.C.; Radu, G.L.

    2011-01-01

    We are presenting a bienzymatic sensor for the determination of polyphenols. An ITO electrode was modified with multiwalled carbon nanotubes, and the enzymes laccase and tyrosinase were co-entrapped into a chitosan matrix. The resulting biosensor was calibrated at -50 mV (vs. the Ag/AgCl reference electrode) using rosmarinic acid, caffeic acid and gallic acid as the substrates. The new biosensor resulted in a 10.7-fold increase in response sensitivity and a considerable improvement of the detection limit (42 nM for rosmarinic acid). Fouling of the surface of the biosensor was prevented by applying the surfactant Tween 20. The data recorded in surfactant medium revealed a significant improvement of the operational stability and an enlarged linear concentration ranges (up to 12 μM for rosmarinic acid). The sensor was used to evaluate the total phenolic content from extracts of Salvia officinalis and cultures of Basilicum callus. (author)

  1. EFSA CEF Panel (EFSA Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids), 2013. Scientific Opinion on Flavouring Group Evaluation 93, Revision 1 (FGE.93Rev1)

    DEFF Research Database (Denmark)

    Beltoft, Vibe Meister; Binderup, Mona-Lise; Frandsen, Henrik Lauritz

    The Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids of the European Food Safety Authority was requested to consider evaluations of flavouring substances assessed since 2000 by the Joint FAO/WHO Expert Committee on Food Additives (the JECFA), and to decide whether further...... through a stepwise approach that integrates information on structure-activity relationships, intake from current uses, toxicological threshold of concern, and available data on metabolism and toxicity. The two substances 5-ethyl-4-methyl-2-(2-methylpropyl)-thiazoline [FL-no: 15.130] and 5-ethyl-4-methyl-2...... and agrees with the JECFA conclusion, “No safety concern at estimated levels of intake as flavouring substances” based on the MSDI approach. Besides the safety assessment of these flavouring substances, the specifications for the materials of commerce have also been considered and for all five substances...

  2. Evaluation of the radioimmunoassay, indirect enzyme linked immunosorbent assay, and dot blot assay for the identification of Xanthomonas campestris pv. phaseoli

    Energy Technology Data Exchange (ETDEWEB)

    Malin, E; Belden, E L; Roth, D

    1985-09-01

    A radioimmunoassay (RIA), an indirect competitive enzyme-linked immunosorbent assay (ELISA), and a dot-blot modification of the ELISA were evaluated for detection and identification of Xanthomonas campestris pv. phaseoli (X. c. pv. phaseoli). RIA and the dot blot tests were specific for X. c. pv. phaseoli; however, significant cross reactions occurred in the indirect competitive ELISA when using anti-X. c. pv. phaseoli antiserum against other closely related bacteria. The sensitivity level of all procedures for X. c. pv. phaseoli was approximately l0/sup 5/ colony forming unitsmL. All procedures were unsatisfactory in reliably detecting low levels of X. c. pv. phaseoli directly from extracts of bean seed. However when used in conjunction with ilution plating the dot blot assay and the RIA would be useful in specifically identifying X. c. pv. phaseoli. The relative merits of these tests for identification of X. c. pv. phaseoli are discussed.

  3. Galactomannan enzyme immunoassay and quantitative Real Time PCR as tools to evaluate the exposure and response in a rat model of aspergillosis after posaconazole prophylaxis.

    Science.gov (United States)

    Cendejas-Bueno, Emilio; Forastiero, Agustina; Ruiz, Isabel; Mellado, Emilia; Buitrago, María José; Gavaldà, Joan; Gomez-Lopez, Alicia

    2016-11-01

    A steroid-immunosuppressed rat model of invasive pulmonary aspergillosis was use to examine the usefulness of galactomannan enzyme immunoassay (GM) and quantitative real time PCR (RT-PCR) in evaluating the association between response and exposure after a high dose of prophylactic posaconazole. Two different strains of Aspergillus fumigatus with different in vitro posaconazole susceptibility were used. Serum concentrations demonstrated similar posaconazole exposure for all treated animals. However, response to posaconazole relied on the in vitro susceptibility of the infecting strain. After prophylaxis, galactomannan index and fungal burden only decreased in those animals infected with the most susceptible strain. This study demonstrated that both biomarkers may be useful tools for predicting efficacy of antifungal compounds in prophylaxis. Copyright © 2015 Elsevier España, S.L.U. and Sociedad Española de Enfermedades Infecciosas y Microbiología Clínica. All rights reserved.

  4. MAPK cascades in guard cell signal transduction

    Directory of Open Access Journals (Sweden)

    Yuree eLee

    2016-02-01

    Full Text Available Guard cells form stomata on the epidermis and continuously respond to endogenous and environmental stimuli to fine-tune the gas exchange and transpirational water loss, processes which involve mitogen-activated protein kinase (MAPK cascades. MAPKs form three-tiered kinase cascades with MAPK kinases and MAPK kinase kinases, by which signals are transduced to the target proteins. MAPK cascade genes are highly conserved in all eukaryotes, and they play crucial roles in myriad developmental and physiological processes. MAPK cascades function during biotic and abiotic stress responses by linking extracellular signals received by receptors to cytosolic events and gene expression. In this review, we highlight recent findings and insights into MAPK-mediated guard cell signaling, including the specificity of MAPK cascades and the remaining questions.

  5. Cascade Error Projection: An Efficient Hardware Learning Algorithm

    Science.gov (United States)

    Duong, T. A.

    1995-01-01

    A new learning algorithm termed cascade error projection (CEP) is presented. CEP is an adaption of a constructive architecture from cascade correlation and the dynamical stepsize of A/D conversion from the cascade back propagation algorithm.

  6. Displacement cascades in diatomic materials

    International Nuclear Information System (INIS)

    Parkin, D.M.; Coulter, C.A.

    1981-01-01

    A new function, the specified-projectile displacement function p/sub ijk/ (E), is introduced to describe displacement cascades in polyatomic materials. This function describes the specific collision events that produce displacements and hence adds new information not previously available. Calculations of p/sub ijk/ (E) for MgO, Al 2 O 3 and TaO are presented and discussed. Results show that the parameters that have the largest effect on displacement collision events are the PKA energy and the mass ratio of the atom types in the material. It is further shown that the microscopic nature of the displacement events changes over the entire recoil energy range relevant to fusion neutron spectra and that these changes are different in materials whose mass ratio is near one than in those where it is far from one

  7. The Geant4 Bertini Cascade

    Energy Technology Data Exchange (ETDEWEB)

    Wright, D.H.; Kelsey, M.H.

    2015-12-21

    One of the medium energy hadron–nucleus interaction models in the GEANT4 simulation toolkit is based partly on the Bertini intranuclear cascade model. Since its initial appearance in the toolkit, this model has been largely re-written in order to extend its physics capabilities and to reduce its memory footprint. Physics improvements include extensions in applicable energy range and incident particle types, and improved hadron–nucleon cross-sections and angular distributions. Interfaces have also been developed which allow the model to be coupled with other GEANT4 models at lower and higher energies. The inevitable speed reductions due to enhanced physics have been mitigated by memory and CPU efficiency improvements. Details of these improvements, along with selected comparisons of the model to data, are discussed.

  8. Availability Cascades & the Sharing Economy

    DEFF Research Database (Denmark)

    Netter, Sarah

    2014-01-01

    attention. This conceptual paper attempts to explain the emergent focus on the sharing economy and associated business and consumption models by applying cascade theory. Risks associated with this behavior will be especially examined with regard to the sustainability claim of collaborative consumption......In search of a new concept that will provide answers to as to how modern societies should not only make sense but also resolve the social and environmental problems linked with our modes of production and consumption, collaborative consumption and the sharing economy are increasingly attracting....... With academics, practitioners, and civil society alike having a shared history in being rather fast in accepting new concepts that will not only provide business opportunities but also a good conscience, this study proposes a critical study of the implications of collaborative consumption, before engaging...

  9. Experimental study of flow through compressor Cascade

    Directory of Open Access Journals (Sweden)

    Satyam Panchal

    2017-09-01

    Full Text Available The objective of this research work is to study the behaviour of flow at the inlet, within the blade passage and at the exit of a compressor cascade. For this purpose, a cascade with six numbers of aerofoil blades was designed and constructed. The cascade was fitted on the cascade test tunnel. Out of six blades two were instrumented for measuring the pressure distribution on the pressure and suction surface. The blades had a parabolic camber line, with a maximum camber position at 40% of the chord from the leading edge of the blade. The profile of the blade was C4, height of the blade was 160 mm, chord length was 80 mm, camber angle was 45° and stagger angle was 30°. Similarly, the length of the cascade was 300 mm, span was 160 mm, pitch was 60 mm, the actual chord of the cascade was 80 mm, the axial chord of the cascade was 70 mm, the stagger angle of the cascade was 30° and the pitch-chord ratio was 0.75. The data was taken and analyzed at −500% of the axial chord before the cascade, −25% of the axial chord before the leading edge, 25%, 50%, 75% and 150% of the axial chord from the leading edge of the blade. The readings were taken from the cascade wall to the mid span position along the pitch wise direction. The angle of incidence was also changed during the experiment and varied from i=−50°, −30°, −10° to 5°.

  10. EFSA CEF Panel (EFSA Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids), 2014. Scientific Opinion on Flavouring Group Evaluation 215 (FGE.215): Seven α,β-Unsaturated Cinnamyl Ketones from subgroup 3.2 of FGE.19

    DEFF Research Database (Denmark)

    Beltoft, Vibe Meister; Binderup, Mona-Lise; Lund, Pia

    The Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids of the European Food Safety Authority was requested to evaluate the genotoxic potential of flavouring substances from subgroup 3.2 of FGE.19 in the Flavouring Group Evaluation 215 (FGE.215). The Flavour Industry has...

  11. EFSA CEF Panel (EFSA Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids), 2014. Scientific Opinion on Flavouring Group Evaluation 304, Revision 1 (FGE.304Rev1): Four carboxamides from Chemical Groups 30

    DEFF Research Database (Denmark)

    Beltoft, Vibe Meister; Binderup, Mona-Lise; Frandsen, Henrik Lauritz

    The Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids of the European Food Safety Authority was requested to evaluate four flavouring substances in the Flavouring Group Evaluation 304, Revision 1 (FGE.304Rev1) using the Procedure in Commission Regulation (EC) No 1565...... criteria and identity for the materials of commerce have been provided for all four candidate substances....

  12. Development and Validation of a Novel LC-MS/MS Opioid Confirmation Assay: Evaluation of β-glucuronidase Enzymes and Sample Cleanup Methods.

    Science.gov (United States)

    Yang, He S; Wu, Alan H B; Lynch, Kara L

    2016-06-01

    With the rise in the use and misuse of prescription opioids, there is an increasing need for the confirmed identification of opioid analgesics in toxicology laboratories. The goals of this study were to (i) systematically evaluate the hydrolysis efficiency of four β-glucuronidase enzymes under optimized condition; (ii) evaluate compound recovery, matrix effects and precision of three protein precipitation plates and (iii) develop and validate a qualitative liquid-chromatography mass spectrometry (LC-MS/MS) assay to identify 13 opioids in urine. A recombinant β-glucuronidase exhibited the best overall hydrolysis efficiency for seven opioid glucuronide conjugates compared with β-glucuronidase from red abalone, Escherichia coli and Patella vulgata One of the protein precipitation plates tested exhibited overall better recovery of the opioids and lower ion suppression compared with the other two plates. An ESI positive mode LC-MS/MS assay for qualitative opioid analysis was developed and validated. Linearity, LOD, precision, matrix effect, recovery, carryover and interference of the method were evaluated. Sixty-two patient samples were analyzed by both a legacy GC-MS opioid method and the LC-MS/MS method, and 22 samples were analyzed by the LC-MS/MS and an LC-MS/MS reference method. The results of the comparisons showed good concordance. Overall, we described an efficient sample preparation procedure for a sensitive qualitative opioid confirmation assay in urine. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  13. Groundwater quality in the Cascade Range and Modoc Plateau, California

    Science.gov (United States)

    Fram, Miranda S.; Shelton, Jennifer L.

    2015-01-01

    Groundwater provides more than 40 percent of California’s drinking water. To protect this vital resource, the State of California created the Groundwater Ambient Monitoring and Assessment (GAMA) Program. The Priority Basin Project of the GAMA Program provides a comprehensive assessment of the State’s groundwater quality and increases public access to groundwater-quality information. The Cascade Range and Modoc Plateau area constitutes one of the study units being evaluated.

  14. Hepatic necro-inflammation and elevated liver enzymes: Evaluation with MRI perfusion imaging with gadoxetic acid in chronic hepatitis patients

    International Nuclear Information System (INIS)

    Chen, B.-B.; Hsu, C.-Y.; Yu, C.-W.; Kao, J.-H.; Lee, H.-S.; Liang, P.-C.; Wei, S.-Y.; Hwang, R.-M.; Shih, T.T.-F.

    2014-01-01

    Aim: To evaluate liver necro-inflammation and function by using gadoxetic acid-enhanced dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI), with histological analysis as the reference standard. Materials and methods: Seventy-nine subjects (21 healthy subjects; 58 chronic hepatitis patients) who received gadoxetic acid-enhanced DCE-MRI were divided into three subgroups: no (A0, n = 31), mild (A1, n = 27), and moderate–severe (A2–A3, n = 21) activities. Two DCE-MRI models were measured: (1) a dual-input single-compartment model to obtain absolute arterial, portal venous, and total blood flow, arterial fraction (ART), distribution volume, and mean transit time; (2) a curve analysis method to obtain peak, slope, and AUC (area under curve). The serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels also obtained. Statistical testing included Kruskal–Wallis tests for continuous data, Pearson's correlation tests, and multiple linear regression analyses. Results: Hepatic necro-inflammatory activity grades were significantly correlated with fibrotic stages, serum ALT level, ART and AUC. ART was helpful to predict the mild activity (≤A1 versus >A1; Az = 0.728), whereas AUC could differentiate no activity from any activity (A0 versus >A0; Az = 0.703). Peak, slope and AUC were all associated with AST and ALT (p < 0.05). Conclusion: Gadoxetic acid-enhanced DCE-MRI parameters may be used to evaluate the severity of hepatic necro-inflammation and function

  15. The Enzyme Function Initiative†

    Science.gov (United States)

    Gerlt, John A.; Allen, Karen N.; Almo, Steven C.; Armstrong, Richard N.; Babbitt, Patricia C.; Cronan, John E.; Dunaway-Mariano, Debra; Imker, Heidi J.; Jacobson, Matthew P.; Minor, Wladek; Poulter, C. Dale; Raushel, Frank M.; Sali, Andrej; Shoichet, Brian K.; Sweedler, Jonathan V.

    2011-01-01

    The Enzyme Function Initiative (EFI) was recently established to address the challenge of assigning reliable functions to enzymes discovered in bacterial genome projects; in this Current Topic we review the structure and operations of the EFI. The EFI includes the Superfamily/Genome, Protein, Structure, Computation, and Data/Dissemination Cores that provide the infrastructure for reliably predicting the in vitro functions of unknown enzymes. The initial targets for functional assignment are selected from five functionally diverse superfamilies (amidohydrolase, enolase, glutathione transferase, haloalkanoic acid dehalogenase, and isoprenoid synthase), with five superfamily-specific Bridging Projects experimentally testing the predicted in vitro enzymatic activities. The EFI also includes the Microbiology Core that evaluates the in vivo context of in vitro enzymatic functions and confirms the functional predictions of the EFI. The deliverables of the EFI to the scientific community include: 1) development of a large-scale, multidisciplinary sequence/structure-based strategy for functional assignment of unknown enzymes discovered in genome projects (target selection, protein production, structure determination, computation, experimental enzymology, microbiology, and structure-based annotation); 2) dissemination of the strategy to the community via publications, collaborations, workshops, and symposia; 3) computational and bioinformatic tools for using the strategy; 4) provision of experimental protocols and/or reagents for enzyme production and characterization; and 5) dissemination of data via the EFI’s website, enzymefunction.org. The realization of multidisciplinary strategies for functional assignment will begin to define the full metabolic diversity that exists in nature and will impact basic biochemical and evolutionary understanding, as well as a wide range of applications of central importance to industrial, medicinal and pharmaceutical efforts. PMID

  16. The Enzyme Function Initiative.

    Science.gov (United States)

    Gerlt, John A; Allen, Karen N; Almo, Steven C; Armstrong, Richard N; Babbitt, Patricia C; Cronan, John E; Dunaway-Mariano, Debra; Imker, Heidi J; Jacobson, Matthew P; Minor, Wladek; Poulter, C Dale; Raushel, Frank M; Sali, Andrej; Shoichet, Brian K; Sweedler, Jonathan V

    2011-11-22

    The Enzyme Function Initiative (EFI) was recently established to address the challenge of assigning reliable functions to enzymes discovered in bacterial genome projects; in this Current Topic, we review the structure and operations of the EFI. The EFI includes the Superfamily/Genome, Protein, Structure, Computation, and Data/Dissemination Cores that provide the infrastructure for reliably predicting the in vitro functions of unknown enzymes. The initial targets for functional assignment are selected from five functionally diverse superfamilies (amidohydrolase, enolase, glutathione transferase, haloalkanoic acid dehalogenase, and isoprenoid synthase), with five superfamily specific Bridging Projects experimentally testing the predicted in vitro enzymatic activities. The EFI also includes the Microbiology Core that evaluates the in vivo context of in vitro enzymatic functions and confirms the functional predictions of the EFI. The deliverables of the EFI to the scientific community include (1) development of a large-scale, multidisciplinary sequence/structure-based strategy for functional assignment of unknown enzymes discovered in genome projects (target selection, protein production, structure determination, computation, experimental enzymology, microbiology, and structure-based annotation), (2) dissemination of the strategy to the community via publications, collaborations, workshops, and symposia, (3) computational and bioinformatic tools for using the strategy, (4) provision of experimental protocols and/or reagents for enzyme production and characterization, and (5) dissemination of data via the EFI's Website, http://enzymefunction.org. The realization of multidisciplinary strategies for functional assignment will begin to define the full metabolic diversity that exists in nature and will impact basic biochemical and evolutionary understanding, as well as a wide range of applications of central importance to industrial, medicinal, and pharmaceutical efforts.

  17. Evaluation of the effect of quercetin treatment on CYP2C9 enzyme activity of diclofenac in healthy human volunteers.

    Science.gov (United States)

    Bedada, Satish Kumar; Neerati, Prasad

    2018-02-01

    The purpose of present study was to evaluate the effect of quercetin on pharmacokinetics of diclofenac sodium (DIC) in healthy volunteers. The open-label, 2 period, sequential study was conducted in 12 healthy volunteers. DIC 100 mg was administered during control and after quercetin phases. Quercetin 500 mg was administered twice daily for 10 days during quercetin phase. Treatment with quercetin significantly enhanced maximum plasma concentration (C max ) , area under the curve (AUC 0-∞ ), and half life, while significantly decreased elimination rate constant (k el ) and apparent oral clearance (CL/F) of DIC compared with control. On the other hand, C max and AUC 0-∞ of 4-hydroxydiclofenac (4-OHDIC) were decreased after quercetin treatment. In addition, geometric mean ratios and 90% confidence intervals for C max and AUC 0-∞ of DIC and 4-OHDIC were both out of the no-effect limits of 0.80-1.25, which indicates a significant pharmacokinetic interaction between quercetin and DIC. Furthermore, quercetin treatment significantly decreased metabolic ratios of C max and AUC 0-∞ suggesting that reduced formation of DIC to 4-OHDIC. The results suggest that quercetin might have inhibited CYP2C9-mediated metabolism of DIC. Accordingly, caution should be taken when quercetin is used in combination with therapeutic drugs metabolized by CYP2C9, and dose adjustment of CYP2C9 substrates may be necessary. Copyright © 2017 John Wiley & Sons, Ltd.

  18. Evaluation of Virological Microparticle Enzyme Immunoassay According to the ISO 15189: Real-Life Experience in a University Hospital.

    Science.gov (United States)

    Lafontaine, Sophie; Prin-Mathieu, Christine; Velay, Aurélie; Agulles, Odette; Schvoerer, Evelyne; Jeulin, Hélène

    2016-01-01

    The International Standard ISO 15189 based on the ISO 9001:2008 emphasizes specific requirements for quality and ability of medical laboratories. The accreditation of medical laboratories according to ISO 15189 includes the validation of biological methods, which depends on collection of bibliographic data and experimental proofs. Moreover, these results must be compared to provider data sheets and independent scientific data. In the immunodiagnostic field, independent published data are deeply lacking. The aim of our work was to share experience of method validation for virological immune markers on the widely used Architect i2000sr. After risk analysis, intra- and inter-assay variability, and inter-sample contamination were evaluated for each method, and sensitivity was investigated for antigen detection tests. A comparison between the two Architect i2000sr available in our laboratory was also performed. All tested methods were consistent with the manufacturer data (from the data sheet). No inter-sample contamination was observed. Both devices are broadly equivalent and can be used indifferently or as a backup solution of the other. To our knowledge, those results are the first independent complete data on the reliability of the Architect i2000sr in real-life experience. These data are needed to the accreditation of our platform and potentially useful for the accreditation of other laboratories using the same equipment.

  19. Genetic algorithm based separation cascade optimization

    International Nuclear Information System (INIS)

    Mahendra, A.K.; Sanyal, A.; Gouthaman, G.; Bera, T.K.

    2008-01-01

    The conventional separation cascade design procedure does not give an optimum design because of squaring-off, variation of flow rates and separation factor of the element with respect to stage location. Multi-component isotope separation further complicates the design procedure. Cascade design can be stated as a constrained multi-objective optimization. Cascade's expectation from the separating element is multi-objective i.e. overall separation factor, cut, optimum feed and separative power. Decision maker may aspire for more comprehensive multi-objective goals where optimization of cascade is coupled with the exploration of separating element optimization vector space. In real life there are many issues which make it important to understand the decision maker's perception of cost-quality-speed trade-off and consistency of preferences. Genetic algorithm (GA) is one such evolutionary technique that can be used for cascade design optimization. This paper addresses various issues involved in the GA based multi-objective optimization of the separation cascade. Reference point based optimization methodology with GA based Pareto optimality concept for separation cascade was found pragmatic and promising. This method should be explored, tested, examined and further developed for binary as well as multi-component separations. (author)

  20. Phytopharmacological evaluation of Byesukar for hypoglycaemic activity and its effect on lipid profile and hepatic enzymes of glucose metabolism in diabetic rats.

    Science.gov (United States)

    Guruvayoorappan, C; Sudha, G

    2008-01-01

    Many anti-diabetic herbal preparations have been recommended in alternative systems of medicine for the treatment of diabetes. No systematic study has been done on the anti-diabetic efficacy of Byesukar, a polyherbal formulation to treat diabetes. The anti-diabetic efficacy of byesukar ethanol extract was evaluated in an animal model of diabetes induced by alloxan. Male Wistar rats were divided in to four groups. Group 1 was normal control group; group 2 and 3 received alloxan. After inducing experimental diabetes group 2 served as diabetic control; group 3 received byesukar (500 mg/kg body weight) orally for 30 consecutive days. Group 4 were normal rats which received byesukar extract alone. The effect of byesukar on glucose level in diabetic rats was studied and the level of glucose metabolizing enzymes (Hexokinase, glucose-6-phosphatase and fructose 1, 6-bisphosphatase) in the liver and kidney were estimated. The effect of byesukar on the serum and tissue lipid profile (Cholesterol, triglycerides, phospholipids and free fatty acids) were also estimated in diabetic rats. Our results indicate that treatment with byesukar resulted in significant reduction of blood glucose, tissue glucose-6-phosphatase and fructose 1, 6- bisphosphatase activity. The decreased tissue hexokinase activity in diabetes state was found to be significantly increased by byesukar treatment. Also the byesukar treated diabetic rats showed a significant decrease in the tissue lipid profile compared to the diabetic rats. In conclusion the decreased blood glucose accompanied with decreased lipid profile and changes in the activities of the glucose metabolizing enzymes shows the antidiabetic effect of byesukar.

  1. Cascaded holographic polymer reflection grating filters for optical-code-division multiple-access applications.

    Science.gov (United States)

    Kostuk, Raymond K; Maeda, Wendi; Chen, Chia-Hung; Djordjevic, Ivan; Vasic, Bane

    2005-12-10

    We evaluate the use of edge-illuminated holographic Bragg filters formed in phenanthrenequinone-doped poly(methyl methacrylate) for optical-code-division multiple-access (OCDMA) coding and decoding applications. Experimental cascaded Bragg filters are formed to select two different wavelengths with a fixed distance between the gratings and are directly coupled to a fiber-measurement system. The configuration and tolerances of the cascaded gratings are shown to be practical for time-wavelength OCDMA applications.

  2. Structured, intensive education maximising engagement, motivation and long-term change for children and young people with diabetes: a cluster randomised controlled trial with integral process and economic evaluation - the CASCADE study.

    Science.gov (United States)

    Christie, Deborah; Thompson, Rebecca; Sawtell, Mary; Allen, Elizabeth; Cairns, John; Smith, Felicity; Jamieson, Elizabeth; Hargreaves, Katrina; Ingold, Anne; Brooks, Lucy; Wiggins, Meg; Oliver, Sandy; Jones, Rebecca; Elbourne, Diana; Santos, Andreia; Wong, Ian C K; O'Neill, Simon; Strange, Vicki; Hindmarsh, Peter; Annan, Francesca; Viner, Russell

    2014-03-01

    organising groups, and work and school commitments. Young people with higher HbA1c levels were less likely to attend. Parents and young people who attended groups described improved family relationships, improved knowledge and understanding, greater confidence and increased motivation to manage diabetes. Twenty-four months after the intervention, nearly half of the young people reported that the groups had made them want to try harder and that they had carried on trying. A high-quality, complex, pragmatic trial of structured education can be delivered alongside standard care in NHS diabetes clinics. Health-care providers benefited from behaviour change skill training and can deliver pragmatic aspects of a National Institute for Health and Care Excellence (NICE)-compliant structured education programme after relatively brief training. The process evaluation provides insight into aspects of the model, and highlights strengths and aspects that may have contributed to the failure to influence primary and secondary outcomes. Current NHS practice dominates CASCADE (Child and Adolescent Structured Competencies Approach to Diabetes Education) in that it achieves the same number of QALYs at a lower cost. The mean cost of providing the intervention was £5098 per site or £683 per child. Members of paediatric diabetes services trained to deliver the CASCADE structured education package using behaviour change techniques did not improve glycaemic control in patients compared with control subjects 1 and 2 years after the intervention. The training workshops for practitioners were well evaluated; however, more intensive training was needed. The intervention cost £683 per patient but was not cost-effective because it did not improve metabolic control. A high-quality, complex, pragmatic trial of structured education can be successfully conducted alongside standard care in NHS diabetes clinics. Pragmatic components of a NICE-compliant structured education programme can be successfully

  3. Enzyme detection by microfluidics

    DEFF Research Database (Denmark)

    2013-01-01

    Microfluidic-implemented methods of detecting an enzyme, in particular a DNA-modifying enzyme, are provided, as well as methods for detecting a cell, or a microorganism expressing said enzyme. The enzyme is detected by providing a nucleic acid substrate, which is specifically targeted...... by that enzyme...

  4. Evaluation of Imbrasia belina meal as a fishmeal substitute in Oreochromis mossambicus diets: Growth performance, histological analysis and enzyme activity

    Directory of Open Access Journals (Sweden)

    Mmaditshaba M. Rapatsa

    2017-02-01

    Full Text Available The main objective of this study was to investigate mopane worm (Imbrasia belina as a protein source in the diet of Oreochromis mossambicus. One thousand five hundred O. mossambicus fingerlings (40 ± 2.5 g were fed five isonitrogenous, isolipidic and isoenergetic diets formulated to contain 30% crude protein and 20 MJ/kggross energy (dry matter basis for 51 days. Fifteen indoor rectangular concrete tanks (1.5 m3 connected to a recirculating system were used. Water temperature ranged between 27 and 29 °C. The diets were prepared by replacing fishmeal with mopane worm meal at 10%, 20%, 40% and 60%. The diets were coded D2, D3, D4 and D5 respectively. A control diet with no mopane worm meal was coded D1. The diets were fed to triplicate groups of O. mossambicus twice a day. Specific growth rate (SGR, Thermal-unit growth coefficient (TGC, protein efficiency ratio (PER and apparent digestibility coefficient (ADC increased with higher inclusion levels of mopane worm meal. Feed conversion ratio (FCR also improved with higher inclusion levels. However, the highest growth performance (SGR: 3.49%; FCR: 1.29 was recorded in fish fed the fishmeal based control diet. Protease, amylase and lipase activities were determined in the intestines. Both protease and amylase activity were significantly higher (P < 0.05 at high mopane worm inclusion levels. It is suggested that the high protein levels of the mopane worm diet elicited high protease activity. The health status of the fish was evaluated by examining the liver and intestine histology. There were no evident histological alterations of either liver or intestine as mopane worm meal inclusion levels increased. This showed that mopane worm meal may be a good candidate for the replacement of fishmeal in O. mossambicus diets. The highest profit index (1.67 was recorded in the 60% mopane worm inclusion level. The lowest profit index was in the control. More studies on mopane worm meal as a substitute

  5. The evaluation of angiotensin-converting enzyme (ACE) gene I/D and IL-4 gene intron 3 VNTR polymorphisms in coronary artery disease.

    Science.gov (United States)

    Basol, Nursah; Celik, Atac; Karakus, Nevin; Ozturk, Sibel Demir; Ozsoy, Sibel Demir; Yigit, Serbulent

    2014-01-01

    Genetic polymorphism is a strong risk factor for coronary artery disease (CAD). In the present study, our aim was to evaluate angiotensin-converting enzyme (ACE) gene I/D polymorphism and interleukin-4 (IL-4) gene Intron 3 variable number of tandem repeat (VNTR) polymorphism in CAD. One hundred and twenty-four CAD patients and one hundred and twenty-three controls were enrolled. Genomic DNA was isolated and genotyped using polymerase chain reaction (PCR) analyses. The risk associated with inheriting the combined genotypes for the two polymorphisms were evaluated and it was found that the individuals who were P2P2-homozygous at IL-4 gene intron 3 VNTR and DD-homozygous at ACE gene I/D have a higher risk of developing CAD. Although, there is no correlation between IL4 VNTR polymorphism and ACE gene polymorphism and CAD, there is a strong association between CAD and co-existence of IL-4 VNTR and ACE gene polymorphisms in the Turkish population. Copyright © 2014 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.

  6. Evaluation of Enzyme-Linked Immunosorbent Assay for Diagnosis of Post-Kala-Azar Dermal Leishmaniasis with Crude or Recombinant k39 Antigen

    Science.gov (United States)

    Salotra, P.; Sreenivas, G.; Nasim, A. A.; Subba Raju, B. V.; Ramesh, V.

    2002-01-01

    The diagnosis of post-kala-azar dermal leishmaniasis (PKDL), a dermatosis that provides the only known reservoir for the parasite Leishmania donovani in India, remains a problem. Timely recognition and treatment of PKDL would contribute significantly to the control of kala-azar. We evaluated here the potential of the enzyme-linked immunosorbent assay (ELISA) as a diagnostic tool for PKDL. Antigen prepared from promastigotes and axenic amastigotes with parasite isolates that were derived from skin lesions of a PKDL patient gave sensitivities of 86.36 and 92%, respectively, in the 88 PKDL cases examined. The specificity of the ELISA test was examined by testing groups of patients with other skin disorders (leprosy and vitiligo) or coendemic infections (malaria and tuberculosis), as well as healthy controls from areas where this disease is endemic or is not endemic. A false-positive reaction was obtained in 14 of 144 (9.8%) of the controls with the promastigote antigen and in 14 of 145 (9.7%) of the controls with the amastigote antigen. Evaluation of the serodiagnostic potential of recombinant k39 by ELISA revealed a higher sensitivity (94.5%) and specificity (93.7%) compared to the other two antigens used. The data demonstrate that ELISA with crude or recombinant antigen k39 provides a relatively simple and less-invasive test for the reliable diagnosis of PKDL. PMID:11874880

  7. Effects of threshold displacement energy on defect production by displacement cascades in α, β and γ-LiAlO2

    International Nuclear Information System (INIS)

    Tsuchihira, H.; Oda, T.; Tanaka, S.

    2013-01-01

    Threshold displacement energy evaluation and a series of displacement cascade simulations in α, β, and γ-LiAlO 2 were performed using molecular dynamics. Threshold displacement energy evaluations indicated that higher absolute ionic charge values and larger densities both increase threshold displacement energy. The displacement cascade simulations suggest that the influence of different crystal structures on the number of interstitial atoms generated in a displacement cascade is explainable almost entirely by the difference of the threshold displacement energy

  8. Aspects of the QCD cascade

    International Nuclear Information System (INIS)

    Olsson, Magnus.

    1993-02-01

    A model is proposed for the production of transverse jets from diffractively excited protons. We propose that transverse jets can be obtained from gluonic bremsstrahlung in a way similar to the emission in DIS. Qualitative agreement is obtained between the model and the uncorrected data published by the UA8 collaboration. Perturbative QCD in the MLLA approximation is applied to multiple jet production in e + e - -annihilation. We propose modified evolution equations for deriving the jet cross sections, defined in the 'k t ' or 'Durham' algorithm. The mean number of jets as a function of the jet resolution is studied, and analytical predictions are compared to the results of MC simulations. We also study a set of differential-difference equations for multiplicity distributions in e + e - -annihilations, supplemented with appropriate boundary conditions. These equations take into account nonsingular terms in the GLAP splitting functions as well as kinematical constraints related to recoil effects. The presence of retarded terms imply that the cascade develops more slowly and reduces the fluctuations. The solutions agree well with MC simulations and experimental data. (authors)

  9. Elevated Liver Enzymes

    Science.gov (United States)

    Symptoms Elevated liver enzymes By Mayo Clinic Staff Elevated liver enzymes may indicate inflammation or damage to cells in the liver. Inflamed or ... than normal amounts of certain chemicals, including liver enzymes, into the bloodstream, which can result in elevated ...

  10. Bursting behaviours in cascaded stimulated Brillouin scattering

    International Nuclear Information System (INIS)

    Liu Zhan-Jun; He Xian-Tu; Zheng Chun-Yang; Wang Yu-Gang

    2012-01-01

    Stimulated Brillouin scattering is studied by numerically solving the Vlasov—Maxwell system. A cascade of stimulated Brillouin scattering can occur when a linearly polarized laser pulse propagates in a plasma. It is found that a stimulated Brillouin scattering cascade can reduce the scattering and increase the transmission of light, as well as introduce a bursting behaviour in the evolution of the laser-plasma interaction. The bursting time in the reflectivity is found to be less than half the ion acoustic period. The ion temperature can affect the stimulated Brillouin scattering cascade, which can repeat several times at low ion temperatures and can be completely eliminated at high ion temperatures. For stimulated Brillouin scattering saturation, higher-harmonic generation and wave—wave interaction of the excited ion acoustic waves can restrict the amplitude of the latter. In addition, stimulated Brillouin scattering cascade can restrict the amplitude of the scattered light. (physics of gases, plasmas, and electric discharges)

  11. Defect accumulation under cascade damage conditions

    DEFF Research Database (Denmark)

    Trinkaus, H.; Singh, B.N.; Woo, C.H.

    1994-01-01

    in terms of this reaction kinetics taking into account cluster production, dissociation, migration and annihilation at extended sinks. Microstructural features which are characteristic of cascade damage and cannot be explained in terms of the conventional single defect reaction kinetics are emphasized......There is now ample evidence from both experimental and computer simulation studies that in displacement cascades not only intense recombination takes place but also efficient clustering of both self-interstitial atoms (SIAs) and vacancies. The size distributions of the two types of defects produced...... reactions kinetics associated with the specific features of cascade damage is described, with emphasis on asymmetries between SIA and vacancy type defects concerning their production, stability, mobility and interactions with other defects. Defect accumulation under cascade damage conditions is discussed...

  12. Cascade theory in isotopic separation processes

    International Nuclear Information System (INIS)

    Agostini, J.P.

    1994-06-01

    Three main areas are developed within the scope of this work: - the first one is devoted to fundamentals: separative power, value function, ideal cascade and square cascade. Applications to two main cases are carried out, namely: Study of binary isotopic mix, Study of processes with a small enrichment coefficient. - The second one is devoted to cascade coupling -high-flux coupling (more widely used and better known) as well as low-flux coupling are presented and compared to one another. - The third one is an outlook on problems linked to cascade transients. Those problem are somewhat intricate and their interest lies mainly into two areas: economics where the start-up time may have a large influence on the interests paid during the construction and start-up period, military productions where the start-up time has a direct bearing on the production schedule. (author). 50 figs. 3 annexes. 12 refs. 6 tabs

  13. τ polarization in SUSY cascade decays

    International Nuclear Information System (INIS)

    Choi, S.Y.; Hagiwara, K.; Kim, Y.G.

    2006-12-01

    τ leptons emitted in cascade decays of supersymmetric particles are polarized. The polarization may be exploited to determine spin and mixing properties of the neutralinos and stau particles involved. (orig.)

  14. MAP kinase cascades in Arabidopsis innate immunity

    DEFF Research Database (Denmark)

    Rasmussen, Magnus Wohlfahrt; Roux, Milena Edna; Petersen, Morten

    2012-01-01

    Plant mitogen-activated protein kinase (MAPK) cascades generally transduce extracellular stimuli into cellular responses. These stimuli include the perception of pathogen-associated molecular patterns (PAMPs) by host transmembrane pattern recognition receptors which trigger MAPK-dependent innate ...

  15. Cascade processes in kaonic and muonic atoms

    International Nuclear Information System (INIS)

    Faifman, M.P.; Men'shikov, L.I.

    2003-01-01

    Cascade processes in exotic (kaonic and muonic) hydrogen/deuterium have been studied with the quantum-classical Monte Carlo code (QCMC) developed for 'ab initio' - calculations. It has been shown that the majority of kaonic hydrogen atoms during cascade are accelerated to high energies E ∼ 100 eV, which leads to a much lower value for the calculated yields Y of x-rays than predicted by the 'standard cascade model'. The modified QCMC scheme has been applied to the study of the cascade in μp and μd muonic atoms. A comparison of the calculated yields for K-series x-rays with experimental data directly indicates that the molecular structure of the hydrogen target and new types of non-radiative transitions are essential for the light muonic atoms, while they are negligible for heavy (kaonic) atoms. These processes have been considered and estimates of their probabilities are presented. (author)

  16. Cascade Error Projection: A New Learning Algorithm

    Science.gov (United States)

    Duong, T. A.; Stubberud, A. R.; Daud, T.; Thakoor, A. P.

    1995-01-01

    A new neural network architecture and a hardware implementable learning algorithm is proposed. The algorithm, called cascade error projection (CEP), handles lack of precision and circuit noise better than existing algorithms.

  17. Real-time monitoring through the use of technology to enhance performances throughout HIV cascades.

    Science.gov (United States)

    Avery, Matthew; Mills, Stephen J; Stephan, Eric

    2017-09-01

    Controlling the HIV epidemic requires strong linkages across a 'cascade' of prevention, testing, and treatment services. Information and communications technology (ICT) offers the potential to monitor and improve the performance of this HIV cascade in real time. We assessed recent (media to expand reach and improve programmatic targeting; technology in healthcare settings to strengthen coordination, guide clinical decision-making and improve clinical interactions; and telephone-based follow-up to improve treatment retention and adherence. With exceptions, publications have tended to be descriptive rather than evaluative, and the evidence-base for the effectiveness of ICT-driven interventions remains mixed. There is widespread recognition of the potential for ICT to improve HIV cascade performance, but with significant challenges. Successful implementation of real-time cascade monitoring will depend upon stakeholder engagement, compatibility with existing workflows, appropriate resource allocation, and managing expectations.

  18. Designing the Cascade inertial confinement fusion reactor

    International Nuclear Information System (INIS)

    Pitts, J.H.

    1987-01-01

    The primary goal in designing inertial confinement fusion (ICF) reactors is to produce electrical power as inexpensively as possible, with minimum activation and without compromising safety. This paper discusses a method for designing the Cascade rotating ceramic-granule-blanket reactor (Pitts, 1985) and its associated power plant (Pitts and Maya, 1985). Although focus is on the cascade reactor, the design method and issues presented are applicable to most other ICF reactors

  19. High energy evolution of soft gluon cascades

    International Nuclear Information System (INIS)

    Shuvaev, A.; Wallon, S.

    2006-01-01

    In this paper we derive an evolution equation for the gluon density in soft gluon cascades emitted from any colored source, in the leading logarithmic approximation of perturbative QCD. We show that this equation has the same form as the BFKL equation in the forward case. An explicit expression for the total cascade wavefunction involving an arbitrary number of soft gluons is obtained. Renormalization of the colored source wavefunction turns out to be responsible for the reggeization of the source. (orig.)

  20. High energy evolution of soft gluon cascades

    Energy Technology Data Exchange (ETDEWEB)

    Shuvaev, A. [St. Petersburg Nuclear Physics Institute, Gatchina, St. Petersburg district (Russian Federation); Wallon, S. [Universite Paris XI, Laboratoire de Physique Theorique, Orsay Cedex (France)

    2006-04-15

    In this paper we derive an evolution equation for the gluon density in soft gluon cascades emitted from any colored source, in the leading logarithmic approximation of perturbative QCD. We show that this equation has the same form as the BFKL equation in the forward case. An explicit expression for the total cascade wavefunction involving an arbitrary number of soft gluons is obtained. Renormalization of the colored source wavefunction turns out to be responsible for the reggeization of the source. (orig.)

  1. Cascade of links in complex networks

    Energy Technology Data Exchange (ETDEWEB)

    Feng, Yeqian; Sun, Bihui [Department of Management Science, School of Government, Beijing Normal University, 100875 Beijing (China); Zeng, An, E-mail: anzeng@bnu.edu.cn [School of Systems Science, Beijing Normal University, 100875 Beijing (China)

    2017-01-30

    Cascading failure is an important process which has been widely used to model catastrophic events such as blackouts and financial crisis in real systems. However, so far most of the studies in the literature focus on the cascading process on nodes, leaving the possibility of link cascade overlooked. In many real cases, the catastrophic events are actually formed by the successive disappearance of links. Examples exist in the financial systems where the firms and banks (i.e. nodes) still exist but many financial trades (i.e. links) are gone during the crisis, and the air transportation systems where the airports (i.e. nodes) are still functional but many airlines (i.e. links) stop operating during bad weather. In this letter, we develop a link cascade model in complex networks. With this model, we find that both artificial and real networks tend to collapse even if a few links are initially attacked. However, the link cascading process can be effectively terminated by setting a few strong nodes in the network which do not respond to any link reduction. Finally, a simulated annealing algorithm is used to optimize the location of these strong nodes, which significantly improves the robustness of the networks against the link cascade. - Highlights: • We propose a link cascade model in complex networks. • Both artificial and real networks tend to collapse even if a few links are initially attacked. • The link cascading process can be effectively terminated by setting a few strong nodes. • A simulated annealing algorithm is used to optimize the location of these strong nodes.

  2. Cascade of links in complex networks

    International Nuclear Information System (INIS)

    Feng, Yeqian; Sun, Bihui; Zeng, An

    2017-01-01

    Cascading failure is an important process which has been widely used to model catastrophic events such as blackouts and financial crisis in real systems. However, so far most of the studies in the literature focus on the cascading process on nodes, leaving the possibility of link cascade overlooked. In many real cases, the catastrophic events are actually formed by the successive disappearance of links. Examples exist in the financial systems where the firms and banks (i.e. nodes) still exist but many financial trades (i.e. links) are gone during the crisis, and the air transportation systems where the airports (i.e. nodes) are still functional but many airlines (i.e. links) stop operating during bad weather. In this letter, we develop a link cascade model in complex networks. With this model, we find that both artificial and real networks tend to collapse even if a few links are initially attacked. However, the link cascading process can be effectively terminated by setting a few strong nodes in the network which do not respond to any link reduction. Finally, a simulated annealing algorithm is used to optimize the location of these strong nodes, which significantly improves the robustness of the networks against the link cascade. - Highlights: • We propose a link cascade model in complex networks. • Both artificial and real networks tend to collapse even if a few links are initially attacked. • The link cascading process can be effectively terminated by setting a few strong nodes. • A simulated annealing algorithm is used to optimize the location of these strong nodes.

  3. Defect production in simulated cascades: Cascade quenching and short-term annealing

    International Nuclear Information System (INIS)

    Heinisch, H.L.

    1983-01-01

    Defect production in displacement cascades in copper has been modeled using the MARLOWE code to generate cascades and the stochastic annealing code ALSOME to simulate cascade quenching and short-term annealing of isolated cascades. Quenching is accomplished by using exaggerated values for defect mobilities and for critical reaction distances in ALSOME for a very short time. The quenched cascades are then short-term annealed with normal parameter values. The quenching parameter values were empirically determined by comparison with results of resistivity measurements. Throughout the collisional, quenching and short-term annealing phases of cascade development, the high energy cascades continue to behave as a collection of independent lower energy lobes. For recoils above about 30 keV the total number of defects and the numbers of free defects scale with the damage energy. As the energy decreases from 30 keV, defect production varies with the changing nature of the cascade configuration, resulting in more defects per unit damage energy. The simulated annealing of a low fluence of interacting cascades revealed an interstitial shielding effect on depleted zones during Stage I recovery. (orig.)

  4. Use of cardiac magnetic resonance imaging to evaluate cardiac structure, function and fibrosis in children with infantile Pompe disease on enzyme replacement therapy.

    Science.gov (United States)

    Barker, Piers C A; Pasquali, Sara K; Darty, Stephen; Ing, Richard J; Li, Jennifer S; Kim, Raymond J; DeArmey, Stephanie; Kishnani, Priya S; Campbell, Michael J

    2010-12-01

    Pompe disease (acid α-glucosidase deficiency) is one of several lysosomal storage diseases amenable to treatment with enzyme replacement therapy (ERT). While echocardiography (echo) has been the standard method to evaluate the cardiac response to ERT, cardiac magnetic resonance imaging (CMR) has the advantage of a better tissue definition and characterization of myocardial fibrosis. However, CMR for Pompe disease is not frequently performed due to a high risk of sedation. We report the first use of CMR in a feasible protocol to quantify left ventricular (LV) mass, function, and the presence of myocardial fibrosis in the Pompe population. Children with Pompe disease on ERT were assessed with transthoracic echo and CMR over a 3 year period at a single institution. Echocardiography was performed using standard techniques without sedation. CMR was performed using retrospectively gated and real-time imaging, with and without sedation. LV mass indexed to body surface area (LVMI) and ejection fraction (EF) were measured by both echo and CMR, and evaluated for change over time. Myocardial fibrosis was assessed by CMR with delayed enhancement imaging 5-10 min after gadolinium contrast using single shot inversion recovery sequences with inversion time set to null the signal from normal myocardium. Seventeen CMR scans were successfully performed in 10 subjects with Pompe disease (median age at first CMR is 9 months, range 1-38 months, 80% male), with sedation only performed in 4 studies. There was a median interval of 5 months (range 0-34 months) from the start of ERT to first CMR (baseline). At baseline, the median indexed LVMI by CMR (140.0 g/m(2), range 43.8-334.0) tended to be lower than that assessed by echo (median 204.0 g/m(2), range 52.0-385.0), but did not reach statistical significance. At baseline, CMR EF was similar to that assessed by echo (55% vs. 55%). Overall, there was no significant decrease in CMR measured LVMI over time (CMR median LVMI at baseline 94 g

  5. Castor Oil Transesterification Catalysed by Liquid Enzymes

    DEFF Research Database (Denmark)

    Andrade, Thalles; Errico, Massimiliano; Christensen, Knud Villy

    2017-01-01

    In the present work, biodiesel production by reaction of non-edible castor oil with methanol under enzymatic catalysis is investigated. Two liquid enzymes were tested: Eversa Transform and Resinase HT. Reactions were performed at 35 °C and with a molar ratio of methanol to oil of 6:1. The reaction...... time was 8 hours. Stepwise addition of methanol was necessary to avoid enzyme inhibition by methanol. In order to minimize the enzyme costs, the influence of enzyme activity loss during reuse of both enzymes was evaluated under two distinct conditions. In the former, the enzymes were recovered...... and fully reused; in the latter, a mixture of 50 % reused and 50 % fresh enzymes was tested. In the case of total reuse after three cycles, both enzymes achieved only low conversions. The biodiesel content in the oil-phase using Eversa Transform was 94.21 % for the first cycle, 68.39 % in the second, and 33...

  6. Formalism of continual integrals for cascade processes with particle fusion

    International Nuclear Information System (INIS)

    Gedalin, Eh.V.

    1987-01-01

    Formalism of continuous integrals for description of cascade processes, in which besides cascade particle reproduction, their synthesis and coalescence take place, is used. Account of cascade particle coalescence leads to the fact that the development of some cascade branches cannot be independent and main equations of the cascade process become functional instead of integral. The method of continuous intagrals permits to construct in the closed form producing functionals for the cascade process and to obtain the rules of their calculation using diagrams. Analytical expressions in the form of continuous integrals for producing functionals describing cascade development are obtained

  7. Production of enzymes by a newly isolated Bacillus sp. TMF-1 in solid state fermentation on agricultural by-products: The evaluation of substrate pretreatment methods.

    Science.gov (United States)

    Salim, Abdalla Ali; Grbavčić, Sanja; Šekuljica, Nataša; Stefanović, Andrea; Jakovetić Tanasković, Sonja; Luković, Nevena; Knežević-Jugović, Zorica

    2017-03-01

    Study on potential of different agro-industrial waste residues for supporting the growth of newly isolated Bacillus sp. TMF-1 strain under solid-state fermentation (SSF) was conducted aiming to produce several industrially valuable enzymes. Since the feasibility of the initial study was confirmed, further objectives included evaluation of several pretreatments of the studied agricultural by-products (soybean meal, sunflower meal, maize bran, maize pericarp, olive oil cake and wheat bran) on the microbial productivity as means of enhancing the yields of produced proteases, α-amylases, cellulases and pectinases. Among acid/alkaline treatment, ultrasound and microwave assisted methods, chemical treatments superiorly affected most of the studied substrates. Highest yields of produced proteases (50.5IUg -1 ) and α-amylases (50.75IUg -1 ) were achieved on alkaline treated corn pericarp. Alkaline treatment also promoted the secretion of cellulases on maize bran (1.19IUg -1 ). Highest yield of pectinases was obtained on untreated soybean meal (64.90IUg -1 ). Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. EFSA CEF Panel (Panel on Food Contac t Materials, Enzymes, Flavourings and Processing Aids , 2013. Scientific Opinion on Flavouring Group Evaluation 2 07 (FGE.2 07 )

    DEFF Research Database (Denmark)

    Beltoft, Vibe Meister; Binderup, Mona-Lise; Lund, Pia

    The Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids of the European Food Safety Authority was requested to evaluate the genotoxic potential of one flavouring substance, 2,6-dimethyl-2,5,7-octatriene-1-ol acetate [FL-no: 09.931], from subgroup 1.1.2 of FGE.19, which...... is considered to be representative for four substances, 12-beta-santalen-14-ol [FL-no: 02.216], 12-alpha-santalen-14-ol [FL-no: 02.217], santalyl acetate [FL-no: 09.034] and santalyl phenylacetate [FL-no: 09.712], from subgroup 2.1 of FGE.19. The Flavour Industry has provided genotoxicity studies......-no: 09.034] and santalyl phenylacetate [FL-no: 09.712] from FGE.19 subgroup 2.1 for which 2,6-dimethyl-2,5,7-octatriene-1-ol acetate [FL-no: 09.931] is representative. © European Food Safety Authority, 2013...

  9. Evaluation of Strains of Metarhizium anisopliae and Beauveria bassiana against Spodoptera litura on the Basis of Their Virulence, Germination Rate, Conidia Production, Radial Growth and Enzyme Activity.

    Science.gov (United States)

    Petlamul, Wanida; Prasertsan, Poonsuk

    2012-06-01

    Ten strains of the entomopathogenic fungi Metarhizium anisopliae and Beauveria bassiana were evaluated to find the most effective strain for optimization studies. The first criterion tested for strain selection was the mortality (> 50%) of Spodoptera litura larvae after inoculation of the fungus for 4 days. Results on several bioassays revealed that B. bassiana BNBCRC showed the most virulence on mortality S. litura larvae (80% mortality). B. bassiana BNBCRC also showed the highest germination rate (72.22%). However, its conidia yield (7.2 × 10(8) conidia/mL) was lower than those of B. bassiana B 14841 (8.3 × 10(8) conidia/mL) and M. anisopliae M6 (8.2 × 10(8) conidia/mL). The highest accumulative radial growth was obtained from the strain B14841 (37.10 mm/day) while the strain BNBCRC showed moderate radial growth (24.40 mm/day). M. anisopliae M6 possessed the highest protease activity (145.00 mU/mL) while M. anisopliae M8 possessed the highest chitinase activity (20.00 mU/mL) during 96~144 hr cultivation. Amongst these criteria, selection based on virulence and germination rate lead to the selection of B. bassiana BNBCRC. B. bassiana B14841 would be selected if based on growth rate while M. anisopliae M6 and M8 possessed the highest enzyme activities.

  10. An Evaluation Study of Enzyme-Linked Immunosorbent Assay (ELISA) Using Recombinant Protein Pap31 for Detection of Antibody against Bartonella bacilliformis Infection among the Peruvian Population

    Science.gov (United States)

    Angkasekwinai, Nasikarn; Atkins, Erin H.; Romero, Sofia; Grieco, John; Chao, Chien Chung; Ching, Wei Mei

    2014-01-01

    Reliable laboratory testing is of great importance to detect Bartonella bacilliformis infection. We evaluated the sensitivity and specificity of the enzyme-linked immunosorbent assay (ELISA) using recombinant protein Pap31 (rPap31) for the detection of antibodies against B. bacilliformis as compared with immunofluorescent assay (IFA). Of the 302 sera collected between 1997 and 2000 among an at-risk Peruvian population, 103 and 34 samples tested positive for IFA-immunoglobulin G (IgG) and IFA-IgM, respectively. By using Youden's index, the cutoff values of ELISA-IgG at 0.915 gave a sensitivity of 84.5% and specificity of 94%. The cutoff values of ELISA-IgM at 0.634 gave a sensitivity of 88.2% and specificity of 85.1%. Using latent class analysis, estimates of sensitivity and specificity of almost all the assays were slightly higher than those of a conventional method of calculation. The test is proved beneficial for discriminating between infected and non-infected individuals with the advantage of low-cost and high-throughput capability. PMID:24515944

  11. Evaluation and Comparison of Enzyme Immunoassay (Eia and Acid Fast Staining with Confirmation by Immunofluorescent Antibody Assay for Detection of Cryptosporidium Species in Infants and Young Children.

    Directory of Open Access Journals (Sweden)

    D Dorostcar Moghaddam

    2005-01-01

    Full Text Available Introduction: Cryptosporidiosis is prevalent world wide, causing a variety of problems ranging from acute, self-limiting diarrhea to fatal cases in immunocompromised persons, particulary those with acquired immunodeficiency (AIDS. Diagnosis of Cryptosporidium is made by identification of oocysts in stool specimens. The detection is most commonly made by the acid-fast staining method followed by microscopic examination which has low specificity and sensitivity. Material and Methods: In the present study, we evaluated diagnostic utility of a commercially available enzyme immunoassay (EIA, which detects Cryptosporidium-Specific antigen (CSA in 204 unprocessed stool specimens obtained from patients less than 3 years of age. Results: When compared with the routine screening procedure applied in this field study (screening by acid-fast staining and microscopy after concentration of positive results by IFA, both sensitivity and specificity were 98%. Of the 139 specimens negative by microscopy, 13 (9.3% were positive by EIA, 11 of which were confirmed by inhibition with antibody to Cryptosporidia-specific antigen. Conclusion: The EIA is an important tool for identifying Cryptosporidium in fecal specimens in field studies since it is sensitive, specific, simple to use and unaffected by the presence of a preservative.

  12. In vitro evaluation of the effect of botanical formulations used in the control of Aedes aegypti L. (Diptera: Culicidae on liver enzymes.

    Directory of Open Access Journals (Sweden)

    Karla Rejane de Andrade Porto

    Full Text Available Abstract: INTRODUCTION: Dengue fever is a viral disease transmitted by the Aedes aegypti Linn. (1792 (Diptera: Culicidae mosquito, which is endemic in several regions of Brazil. Alternative methods for the control of the vector include botanical insecticides, which offer advantages such as lower environmental contamination levels and less likelihood of resistant populations. Thus, in this study, the ability of botanical insecticide formulations to inhibit the activity of the liver enzymes serum cholinesterase and malate dehydrogenase was evaluated. METHODS: Inhibition profiles were assessed using in vitro assays for cholinesterase and malate dehydrogenase activity and quantitated by ultraviolet-visible spectroscopy at 410nm to 340nm. RESULTS Insecticide products formulated from cashew nutshell liquid [A] and ricinoleic acid [B] showed cholinesterase activity levels of 6.26IU/mL and 6.61IU/mL, respectively, while the control level for cholinesterase was 5-12IU/mL. The products did not affect the level of 0.44IU/mL established for malate dehydrogenase, as the levels produced by [A] and [B] were 0.43IU/mL and 0.45IU/mL, respectively. CONCLUSIONS Our findings show that in vitro testing of the formulated products at concentrations lethal to A. aegypti did not affect the activity of cholinesterase and malate dehydrogenase, indicating the safety of these products.

  13. In vitro evaluation of the effect of botanical formulations used in the control of Aedes aegypti L. (Diptera: Culicidae) on liver enzymes.

    Science.gov (United States)

    Porto, Karla Rejane de Andrade; Motti, Priscilla Rezende; Machado, Alexandre Alves; Roel, Antonia Railda

    2016-01-01

    Dengue fever is a viral disease transmitted by the Aedes aegypti Linn. (1792) (Diptera: Culicidae) mosquito, which is endemic in several regions of Brazil. Alternative methods for the control of the vector include botanical insecticides, which offer advantages such as lower environmental contamination levels and less likelihood of resistant populations. Thus, in this study, the ability of botanical insecticide formulations to inhibit the activity of the liver enzymes serum cholinesterase and malate dehydrogenase was evaluated. Inhibition profiles were assessed using in vitro assays for cholinesterase and malate dehydrogenase activity and quantitated by ultraviolet-visible spectroscopy at 410nm to 340nm. Insecticide products formulated from cashew nutshell liquid [A] and ricinoleic acid [B] showed cholinesterase activity levels of 6.26IU/mL and 6.61IU/mL, respectively, while the control level for cholinesterase was 5-12IU/mL. The products did not affect the level of 0.44IU/mL established for malate dehydrogenase, as the levels produced by [A] and [B] were 0.43IU/mL and 0.45IU/mL, respectively. Our findings show that in vitro testing of the formulated products at concentrations lethal to A. aegypti did not affect the activity of cholinesterase and malate dehydrogenase, indicating the safety of these products.

  14. Expression of sheep pathogen Babesia sp. Xinjiang rhoptry-associated protein 1 and evaluation of its diagnostic potential by enzyme-linked immunosorbent assay.

    Science.gov (United States)

    Niu, Qingli; Liu, Zhijie; Yang, Jifei; Yu, Peifa; Pan, Yuping; Zhai, Bintao; Luo, Jianxun; Guan, Guiquan; Yin, Hong

    2016-12-01

    Ovine babesiosis is one of the most important tick-borne haemoparasitic diseases of small ruminants. The ovine parasite Babesia sp. Xinjiang is widespread in China. In this study, recombinant full-length XJrRAP-1aα2 (rhoptry-associated protein 1aα2) and C-terminal XJrRAP-1aα2 CT of Babesia sp. Xinjiang were expressed and used to evaluate their diagnostic potential for Babesia sp. Xinjiang infections by indirect enzyme-linked immunosorbent assay (ELISA). Purified XJrRAP-1aα2 was tested for reactivity with sera from animals experimentally infected with Babesia sp. Xinjiang and other haemoparasites using Western blotting and ELISA. The results showed no cross-reactivities between XJrRAP-1aα2 CT and sera from animals infected by other pathogens. High level of antibodies against RAP-1a usually lasted 10 weeks post-infection (wpi). A total of 3690 serum samples from small ruminants in 23 provinces located in 59 different regions of China were tested by ELISA. The results indicated that the average positive rate was 30·43%, and the infections were found in all of the investigated provinces. This is the first report on the expression and potential use of a recombinant XJrRAP-1aα2 CT antigen for the development of serological assays for the diagnosis of ovine babesiosis, caused by Babesia sp. Xinjiang.

  15. Prediction of therapeutic response in steroid-treated pulmonary sarcoidosis. Evaluation of clinical parameters, bronchoalveolar lavage, gallium-67 lung scanning, and serum angiotensin-converting enzyme levels

    International Nuclear Information System (INIS)

    Hollinger, W.M.; Staton, G.W. Jr.; Fajman, W.A.; Gilman, M.J.; Pine, J.R.; Check, I.J.

    1985-01-01

    To find a pretreatment predictor of steroid responsiveness in pulmonary sarcoidosis the authors studied 21 patients before and after steroid treatment by clinical evaluation, pulmonary function tests, bronchoalveolar lavage (BAL), gallium-67 lung scan, and serum angiotensin-converting enzyme (SACE) level. Although clinical score, forced vital capacity (FVC), BAL percent lymphocytes (% lymphs), quantitated gallium-67 lung uptake, and SACE levels all improved with therapy, only the pretreatment BAL % lymphs correlated with the improvement in FVC (r = 0.47, p less than 0.05). Pretreatment BAL % lymphs of greater than or equal to 35% predicted improvement in FVC of 10/11 patients, whereas among 10 patients with BAL % lymphs less than 35%, 5 patients improved and 5 deteriorated. Clinical score, pulmonary function parameters, quantitated gallium-67 lung uptake, and SACE level used alone, in combination with BAL % lymphs or in combination with each other, did not improve this predictive value. The authors conclude that steroid therapy improves a number of clinical and laboratory parameters in sarcoidosis, but only the pretreatment BAL % lymphs are useful in predicting therapeutic responsiveness

  16. EFSA Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids (CEF); Scientific Opinion on Flavouring Group Evaluation 96 (FGE.96): Consideration of 88 flavouring substances considered by EFSA for which EU production volumes / anticipated production volumes have been submitted

    DEFF Research Database (Denmark)

    Larsen, John Christian; Nørby, Karin Kristiane; Beltoft, Vibe Meister

    The Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids of the European Food Safety Authority was requested to consider evaluations of flavouring substances assessed since 2000 by the Joint FAO/WHO Expert Committee on Food Additives (the JECFA), and to decide whether further...

  17. Gaucher disease: MR evaluation of bone marrow features during treatment with enzyme replacement; Morbus Gaucher: Analyse der Knochenmarkveraenderungen in der MRT waehrend Enzymersatztherapie

    Energy Technology Data Exchange (ETDEWEB)

    Poll, L.W.; Koch, J.A.; Boerner, D.; Cohnen, M.; Jung, G.; Scherer, A.; Moedder, U. [Duesseldorf Univ. (DF). Inst. fuer Diagnostische Radiologie; Dahl, S. vom; Haeussinger, D. [Duesseldorf Univ. (Germany). Klinik fuer Gastroenterologie, Hepatologie und Infektiologie; Willers, R. [Rechenzentrum, Heinrich-Heine-Univ. Duesseldorf (Germany); Niederau, C. [Innere Abt., St. Josef-Hospital Oberhausen, Akademisches Lehrkrankenhaus der Univ. Essen (Germany)

    2001-10-01

    Purpose: Enzyme replacement therapy (ERT) arrests and reverses the hematological and visceral symptoms of adult Gaucher disease, the most frequent lysosomal storage disorder. There are only a few studies available evaluating bone disease during ERT. The aim of this study was to investigate the features of bone marrow (bm) by magnetic resonance imaging (MRI) in these patients during ERT. Materials and Methods: MRI was performed prospectively in thirty adult type I Gaucher patients before and during ERT with a mean follow-up of 3 years. Spin-echo sequences (T{sub 1}/T{sub 2}) of the lower extremities were obtained and the reconversion (response) or lack of reconversion (non-response) to fatty marrow during treatment was analyzed. The morphological features of bm involvement, a homogeneous or non-homogeneous distribution of bm changes and focal bone lesions surrounded by a rim of reduced signal intensity (SI), were analyzed. Results: Infiltration of bm by Gaucher cells is characterized by a reduction of Sl on both T{sub 1}- and T{sub 2}-weighted sequences. Bone marrow responses were seen in 19 patients (63%) during treatment. Focal bone lesions, surrounded by a rim of reduced Sl, did not respond to ERT and correlated with a non-homogenous distribution of bone involvement and splenectomy. (orig.) [German] Ziel: Unter Enzymersatztherapie (enzyme replacement therapy = ERT) zeigen Patienten mit adulter Form des Morbus Gaucher, der haeufigsten lysosomalen Speicherkrankheit, eine deutliche Besserung der haematologischen und visceralen Symptome. Bislang liegen nur wenige Untersuchungen zur Analyse der Knochenveraenderungen waehrend der ERT vor. Ziel war es, die Knochenmarkveraenderungen bei Gaucher-Patienten waehrend der Enzymersatztherapie mit Alglucerase/Imiglucerase in der Magnetresonanztomographie (MRT) zu evaluieren. Material und Methoden: In einer prospektiven Untersuchung wurden 30 adulte Patienten mit gesichertem Morbus Gaucher vor und waehrend der ERT in der MRT

  18. Evaluation of serum galactomannan enzyme immunoassay at two different cut-offs for the diagnosis of invasive aspergillosis in patients with febrile neutropenia

    Directory of Open Access Journals (Sweden)

    Ritin Mohindra

    2017-01-01

    Full Text Available Background: Invasive aspergillosis (IA is an increasingly common and fatal opportunistic fungal infection in patients with haematological diseases. Early diagnosis is difficult as mycological culture techniques have low sensitivity and the radiological tools have low specificity. Galactomannan enzyme immunoassay (GEI detects galactomannan in the human serum with a reported sensitivity and specificity between 30% and 100%. Aims: The aim of this study was to analyse the role of GEI in diagnosis of IA in patients with febrile neutropenia and to evaluate the role of GEI in the diagnosis of IA as per the revised (2008 European Organization for Research and Treatment of Cancer–Mycoses Study Group (EORTC–MSG criteria at two different optical density (OD cut-offs of 0.5 and 1.0. Setting: This prospective study was conducted in Safdarjung Hospital, New Delhi, India. Methods: GEI testing was performed in adult patients of febrile neutropenia with evidence of IA. Results at two different OD indices (ODIs of 0.5 and 1.0 were analysed. The evaluation of the diagnostic parameter, that is, GEI was measured in terms of sensitivity, specificity and positive and negative predictive value and was validated with the revised (2008 EORTC–MSG diagnostic criteria of IA. Results: One hundred and eleven patients had evidence of IA, of which 79 patients were GEI positive when cut-off ODI was 0.5, whereas with cut-off ODI 1.0, 55 patients were GEI positive. Conclusion: ODI of 1.0 should be considered as positive while in patients with OD between 0.5 and 1.0, repeat sampling from the patient is recommended.

  19. Evaluation of treatment response to enzyme replacement therapy with Velaglucerase alfa in patients with Gaucher disease using whole-body magnetic resonance imaging.

    Science.gov (United States)

    Laudemann, K; Moos, L; Mengel, E; Lollert, A; Hoffmann, C; Brixius-Huth, M; Wagner, D; Düber, C; Staatz, G

    2016-03-01

    This was a retrospective data analysis to evaluate the treatment response to enzyme replacement therapy (ERT) with Velaglucerase alfa using whole-body magnetic resonance imaging (MRI). A baseline and follow-up MRI were performed on 18 Gaucher Type 1 patients at an interval of 11.6 months. The MRI score systems determined the Bone-Marrow-Burden (BMB) score, the Düsseldorf-Gaucher score (DGS), and the Vertebra-Disc-Ratio (VDR). The Severity Score Index Type 1 (GD-DS3) was also assessed. The baseline MRI medians were: BMB, 7.00; DGS, 3.00; and VDR: 1.70; while, the follow-up MRI medians were: BMB, 7.00; DGS, 3.00; and VDR: 1.73. The baseline GD-DS3 median was 2.40 (BMB excl.: 0.50) and the follow-up median was 2.00 (BMB excl.: 0.50). There was weak statistical significance with the Wilcoxon signed-rank test for the DGS (p=0.034) and GD-DS3 (p=0.047) between both MRIs. Velaglucerase alfa therapy is a effective long-term treatment for Gaucher Type 1 patients who are newly diagnosed or switching therapies. Measurements with whole-body MRI and an objective scoring system were reliable tools for detecting early stage bone marrow activity. Further research is needed to evaluate the "Booster-Effect" of Velaglucerase alfa therapy in Gaucher skeletal disease. Copyright © 2015 Elsevier Inc. All rights reserved.

  20. Comparative evaluation of the Ridascreen Verotoxin enzyme immunoassay for detection of Shiga-toxin producing strains of Escherichia coli (STEC) from food and other sources.

    Science.gov (United States)

    Beutin, L; Steinrück, H; Krause, G; Steege, K; Haby, S; Hultsch, G; Appel, B

    2007-03-01

    To evaluate the suitability of the commercially distributed Ridascreen Verotoxin enzyme immunoassay (EIA) for detection of known genetic types of the Vero (Shiga) toxins 1 (Stx1) and 2 (Stx2) families and to determine its relative sensitivity and specificity. The Ridascreen-EIA was compared with the Vero cell assay, a P(1)-glycoprotein receptor EIA and with stx gene-specific PCs for detection of Stx with 43 Shiga toxin-producing strains of Escherichia coli (STEC) reference strains and with 241 test strains. The Ridascreen-EIA detects strains producing Stx1 and variants Stx1c and Stx1d, as well as Stx2 and variants Stx2d1, Stx2d2, Stx2e, Stx2d, Stx2-O118 (Stx2d-ount), Stx2-NV206, Stx2f and Stx2g. The assay showed a relative sensitivity of 95.7% and a relative specificity of 98.7%. Some of the Stx2-O118-, Stx2e- and Stx2g-producing STEC were not detected with the Ridascreen-EIA probably because of low amount of toxin produced by these strains. The Ridascreen-EIA is able to detect all known types of Stx and is applicable for routine screening of bacterial isolates owing to its high specificity. It is less applicable for testing samples where low amounts of Stx are expected, such as mixed cultures and certain Stx2 variants. This study presents a first comprehensive evaluation of the Ridascreen-EIA, a rapid standardized STEC screening test for routine diagnostic laboratories. Data are presented on the type of the spectrum of Stx that are detected with this immunoassay and its advantages and limits for practical use.

  1. Risk of Visual Impairment and Intracranial Hypertension After Space Flight: Evaluation of the Role of Polymorphism of Enzymes Involved in One-Carbon Metabolism

    Science.gov (United States)

    Smith, S. M.; Gregory, J. F.; Zeisel, G. H.; Gibson, C. R.; Mader, T. H.; Kinchen, J.; Ueland, P.; Ploutz-Snyder, R.; Heer, M.; Zwart, S. R.

    2016-01-01

    Data from the Nutritional Status Assessment protocol provided biochemical evidence that the one-carbon metabolic pathway may be altered in individuals experiencing vision-related issues during and after space flight (1, 2). Briefly, serum concentrations of homocysteine, cystathionine, 2-methylcitric acid, and methylmalonic acid were significantly (P<0.001) higher (25-45%) in astronauts with ophthalmic changes than in those without such changes (1). These differences existed before, during, and after flight. Serum folate was lower (P<0.01) during flight in individuals with ophthalmic changes. Preflight serum concentrations of cystathionine and 2-methylcitric acid, and mean in-flight serum folate, were significantly (P<0.05) correlated with postflight changes in refraction (1). A follow-up study was conducted to evaluate a small number of known polymorphisms of enzymes in the one-carbon pathway, and to evaluate how these relate to vision and other medical aspects of the eye. Specifically, we investigated 5 polymorphisms in MTRR, MTHFR, SHMT, and CBS genes and their association with ophthalmic changes after flight in 49 astronauts. The number of G alleles of MTRR 66 and C alleles of SHMT1 1420 both contributed to the odds of visual disturbances (3). Block regression showed that B-vitamin status at landing and genetics were significant predictors for many of the ophthalmic outcomes studied (3). In conclusion, we document an association between MTRR 66 and SHMT1 1420 polymorphisms and space flightinduced vision changes. These data document that individuals with an altered 1-carbon metabolic pathway may be predisposed to anatomic and/or physiologic changes that render them susceptible to ophthalmic damage during space flight.

  2. Cascade phenomenon against subsequent failures in complex networks

    Science.gov (United States)

    Jiang, Zhong-Yuan; Liu, Zhi-Quan; He, Xuan; Ma, Jian-Feng

    2018-06-01

    Cascade phenomenon may lead to catastrophic disasters which extremely imperil the network safety or security in various complex systems such as communication networks, power grids, social networks and so on. In some flow-based networks, the load of failed nodes can be redistributed locally to their neighboring nodes to maximally preserve the traffic oscillations or large-scale cascading failures. However, in such local flow redistribution model, a small set of key nodes attacked subsequently can result in network collapse. Then it is a critical problem to effectively find the set of key nodes in the network. To our best knowledge, this work is the first to study this problem comprehensively. We first introduce the extra capacity for every node to put up with flow fluctuations from neighbors, and two extra capacity distributions including degree based distribution and average distribution are employed. Four heuristic key nodes discovering methods including High-Degree-First (HDF), Low-Degree-First (LDF), Random and Greedy Algorithms (GA) are presented. Extensive simulations are realized in both scale-free networks and random networks. The results show that the greedy algorithm can efficiently find the set of key nodes in both scale-free and random networks. Our work studies network robustness against cascading failures from a very novel perspective, and methods and results are very useful for network robustness evaluations and protections.

  3. Overall ecologic evaluation of cascading use of wood. Environmental impacts of substantial and energetic systems for utilization of wood in comparison; Gesamtoekologische Bewertung der Kaskadennutzung von Holz. Umweltauswirkungen stofflicher und energetischer Holznutzungssysteme im Vergleich

    Energy Technology Data Exchange (ETDEWEB)

    Gaertner, Sven; Hienz, Gunnar; Keller, Heiko; Mueller-Lindenlauf, Maria

    2013-01-15

    Wood demand is rising and its production can only be extended to a certain degree. This requires a prioritisation of wood use options. Therefore, the environmental aspects of using wood for energy production or as a material with and without cascading recycling steps of stepwise lower value are studied in a comprehensive life cycle assessment (LCA). In addition, the environmental impacts of tapping new wood resources are assessed qualitatively. The results show that under most conditions the environmental impacts are the lower the more steps of a high-value material use are performed before the wood is used for energy production. One has to consider, though, that extended material use cascades can cause decades of delays of the energy recovery step, which may lead to the replacement of cleaner energy sources in the future and thus impair the results for the long-lived wood products. At the same time, wood products can represent a temporary or even - if material wood use generally increases - a long-term carbon stock. This leads to a delay of the greenhouse effect. Depending on the assessment method, these opposing effects result in unchanged to diminished impacts of long-lived wood products on the climate. Nevertheless, from an environmental point of view, high-value material use is advantageous compared to a direct use of wood for energy production independent of the assessment method. When comparing material use options of wood, especially the high-quality use of high-value wood assortments (e.g. solid wood as construction wood) is associated with positive results from an environmental perspective. In this context, the main effects on the LCA results come from the choice of the non-wood reference product and its associated environmental impacts. Regarding the direct use of wood for energy production, the most advantageous option from an environmental point of view is a combined heat and power plant (CHP) with a high overall efficiency.

  4. Defect production in simulated cascades: cascade quenching and short-term annealing

    International Nuclear Information System (INIS)

    Heinisch, H.L.

    1982-01-01

    Defect production in high energy displacement cascades has been modeled using the computer code MARLOWE to generate the cascades and the stochastic computer code ALSOME to simulate the cascade quenching and short-term annealing of isolated cascades. The quenching is accomplished by using ALSOME with exaggerated values for defect mobilities and critical reaction distanes for recombination and clustering, which are in effect until the number of defect pairs is equal to the value determined from resistivity experiments at 4K. Then normal mobilities and reaction distances are used during short-term annealing to a point representative of Stage III recovery. Effects of cascade interactions at low fluences are also being investigated. The quenching parameter values were empirically determined for 30 keV cascades. The results agree well with experimental information throughout the range from 1 keV to 100 keV. Even after quenching and short-term annealing the high energy cascades behave as a collection of lower energy subcascades and lobes. Cascades generated in a crystal having thermal displacements were found to be in better agreement with experiments after quenching and annealing than those generated in a non-thermal crystal

  5. EFSA CEF Panel (EFSA Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids), 2014. Scientific Opinion on Flavouring Group Evaluation 11, Revision 3 (FGE.11Rev3): Aliphatic dialcohols, diketones, and hydroxyketones from chemical groups 8 and 10

    DEFF Research Database (Denmark)

    Beltoft, Vibe Meister; Frandsen, Henrik Lauritz; Nørby, Karin Kristiane

    The Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids of the European Food Safety Authority was requested to evaluate 11 flavouring substances in the Flavouring Group Evaluation 11, Revision 3, using the Procedure in Commission Regulation (EC) No 1565/2000. The substances......, the specifications for the materials of commerce have also been considered. Specifications including complete purity criteria and identity for the materials of commerce have been provided for all candidate substances....

  6. EFSA CEF Panel (EFSA Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids), 2015. Scientific Opinion on Flavouring Group Evaluation 21, Revision 5 (FGE.21Rev5): Thiazoles, thiophenes, thiazoline and thienyl derivatives from chemical groups 29 and 30

    DEFF Research Database (Denmark)

    Nørby, Karin Kristiane; Beltoft, Vibe Meister

    The Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids of the European Food Safety Authority was requested to evaluate 41 flavouring substances in Flavouring Group Evaluation 21, Revision 5, using the Procedure in Commission Regulation (EC) No 1565/2000. This revision...... have also been considered. Adequate specifications, including complete purity criteria and identity for the materials of commerce, have been provided for all 41 candidate substances....

  7. EFSA Panel on Food Contact Material, Enzymes, Flavourings and Processing Aids (CEF); Scientific Opinion on Flavouring Group Evaluation 47, Revision 1: Bi- and tricyclic secondary, ketones and related esters from chemical groups 7 and 8

    DEFF Research Database (Denmark)

    Larsen, John Christian; Nørby, Karin Kristiane; Beltoft, Vibe Meister

    The Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids of the European Food Safety Authority was requested to evaluate six flavouring substances in the Flavouring Group Evaluation 47, including an additional two substances in this Revision 1, using the Procedure in Commission...... of these flavouring substances, the specifications for the materials of commerce have also been considered. Adequate specifications including complete purity criteria and identity fo the materials of commerce have been provided for all six candidate substances....

  8. Evaluation of the effects of hydroalcoholic extract of Berberis vulgaris root on the activity of liver enzymes in male hypercholesterolemic rats

    Directory of Open Access Journals (Sweden)

    Soheila Taheri

    2012-06-01

    Conclusion: Noticing the antioxidant properties of B. vulgaris root extract  and its effects on reducing the activity of liver enzymes, the extract of this plant can be a good choice for improving the function of liver.

  9. Comparative evaluation of fermented and non-fermented de-oiled rice bran with or without exogenous enzymes supplementation in the diet of Labeo rohita (Hamilton, 1822).

    Science.gov (United States)

    Ranjan, Amit; Sahu, Narottam Prasad; Deo, Ashutosh Dharmendra; Kumar, H Sanath; Kumar, Sarvendra; Jain, Kamal Kant

    2018-03-29

    A 60-day feeding trial was conducted to study the effect of exogenous enzymes (xylanase and phytase) supplementation in the non-fermented and fermented de-oiled rice bran (DORB)-based diet of Labeo rohita. Four test diets (T1-DORB-based diet, T2-fermented DORB-based diet, T3-phytase and xylanase supplemented DORB-based diet, and T4-phytase and xylanase supplemented fermented DORB-based diet) were formulated and fed to the respective groups. Test diets T3 and T4 were supplemented with 0.01% xylanase (16,000 U kg -1 ) and 0.01% phytase (500 U kg -1 ) enzymes. One hundred twenty juveniles of L. rohita, with an average weight 5.01 ± 0.02 g, were stocked in 12 uniform size plastic rectangular tanks in triplicate with 10 fishes per tank following a completely randomized design (CRD). Exogenous enzyme supplementation to the T3 group significantly improved the growth performance of L. rohita (p exogenous enzymes. The carcass composition (except CP %), enzyme activities (except amylase activity), globulin, and A/G ratio did not vary significantly (p > 0.05). Based on the results of the present study, it is concluded that exogenous enzyme supplementation significantly increases the growth of fish fed with DORB-based diet.

  10. Evaluation of Two Enzyme-Linked Immunosorbent Assay Kits for Chikungunya Virus IgM Using Samples from Deceased Organ and Tissue Donors

    Science.gov (United States)

    Altrich, Michelle L.; Nowicki, Marek J.

    2016-01-01

    The identification of nearly 3,500 cases of chikungunya virus (CHIKV) infection in U.S. residents returning in 2014 and 2015 from areas in which it is endemic has raised concerns within the transplant community that, should recently infected individuals become organ and/or tissue donors, CHIKV would be transmitted to transplant recipients. Thus, tests designed to detect recent CHIKV infection among U.S. organ and tissue donors may become necessary in the future. Accordingly, we evaluated 2 enzyme-linked immunosorbent assays (ELISAs) for CHIKV IgM readily available in the United States using 1,000 deidentified serum or plasma specimens collected from donors between November 2014 and March 2015. The Euroimmun indirect ELISA identified 38 reactive specimens; however, all 38 were negative for CHIKV IgG and IgM in immunofluorescence assays (IFAs) conducted at a reference laboratory and, thus, were falsely reactive in the Euroimmun CHIKV IgM assay. The InBios IgM-capture ELISA identified 26 reactive samples, and one was still reactive (index ≥ 1.00) when retested using the InBios kit with a background subtraction modification to identify false reactivity. This reactive specimen was CHIKV IgM negative but IgG positive by IFAs at two reference laboratories; plaque reduction neutralization testing (PRNT) demonstrated CHIKV-specific reactivity. The IgG and PRNT findings strongly suggest that the InBios CHIKV IgM-reactive result represents true reactivity, even though the IgM IFA result was negative. If testing organ/tissue donors for CHIKV IgM becomes necessary, the limitations of the currently available CHIKV IgM ELISAs and options for their optimization must be understood to avoid organ/tissue wastage due to falsely reactive results. PMID:27535838

  11. Development and evaluation of an avian influenza, neuraminidase subtype 1, indirect enzyme-linked immunosorbent assay for poultry using the differentiation of infected from vaccinated animals control strategy.

    Science.gov (United States)

    Liu, Y; Mundt, E; Mundt, A; Sylte, M; Suarez, D L; Swayne, D E; García, M

    2010-03-01

    An indirect enzyme-linked immunosorbent assay (ELISA) was developed using baculovirus, purified, recombinant N1 protein from A/chicken/Indonesia/PA7/2003 (H5N1) virus. The N1-ELISA showed high selectivity for detection of N1 antibodies, with no cross-reactivity with other neuraminidase subtypes, and broad reactivity with sera to N1 subtype isolates from North American and Eurasian lineages. Sensitivity of the N1-ELISA to detect N1 antibodies in turkey sera, collected 3 wk after H1N1 vaccination, was comparable to detection of avian influenza antibodies by the commercial, indirect ELISAs ProFLOK AIV Plus ELISA Kit (Synbiotics, Kansas City, MO) and Avian Influenza Virus Antibody Test Kit (IDEXX, Westbrook, ME). However, 6 wk after vaccination, the Synbiotics ELISA kit performed better than the N1-ELISA and the IDEXX ELISA kit. An evaluation was made of the ability of the N1-ELISA to discriminate vaccinated chickens from subsequently challenged chickens. Two experiments were conducted, chickens were vaccinated with inactivated H5N2 and H5N9 viruses and challenged with highly pathogenic H5N1 virus, and chickens were vaccinated with recombinant poxvirus vaccine encoding H7 and challenged with highly pathogenic H7N1 virus. Serum samples were collected at 14 days postchallenge and tested by hemagglutination inhibition (HI), quantitative neuraminidase inhibition (NI), and N1-ELISA. At 2 days postchallenge, oropharyngeal swabs were collected for virus isolation (VI) to confirm infection. The N1-ELISA was in fair agreement with VI and HI results. Although the N1-ELISA showed a lower sensitivity than the NI assay, it was demonstrated that detection of N1 antibodies by ELISA was an effective and rapid assay to identify exposure to the challenge virus in vaccinated chickens. Therefore, N1-ELISA can facilitate a vaccination strategy with differentiation of infected from vaccinated animals using a neuraminidase heterologous approach.

  12. Numerical routine for magnetic heat pump cascading

    DEFF Research Database (Denmark)

    Filonenko, Konstantin; Lei, Tian; Engelbrecht, Kurt

    Heat pumps use low-temperature heat absorbed from the energy source to create temperature gradient (TG) across the energy sink. Magnetic heat pumps (MHP) can perform this function through operating active magnetic regeneration (AMR) cycle. For building heating, TGs of up to a few K might...... and 3 K. Changing the number of MHPs, we optimized input parameters to achieve maximum heating powers. We have found that both maximum heating power and COP decrease together with number of heat pumps, but the TGs and the temperature span can be largely increased. References [1] M. Tahavori et al., “A...... be necessary, which is hardly achievable with a single MHP and such techniques as cascading are required. Series and parallel cascading increase the AMR span and heating power, respectively, but do not change TG. Therefore, the intermediate type of cascading was proposed with individual MHPs separately...

  13. Non-spill control squared cascade

    International Nuclear Information System (INIS)

    Kai, Tsunetoshi; Inoue, Yoshiya; Oya, Akio; Suemori, Nobuo.

    1974-01-01

    Object: To reduce a mixed loss thus enhancing separating efficiency by the provision of a simple arrangement wherein a reflux portion in a conventional spill control squared cascade is replaced by a special stage including centrifugal separators. Structure: Steps in the form of a square cascade, in which a plurality of centrifugal separators are connected by pipe lines, are accumulated in multistage fashion to form a squared cascade. Between the adjoining steps is disposed a special stage including a centrifugal separator which receives both lean flow from the upper step and rich flow from the lower step. The centrifugal separator in the special stage has its rich side connected to the upper step and its lean side connected to the lower step. Special stages are each disposed at the upper side of the uppermost step and at the lower side of the lowermost step. (Kamimura, M.)

  14. Sample Selection for Training Cascade Detectors.

    Science.gov (United States)

    Vállez, Noelia; Deniz, Oscar; Bueno, Gloria

    2015-01-01

    Automatic detection systems usually require large and representative training datasets in order to obtain good detection and false positive rates. Training datasets are such that the positive set has few samples and/or the negative set should represent anything except the object of interest. In this respect, the negative set typically contains orders of magnitude more images than the positive set. However, imbalanced training databases lead to biased classifiers. In this paper, we focus our attention on a negative sample selection method to properly balance the training data for cascade detectors. The method is based on the selection of the most informative false positive samples generated in one stage to feed the next stage. The results show that the proposed cascade detector with sample selection obtains on average better partial AUC and smaller standard deviation than the other compared cascade detectors.

  15. Sample Selection for Training Cascade Detectors.

    Directory of Open Access Journals (Sweden)

    Noelia Vállez

    Full Text Available Automatic detection systems usually require large and representative training datasets in order to obtain good detection and false positive rates. Training datasets are such that the positive set has few samples and/or the negative set should represent anything except the object of interest. In this respect, the negative set typically contains orders of magnitude more images than the positive set. However, imbalanced training databases lead to biased classifiers. In this paper, we focus our attention on a negative sample selection method to properly balance the training data for cascade detectors. The method is based on the selection of the most informative false positive samples generated in one stage to feed the next stage. The results show that the proposed cascade detector with sample selection obtains on average better partial AUC and smaller standard deviation than the other compared cascade detectors.

  16. Multilevel Inverter by Cascading Industrial VSI

    DEFF Research Database (Denmark)

    Teodorescu, Remus; Blaabjerg, Frede; Pedersen, John Kim

    2002-01-01

    In this paper the modularity concept applied to medium-voltage adjustable speed drives is addressed. First, the single-phase cascaded voltage-source inverter that uses series connection of IGBT H-bridge modules with isolated dc-buses is presented. Next, a novel three-phase cascaded voltage......-source inverter that uses three IGBT triphase inverter modules along with an output transformer to obtain a 3 p.u. multilevel output voltage is introduced. The system yields in high-quality multistep voltage with up to 4 levels and low dv/dt, balanced operation of the inverter modules, each supplying a third...... of the motor rated kVA. The concept of using cascaded inverters is further extended to a new modular motor-modular inverter system where the motor winding connections are reconnected into several three-phase groups, either six-lead or 12-lead connection according to the voltage level, each powered...

  17. KEWPIE: a dynamical cascade code for decaying exited compound nuclei

    OpenAIRE

    Bouriquet, Bertrand; Abe, Yasuhisa; Boilley, David

    2003-01-01

    A new dynamical cascade code for decaying hot nuclei is proposed and specially adapted to the synthesis of super-heavy nuclei. For such a case, the interesting channel is the tiny fraction that will decay through particles emission, thus the code avoids classical Monte-Carlo methods and proposes a new numerical scheme. The time dependence is explicitely taken into account in order to cope with the fact that fission decay rate might not be constant. The code allows to evaluate both statistical...

  18. KEWPIE: A dynamical cascade code for decaying exited compound nuclei

    Science.gov (United States)

    Bouriquet, Bertrand; Abe, Yasuhisa; Boilley, David

    2004-05-01

    A new dynamical cascade code for decaying hot nuclei is proposed and specially adapted to the synthesis of super-heavy nuclei. For such a case, the interesting channel is of the tiny fraction that will decay through particles emission, thus the code avoids classical Monte-Carlo methods and proposes a new numerical scheme. The time dependence is explicitely taken into account in order to cope with the fact that fission decay rate might not be constant. The code allows to evaluate both statistical and dynamical observables. Results are successfully compared to experimental data.

  19. Cascade Processes in Muonic Hydrogen Atoms

    International Nuclear Information System (INIS)

    Faifman, M. P.; Men'Shikov, L. I.

    2001-01-01

    The QCMC scheme created earlier for cascade calculations in heavy hadronic atoms of hydrogen isotopes has been modified and applied to the study of cascade processes in the μp muonic hydrogen atoms. The distribution of μp atoms over kinetic energies has been obtained and the yields of K-series X-rays per one stopped muon have been calculated.Comparison with experimental data indicated directly that for muonic and pionic atoms new types of non-radiative transitions are essential, while they are negligible for heavy (kaonic, antiprotonic, etc.) atoms. These processes have been considered and their probabilities have been estimated.

  20. Volcano geodesy in the Cascade arc, USA

    Science.gov (United States)

    Poland, Michael; Lisowski, Michael; Dzurisin, Daniel; Kramer, Rebecca; McLay, Megan; Pauk, Benjamin

    2017-01-01

    Experience during historical time throughout the Cascade arc and the lack of deep-seated deformation prior to the two most recent eruptions of Mount St. Helens might lead one to infer that Cascade volcanoes are generally quiescent and, specifically, show no signs of geodetic change until they are about to erupt. Several decades of geodetic data, however, tell a different story. Ground- and space-based deformation studies have identified surface displacements at five of the 13 major Cascade arc volcanoes that lie in the USA (Mount Baker, Mount St. Helens, South Sister, Medicine Lake, and Lassen volcanic center). No deformation has been detected at five volcanoes (Mount Rainier, Mount Hood, Newberry Volcano, Crater Lake, and Mount Shasta), and there are not sufficient data at the remaining three (Glacier Peak, Mount Adams, and Mount Jefferson) for a rigorous assessment. In addition, gravity change has been measured at two of the three locations where surveys have been repeated (Mount St. Helens and Mount Baker show changes, while South Sister does not). Broad deformation patterns associated with heavily forested and ice-clad Cascade volcanoes are generally characterized by low displacement rates, in the range of millimeters to a few centimeters per year, and are overprinted by larger tectonic motions of several centimeters per year. Continuous GPS is therefore the best means of tracking temporal changes in deformation of Cascade volcanoes and also for characterizing tectonic signals so that they may be distinguished from volcanic sources. Better spatial resolution of volcano deformation can be obtained through the use of campaign GPS, semipermanent GPS, and interferometric synthetic aperture radar observations, which leverage the accumulation of displacements over time to improve signal to noise. Deformation source mechanisms in the Cascades are diverse and include magma accumulation and withdrawal, post-emplacement cooling of recent volcanic deposits, magmatic

  1. Volcano geodesy in the Cascade arc, USA

    Science.gov (United States)

    Poland, Michael P.; Lisowski, Michael; Dzurisin, Daniel; Kramer, Rebecca; McLay, Megan; Pauk, Ben

    2017-08-01

    Experience during historical time throughout the Cascade arc and the lack of deep-seated deformation prior to the two most recent eruptions of Mount St. Helens might lead one to infer that Cascade volcanoes are generally quiescent and, specifically, show no signs of geodetic change until they are about to erupt. Several decades of geodetic data, however, tell a different story. Ground- and space-based deformation studies have identified surface displacements at five of the 13 major Cascade arc volcanoes that lie in the USA (Mount Baker, Mount St. Helens, South Sister, Medicine Lake, and Lassen volcanic center). No deformation has been detected at five volcanoes (Mount Rainier, Mount Hood, Newberry Volcano, Crater Lake, and Mount Shasta), and there are not sufficient data at the remaining three (Glacier Peak, Mount Adams, and Mount Jefferson) for a rigorous assessment. In addition, gravity change has been measured at two of the three locations where surveys have been repeated (Mount St. Helens and Mount Baker show changes, while South Sister does not). Broad deformation patterns associated with heavily forested and ice-clad Cascade volcanoes are generally characterized by low displacement rates, in the range of millimeters to a few centimeters per year, and are overprinted by larger tectonic motions of several centimeters per year. Continuous GPS is therefore the best means of tracking temporal changes in deformation of Cascade volcanoes and also for characterizing tectonic signals so that they may be distinguished from volcanic sources. Better spatial resolution of volcano deformation can be obtained through the use of campaign GPS, semipermanent GPS, and interferometric synthetic aperture radar observations, which leverage the accumulation of displacements over time to improve signal to noise. Deformation source mechanisms in the Cascades are diverse and include magma accumulation and withdrawal, post-emplacement cooling of recent volcanic deposits, magmatic

  2. Interferometric modulation of quantum cascade interactions

    Science.gov (United States)

    Cusumano, Stefano; Mari, Andrea; Giovannetti, Vittorio

    2018-05-01

    We consider many-body quantum systems dissipatively coupled by a cascade network, i.e., a setup in which interactions are mediated by unidirectional environmental modes propagating through a linear optical interferometer. In particular we are interested in the possibility of inducing different effective interactions by properly engineering an external dissipative network of beam splitters and phase shifters. In this work we first derive the general structure of the master equation for a symmetric class of translation-invariant cascade networks. Then we show how, by tuning the parameters of the interferometer, one can exploit interference effects to tailor a large variety of many-body interactions.

  3. Quantification of the glycogen cascade system: the ultrasensitive responses of liver glycogen synthase and muscle phosphorylase are due to distinctive regulatory designs

    Directory of Open Access Journals (Sweden)

    Venkatesh KV

    2005-05-01

    Full Text Available Abstract Background Signaling pathways include intricate networks of reversible covalent modification cycles. Such multicyclic enzyme cascades amplify the input stimulus, cause integration of multiple signals and exhibit sensitive output responses. Regulation of glycogen synthase and phosphorylase by reversible covalent modification cycles exemplifies signal transduction by enzyme cascades. Although this system for regulating glycogen synthesis and breakdown appears similar in all tissues, subtle differences have been identified. For example, phosphatase-1, a dephosphorylating enzyme of the system, is regulated quite differently in muscle and liver. Do these small differences in regulatory architecture affect the overall performance of the glycogen cascade in a specific tissue? We address this question by analyzing the regulatory structure of the glycogen cascade system in liver and muscle cells at steady state. Results The glycogen cascade system in liver and muscle cells was analyzed at steady state and the results were compared with literature data. We found that the cascade system exhibits highly sensitive switch-like responses to changes in cyclic AMP concentration and the outputs are surprisingly different in the two tissues. In muscle, glycogen phosphorylase is more sensitive than glycogen synthase to cyclic AMP, while the opposite is observed in liver. Furthermore, when the liver undergoes a transition from starved to fed-state, the futile cycle of simultaneous glycogen synthesis and degradation switches to reciprocal regulation. Under such a transition, different proportions of active glycogen synthase and phosphorylase can coexist due to the varying inhibition of glycogen-synthase phosphatase by active phosphorylase. Conclusion The highly sensitive responses of glycogen synthase in liver and phosphorylase in muscle to primary stimuli can be attributed to distinctive regulatory designs in the glycogen cascade system. The different

  4. Antioxidant properties of digestive enzyme-treated fibre-rich fractions from wheat, finger millet, pearl millet and sorghum: A comparative evaluation

    Directory of Open Access Journals (Sweden)

    Aisha Siddiq A.

    2015-12-01

    Full Text Available Whole grains are rich in antioxidant components (AC, most of which are bound to fibre fraction and released during digestion. The study investigated the effect of digestive enzymes on the antioxidant properties of fibre-rich fractions from wheat (Triticum aestivum, finger millet (Eleusine coracana, pearl millet (Pennisetum typhoides and sorghum (Sorghum bicolor. Coarse (CF and fine fractions (FF of milled flour were separated using a standard sieve and analysed for nutritional composition, AC extractable in different solvents and antioxidant activity (AA in untreated and enzyme-treated fractions. The CF had a higher range of insoluble dietary fibre (17.26–20.93% than FF (10.65–17.29%. The highest amount of polyphenols and flavonoids was extractable in different solvents from finger millet and pearl millet, respectively. FF of pearl millet showed higher total AA in all solvents. Enzyme-treated samples had a much higher content of AC as well as higher total AA. Free radical scavenging assay revealed that enzyme-treated millet flours had higher activity in comparison to wheat. Between fractions, wheat exhibited variable results. Among millets, CF of finger millet and FF of pearl millet and sorghum had higher AA. In conclusion, digestive enzyme treatment released more AC from grains, and exhibited a higher AA.

  5. Enzymes in lipid modification: From classical biocatalysis with commercial enzymes to advanced protein engineering tools

    Directory of Open Access Journals (Sweden)

    Bornscheuer Uwe T.

    2013-01-01

    Full Text Available In this review, the application of enzymes, especially lipases, for the modification of fats and oils is covered. This includes the lipase-catalyzed selective production of structured triglycerides and the isolation or incorporation of specific fatty acids. Protein engineering methods to modify lipases on a molecular level were used to alter the fatty acid chain-length and ‘‘trans over cis’’ selectivity of lipase A from Candida antarctica. Furthermore, an enzymatic cascade reaction to remove 3-monochloropropanediol and the identification of a phospholipase C for degumming are briefly covered.

  6. EFSA CEF Panel (EFSA Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids ), 2014. Scientific Opinion on Flavouring Group Evaluation 200 (FGE.200): 74 α , β -unsaturated aldehydes and precursors from subgroup 1.1.1 of FGE.19

    DEFF Research Database (Denmark)

    Beltoft, Vibe Meister; Binderup, Mona-Lise; Frandsen, Henrik Lauritz

    The Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids of the European Food Safety Authority was requested to evaluate the genotoxic potential of 74 flavouring substances from subgroup 1.1.1 of FGE.19 in the Flavouring Group Evaluation 200 (FGE.200). The Flavour Industry has...... provided additional genotoxicity studies for one representative substance in FGE.200, namely hex-2(trans)-enal [FL-no 05.073], and for other two substances in the same subgroup, namely 2-dodecenal [05.037] and 2-nonenal [05.171]. The Panel has evaluated these data and concluded that the concern still...

  7. Assessment of parameters of gas centrifuge and separation cascade basing on integral characteristics of separation plant

    Energy Technology Data Exchange (ETDEWEB)

    Borisevich, Valentin, E-mail: VDBorisevich@mephi.ru [National Research Nuclear University MEPhI, Kashirskoe Shosse 31, Moscow 115409 (Russian Federation); National Research Center “Kurchatov Institute”, Kurchatov Square 1, Moscow 123182 (Russian Federation); Borshchevskiy, Michael, E-mail: Michael_mephi@mail.ru [National Research Nuclear University MEPhI, Kashirskoe Shosse 31, Moscow 115409 (Russian Federation); Andronov, Igor, E-mail: andronov@imp.kiae.ru [National Research Center “Kurchatov Institute”, Kurchatov Square 1, Moscow 123182 (Russian Federation); Senchenkov, Sergey, E-mail: senchenkov@imp.kiae.ru [National Research Center “Kurchatov Institute”, Kurchatov Square 1, Moscow 123182 (Russian Federation)

    2013-12-15

    Highlights: • We developed the calculation method to assess a feed flow rate into a gas centrifuge. • It is based on the knowledge of the integral characteristics of a separation plant. • Our method is verified by comparison with the results of the independent one. • The method also allows to specify other features of the separation cascade work. - Abstract: A calculation technique to assess a feed flow rate into a single GC, a total number of centrifuges in a separation cascade and to determine its likely configurations basing on the known integral characteristics of a centrifugal plant is developed. Evaluation of characteristics of the industrial gas centrifuge TC-12 and separation cascades of the NEF plant performed by two independent calculation techniques demonstrates their satisfactory agreement. This methodology would help to some extent the nuclear inspectors in evaluating and assessing the capability of an enrichment facility, and discovering any use for undeclared purposes.

  8. Enzyme inhibition by iminosugars

    DEFF Research Database (Denmark)

    López, Óscar; Qing, Feng-Ling; Pedersen, Christian Marcus

    2013-01-01

    Imino- and azasugar glycosidase inhibitors display pH dependant inhibition reflecting that both the inhibitor and the enzyme active site have groups that change protonation state with pH. With the enzyme having two acidic groups and the inhibitor one basic group, enzyme-inhibitor complexes...

  9. Cascading effects of overfishing marine systems

    NARCIS (Netherlands)

    Scheffer, M.; Carpenter, S.; Young, de B.

    2005-01-01

    Profound indirect ecosystem effects of overfishing have been shown for coastal systems such as coral reefs and kelp forests. A new study from the ecosystem off the Canadian east coast now reveals that the elimination of large predatory fish can also cause marked cascading effects on the pelagic food

  10. Plant MAPK cascades: Just rapid signaling modules?

    KAUST Repository

    Boudsocq, Marie; Danquah, Agyemang; Zé licourt, Axel de; Hirt, Heribert; Colcombet, Jean

    2015-01-01

    rapid MAPK activation, we showed that the activation of the new MAPK module is delayed and relies on the MAP3K protein synthesis. In this addendum, we discuss the role of this original and unexpected activation mechanism of MAPK cascades which suggests

  11. Computer simulation of high energy displacement cascades

    International Nuclear Information System (INIS)

    Heinisch, H.L.

    1990-01-01

    A methodology developed for modeling many aspects of high energy displacement cascades with molecular level computer simulations is reviewed. The initial damage state is modeled in the binary collision approximation (using the MARLOWE computer code), and the subsequent disposition of the defects within a cascade is modeled with a Monte Carlo annealing simulation (the ALSOME code). There are few adjustable parameters, and none are set to physically unreasonable values. The basic configurations of the simulated high energy cascades in copper, i.e., the number, size and shape of damage regions, compare well with observations, as do the measured numbers of residual defects and the fractions of freely migrating defects. The success of these simulations is somewhat remarkable, given the relatively simple models of defects and their interactions that are employed. The reason for this success is that the behavior of the defects is very strongly influenced by their initial spatial distributions, which the binary collision approximation adequately models. The MARLOWE/ALSOME system, with input from molecular dynamics and experiments, provides a framework for investigating the influence of high energy cascades on microstructure evolution. (author)

  12. Energy Cascade in Fermi-Pasta Models

    Science.gov (United States)

    Ponno, A.; Bambusi, D.

    We show that, for long-wavelength initial conditions, the FPU dynamics is described, up to a certain time, by two KdV-like equations, which represent the resonant Hamiltonian normal form of the system. The energy cascade taking place in the system is then quantitatively characterized by arguments of dimensional analysis based on such equations.

  13. Molecular dynamics studies of displacement cascades

    International Nuclear Information System (INIS)

    Averback, R.S.; Hsieh, Horngming; Diaz de la Rubia, T.

    1990-02-01

    Molecular-dynamics simulations of cascades in Cu and Ni with primary-knock-on energies up to 5 keV and lattice temperatures in the range 0 K--700 K are described. Interatomic forces were represented by either the Gibson II (Cu) or Johnson-Erginsoy (Ni) potentials in most of this work, although some simulations using ''Embedded Atom Method'' potentials, e.g., for threshold events in Ni 3 Al, are also presented. The results indicate that the primary state of damage produced by displacement cascades is controlled by two phenomena, replacement collision sequences during the collisional phase of the cascade and local melting during the thermal spike. As expected, the collisional phase is rather similar in Cu and Ni, however, the thermal spike is of longer duration and has a more pronounced influence in Cu than Ni. When the ambient temperature of the lattice is increased, the melt zones are observed to both increase in size and cool more slowly. This has the effect of reducing defect production and enhancing atomic mixing and disordering. The implications of these results for defect production, cascade collapse, atomic disordering will be discussed. 34 refs., 7 figs., 2 tabs

  14. Impedance interactions in bidirectional cascaded converter

    DEFF Research Database (Denmark)

    Tian, Yanjun; Loh, Poh Chiang; Chen, Zhe

    2016-01-01

    A cascaded converter is built by connecting one elementary converter to another. Output impedance of one converter will therefore interact with input impedance of the other converter. This interaction will change when power flow reverses. To compare this difference, an investigation is performed...

  15. Forecasting Social Unrest Using Activity Cascades.

    Science.gov (United States)

    Cadena, Jose; Korkmaz, Gizem; Kuhlman, Chris J; Marathe, Achla; Ramakrishnan, Naren; Vullikanti, Anil

    2015-01-01

    Social unrest is endemic in many societies, and recent news has drawn attention to happenings in Latin America, the Middle East, and Eastern Europe. Civilian populations mobilize, sometimes spontaneously and sometimes in an organized manner, to raise awareness of key issues or to demand changes in governing or other organizational structures. It is of key interest to social scientists and policy makers to forecast civil unrest using indicators observed on media such as Twitter, news, and blogs. We present an event forecasting model using a notion of activity cascades in Twitter (proposed by Gonzalez-Bailon et al., 2011) to predict the occurrence of protests in three countries of Latin America: Brazil, Mexico, and Venezuela. The basic assumption is that the emergence of a suitably detected activity cascade is a precursor or a surrogate to a real protest event that will happen "on the ground." Our model supports the theoretical characterization of large cascades using spectral properties and uses properties of detected cascades to forecast events. Experimental results on many datasets, including the recent June 2013 protests in Brazil, demonstrate the effectiveness of our approach.

  16. Forecasting Social Unrest Using Activity Cascades.

    Directory of Open Access Journals (Sweden)

    Jose Cadena

    Full Text Available Social unrest is endemic in many societies, and recent news has drawn attention to happenings in Latin America, the Middle East, and Eastern Europe. Civilian populations mobilize, sometimes spontaneously and sometimes in an organized manner, to raise awareness of key issues or to demand changes in governing or other organizational structures. It is of key interest to social scientists and policy makers to forecast civil unrest using indicators observed on media such as Twitter, news, and blogs. We present an event forecasting model using a notion of activity cascades in Twitter (proposed by Gonzalez-Bailon et al., 2011 to predict the occurrence of protests in three countries of Latin America: Brazil, Mexico, and Venezuela. The basic assumption is that the emergence of a suitably detected activity cascade is a precursor or a surrogate to a real protest event that will happen "on the ground." Our model supports the theoretical characterization of large cascades using spectral properties and uses properties of detected cascades to forecast events. Experimental results on many datasets, including the recent June 2013 protests in Brazil, demonstrate the effectiveness of our approach.

  17. Gene regulation by MAP kinase cascades

    DEFF Research Database (Denmark)

    Fiil, Berthe Katrine; Petersen, Klaus; Petersen, Morten

    2009-01-01

    Mitogen-activated protein kinase (MAPK) cascades are signaling modules that transduce extracellular stimuli to a range of cellular responses. Research in yeast and metazoans has shown that MAPK-mediated phosphorylation directly or indirectly regulates the activity of transcription factors. Plant ...

  18. The Attention Cascade Model and Attentional Blink

    Science.gov (United States)

    Shih, Shui-I

    2008-01-01

    An attention cascade model is proposed to account for attentional blinks in rapid serial visual presentation (RSVP) of stimuli. Data were collected using single characters in a single RSVP stream at 10 Hz [Shih, S., & Reeves, A. (2007). "Attentional capture in rapid serial visual presentation." "Spatial Vision", 20(4), 301-315], and single words,…

  19. Cascaded FSO-VLC Communication System

    KAUST Repository

    Gupta, Akash; Sharma, Nikhil; Garg, Parul; Alouini, Mohamed-Slim

    2017-01-01

    The proposed cascaded free space optics (FSO)-visible light communication (VLC) system consists of multiple VLC access points which caters the end users connected via a decode and forward (DF) relay to the FSO backhaul link. The FSO link is assumed

  20. A simple method for potential flow simulation of cascades

    Indian Academy of Sciences (India)

    vortex panel method to simulate potential flow in cascades is presented. The cascade ... The fluid loading on the blades, such as the normal force and pitching moment, may ... of such discrete infinite array singularities along the blade surface.

  1. Evaluation of an enzyme-linked immunosorbent assay for serological surveillance of infection with Actinobacillus pleuropneumoniae serotype 5 in pig herds

    DEFF Research Database (Denmark)

    Klausen, Joan; Andresen, Lars Ole; Barfod, Kristen

    2002-01-01

    An indirect enzyme-linked immunoassay for serological surveillance of infection of pigs with Actinobacillus pleuropneumoniae (Ap) serotype 5 was developed. The antigen used was prepared from Ap serotype 5b strain L20. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis...

  2. Evaluation of enzyme-linked immunosorbent assays based on monoclonal antibodies for the serology and antigen detection in canine parvovirus infections.

    NARCIS (Netherlands)

    G.F. Rimmelzwaan (Guus); N. Juntti; B. Klingeborn; J. Groen (Jan); F.G.C.M. Uytdehaag (Fons); A.D.M.E. Osterhaus (Albert)

    1990-01-01

    textabstractAn enzyme-linked immunosorbent assay (ELISA) system was developed for the detection of canine parvovirus (CPV) or CPV antigen in dog faeces and two other ELISA systems were developed for the detection of CPV-specific antibodies in dog sera. The ELISA's were based on the use of

  3. Evaluation of a commercial competitive enzyme-linked immunosorbent assay for detection of avian influenza virus subtype H5 antibodies in zoo birds

    DEFF Research Database (Denmark)

    Jensen, Trine Hammer; Andersen, Jannie Holmegaard; Hjulsager, Charlotte Kristiane

    2017-01-01

    The hemagglutination inhibition (HI) test is the current gold standard for detecting antibodies to avian influenza virus (AIV). Enzyme-linked immunosorbent assays (ELISAs) have been explored for use in poultry and certain wild bird species because of high efficiency and lower cost. This study com...

  4. Evaluation of the synergistic effect of Allium sativum, Eugenia jambolana, Momordica charantia, Ocimum sanctum and Psidium guajav on hepatic and intestinal drug metabolizing enzymes in rats

    Directory of Open Access Journals (Sweden)

    Devendra Kumar

    2016-12-01

    Full Text Available Aims/Background: Present study investigated the synergistic effect of polyherbal formulations (PHF of Allium sativum L Eugenia jambolana Lam., Momordica charantia L., Ocimum sanctum Linn and Psidium guajava L. in the inhibition/induction of hepatic and intestinal CYPs and Phase-II conjugated drug metabolizing enzymes. Consumption of these herbal remedy has been extensively documented for diabetes treatment in Auyureda. Methodology: PHF of these five herbs was prepared and different doses were orally administered to Sprague Dawley rats of different groups except control group. Expression of mRNA and activity of drug metabolizing enzymes were examined by RT-PCR and HPLC in isolated liver and intestine microsomes in PHF pretreated rats. Results: Activities of hepatic and intestinal Phase-II enzyme levels increased along with mRNA levels except CYP3A mRNA level. PHF administration increases the activity of hepatic and intestinal UDPGT and GST in response to dose and time; however, activity of hepatic SULT increased at higher doses. Conclusions: CYPs and Phase-II conjugated enzymes levels can be modulated in dose and time dependent manner. Observations suggest that poly herbal formulation might be a possible cause of herb-drug interaction, due to changes in pharmacokinetic of crucial CYPs and Phase-II substrate drug. [J Complement Med Res 2016; 5(4.000: 372-382

  5. Cascade theory in isotopic separation processes; Theorie des cascades en separation isotopique

    Energy Technology Data Exchange (ETDEWEB)

    Agostini, J P

    1994-06-01

    Three main areas are developed within the scope of this work: - the first one is devoted to fundamentals: separative power, value function, ideal cascade and square cascade. Applications to two main cases are carried out, namely: Study of binary isotopic mix, Study of processes with a small enrichment coefficient. - The second one is devoted to cascade coupling -high-flux coupling (more widely used and better known) as well as low-flux coupling are presented and compared to one another. - The third one is an outlook on problems linked to cascade transients. Those problem are somewhat intricate and their interest lies mainly into two areas: economics where the start-up time may have a large influence on the interests paid during the construction and start-up period, military productions where the start-up time has a direct bearing on the production schedule. (author). 50 figs. 3 annexes. 12 refs. 6 tabs.

  6. APP processing and the APP-KPI domain involvement in the amyloid cascade.

    Science.gov (United States)

    Menéndez-González, M; Pérez-Pinera, P; Martínez-Rivera, M; Calatayud, M T; Blázquez Menes, B

    2005-01-01

    Alternative APP mRNA splicing can generate isoforms of APP containing a Kunitz protease inhibitor (KPI) domain. KPI is one of the main serine protease inhibitors. Protein and mRNA KPI(+)APP levels are elevated in Alzheimer's disease (AD) brain and are associated with increased amyloid beta deposition. In the last years increasing evidence on multiple points in the amyloid cascade where KPI(+)APP is involved has been accumulated, admitting an outstanding position in the pathogenesis of AD to the KPI domain. This review focuses on the APP processing, the molecular activity of KPI and its physiological and pathological roles and the KPI involvement in the amyloid cascade through the nerve growth factor, the lipoprotein receptor-related protein, the tumor necrosis factor-alpha converting enzyme and the Notch1 protein.

  7. Particle fluxes in atomic collision cascades

    International Nuclear Information System (INIS)

    Sckerl, B.W.; Sigmund, P.; Vicanek, M.

    1996-01-01

    The flux of recoil atoms in atomic collision cascades induced by an ion beam or another source of energetic particles in a material is known to approach isotropy at kinetic energies far below the beam energy. A variety of irradiation effects can be explained satisfactorily on the basis of an isotropic particle flux, but significant deviations from this simple behavior are known to exist. While numerous examples have been studied by numerical simulation of cascade processes, the systematics is, by and large, unknown. The present study aims at general scaling properties and estimates of the magnitude of moderate deviations from isotropy and their spatial dependence for a wide range of beam and material parameters. Anisotropies introduced by crystal structure are ignored. Although it is well established that cascade anisotropy is related to the momentum of beam particles, previous attempts to quantify this relation have failed. We have found that there are two leading correction terms to the isotropic particle flux, a well-known term centered around the beam direction as a symmetry axis and a new term proportional to the gradient of the deposited-energy density. As a general rule the two contributions are either both significant or both negligible. Specific situations in which the gradient term dominates are, however, of considerable interest in applications. The parameters which characterize the anisotropy of collision cascades also determine the deposition of momentum, but the connection is less straightforward than asserted hitherto. General principles are first illustrated on the specific case of elastic-collision cascades under self-bombardment which contains the essentials. Thereafter several generalizations are made, including atomic binding forces and inelasticity as well as allowance for multicomponent materials. Application areas in mixing and sputtering are outlined. (au) 58 refs

  8. Acceptability and feasibility of an e-mental health intervention for parents of childhood cancer survivors: "Cascade".

    Science.gov (United States)

    Wakefield, Claire E; Sansom-Daly, Ursula M; McGill, Brittany C; Ellis, Sarah J; Doolan, Emma L; Robertson, Eden G; Mathur, Sanaa; Cohn, Richard J

    2016-06-01

    The aim of this study was to evaluate the feasibility and acceptability of "Cascade": an online, group-based, cognitive behavioral therapy intervention, delivered "live" by a psychologist, to assist parents of children who have completed cancer treatment. Forty-seven parents were randomized to Cascade (n = 25) or a 6-month waitlist (n = 22). Parents completed questionnaires at baseline, 1-2 weeks and 6 months post-intervention. Thirty parents completed full evaluations of the Cascade program (n = 21 randomized to Cascade, n = 9 completed Cascade post-waitlist). Ninety-six percent of Cascade participants completed the intervention (n = 24/25). Eighty percent of parents completed every questionnaire (mean completion time 25 min (SD = 12)). Cascade was described as at least "somewhat" helpful by all parents. None rated Cascade as "very/quite" burdensome. Parents reported that the "online format was easy to use" (n = 28, 93.3 %), "I learnt new skills" (n = 28, 93.3 %), and "I enjoyed talking to others" (n = 29, 96.7 %). Peer-to-peer benefits were highlighted by good group cohesion scores. Cascade is highly acceptable and feasible. Its online delivery mechanism may address inequities in post-treatment support for parents, a particularly acute concern for rural/remote families. Future research needs to establish the efficacy of the intervention. ACTRN12613000270718, https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?ACTRN=12613000270718.

  9. A Study of the Impact of Peak Demand on Increasing Vulnerability of Cascading Failures to Extreme Contingency Events

    Energy Technology Data Exchange (ETDEWEB)

    Vyakaranam, Bharat GNVSR; Vallem, Mallikarjuna R.; Nguyen, Tony B.; Samaan, Nader A.; Berscheid, Alan P.; Makarov, Yuri V.; Diao, Ruisheng

    2017-10-02

    The vulnerability of large power systems to cascading failures and major blackouts has become evident since the Northeast blackout in 1965. Based on analyses of the series of cascading blackouts in the past decade, the research community realized the urgent need to develop better methods, tools, and practices for performing cascading-outage analysis and for evaluating mitigations that are easily accessible by utility planning engineers. PNNL has developed the Dynamic Contingency Analysis Tool (DCAT) as an open-platform and publicly available methodology to help develop applications that aim to improve the capabilities of power planning engineers to assess the impact and likelihood of extreme contingencies and potential cascading events across their systems and interconnections. DCAT analysis will help identify potential vulnerabilities and allow study of mitigation solutions to reduce the risk of cascading outages in technically sound and effective ways. Using the DCAT capability, we examined the impacts of various load conditions to identify situations in which the power grid may encounter cascading outages that could lead to potential blackouts. This paper describes the usefulness of the DCAT tool and how it helps to understand potential impacts of load demand on cascading failures on the power system.

  10. EFSA Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids (CEF); Scientific Opinion on Flavouring Group Evaluation 21, Revision 3 (FGE.21Rev3): Thiazoles, thiophenes, thiazoline and thienyl derivatives from chemical groups 29 and 30

    DEFF Research Database (Denmark)

    Larsen, John Christian; Nørby, Karin Kristiane; Beltoft, Vibe Meister

    The Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids of the European Food Safety Authority was requested to evaluate 59 flavouring substances in the Flavouring Group Evaluation 21, including an additional three substances in this Revision 3, using the Procedure in Commiss......The Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids of the European Food Safety Authority was requested to evaluate 59 flavouring substances in the Flavouring Group Evaluation 21, including an additional three substances in this Revision 3, using the Procedure.......086, 15.090, 15.099, 15.114, 15.119 and 15.133] were considered to have genotoxic potential. The remaining 52 substances were evaluated through a stepwise approach (the Procedure) that integrates information on structure-activity relationships, intake from current uses, toxicological threshold of concern.......092, 15.093, 15.094, 15.096, 15.097, 15.106, 15.107, 15.129 and 15.135] evaluated through the Procedure, no appropriate NOAEL was available and additional data are required. Besides the safety assessment of these flavouring substances, the specifications for the materials of commerce have also been...

  11. EFSA Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids (CEF); Scientific Opinion on Flavouring Group Evaluation 300 (FGE.300): One cyclo-aliphatic amide from chemical group 33

    DEFF Research Database (Denmark)

    Larsen, John Christian; Nørby, Karin Kristiane; Beltoft, Vibe Meister

    The Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids of the European Food Safety Authority was requested to evaluate a flavouring substance in the Flavouring Group Evaluation 300 using the Procedure in Commission Regulation (EC) No 1565/2000. The substance was not conside......The Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids of the European Food Safety Authority was requested to evaluate a flavouring substance in the Flavouring Group Evaluation 300 using the Procedure in Commission Regulation (EC) No 1565/2000. The substance...... was not considered to have genotoxic potential. The substance was evaluated through a stepwise approach (the Procedure) that integrates information on structure-activity relationships, intake from current uses, toxicological threshold of concern, and available data on metabolism and toxicity. The Panel concluded...... that for the substance [FL-no: 16.115] evaluated through the Procedure, no appropriate NOAEL was available and additional data are required. Besides the safety assessment of this flavouring substance, the specifications for the materials of commerce have also been considered. The composition of the stereoisomeric...

  12. Cascade Analysis of a Floating Wind Turbine Rotor

    International Nuclear Information System (INIS)

    Eliassen, Lene; Jakobsen, Jasna B; Knauer, Andreas; Nielsen, Finn Gunnar

    2014-01-01

    Mounting a wind turbine on a floating foundation introduces more complexity to the aerodynamic loading. The floater motion contains a wide range of frequencies. To study some of the basic dynamic load effect on the blades due to these motions, a two-dimensional cascade approach, combined with a potential vortex method, is used. This is an alternative method to study the aeroelastic behavior of wind turbines that is different from the traditional blade element momentum method. The analysis tool demands little computational power relative to a full three dimensional vortex method, and can handle unsteady flows. When using the cascade plane, a ''cut'' is made at a section of the wind turbine blade. The flow is viewed parallel to the blade axis at this cut. The cascade model is commonly used for analysis of turbo machineries. Due to the simplicity of the code it requires little computational resources, however it has limitations in its validity. It can only handle two-dimensional potential flow, i.e. including neither three-dimensional effects, such as the tip loss effect, nor boundary layers and stall effects are modeled. The computational tool can however be valuable in the overall analysis of floating wind turbines, and evaluation of the rotor control system. A check of the validity of the vortex panel code using an airfoil profile is performed, comparing the variation of the lift force, to the theoretically derived Wagner function. To analyse the floating wind turbine, a floating structure with hub height 90 m is chosen. An axial motion of the rotor is considered

  13. Probabilistic study of cascading failures in complex interdependent lifeline systems

    International Nuclear Information System (INIS)

    Hernandez-Fajardo, Isaac; Dueñas-Osorio, Leonardo

    2013-01-01

    The internal complexity of lifeline systems and their standing interdependencies can operate in conjunction to amplify the negative effects of external disruptions. This paper introduces a simulation-based methodology to evaluate the joint impact of interdependence, component fragilities, and cascading failures in systemic fragility estimates. The proposed strategy uses a graph model of interdependent networks, an enhanced betweenness centrality for cascading failures approximation, and an interdependence model accounting for coupling uncertainty in the simulation of damage propagation for probabilistic performance assessment. This methodology is illustrated through its application to a realistic set of power and water networks subjected to earthquake scenarios and random failures. Test case results reveal two key insights: (1) the intensity of a perturbation influences interdependent systemic fragility by shaping the magnitudes of initial component damage and, sometimes counter-intuitively, the subsequent interdependence effects and (2) increasing local redundancy mitigates the effects of interdependence on systemic performance, but such intervention is incapable of eliminating interdependent effects completely. The previous insights provide basic guidelines for the design of systemic retrofitting policies. Additionally, the limitations of local capacity redundancy as a fragility control measure highlight the need for a critical assessment of intervention strategies in distributed infrastructure networks. Future work will assess the fragility-reduction efficiency of strategies involving informed manipulation of individual systemic topologies and the interdependence interfaces connecting them. - Highlights: ► An new simulation methodology effectively produces interdependent fragility assessments, IFAs. ► IFAs include perturbation action, cascading failures, and interdependent effects. ► Method tested using coupled networks exposed to earthquake and random

  14. EFSA CEF Panel (EFSA Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids) , 2016. Scientific Opinion on Flavouring Group Evaluation 90, Revision 1 (FGE.90Rev1): consideration of six substances evaluated by JECFA (68th meeting) structurally related to aliphatic, alicyclic and aromatic saturated and unsaturated tertiary alcohols, aromatic tertiary alcohols and their esters evaluated by EFSA in FGE.18Rev1 and FGE.75Rev1

    DEFF Research Database (Denmark)

    Beltoft, Vibe Meister; Nørby, Karin Kristiane

    The Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids of EFSA was requested to consider evaluations of flavouring substances assessed since 2000 by the Joint FAO/WHO Expert Committee on Food Additives (the JECFA), and to decide whether further evaluation is necessary...... refined exposure estimation and to judge whether a re-evaluation according to the Procedure is needed....

  15. Modeling the role of covalent enzyme modification in Escherichia coli nitrogen metabolism

    International Nuclear Information System (INIS)

    Kidd, Philip B; Wingreen, Ned S

    2010-01-01

    In the bacterium Escherichia coli, the enzyme glutamine synthetase (GS) converts ammonium into the amino acid glutamine. GS is principally active when the cell is experiencing nitrogen limitation, and its activity is regulated by a bicyclic covalent modification cascade. The advantages of this bicyclic-cascade architecture are poorly understood. We analyze a simple model of the GS cascade in comparison to other regulatory schemes and conclude that the bicyclic cascade is suboptimal for maintaining metabolic homeostasis of the free glutamine pool. Instead, we argue that the lag inherent in the covalent modification of GS slows the response to an ammonium shock and thereby allows GS to transiently detoxify the cell, while maintaining homeostasis over longer times

  16. EFSA CEF Panel (EFSA Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids), 2015. Scientific Opinion on Flavouring Group Evaluation 303, Revision 1 (FGE.303Rev1): Spilanthol from chemical group 30

    DEFF Research Database (Denmark)

    Beltoft, Vibe Meister; Nørby, Karin Kristiane

    The Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids of the European Food Safety Authority was requested to evaluate the flavouring substance spilanthol [FL-no: 16.121] in Flavouring Group Evaluation 303, Revision 1, using the Procedure according to Commission Regulation...... (MSDI) approach. Besides the safety assessment of the flavouring substance, the specifications for the material of commerce have also been considered. Adequate specifications including complete purity criteria and identity for the material of commerce have been provided for the candidate substance....

  17. EFSA CEF Panel (EFSA Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids), 2015. Scientific Opinion on Flavouring Group Evaluation 25, Revision 3 (FGE.25Rev3): Aliphatic hydrocarbons from chemical group 31

    DEFF Research Database (Denmark)

    Nørby, Karin Kristiane; Beltoft, Vibe Meister

    The Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids of the European Food Safety Authority was requested to evaluate 14 flavouring substances in the Flavouring Group Evaluation 25, Revision 3, using the Procedure in Commission Regulation (EC) No 1565/2000. None...... on the basis of the MSDI approach. Besides the safety assessment of these flavouring substances, the specifications for the materials of commerce have also been considered. Adequate specifications including complete purity and identity criteria for the materials of commerce have been provided for all 14...

  18. The correlation of defect distribution in collisional phase with measured cascade collapse probability

    International Nuclear Information System (INIS)

    Morishita, K.; Ishino, S.; Sekimura, N.

    1995-01-01

    The spatial distributions of atomic displacement at the end of the collisional phase of cascade damage processes were calculated using the computer simulation code MARLOWE, which is based on the binary collision approximation (BCA). The densities of the atomic displacement were evaluated in high dense regions (HDRs) of cascades in several pure metals (Fe, Ni, Cu, Ag, Au, Mo and W). They were compared with the measured cascade collapse probabilities reported in the literature where TEM observations were carried out using thin metal foils irradiated by low-dose ions at room temperature. We found that there exists the minimum or ''critical'' values of the atomic displacement densities for the HDR to collapse into TEM-visible vacancy clusters. The critical densities are generally independent of the cascade energy in the same metal. Furthermore, the material dependence of the critical densities can be explained by the difference in the vacancy mobility at the melting temperature of target materials. This critical density calibration, which is extracted from the ion-irradiation experiments and the BCA simulations, is applied to estimation of cascade collapse probabilities in the metals irradiated by fusion neutrons. (orig.)

  19. Evaluation of an egg yolk enzyme-linked immunosorbent assay antibody test and its use to assess the prevalence of Mycoplasma gallisepticum infection in laying hens in Italy

    Directory of Open Access Journals (Sweden)

    Marco Tamba

    2010-01-01

    Full Text Available The prevalence of Mycoplasma gallisepticum infection in commercial layers was established by the presence of antibodies in eggs. Saline-extracted yolks were used with a commercial enzyme-linked immunosorbent assay kit. For the prevalence study, yolks from 30 eggs were obtained from each of 66 flocks coming from 36 layer farms. The prevalence of egg antibodies to Mycoplasma gallisepticum was 33.3% in single-age farms and 77.8% in multi-age farms. In 27 flocks, antibody titers were compared with results obtained from blood samples taken in the same flock and in the same period and analyzed with the same kit. This study has confirmed that egg yolk enzyme-linked immunosorbent assay antibody test is a suitable and practical approach for assessing the flock prevalence of Mycoplasma gallisepticum infection in layer hens.

  20. Quantum Cascade Lasers Modulation and Applications

    Science.gov (United States)

    Luzhansky, Edward

    The mid-wave IR (MWIR) spectral band, extending from 3 to 5 microns, is considered to be a low loss atmospheric window. There are several spectral sub-bands with relatively low atmospheric attenuation in this region making it popular for various commercial and military applications. Relatively low thermal and solar background emissions, effective penetration through the natural and anthropogenic obscurants and eye safety add to the long list of advantages of MWIR wavelengths. Quantum Cascade Lasers are compact semiconductor devices capable of operating in MWIR spectrum. They are based on inter-subband transitions in a multiple-quantum-well (QW) hetero-structure, designed by means of band-structure engineering. The inter-subband nature of the optical transition has several key advantages. First, the emission wavelength is primarily a function of the QW thickness. This characteristic allows choosing well-understood and reliable semiconductors for the generation of light in a wavelength range of interest. Second, a cascade process in which tens of photons are generated per injected electron. This cascading process is behind the intrinsic high-power capabilities of QCLs. This dissertation is focused on modulation properties of Quantum Cascade Lasers. Both amplitude and phase/frequency modulations were studied including modulation bandwidth, modulation efficiency and chirp linearity. Research was consisted of the two major parts. In the first part we describe the theory of frequency modulation (FM) response of Distributed Feedback Quantum Cascade Lasers (DFB QCL). It includes cascading effect on the QCL's maximum modulation frequency. The "gain levering" effect for the maximum FM response of the two section QCLs was studied as well. In the second part of research we concentrated on the Pulse Position Amplitude Modulation of a single section QCL. The low complexity, low size, weight and power Mid-Wavelength Infra-Red optical communications transceiver concept is

  1. An integrated software system for core design and safety analyses: Cascade-3D

    International Nuclear Information System (INIS)

    Wan De Velde, A.; Finnemann, H.; Hahn, T.; Merk, S.

    1999-01-01

    The new Siemens program system CASCADE-3D (Core Analysis and Safety Codes for Advanced Design Evaluation) links some of the most advanced code packages for in-core fuel management and accident analysis: SAV95, PANBOX/COBRA and RELAP5. Consequently by using CASCADE-3D the potential of modern fuel assemblies and in-core fuel management strategies can be much better utilized because safety margins which had been reduced due to conservative methods are now predicted more accurately. By this innovative code system the customers can now take full advantage of the recent progress in fuel assembly design and in-core fuel management. (authors)

  2. The integrated code system CASCADE-3D for advanced core design and safety analysis

    International Nuclear Information System (INIS)

    Neufert, A.; Van de Velde, A.

    1999-01-01

    The new program system CASCADE-3D (Core Analysis and Safety Codes for Advanced Design Evaluation) links some of Siemens advanced code packages for in-core fuel management and accident analysis: SAV95, PANBOX/COBRA and RELAP5. Consequently by using CASCADE-3D the potential of modern fuel assemblies and in-core fuel management strategies can be much better utilized because safety margins which had been reduced due to conservative methods are now predicted more accurately. By this innovative code system the customers can now take full advantage of the recent progress in fuel assembly design and in-core fuel management.(author)

  3. Spatial localization of the first and last enzymes effectively connects active metabolic pathways in bacteria

    OpenAIRE

    Meyer, Pablo; Cecchi, Guillermo; Stolovitzky, Gustavo

    2014-01-01

    Background Although much is understood about the enzymatic cascades that underlie cellular biosynthesis, comparatively little is known about the rules that determine their cellular organization. We performed a detailed analysis of the localization of E.coli GFP-tagged enzymes for cells growing exponentially. Results We found that out of 857 globular enzymes, at least 219 have a discrete punctuate localization in the cytoplasm and catalyze the first or the last reaction in 60% of biosynthetic ...

  4. A clinical trial of the angiotensin-converting-enzyme inhibitor trandolapril in patients with left ventricular dysfunction after myocardial infarction. Trandolapril Cardiac Evaluation (TRACE) Study Group

    DEFF Research Database (Denmark)

    Køber, L; Torp-Pedersen, C; Carlsen, J E

    1995-01-01

    myocardial infarctions confirmed by enzyme studies. A total of 2606 patients had echocardiographic evidence of left ventricular systolic dysfunction (ejection fraction, ....86; 95 percent confidence interval, 0.66 to 1.13; P = 0.29). CONCLUSIONS. Long-term treatment with trandolapril in patients with reduced left ventricular function soon after myocardial infarction significantly reduced the risk of overall mortality, mortality from cardiovascular causes, sudden death...

  5. Cost-effective production of cellulose hydrolysing enzymes from Trichoderma sp. RCK65 under SSF and its evaluation in saccharification of cellulosic substrates.

    Science.gov (United States)

    Chakraborty, Subhojit; Gupta, Rishi; Jain, Kavish Kumar; Kuhad, Ramesh Chander

    2016-11-01

    Trichoderma sp. is a potential cellulase producing mesophilic fungi which grow under mild acidic condition. In this study, growth and nutritional conditions were manipulated for the maximum and cost-effective production of cellulase using lab strain Trichoderma sp. RCK65 and checked for its efficiency in hydrolysis of Prosopis juliflora (a woody substrate). Preliminary studies suggested that when 48 h old secondary fungal culture (20 % v/w) was inoculated in wheat bran moistened with mineral salt solution (pH 4.5 and 1:3 solid to moisture ratio), incubated at 30 °C and after 72 h, it produced maximum cellulase (CMCase 145 U/gds, FPase 38 U/gds and β-glucosidase 105 U/gds). However, using statistical approach a S:L ratio (1:1) was surprisingly found to be optimum that improved cellulase that is CMCase activity by 6.21 %, FPase activity by 23.68 % and β-glucosidase activity by 37.28 %. The estimated cost of crude enzyme (Rs. 5.311/1000 FPase units) seems to be economically feasible which may be due to high enzyme titre, less cultivation time and low media cost. Moreover, when the crude enzyme was used to saccharify pretreated Prosopis juliflora (a woody substrate), it resulted up to 83 % (w/w) saccharification.

  6. Estimating optical feedback from a chalcogenide fiber in mid-infrared quantum cascade lasers

    Directory of Open Access Journals (Sweden)

    L. Jumpertz

    2016-10-01

    Full Text Available The amount of optical feedback originating from a chalcogenide fiber used to couple light from a mid-infrared quantum cascade laser is evaluated experimentally. Threshold reduction measurements on the fibered laser, combined with an analytical study of a rate equations model of the laser under optical feedback, allow estimating the feedback strength between 11% and 15% depending on the fiber cleavage quality. While this remains below the frontier of the chaotic regime, it is sufficient to deeply modify the optical spectrum of a quantum cascade laser. Hence for applications such as gas spectroscopy, where the shape of the optical spectrum is of prime importance, the use of mid-infrared optical isolators may be necessary for fibered quantum cascade lasers to be fully exploited.

  7. A method for measuring the velocity flow field in the vicinity of a moving cascade

    International Nuclear Information System (INIS)

    Bammert, K.; Mobarak, A.

    1977-01-01

    Centrifugal compressors and blowers are often used for recycling the coolant gas in gas-cooled reactors. To achieve the required pressure ratios, highly loaded centrifugal compressors are built. The paper deals with a method of measuring the flow field in the vicinity of a moving impeller or cascade with hot wires. The relative flow pattern induced ahead of a cascade or impeller or the rotating wakes behind a moving cascade (which is important for loss evaluation) could be now measured with the help of a single hot wire. The wire should be rotated about the axis of the probe for 3 different inclinations with respect to the approaching flow. The method has been used for measuring the flow field in the vicinity of the inducer of a highly loaded centrifugal compressor. The results and the accuracy of the method are discussed and the mean values have been compared with the theoretically estimated velocities. (orig.) [de

  8. Realized gains from block-plot coastal Douglas-fir trials in the northern Oregon Cascades

    Science.gov (United States)

    Terrence Z. Ye; Keith J.S. Jayawickrama; J. Bradley. St. Clair

    2010-01-01

    Realized gains for coastal Douglas-fir (Pseudotsuga menziesii var. menziesii) were evaluated using data collected from 15-year-old trees from five field trials planted in large block plots in the northern Oregon Cascades. Three populations with different genetic levels (elite--high predicted gain; intermediate--moderate predicted gain; and an...

  9. Non-radiometric immunoassays fluoroimmunoassay (FIA) and fluorometric enzyme immunoassay (FEIA) and radioimmunoassay (RIA) for evaluation of thyroid function in normal and hypothyroid dogs

    Energy Technology Data Exchange (ETDEWEB)

    Jerico, M.M.; Larsson, C.E. [Sao Paulo Univ., SP (Brazil). Faculdade de Medicina Veterinaria e Zootecnia. Dept. de Clinica Medica]. E-mail: marciajerico@hotmail.com; Mendonca, B.B. [Sao Paulo Univ., SP (Brazil). Faculdade de Medicina . Lab. de Hormonios e Genetica Molecular; Otsuka, M. [Sao Paulo Univ., SP (Brazil). Faculdade de Medicina Veterinaria e Zootecnia. Hospital Veterinario; Maganin Junior, A. [Canil da Policia Militar do Estado de Sao Paulo, SP (Brazil)

    2001-07-01

    We proposed the comparison of thyroxine (T4) and free thyroxine (FT4) measurements by fluoroimmunoassay (FIA) and fluorometric enzyme immunoassay (FEIA) with radioimmunoassay (RIA) in thyroid function evaluation of normal (n=50) and hypothyroid dogs (n=9). T4 and FT4 serum concentrations were measured in basal conditions and 6 h after TRH stimulation (200 mug/IV). All our reference values are based on the 5th and 95th percentile. The reference values for basal T4 in healthy dogs were 0.50 to 2.35 mug/dL (FIA), 0.50 to 2.51 mug/dL (FEIA) and 0.35 to 0.74 mug/dL (RIA). After TRH, the values were >= 1.37 mug/dL (FIA), >= 0,26 mug/dL (FEIA) and >= 0.40 mug/dL (RIA). Basal FT4 values in healthy dogs were 0.65 to 2.20 ng/dL (FIA), 0.38 to 1.43 ng/dL (FEIA) and 0.10 to 1.24 ng/dL (RIA). After TRH, the values were >= 1.30 ng/dL (FIA), >= 0.77 ng/dL (FEIA) and >=0.50 ng/dL (RIA). In hypothyroid dogs, the mean +- SD for T4 in basal conditions and after TRH were 0.24 +- 0.20 mug/dL and 0.26 +- 0.20 mug/dL (FIA), 0.27 +- 0.12 mug/dL and 0.32 +- 0.51 mug/dL (FEIA) and 0.19 +- 0.30 mug/dL and 0,24 +- 0.09 mug/dL (RIA), respectively. In the same group the mean +- SD basal FT4 values and after TRH were 0.28 +- 0.33 ng/dL and 0.28 +- 0.39 ng/dL (FIA), 0,12 +- 0.26 ng/dL and 0.23 +- 0.56 ng/dL (FEIA) and 0,15 +- 0,15 ng/dL and 0,17 +- 0,28 ng/dL (RIA), respectively. Significant differences (p<0.05) between the normal and hypothyroid groups (Kruskall-Wallis test) were observed in the three methods and between basal and stimulated values in normal dogs (Wilcoxon test), by the three methods. The best sensitivity for diagnosing hypothyroidism was obtained through T4 values (100%), and the best specificity through FT4 values (100%), both determined by FIA after TRH stimulation. We conclude that T4 and FT4 measured by fluoroimmunoassay after TRH stimulation can be an excellent alternative. (author)

  10. Non-radiometric immunoassays (fluoroimmunoassay (FIA) and fluorometric enzyme immunoassay (FEIA) and radioimmunoassay (RIA) for evaluation of thyroid function in normal and hypothyroid dogs

    International Nuclear Information System (INIS)

    Jerico, M.M.; Larsson, C.E.

    2001-01-01

    We proposed the comparison of thyroxine (T4) and free thyroxine (FT4) measurements by fluoroimmunoassay (FIA) and fluorometric enzyme immunoassay (FEIA) with radioimmunoassay (RIA) in thyroid function evaluation of normal (n=50) and hypothyroid dogs (n=9). T4 and FT4 serum concentrations were measured in basal conditions and 6 h after TRH stimulation (200 mug/IV). All our reference values are based on the 5th and 95th percentile. The reference values for basal T4 in healthy dogs were 0.50 to 2.35 mug/dL (FIA), 0.50 to 2.51 mug/dL (FEIA) and 0.35 to 0.74 mug/dL (RIA). After TRH, the values were >= 1.37 mug/dL (FIA), >= 0,26 mug/dL (FEIA) and >= 0.40 mug/dL (RIA). Basal FT4 values in healthy dogs were 0.65 to 2.20 ng/dL (FIA), 0.38 to 1.43 ng/dL (FEIA) and 0.10 to 1.24 ng/dL (RIA). After TRH, the values were >= 1.30 ng/dL (FIA), >= 0.77 ng/dL (FEIA) and >=0.50 ng/dL (RIA). In hypothyroid dogs, the mean +- SD for T4 in basal conditions and after TRH were 0.24 +- 0.20 mug/dL and 0.26 +- 0.20 mug/dL (FIA), 0.27 +- 0.12 mug/dL and 0.32 +- 0.51 mug/dL (FEIA) and 0.19 +- 0.30 mug/dL and 0,24 +- 0.09 mug/dL (RIA), respectively. In the same group the mean +- SD basal FT4 values and after TRH were 0.28 +- 0.33 ng/dL and 0.28 +- 0.39 ng/dL (FIA), 0,12 +- 0.26 ng/dL and 0.23 +- 0.56 ng/dL (FEIA) and 0,15 +- 0,15 ng/dL and 0,17 +- 0,28 ng/dL (RIA), respectively. Significant differences (p<0.05) between the normal and hypothyroid groups (Kruskall-Wallis test) were observed in the three methods and between basal and stimulated values in normal dogs (Wilcoxon test), by the three methods. The best sensitivity for diagnosing hypothyroidism was obtained through T4 values (100%), and the best specificity through FT4 values (100%), both determined by FIA after TRH stimulation. We conclude that T4 and FT4 measured by fluoroimmunoassay after TRH stimulation can be an excellent alternative. (author)

  11. Enzymes for improved biomass conversion

    Science.gov (United States)

    Brunecky, Roman; Himmel, Michael E.

    2016-02-02

    Disclosed herein are enzymes and combinations of the enzymes useful for the hydrolysis of cellulose and the conversion of biomass. Methods of degrading cellulose and biomass using enzymes and cocktails of enzymes are also disclosed.

  12. EFSA Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids (CEF); Scientific Opinion on Flavouring Group Evaluation 10, Revision 2 (FGE.10Rev2): Aliphatic primary and secondary saturated and unsaturated alcohols, aldehydes, acetals, carboxylic acids and esters containing

    DEFF Research Database (Denmark)

    Larsen, John Christian; Nørby, Karin Kristiane; Beltoft, Vibe Meister

    The Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids of the European Food Safety Authority was requested to evaluate 61 flavouring substances in the Flavouring Group Evaluation 10, Revision 2, using the Procedure in Commission Regulation (EC) No 1565/2000. None of the sub......The Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids of the European Food Safety Authority was requested to evaluate 61 flavouring substances in the Flavouring Group Evaluation 10, Revision 2, using the Procedure in Commission Regulation (EC) No 1565/2000. None...... of the substances were considered to have genotoxic potential. The substances were evaluated through a stepwise approach (the Procedure) that integrates information on structure-activity relationships, intake from current uses, toxicological threshold of concern, and available data on metabolism and toxicity....... The Panel concluded that the 61 substances do not give rise to safety concerns at their levels of dietary intake, estimated on the basis of the MSDI approach. Besides the safety assessment of these flavouring substances, the specifications for the materials of commerce have also been considered. For four...

  13. EFSA Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids (CEF); Scientific Opinion on Flavouring Group Evaluation 25, Revision 2 (FGE.25Rev2): Aliphatic and aromatic hydrocarbons from chemical group 31

    DEFF Research Database (Denmark)

    Larsen, John Christian; Nørby, Karin Kristiane; Beltoft, Vibe Meister

    The Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids of the European Food Safety Authority was requested to evaluate 37 flavouring substances in the Flavouring Group Evaluation 25, Revision 2, using the Procedure in Commission Regulation (EC) No 1565/2000. None of the sub......The Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids of the European Food Safety Authority was requested to evaluate 37 flavouring substances in the Flavouring Group Evaluation 25, Revision 2, using the Procedure in Commission Regulation (EC) No 1565/2000. None...... of the substances were considered to have genotoxic potential. The substances were evaluated through a stepwise approach (the Procedure) that integrates information on structure-activity relationships, intake from current uses, toxicological threshold of concern, and available data on metabolism and toxicity...... assessment of these flavouring substances, the specifications for the materials of commerce have also been considered. For five substances, the composition of the stereoisomeric mixture has to be specified further....

  14. Cascading failure in the wireless sensor scale-free networks

    Science.gov (United States)

    Liu, Hao-Ran; Dong, Ming-Ru; Yin, Rong-Rong; Han, Li

    2015-05-01

    In the practical wireless sensor networks (WSNs), the cascading failure caused by a failure node has serious impact on the network performance. In this paper, we deeply research the cascading failure of scale-free topology in WSNs. Firstly, a cascading failure model for scale-free topology in WSNs is studied. Through analyzing the influence of the node load on cascading failure, the critical load triggering large-scale cascading failure is obtained. Then based on the critical load, a control method for cascading failure is presented. In addition, the simulation experiments are performed to validate the effectiveness of the control method. The results show that the control method can effectively prevent cascading failure. Project supported by the Natural Science Foundation of Hebei Province, China (Grant No. F2014203239), the Autonomous Research Fund of Young Teacher in Yanshan University (Grant No. 14LGB017) and Yanshan University Doctoral Foundation, China (Grant No. B867).

  15. Invariant mass distributions in cascade decays

    CERN Document Server

    Miller, D J; Raklev, A R

    2006-01-01

    We derive analytical expressions for the shape of the invariant mass distributions of massless Standard Model endproducts in cascade decays involving massive New Physics (NP) particles, D -> Cc -> Bbc -> Aabc, where the final NP particle A in the cascade is unobserved and where two of the particles a, b, c may be indistinguishable. Knowledge of these expressions can improve the determination of NP parameters at the LHC. The shape formulas are composite, but contain nothing more complicated than logarithms of simple expressions. We study the effects of cuts, final state radiation and detector effects on the distributions through Monte Carlo simulations, using a supersymmetric model as an example. We also consider how one can deal with the width of NP particles and with combinatorics from the misidentification of final state particles. The possible mismeasurements of NP masses through `feet' in the distributions are discussed. Finally, we demonstrate how the effects of different spin configurations can be inclu...

  16. Invariant mass distributions in cascade decays

    International Nuclear Information System (INIS)

    Miller, David J.; Osland, Per; Raklev, Are R.

    2006-01-01

    We derive analytical expressions for the shape of the invariant mass distributions of massless Standard Model endproducts in cascade decays involving massive New Physics (NP) particles, D→Cc→Bbc→Aabc, where the final NP particle A in the cascade is unobserved and where two of the particles a, b, c may be indistinguishable. Knowledge of these expressions can improve the determination of NP parameters at the LHC. The shape formulas are composite, but contain nothing more complicated than logarithms of simple expressions. We study the effects of cuts, final state radiation and detector effects on the distributions through Monte Carlo simulations, using a supersymmetric model as an example. We also consider how one can deal with the width of NP particles and with combinatorics from the misidentification of final state particles. The possible mismeasurements of NP masses through 'feet' in the distributions are discussed. Finally, we demonstrate how the effects of different spin configurations can be included in the distributions

  17. Cascade-based attacks on complex networks

    Science.gov (United States)

    Motter, Adilson E.; Lai, Ying-Cheng

    2002-12-01

    We live in a modern world supported by large, complex networks. Examples range from financial markets to communication and transportation systems. In many realistic situations the flow of physical quantities in the network, as characterized by the loads on nodes, is important. We show that for such networks where loads can redistribute among the nodes, intentional attacks can lead to a cascade of overload failures, which can in turn cause the entire or a substantial part of the network to collapse. This is relevant for real-world networks that possess a highly heterogeneous distribution of loads, such as the Internet and power grids. We demonstrate that the heterogeneity of these networks makes them particularly vulnerable to attacks in that a large-scale cascade may be triggered by disabling a single key node. This brings obvious concerns on the security of such systems.

  18. Cascade Apartments: Deep Energy Multifamily Retrofit

    Energy Technology Data Exchange (ETDEWEB)

    Gordon, A. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Mattheis, L. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Kunkle, R. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Howard, L. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Lubliner, M. [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2014-02-01

    In December of 2009-10, King County Housing Authority (KCHA) implemented energy retrofit improvements in the Cascade multifamily community, located in Kent, Washington (marine climate.)This research effort involved significant coordination from stakeholders KCHA, WA State Department of Commerce, utility Puget Sound Energy, and Cascade tenants. This report focuses on the following three primary BA research questions : 1. What are the modeled energy savings using DOE low income weatherization approved TREAT software? 2. How did the modeled energy savings compare with measured energy savings from aggregate utility billing analysis? 3. What is the Savings to Investment Ratio (SIR) of the retrofit package after considering utility window incentives and KCHA capitol improvement funding.

  19. Immobilized enzymes and cells

    Energy Technology Data Exchange (ETDEWEB)

    Bucke, C; Wiseman, A

    1981-04-04

    This article reviews the current state of the art of enzyme and cell immobilization and suggests advances which might be made during the 1980's. Current uses of immobilized enzymes include the use of glucoamylase in the production of glucose syrups from starch and glucose isomerase in the production of high fructose corn syrup. Possibilities for future uses of immobilized enzymes and cells include the utilization of whey and the production of ethanol.

  20. Profiling the orphan enzymes

    Science.gov (United States)

    2014-01-01

    The emergence of Next Generation Sequencing generates an incredible amount of sequence and great potential for new enzyme discovery. Despite this huge amount of data and the profusion of bioinformatic methods for function prediction, a large part of known enzyme activities is still lacking an associated protein sequence. These particular activities are called “orphan enzymes”. The present review proposes an update of previous surveys on orphan enzymes by mining the current content of public databases. While the percentage of orphan enzyme activities has decreased from 38% to 22% in ten years, there are still more than 1,000 orphans among the 5,000 entries of the Enzyme Commission (EC) classification. Taking into account all the reactions present in metabolic databases, this proportion dramatically increases to reach nearly 50% of orphans and many of them are not associated to a known pathway. We extended our survey to “local orphan enzymes” that are activities which have no representative sequence in a given clade, but have at least one in organisms belonging to other clades. We observe an important bias in Archaea and find that in general more than 30% of the EC activities have incomplete sequence information in at least one superkingdom. To estimate if candidate proteins for local orphans could be retrieved by homology search, we applied a simple strategy based on the PRIAM software and noticed that candidates may be proposed for an important fraction of local orphan enzymes. Finally, by studying relation between protein domains and catalyzed activities, it appears that newly discovered enzymes are mostly associated with already known enzyme domains. Thus, the exploration of the promiscuity and the multifunctional aspect of known enzyme families may solve part of the orphan enzyme issue. We conclude this review with a presentation of recent initiatives in finding proteins for orphan enzymes and in extending the enzyme world by the discovery of new

  1. Output Control Using Feedforward And Cascade Controllers

    Science.gov (United States)

    Seraji, Homayoun

    1990-01-01

    Report presents theoretical study of open-loop control elements in single-input, single-output linear system. Focus on output-control (servomechanism) problem, in which objective is to find control scheme that causes output to track certain command inputs and to reject certain disturbance inputs in steady state. Report closes with brief discussion of characteristics and relative merits of feedforward, cascade, and feedback controllers and combinations thereof.

  2. Modeling techniques for quantum cascade lasers

    Energy Technology Data Exchange (ETDEWEB)

    Jirauschek, Christian [Institute for Nanoelectronics, Technische Universität München, D-80333 Munich (Germany); Kubis, Tillmann [Network for Computational Nanotechnology, Purdue University, 207 S Martin Jischke Drive, West Lafayette, Indiana 47907 (United States)

    2014-03-15

    Quantum cascade lasers are unipolar semiconductor lasers covering a wide range of the infrared and terahertz spectrum. Lasing action is achieved by using optical intersubband transitions between quantized states in specifically designed multiple-quantum-well heterostructures. A systematic improvement of quantum cascade lasers with respect to operating temperature, efficiency, and spectral range requires detailed modeling of the underlying physical processes in these structures. Moreover, the quantum cascade laser constitutes a versatile model device for the development and improvement of simulation techniques in nano- and optoelectronics. This review provides a comprehensive survey and discussion of the modeling techniques used for the simulation of quantum cascade lasers. The main focus is on the modeling of carrier transport in the nanostructured gain medium, while the simulation of the optical cavity is covered at a more basic level. Specifically, the transfer matrix and finite difference methods for solving the one-dimensional Schrödinger equation and Schrödinger-Poisson system are discussed, providing the quantized states in the multiple-quantum-well active region. The modeling of the optical cavity is covered with a focus on basic waveguide resonator structures. Furthermore, various carrier transport simulation methods are discussed, ranging from basic empirical approaches to advanced self-consistent techniques. The methods include empirical rate equation and related Maxwell-Bloch equation approaches, self-consistent rate equation and ensemble Monte Carlo methods, as well as quantum transport approaches, in particular the density matrix and non-equilibrium Green's function formalism. The derived scattering rates and self-energies are generally valid for n-type devices based on one-dimensional quantum confinement, such as quantum well structures.

  3. Modeling techniques for quantum cascade lasers

    Science.gov (United States)

    Jirauschek, Christian; Kubis, Tillmann

    2014-03-01

    Quantum cascade lasers are unipolar semiconductor lasers covering a wide range of the infrared and terahertz spectrum. Lasing action is achieved by using optical intersubband transitions between quantized states in specifically designed multiple-quantum-well heterostructures. A systematic improvement of quantum cascade lasers with respect to operating temperature, efficiency, and spectral range requires detailed modeling of the underlying physical processes in these structures. Moreover, the quantum cascade laser constitutes a versatile model device for the development and improvement of simulation techniques in nano- and optoelectronics. This review provides a comprehensive survey and discussion of the modeling techniques used for the simulation of quantum cascade lasers. The main focus is on the modeling of carrier transport in the nanostructured gain medium, while the simulation of the optical cavity is covered at a more basic level. Specifically, the transfer matrix and finite difference methods for solving the one-dimensional Schrödinger equation and Schrödinger-Poisson system are discussed, providing the quantized states in the multiple-quantum-well active region. The modeling of the optical cavity is covered with a focus on basic waveguide resonator structures. Furthermore, various carrier transport simulation methods are discussed, ranging from basic empirical approaches to advanced self-consistent techniques. The methods include empirical rate equation and related Maxwell-Bloch equation approaches, self-consistent rate equation and ensemble Monte Carlo methods, as well as quantum transport approaches, in particular the density matrix and non-equilibrium Green's function formalism. The derived scattering rates and self-energies are generally valid for n-type devices based on one-dimensional quantum confinement, such as quantum well structures.

  4. How periodic are terahertz quantum cascade lasers?

    International Nuclear Information System (INIS)

    Kubis, T; Vogl, P

    2009-01-01

    We apply a novel non-equilibrium Green's function method for open quantum devices to analyze quantum cascade lasers. We find the carrier distribution in typical resonant phonon THz-QCLs to develop a periodicity that differs from the geometric periodicity of the QCL. We propose a design improvement that thermalizes electrons at threshold bias and thereby pins the electron density to the QCL periodicity.

  5. How periodic are terahertz quantum cascade lasers?

    Energy Technology Data Exchange (ETDEWEB)

    Kubis, T; Vogl, P, E-mail: tillmann.kubis@wsi.tum.d [Walter Schottky Institute, Technische Universitaet Muenchen, Am Coulombwall 3, 85748 Garching (Germany)

    2009-11-15

    We apply a novel non-equilibrium Green's function method for open quantum devices to analyze quantum cascade lasers. We find the carrier distribution in typical resonant phonon THz-QCLs to develop a periodicity that differs from the geometric periodicity of the QCL. We propose a design improvement that thermalizes electrons at threshold bias and thereby pins the electron density to the QCL periodicity.

  6. Cascade of circulations in fluid turbulence.

    Science.gov (United States)

    Eyink, Gregory L

    2006-12-01

    Kelvin's theorem on conservation of circulations is an essential ingredient of Taylor's theory of turbulent energy dissipation by the process of vortex-line stretching. In previous work, we have proposed a nonlinear mechanism for the breakdown of Kelvin's theorem in ideal turbulence at infinite Reynolds number. We develop here a detailed physical theory of this cascade of circulations. Our analysis is based upon an effective equation for large-scale coarse-grained velocity, which contains a turbulent-induced vortex force that can violate Kelvin's theorem. We show that singularities of sufficient strength, which are observed to exist in turbulent flow, can lead to nonvanishing dissipation of circulation for an arbitrarily small coarse-graining length in the effective equations. This result is an analog for circulation of Onsager's theorem on energy dissipation for singular Euler solutions. The physical mechanism of the breakdown of Kelvin's theorem is diffusion of lines of large-scale vorticity out of the advected loop. This phenomenon can be viewed as a classical analog of the Josephson-Anderson phase-slip phenomenon in superfluids due to quantized vortex lines. We show that the circulation cascade is local in scale and use this locality to develop concrete expressions for the turbulent vortex force by a multiscale gradient expansion. We discuss implications for Taylor's theory of turbulent dissipation and we point out some related cascade phenomena, in particular for magnetic flux in magnetohydrodynamic turbulence.

  7. Cascade laser applications: trends and challenges

    Science.gov (United States)

    d'Humières, B.; Margoto, Éric; Fazilleau, Yves

    2016-03-01

    When analyses need rapid measurements, cost effective monitoring and miniaturization, tunable semiconductor lasers can be very good sources. Indeed, applications like on-field environmental gas analysis or in-line industrial process control are becoming available thanks to the advantage of tunable semiconductor lasers. Advances in cascade lasers (CL) are revolutionizing Mid-IR spectroscopy with two alternatives: interband cascade lasers (ICL) in the 3-6μm spectrum and quantum cascade lasers (QCL), with more power from 3 to 300μm. The market is getting mature with strong players for driving applications like industry, environment, life science or transports. CL are not the only Mid-IR laser source. In fact, a strong competition is now taking place with other technologies like: OPO, VCSEL, Solid State lasers, Gas, SC Infrared or fiber lasers. In other words, CL have to conquer a share of the Mid-IR application market. Our study is a market analysis of CL technologies and their applications. It shows that improvements of components performance, along with the progress of infrared laser spectroscopy will drive the CL market growth. We compare CL technologies with other Mid-IR sources and estimate their share in each application market.

  8. Honeywell Cascade Distiller System Performance Testing Interim Results

    Science.gov (United States)

    Callahan, Michael R.; Sargusingh, Miriam

    2014-01-01

    The ability to recover and purify water through physiochemical processes is crucial for realizing long-term human space missions, including both planetary habitation and space travel. Because of their robust nature, distillation systems have been actively pursued as one of the technologies for water recovery. The Cascade Distillation System (CDS) is a vacuum rotary distillation system with potential for greater reliability and lower energy costs than existing distillation systems. The CDS was previously under development through Honeywell and NASA. In 2009, an assessment was performed to collect data to support down-selection and development of a primary distillation technology for application in a lunar outpost water recovery system. Based on the results of this testing, an expert panel concluded that the CDS showed adequate development maturity, TRL-4, together with the best product water quality and competitive weight and power estimates to warrant further development. The Advanced Exploration Systems (AES) Water Recovery Project (WRP) worked to address weaknesses identified by The Panel; namely bearing design and heat pump power efficiency. Testing at the NASA-JSC Advanced Exploration System Water Laboratory (AES Water Lab) using a prototype Cascade Distillation Subsystem (CDS) wastewater processor (Honeywell International, Torrance, Calif.) with test support equipment and control system developed by Johnson Space Center was performed to evaluate performance of the system with the upgrades. The CDS will also have been challenged with ISS analog waste streams and a subset of those being considered for Exploration architectures. This paper details interim results of the AES WRP CDS performance testing.

  9. EFSA Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids (CEF); Scientific Opinion on Flavouring Group Evaluation 17, Revision 2 (FEG.17Rev2): Pyrazine derivatives from chemical group 24

    DEFF Research Database (Denmark)

    Larsen, John Christian; Nørby, Karin Kristiane; Beltoft, Vibe Meister

    The Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids of the European Food Safety Authority was requested to evaluate 21 flavouring substances in the Flavouring Group Evaluation 17, Revision 2, using the Procedure in Commission Regulation (EC) No 1565/2000. From the in vitro...... substance [FL-no: 14.051] no intake data are available preventing it from being evaluated through the Procedure. The remaining 18 substances were evaluated through a stepwise approach that integrates information on structure-activity relationships, intake from current uses, toxicological threshold...... intake, estimated on the basis of the MSDI approach. For the remaining substance [FL-no: 14.052] additional toxicity data are required. Besides the safety assessment of these flavouring substances, the specifications for the materials of commerce have also been considered and for two substances...

  10. Metrological aspects of enzyme production

    International Nuclear Information System (INIS)

    Kerber, T M; Pereira-Meirelles, F V; Dellamora-Ortiz, G M

    2010-01-01

    Enzymes are frequently used in biotechnology to carry out specific biological reactions, either in industrial processes or for the production of bioproducts and drugs. Microbial lipases are an important group of biotechnologically valuable enzymes that present widely diversified applications. Lipase production by microorganisms is described in several published papers; however, none of them refer to metrological evaluation and the estimation of the uncertainty in measurement. Moreover, few of them refer to process optimization through experimental design. The objectives of this work were to enhance lipase production in shaken-flasks with Yarrowia lipolytica cells employing experimental design and to evaluate the uncertainty in measurement of lipase activity. The highest lipolytic activity obtained was about three- and fivefold higher than the reported activities of CRMs BCR-693 and BCR-694, respectively. Lipase production by Y. lipolytica cells aiming the classification as certified reference material is recommended after further purification and stability studies

  11. Is Neurotoxicity of Metallic Nanoparticles the Cascades of Oxidative Stress?

    Science.gov (United States)

    Song, Bin; Zhang, YanLi; Liu, Jia; Feng, XiaoLi; Zhou, Ting; Shao, LongQuan

    2016-06-01

    With the rapid development of nanotechnology, metallic (metal or metal oxide) nanoparticles (NPs) are widely used in many fields such as cosmetics, the food and building industries, and bio-medical instruments. Widespread applications of metallic NP-based products increase the health risk associated with human exposures. Studies revealed that the brain, a critical organ that consumes substantial amounts of oxygen, is a primary target of metallic NPs once they are absorbed into the body. Oxidative stress (OS), apoptosis, and the inflammatory response are believed to be the main mechanisms underlying the neurotoxicity of metallic NPs. Other studies have disclosed that antioxidant pretreatment or co-treatment can reverse the neurotoxicity of metallic NPs by decreasing the level of reactive oxygen species, up-regulating the activities of antioxidant enzymes, decreasing the proportion of apoptotic cells, and suppressing the inflammatory response. These findings suggest that the neurotoxicity of metallic NPs might involve a cascade of events following NP-induced OS. However, additional research is needed to determine whether NP-induced OS plays a central role in the neurotoxicity of metallic NPs, to develop a comprehensive understanding of the correlations among neurotoxic mechanisms and to improve the bio-safety of metallic NP-based products.

  12. Modeling of cascade and sub-cascade formation at high pka energies in irradiated fusion structural materials

    International Nuclear Information System (INIS)

    Ryazanov, A.; Metelkin, E.V.; Semenov, E.A.

    2007-01-01

    Full text of publication follows: A new theoretical model is developed for the investigations of cascade and sub-cascade formation in fusion structural materials under fast neutron irradiation at high primary knock atom (PKA) energies. Under 14 MeV neutron irradiation especially of light fusion structural materials such as Be, C, SiC materials PKA will have the energies up to 1 MeV. At such high energies it is very difficult to use the Monte Carlo or molecular dynamic simulations. The developed model is based on the analytical consideration of elastic collisions between displaced moving atoms into atomic cascades produced by a PKAs with the some kinetic energy obtained from fast neutrons. The Tomas-Fermy interaction potential is used for the describing of elastic collisions between moving atoms. The suggested model takes into account also the electronic losses for moving atoms between elastic collisions. The self consistent criterion for sub-cascade formation is suggested here which is based on the comparison of mean distance between two consequent PKA collisions and size of sub-cascade produced by PKA. The analytical relations for the most important characteristics of cascades and sub-cascade are determined including the average number of sub-cascades per one PKA in the dependence on PKA energy, the distance between sub-cascades and the average cascade and sub-cascade sizes as a function of PKA energy. The developed model allows determining the total numbers, distribution functions of cascades and sub-cascades in dependence on their sizes and generation rate of cascades and sub-cascades for different fusion neutron energy spectra. Based on the developed model the numerical calculations for main characteristics of cascades and sub-cascades in different fusion structural materials are performed using the neutron flux and PKA energy spectra for fusion reactors: ITER and DEMO. The main characteristics for cascade and sub-cascade formation are calculated here for the

  13. Artificial Enzymes, "Chemzymes"

    DEFF Research Database (Denmark)

    Bjerre, Jeannette; Rousseau, Cyril Andre Raphaël; Pedersen, Lavinia Georgeta M

    2008-01-01

    Enzymes have fascinated scientists since their discovery and, over some decades, one aim in organic chemistry has been the creation of molecules that mimic the active sites of enzymes and promote catalysis. Nevertheless, even today, there are relatively few examples of enzyme models that successf......Enzymes have fascinated scientists since their discovery and, over some decades, one aim in organic chemistry has been the creation of molecules that mimic the active sites of enzymes and promote catalysis. Nevertheless, even today, there are relatively few examples of enzyme models...... that successfully perform Michaelis-Menten catalysis under enzymatic conditions (i.e., aqueous medium, neutral pH, ambient temperature) and for those that do, very high rate accelerations are seldomly seen. This review will provide a brief summary of the recent developments in artificial enzymes, so called...... "Chemzymes", based on cyclodextrins and other molecules. Only the chemzymes that have shown enzyme-like activity that has been quantified by different methods will be mentioned. This review will summarize the work done in the field of artificial glycosidases, oxidases, epoxidases, and esterases, as well...

  14. Magnetically responsive enzyme powders

    Energy Technology Data Exchange (ETDEWEB)

    Pospiskova, Kristyna, E-mail: kristyna.pospiskova@upol.cz [Regional Centre of Advanced Technologies and Materials, Palacky University, Slechtitelu 11, 783 71 Olomouc (Czech Republic); Safarik, Ivo, E-mail: ivosaf@yahoo.com [Regional Centre of Advanced Technologies and Materials, Palacky University, Slechtitelu 11, 783 71 Olomouc (Czech Republic); Department of Nanobiotechnology, Institute of Nanobiology and Structural Biology of GCRC, Na Sadkach 7, 370 05 Ceske Budejovice (Czech Republic)

    2015-04-15

    Powdered enzymes were transformed into their insoluble magnetic derivatives retaining their catalytic activity. Enzyme powders (e.g., trypsin and lipase) were suspended in various liquid media not allowing their solubilization (e.g., saturated ammonium sulfate and highly concentrated polyethylene glycol solutions, ethanol, methanol, 2-propanol) and subsequently cross-linked with glutaraldehyde. Magnetic modification was successfully performed at low temperature in a freezer (−20 °C) using magnetic iron oxides nano- and microparticles prepared by microwave-assisted synthesis from ferrous sulfate. Magnetized cross-linked enzyme powders were stable at least for two months in water suspension without leakage of fixed magnetic particles. Operational stability of magnetically responsive enzymes during eight repeated reaction cycles was generally without loss of enzyme activity. Separation of magnetically modified cross-linked powdered enzymes from reaction mixtures was significantly simplified due to their magnetic properties. - Highlights: • Cross-linked enzyme powders were prepared in various liquid media. • Insoluble enzymes were magnetized using iron oxides particles. • Magnetic iron oxides particles were prepared by microwave-assisted synthesis. • Magnetic modification was performed under low (freezing) temperature. • Cross-linked powdered trypsin and lipase can be used repeatedly for reaction.

  15. Targeted enzyme prodrug therapies.

    Science.gov (United States)

    Schellmann, N; Deckert, P M; Bachran, D; Fuchs, H; Bachran, C

    2010-09-01

    The cure of cancer is still a formidable challenge in medical science. Long-known modalities including surgery, chemotherapy and radiotherapy are successful in a number of cases; however, invasive, metastasized and inaccessible tumors still pose an unresolved and ongoing problem. Targeted therapies designed to locate, detect and specifically kill tumor cells have been developed in the past three decades as an alternative to treat troublesome cancers. Most of these therapies are either based on antibody-dependent cellular cytotoxicity, targeted delivery of cytotoxic drugs or tumor site-specific activation of prodrugs. The latter is a two-step procedure. In the first step, a selected enzyme is accumulated in the tumor by guiding the enzyme or its gene to the neoplastic cells. In the second step, a harmless prodrug is applied and specifically converted by this enzyme into a cytotoxic drug only at the tumor site. A number of targeting systems, enzymes and prodrugs were investigated and improved since the concept was first envisioned in 1974. This review presents a concise overview on the history and latest developments in targeted therapies for cancer treatment. We cover the relevant technologies such as antibody-directed enzyme prodrug therapy (ADEPT), gene-directed enzyme prodrug therapy (GDEPT) as well as related therapies such as clostridial- (CDEPT) and polymer-directed enzyme prodrug therapy (PDEPT) with emphasis on prodrug-converting enzymes, prodrugs and drugs.

  16. Enzymes in Fermented Fish.

    Science.gov (United States)

    Giyatmi; Irianto, H E

    Fermented fish products are very popular particularly in Southeast Asian countries. These products have unique characteristics, especially in terms of aroma, flavor, and texture developing during fermentation process. Proteolytic enzymes have a main role in hydrolyzing protein into simpler compounds. Fermentation process of fish relies both on naturally occurring enzymes (in the muscle or the intestinal tract) as well as bacteria. Fermented fish products processed using the whole fish show a different characteristic compared to those prepared from headed and gutted fish. Endogenous enzymes like trypsin, chymotrypsin, elastase, and aminopeptidase are the most involved in the fermentation process. Muscle tissue enzymes like cathepsins, peptidases, transaminases, amidases, amino acid decarboxylases, glutamic dehydrogenases, and related enzymes may also play a role in fish fermentation. Due to the decreased bacterial number during fermentation, contribution of microbial enzymes to proteolysis may be expected prior to salting of fish. Commercial enzymes are supplemented during processing for specific purposes, such as quality improvement and process acceleration. In the case of fish sauce, efforts to accelerate fermentation process and to improve product quality have been studied by addition of enzymes such as papain, bromelain, trypsin, pepsin, and chymotrypsin. © 2017 Elsevier Inc. All rights reserved.

  17. Determination of soluble dietary fibre content of Okara treated with high hydrostatic pressure and enzymes: a comparative evaluation of two methods (AOAC and HPLC-ELSD).

    Science.gov (United States)

    Pérez-López, E; Mateos-Aparicio, I; Rupérez, P

    2017-04-01

    Okara is a promising by-product from soybean and a rich source of dietary fibre, chiefly insoluble (IDF). To increase its solubility and functionality, a treatment with high hydrostatic pressure (HHP) assisted by food grade enzymes - Ultraflo ® L or Viscozyme ® L- has been performed. To monitor the effectiveness, an analysis of dietary fibre, mainly the soluble fraction (SDF), was accomplished by the AOAC enzymatic-gravimetric method with dialysis followed by both, spectrophotometric methods and High Performance Liquid Chromatography with Evaporative Light Scattering Detector (HPLC-ELSD) analysis of the soluble fraction. A significant increase in SDF (≈1.5-times) to the expense of a decrease in IDF was shown and chromatograms revealed two peaks of 95 and 22 kDa. Thus, treated Okara possessed a more balanced and convenient ratio of soluble to insoluble dietary fibre, which could have health benefits as prebiotic. Inbuilt interferences of the official AOAC's method for dietary fibre were confirmed and the direct HPLC-ELSD approach was about twice more sensitive than spectrophotometric methods. Consequently, the direct HPLC-ELSD analysis of the supernatant is proposed as a cheaper, faster and reliable method. Combined HHP-treatments plus specific enzymes represent a promising alternative for the valorisation and preservation of agrofood by-products.

  18. Analysis and Evaluation of the Inhibitory Mechanism of a Novel Angiotensin-I-Converting Enzyme Inhibitory Peptide Derived from Casein Hydrolysate.

    Science.gov (United States)

    Tu, Maolin; Liu, Hanxiong; Zhang, Ruyi; Chen, Hui; Mao, Fengjiao; Cheng, Shuzhen; Lu, Weihong; Du, Ming

    2018-04-25

    Casein hydrolysates exert various biological activities, and the responsible functional peptides are being identified from them continuously. In this study, the tryptic casein hydrolysate was fractionated by an ultrafiltration membrane (3 kDa), and the peptides were identified by capillary electrophoresis-quadrupole-time-of-flight-tandem mass spectrometry. Meanwhile, in silico methods were used to analyze the toxicity, solubility, stability, and affinity between the peptides and angiotensin-I-converting enzyme (ACE). Finally, a new angiotensin-I-converting enzyme inhibitory (ACEI) peptide, EKVNELSK, derived from α s1 -casein (fragment 35-42) was screened. The half maximal inhibitory concentration value of the peptide is 5.998 mM, which was determined by a high-performance liquid chromatography method. The Lineweaver-Burk plot indicated that this peptide is a mixed-type inhibitor against ACE. Moreover, Discovery Studio 2017 R2 software was adopted to perform molecular docking to propose the potential mechanisms underlying the ACEI activity of the peptide. These results indicated that EKVNELSK is a new ACEI peptide identified from casein hydrolysate.

  19. Evaluation of liver enzyme levels in workers exposed to vinyl chloride vapors in a petrochemical complex: a cross-sectional study

    Directory of Open Access Journals (Sweden)

    Dolati Mandana

    2007-08-01

    Full Text Available Abstract Background Polyvinyl chloride is used in production and manufacturing of many essential tools (e.g. plastic pipes, photography films, etc.. Its production is impossible without the use of vinyl chloride monomer (VCM, which can cause liver damage in long-term. In this study we intend to assess the effects of mild to moderate long term exposure to VCM on liver and to assess the importance of liver enzyme measurements as a screening tool. Methods In this study, liver enzyme levels of 52 workers were compared to 48 control workers using the T-test. The cases all worked in a PVC production unit in a petrochemical complex and the controls were randomly selected from office personnel of the same complex. A questionnaire was also filled in about information such as age, weight, work history, etc. in both groups. Results Mean comparisons for ALP and GGT using T-test showed statistically significant differences between the two groups. For AST, ALT and bilirubin (total, direct the mean was higher in the case group but this difference was not statistically significant. Discussion This study showed that mild exposure to VCM can cause mild liver cholestasis. So, using cholestasis assessment tests such as ALP and GGT should be considered in periodic assessment of liver function in PVC producing units.

  20. Evaluation of a newly designed sandwich enzyme linked immunosorbent assay for the detection of hydatid antigen in serum, urine and cyst fluid for diagnosis of cystic echinococcosis.

    Science.gov (United States)

    Chaya, Dr; Parija, Subhash Chandra

    2013-07-01

    Cystic echinococcosis (CE) is a zoonotic disease of humans with variable clinical manifestations. Imaging and immunological methods are currently the mainstay of diagnosis of this disease. Although the immunological tests for detection of anti-echinococcal antibodies have several disadvantages, they are widely being used. Antigen is far more superior than antibody detection test as they can provide a specific parasitic diagnosis. A sandwich enzyme linked immunosorbent assay (ELISA) was designed using antibodies to 24 kDa urinary hydatid antigen for the detection of hydatid antigens in urine, serum and cyst fluid specimens. The performance of this novel test was compared with that of other hydatid antibody detection ELISA and enzyme immune transfer blot (EITB) using radiological and surgical confirmation as the gold standard. The antigen detection ELISA showed 100% sensitivity and specificity when tested with cyst fluid. On testing urine and serum, the antigen detection ELISA was found to be more specific than antibody detection ELISA. EITB was found to be the most sensitive and specific test. ELISA using polyclonal antibodies against 24 kDa urinary hydatid protein was moderately sensitive to detect hydatid antigen in serum and urine. Hence polyclonal antibodies to 24 kDa urinary hydatid antigen can be used as an alternative source of antibody to detect hydatid antigen in serum, urine and cyst fluid. In the present study, EITB was found to be highly specific test for detection of hydatid antibodiesin serum. 24 kDa protein was found to be specific and of diagnostic value in CE.

  1. Bioinformatic evaluation of L-arginine catabolic pathways in 24 cyanobacteria and transcriptional analysis of genes encoding enzymes of L-arginine catabolism in the cyanobacterium Synechocystis sp. PCC 6803

    Directory of Open Access Journals (Sweden)

    Pistorius Elfriede K

    2007-11-01

    Full Text Available Abstract Background So far very limited knowledge exists on L-arginine catabolism in cyanobacteria, although six major L-arginine-degrading pathways have been described for prokaryotes. Thus, we have performed a bioinformatic analysis of possible L-arginine-degrading pathways in cyanobacteria. Further, we chose Synechocystis sp. PCC 6803 for a more detailed bioinformatic analysis and for validation of the bioinformatic predictions on L-arginine catabolism with a transcript analysis. Results We have evaluated 24 cyanobacterial genomes of freshwater or marine strains for the presence of putative L-arginine-degrading enzymes. We identified an L-arginine decarboxylase pathway in all 24 strains. In addition, cyanobacteria have one or two further pathways representing either an arginase pathway or L-arginine deiminase pathway or an L-arginine oxidase/dehydrogenase pathway. An L-arginine amidinotransferase pathway as a major L-arginine-degrading pathway is not likely but can not be entirely excluded. A rather unusual finding was that the cyanobacterial L-arginine deiminases are substantially larger than the enzymes in non-photosynthetic bacteria and that they are membrane-bound. A more detailed bioinformatic analysis of Synechocystis sp. PCC 6803 revealed that three different L-arginine-degrading pathways may in principle be functional in this cyanobacterium. These are (i an L-arginine decarboxylase pathway, (ii an L-arginine deiminase pathway, and (iii an L-arginine oxidase/dehydrogenase pathway. A transcript analysis of cells grown either with nitrate or L-arginine as sole N-source and with an illumination of 50 μmol photons m-2 s-1 showed that the transcripts for the first enzyme(s of all three pathways were present, but that the transcript levels for the L-arginine deiminase and the L-arginine oxidase/dehydrogenase were substantially higher than that of the three isoenzymes of L-arginine decarboxylase. Conclusion The evaluation of 24

  2. Therapeutic Enzymes: Applications and Approaches to Pharmacological Improvement.

    Science.gov (United States)

    Yari, Maryam; Ghoshoon, Mohammad B; Vakili, Bahareh; Ghasemi, Younes

    2017-01-01

    Among therapeutic proteins, enzymes represent small and of course profitable market. They can be used to treat important, rare, and deadly diseases. Enzyme therapy is the only available treatment for certain disorders. Here, pharmaceutical enzymes are reviewed. They are categorized in four main groups, enzymes in replacement therapy, enzymes in cancer treatment, enzymes for fibrinolysis, and finally enzymes that are used topically for various treatments. Furthermore, enzyme gene therapy and future perspective of therapeutic enzymes are mentioned in brief. There are many important approved enzymes in pharmaceutical market. Several approaches such as point mutation, fusion protein designing, glycoengineering, and PEGylation were used to achieve improved enzymes. Although sometimes enzymes were engineered to facilitate production and purification process, appropriate delivery to target sites, extending half-life, and reducing immunogenicity are among the main goals of engineering approaches. Overall, enzymes play a critical role in treatment of common and rare diseases. Evaluation of new enzymes as well as improvement of approved enzymes are of the most important challenges in biotechnology. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  3. EFSA Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids (CEF); Scientific Opinion on Flavouring Group Evaluation 12, Revision 2 (FGE.12Rev2): Primary saturated or unsaturated alicyclic alcohol, aldehyde, acid, and esters from chemical group 7

    DEFF Research Database (Denmark)

    Larsen, John Christian; Nørby, Karin Kristiane; Beltoft, Vibe Meister

    The European Food Safety Authority (EFSA) asked the Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids (the Panel) to provide scientific advice to the Commission on the implications for human health of chemically defined flavouring substances used in or on foodstuffs....... However, this does not preclude evaluation of the flavouring substances in the present group using the Procedure (SCF, 1999a). It is considered that on the basis of the default MSDI approach these nine flavouring substances would not give rise to safety concerns at the estimated levels of intake arising...

  4. EFSA CEF Panel (EFSA Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids), 2014. Scientific Opinion on Flavouring Group Evaluation 300, Revision 1 (FGE.300Rev1): One cyclo-aliphatic amide from chemical group 33

    DEFF Research Database (Denmark)

    Beltoft, Vibe Meister; Frandsen, Henrik Lauritz; Nørby, Karin Kristiane

    The Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids of the European Food Safety Authority was requested to evaluate a flavouring substance,cyclopropanecarboxylic acid (2-isopropyl-5-methyl-cyclohexyl)-amide [FL-no: 16.115] in the Flavouring Group Evaluation 300, Revision 1....... The substance was not considered to have genotoxic potential. The substance was evaluated through a stepwise approach (the Procedure) that integrates information on structure-activity relationships, intake from current uses, toxicological threshold of concern, and available data on metabolism and toxicity....... The Panel concluded that the substance [FL-no: 16.115] does not give rise to safety concern at its levels of dietary intake estimated on the basis of the Maximised Survey-derived Daily Intake MSDI approach. Besides the safety assessment of this flavouring substance, the specifications for the material...

  5. EFSA Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids (CEF); Scientific Opinion on Flavouring Group Evaluation 22, Revision 1 (FGE.22Rev1): Ring substituted phenolic substances from chemical groups 21 and 25

    DEFF Research Database (Denmark)

    Larsen, John Christian; Nørby, Karin Kristiane; Beltoft, Vibe Meister

    The Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids of the European Food Safety Authority was requested to evaluate 28 flavouring substances in the Flavouring Group Evaluation 22, Revision 1, using the Procedure in Commission Regulation (EC) No 1565/2000. The substance 3...... through a stepwise approach (the Procedure) that integrates information on structure-activity relationships, intake from current uses, toxicological threshold of concern, and available data on metabolism and toxicity. The Panel concluded that these 27 candidate substances do not give rise to safety...... concerns at their levels of dietary intake, estimated on the basis of the MSDI approach. Adequate specifications for the materials of commerce are available for all 27 flavouring substances evaluated through the Procedure....

  6. EFSA Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids (CEF); Scientific Opinion on Flavouring Group Evaluation 10, Revision 3 (FGE.10Rev3): Aliphatic primary and secondary saturated and unsaturated alcohols, aldehydes, acetals, carboxylic acids and esters containing

    DEFF Research Database (Denmark)

    Larsen, John Christian; Nørby, Karin Kristiane; Beltoft, Vibe Meister

    The Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids of the European Food Safety Authority was requested to evaluate 63 flavouring substances in the Flavouring Group Evaluation 10, including additional two substances in this Revision 3, using the Procedure in Commission...... threshold of concern, and available data on metabolism and toxicity. The Panel concluded that the 62 substances do not give rise to safety concerns at their levels of dietary intake, estimated on the basis of the MSDI approach. Besides the safety assessment of these flavouring substances, the specifications...... for the materials of commerce have also been considered. For four substances evaluated through the Procedure, the stereoisomeric composition has not been specified sufficiently....

  7. Arginine kinase in Toxocara canis: Exon-intron organization, functional analysis of site-directed mutants and evaluation of putative enzyme inhibitors.

    Science.gov (United States)

    Wickramasinghe, Susiji; Yatawara, Lalani; Nagataki, Mitsuru; Agatsuma, Takeshi

    2016-10-01

    To determine exon/intron organization of the Toxocara canis (T. canis) AK (TCAK) and to test green and black tea and several other chemicals against the activity of recombinant TCAK in the guanidino-specific region by site-directed mutants. Amplification of genomic DNA fragments containing introns was carried out by PCRs. The open-reading frame (1200 bp) of TCAK (wild type) was cloned into the BamH1/SalI site of pMAL-c2X. The maltose-binding protein-TCAK fusion protein was expressed in Escherichia coli TB1 cells. The purity of the expressed enzyme was verified by SDS-PAGE. Mutations were introduced into the guanidino-specific region and other areas of pMAL/TCAK by PCR. Enzyme activity was measured with an NADH-linked assay at 25 °C for the forward reaction (phosphagen synthesis). Arginine kinase in T. canis has a seven-exon/six-intron gene structure. The lengths of the introns ranged from 542 bp to 2 500 bp. All introns begin with gt and end with ag. Furthermore, we measured the enzyme activity of site-directed mutants of the recombinant TCAK. The K m value of the mutant (Alanine to Serine) decreased indicating a higher affinity for substrate arginine than the wild-type. The K m value of the mutant (Serine to Glycine) increased to 0.19 mM. The K m value (0.19 mM) of the double mutant (Alanine-Serine to Serine-Glycine) was slightly greater than in the wild-type (0.12 mM). In addition, several other chemicals were tested; including plant extract Azadiracta indica (A. indica), an aminoglycoside antibiotic (aminosidine), a citrus flavonoid glycoside (rutin) and a commercially available catechin mixture against TCAK. Green and black tea (1:10 dilution) produced 15% and 25% inhibition of TCAK, respectively. The extract of A. indica produced 5% inhibition of TCAK. Moreover, green and black tea produced a non-competitive type of inhibition and A. indica produced a mixed-type of inhibition on TCAK. Arginine kinase in T. canis has a seven-exon/six-intron gene

  8. A multi-enzymatic cascade reaction for the stereoselective production of γ-oxyfunctionalyzed amino acids

    Directory of Open Access Journals (Sweden)

    Junichi eEnoki

    2016-04-01

    Full Text Available A stereoselective three-enzyme cascade for synthesis of diasteromerically pure γ-oxyfunctionalized α-amino acids was developed. By coupling a dynamic kinetic resolution using an N-acylamino acid racemase and an L-selective aminoacylase from Geobacillus thermoglucosidasius with a stereoselective isoleucine dioxygenase from Bacillus thuringiensis, diastereomerically pure oxidized amino acids were produced from racemic N-acetylamino acids. The three enzymes differ in their optimal temperature and pH-spectra. Their different metal cofactor dependencies lead to inhibitory effects. Under optimized conditions, racemic N-acetylmethionine was quantitatively converted into L-methionine-(S-sulfoxide with 97% conversion and 95% de. The combination of these three different biocatalysts allows the direct synthesis of diastereopure oxyfunctionalized amino acids from inexpensive racemic starting material.

  9. EFSA Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids (CEF); Scientific Opinion on Flavouring Group Evaluation 303 (FGE.303): Spilanthol from chemical group 30

    DEFF Research Database (Denmark)

    Larsen, John Christian; Nørby, Karin Kristiane; Beltoft, Vibe Meister

    The Scientific Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids (the Panel) was asked to provide scientific advice to the Commission on the implications for human health of chemically defined flavouring substances used in or on foodstuffs in the Member States. In particular...... of the flavouring substances in Europe. However, when the Panel examined the information provided by the European Flavouring Industry on the use levels in various foods, it appeared obvious that the MSDI approach in a number of cases would grossly underestimate the intake by regular consumers of products flavoured...... whether the conclusion for the candidate substance can be applied to the material of commerce, it is necessary to consider the available specifications. Adequate specifications including complete purity criteria and identity for the material of commerce have been provided for the flavouring substance...

  10. [Study of enzymes of xenobiotic metabolism in the evaluation of quality of protein-containing wheat germ flakes and wallpaper flour].

    Science.gov (United States)

    Martinchuk, A N; E En Gyn; Safronova, A M; Peskova, E V

    1991-01-01

    Intake of wheat upholstery meal by growing rats was attended by a sharp decrease in the content and activity of xenobiotic metabolism enzymes in the hepatic microsomes, that was caused by the low biological value of the meal proteins. Hepatic microsomes of the rats that were fed with wheat germ flakes showed increased specific content of cytochromes P-450 and b5, but the total blood protein content per 100 g of body mass was lower than during casein consumption. No significant changes were detected in hydroxylation rate of benz(a)pyrene, aniline and ethylmorphine. During consumption of wheat germ flakes induction of UDP-glucuronide-transferase was detected in hepatic microsomes. Wheat germ flakes induced a 5-fold increase of Se-dependent glutathione peroxidase activity. Wheat germ flakes produced no significant effect on glutathione-S-aryltransferase and glutathione reductase activity.

  11. Development and evaluation of a blocking enzyme-linked immunosorbent assay and virus neutralization assay to detect antibodies to viral hemorrhagic septicemia virus

    Science.gov (United States)

    Wilson, Anna; Goldberg, Tony; Marcquenski, Susan; Olson, Wendy; Goetz, Frederick; Hershberger, Paul; Hart, Lucas M.; Toohey-Kurth, Kathy

    2014-01-01

    Viral hemorrhagic septicemia virus (VHSV) is a target of surveillance by many state and federal agencies in the United States. Currently, the detection of VHSV relies on virus isolation, which is lethal to fish and indicates only the current infection status. A serological method is required to ascertain prior exposure. Here, we report two serologic tests for VHSV that are nonlethal, rapid, and species independent, a virus neutralization (VN) assay and a blocking enzyme-linked immunosorbent assay (ELISA). The results show that the VN assay had a specificity of 100% and sensitivity of 42.9%; the anti-nucleocapsid-blocking ELISA detected nonneutralizing VHSV antibodies at a specificity of 88.2% and a sensitivity of 96.4%. The VN assay and ELISA are valuable tools for assessing exposure to VHSV.

  12. Enzymes evaluation for the polymeric filter cake removal; Avaliacao de enzimas para remocao de reboco formado por fluidos polimericos de base agua

    Energy Technology Data Exchange (ETDEWEB)

    Kameda, Etel; Coelho, Maria Alice Z. [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Escola de Quimica; Langone, Marta A.P. [Universidade do Estado do Rio de Janeiro (UERJ), RJ (Brazil). Inst. de Quimica; Queiroz Neto, Joao C. de [PETROBRAS, Rio de Janeiro, RJ (Brazil). Centro de Pesquisas (CENPES)

    2004-07-01

    In the drilling wells in horizontal or complex configurations, the drilling fluid contact with the productive zone can reduce the productivity by fluid invasion in the borehole wall. Drilling fluids usually comprise natural polymers as starch and xanthan gum. These polymers are deposited as the filter-cake on the wellbore wall. A common approach to remove this filter-cake is the application of acids or strong oxidative solutions. However, these are non-specific species which will react with any encountered that is acid soluble or oxidizable. An alternative is the use of enzymatic preparations that are able to hydrolyze such polymers. The enzymes catalyze only certain specific substrates, are inherently environmentally friendly, the enzymatic degradation rate is slower than that achieved by the oxidative species, so the enzymes produces an uniform filter cake degradation. In this work, the kinetic behaviors of an enzymatic filter-cake breaker and a commercial thermo stable enzymatic complex were analyzed. Both kinetic profiles were very similar, as well as its electrophoresis analysis. The protein in each product showed identical molecular weight. The commercial enzymatic complex stability remained 58.56% of enzymatic activity after 30 days at 40 deg C. Stability at wellbore conditions can be considered similar for both products. At 65 deg C they showed the same enzymatic activity after 8 hours. After 3 hours at 80 deg C, the commercial enzymatic complex remained 29.89% of the initial activity and the filter-cake breaker 61.73%, while at 95 deg C remained 4.39% and 11.60% of the initial activity, respectively, after 15 minutes. (author)

  13. Heat cascading regenerative sorption heat pump

    Science.gov (United States)

    Jones, Jack A. (Inventor)

    1995-01-01

    A simple heat cascading regenerative sorption heat pump process with rejected or waste heat from a higher temperature chemisorption circuit (HTCC) powering a lower temperature physisorption circuit (LTPC) which provides a 30% total improvement over simple regenerative physisorption compression heat pumps when ammonia is both the chemisorbate and physisorbate, and a total improvement of 50% or more for LTPC having two pressure stages. The HTCC contains ammonia and a chemisorbent therefor contained in a plurality of canisters, a condenser-evaporator-radiator system, and a heater, operatively connected together. The LTPC contains ammonia and a physisorbent therefor contained in a plurality of compressors, a condenser-evaporator-radiator system, operatively connected together. A closed heat transfer circuit (CHTC) is provided which contains a flowing heat transfer liquid (FHTL) in thermal communication with each canister and each compressor for cascading heat from the HTCC to the LTPC. Heat is regenerated within the LTPC by transferring heat from one compressor to another. In one embodiment the regeneration is performed by another CHTC containing another FHTL in thermal communication with each compressor. In another embodiment the HTCC powers a lower temperature ammonia water absorption circuit (LTAWAC) which contains a generator-absorber system containing the absorbent, and a condenser-evaporator-radiator system, operatively connected together. The absorbent is water or an absorbent aqueous solution. A CHTC is provided which contains a FHTL in thermal communication with the generator for cascading heat from the HTCC to the LTAWAC. Heat is regenerated within the LTAWAC by transferring heat from the generator to the absorber. The chemical composition of the chemisorbent is different than the chemical composition of the physisorbent, and the absorbent. The chemical composition of the FHTL is different than the chemisorbent, the physisorbent, the absorbent, and ammonia.

  14. Cascade plant control by timer method

    International Nuclear Information System (INIS)

    Kiguchi, Takashi; Inoue, Kotaro; Kawai, Toshio; Senoo, Makoto.

    1970-01-01

    The present invention relates to a method of controlling uranium flow rate through a cascaded centrifuge plant for the purpose of enriching uranium 235. Such a cascade includes multiple gas separation stage each of which consists of a plurality of centrifuges. The product gas usually includes a large amount of He gas, and a cold trap is used to eliminate the He from UF 6 . The cold trap is operated periodically in such a way that the mixed gas of He and UF 6 is cooled to solidify only UF 6 and then warmed to obtain UF 6 by gasification. In order to operate the plant continuously, parallel multiple cold traps are operated alternatively. The operating conditions in such a complex cascade system are difficult to alter by conventional control methods. The present invention provides a rapid method of controlling the system when a certain percentage of the centrifuges in one stage malfunction. The control system consists of timers which are provided one for each cold trap to control the operational period of the trap. For example, if 20% of the centrifuges in a particular stage malfunction, the timer period of the cold traps attached to the normally operating centrifuge within the stage is maintained, and the period of all the other centrifuges are changed to 10/8 times that of the initial value. In this way the flow volume through all centrifuges except that in the particular stage is reduced to 80% of the initial value and the operation of the system can be continued with reduced efficiency. (Masui, R.)

  15. Amyloid cascade hypothesis: Pathogenesis and therapeutic strategies in Alzheimer's disease.

    Science.gov (United States)

    Barage, Sagar H; Sonawane, Kailas D

    2015-08-01

    Alzheimer's disease is an irreversible, progressive neurodegenerative disorder. Various therapeutic approaches are being used to improve the cholinergic neurotransmission, but their role in AD pathogenesis is still unknown. Although, an increase in tau protein concentration in CSF has been described in AD, but several issues remains unclear. Extensive and accurate analysis of CSF could be helpful to define presence of tau proteins in physiological conditions, or released during the progression of neurodegenerative disease. The amyloid cascade hypothesis postulates that the neurodegeneration in AD caused by abnormal accumulation of amyloid beta (Aβ) plaques in various areas of the brain. The amyloid hypothesis has continued to gain support over the last two decades, particularly from genetic studies. Therefore, current research progress in several areas of therapies shall provide an effective treatment to cure this devastating disease. This review critically evaluates general biochemical and physiological functions of Aβ directed therapeutics and their relevance. Copyright © 2015 Elsevier Ltd. All rights reserved.

  16. Cascade Distillation System Design for Safety and Mission Assurance

    Science.gov (United States)

    Sarguisingh, Miriam; Callahan, Michael R.; Okon, Shira

    2015-01-01

    Per the NASA Human Health, Life Support and Habitation System Technology Area 06 report "crewed missions venturing beyond Low-Earth Orbit (LEO) will require technologies with improved reliability, reduced mass, self-sufficiency, and minimal logistical needs as an emergency or quick-return option will not be feasible".1 To meet this need, the development team of the second generation Cascade Distillation System (CDS 2.0) chose a development approach that explicitly incorporate consideration of safety, mission assurance, and autonomy. The CDS 2.0 preliminary design focused on establishing a functional baseline that meets the CDS core capabilities and performance. The critical design phase is now focused on incorporating features through a deliberative process of establishing the systems failure modes and effects, identifying mitigation strategies, and evaluating the merit of the proposed actions through analysis and test. This paper details results of this effort on the CDS 2.0 design.

  17. Trophic Cascades Induced by Lobster Fishing Are Not Ubiquitous in Southern California Kelp Forests

    Science.gov (United States)

    Guenther, Carla M.; Lenihan, Hunter S.; Grant, Laura E.; Lopez-Carr, David; Reed, Daniel C.

    2012-01-01

    Fishing can trigger trophic cascades that alter community structure and dynamics and thus modify ecosystem attributes. We combined ecological data of sea urchin and macroalgal abundance with fishery data of spiny lobster (Panulirus interruptus) landings to evaluate whether: (1) patterns in the abundance and biomass among lobster (predator), sea urchins (grazer), and macroalgae (primary producer) in giant kelp forest communities indicated the presence of top-down control on urchins and macroalgae, and (2) lobster fishing triggers a trophic cascade leading to increased sea urchin densities and decreased macroalgal biomass. Eight years of data from eight rocky subtidal reefs known to support giant kelp forests near Santa Barbara, CA, USA, were analyzed in three-tiered least-squares regression models to evaluate the relationships between: (1) lobster abundance and sea urchin density, and (2) sea urchin density and macroalgal biomass. The models included reef physical structure and water depth. Results revealed a trend towards decreasing urchin density with increasing lobster abundance but little evidence that urchins control the biomass of macroalgae. Urchin density was highly correlated with habitat structure, although not water depth. To evaluate whether fishing triggered a trophic cascade we pooled data across all treatments to examine the extent to which sea urchin density and macroalgal biomass were related to the intensity of lobster fishing (as indicated by the density of traps pulled). We found that, with one exception, sea urchins remained more abundant at heavily fished sites, supporting the idea that fishing for lobsters releases top-down control on urchin grazers. Macroalgal biomass, however, was positively correlated with lobster fishing intensity, which contradicts the trophic cascade model. Collectively, our results suggest that factors other than urchin grazing play a major role in controlling macroalgal biomass in southern California kelp forests, and

  18. Energy cascading in large district heating systems

    International Nuclear Information System (INIS)

    Mayer, F.W.

    1978-01-01

    District heat transfer is the most economical utilization of the waste heat of power plants. Optimum utilization and heat transfer over large distances are possible because of a new energy distribution system, the ''energy cascading system,'' in which heat is transferred to several consumer regions at different temperature ranges. It is made more profitable by the use of heat pumps. The optimum flow-line temperature is 368 0 K, and the optimum return-line temperature is 288 0 K, resulting in an approximately 50% reduction of electric power loss at the power plant

  19. The identification of a cascade hypernucleus

    CERN Document Server

    Mondal, A S; Husain, A; Kasim, M M

    1979-01-01

    In a systematic search for rare hypernuclear species in nuclear emulsion exposed to 3.0 GeV/c K/sup -/-mesons at the CERN PS, an event with three connecting stars has been observed. The two secondary stars are most probably due to the decay of a cascade hypernucleus according to the following channel: /sub Xi //sup -13/-C to /sub Lambda //sup 8 /Be+/sub Lambda //sup 5/He+Q. The binding energy of the Xi - hypernucleus is B/sub Xi /-(/sub Xi //sup 13/-C)=(18.1+or-3.2) MeV. (11 refs).

  20. Cascaded recompression closed brayton cycle system

    Energy Technology Data Exchange (ETDEWEB)

    Pasch, James J.

    2018-01-02

    The present disclosure is directed to a cascaded recompression closed Brayton cycle (CRCBC) system and method of operation thereof, where the CRCBC system includes a compressor for compressing the system fluid, a separator for generating fluid feed streams for each of the system's turbines, and separate segments of a heater that heat the fluid feed streams to different feed temperatures for the system's turbines. Fluid exiting each turbine is used to preheat the fluid to the turbine. In an embodiment, the amount of heat extracted is determined by operational costs.

  1. Tracking Control for Switched Cascade Nonlinear Systems

    Directory of Open Access Journals (Sweden)

    Xiaoxiao Dong

    2015-01-01

    Full Text Available The issue of H∞ output tracking for switched cascade nonlinear systems is discussed in this paper, where not all the linear parts of subsystems are stabilizable. The conditions of the solvability for the issue are given by virtue of the structural characteristics of the systems and the average dwell time method, in which the total activation time for stabilizable subsystems is longer than that for the unstabilizable subsystems. At last, a simulation example is used to demonstrate the validity and advantages of the proposed approach.

  2. Cascaded Quadratic Soliton Compression in Waveguide Structures

    DEFF Research Database (Denmark)

    Guo, Hairun

    between the Kerr nonlinear effects and the dispersive effects in the medium. A Kerr-like nonlinearity is produced through the cascaded phase mismatched quadratic process, e.g. the second harmonic generation process, which can be flexibly tuned in both the sign and the amplitude, making possible a strong......-phase-matching technology is not necessarily needed. In large-RI-changed waveguides, CQSC is extended to the mid-infrared range to generate single-cycle pulses with purely nonlinear interactions, since an all-normal dispersion profile could be achieved within the guidance band. We believe that CQSC in quadratic waveguides...

  3. Plant MAPK cascades: Just rapid signaling modules?

    KAUST Repository

    Boudsocq, Marie

    2015-08-27

    © 2015 Taylor & Francis Group, LLC. Abscisic acid (ABA) is a major phytohormone mediating important stress-related processes. We recently unveiled an ABA-activated MAPK signaling module constituted of MAP3K17/18-MKK3-MPK1/2/7/14. Unlike classical rapid MAPK activation, we showed that the activation of the new MAPK module is delayed and relies on the MAP3K protein synthesis. In this addendum, we discuss the role of this original and unexpected activation mechanism of MAPK cascades which suggests that MAPKs can regulate both early and longterm plant stress responses.

  4. Atom localization with double-cascade configuration

    International Nuclear Information System (INIS)

    Gordeev, Maksim Yu; Rozhdestvensky, Yuri V; Efremova, Ekaterina A

    2016-01-01

    We investigate the one-dimensional (1D) and two-dimensional (2D) atom localization of a four-level system in a double-cascade configuration. We demonstrate the possibility of 1D localization in the field of a standing wave, 2D localization in the field of two standing waves and 2D localization only in the field of running waves by using different configurations of driven waves on transitions. In addition, for each configuration we reached a high-precision atom localization in one of the states at scales much smaller than the wavelength of the incident optical radiation. (paper)

  5. Cascaded recompression closed brayton cycle system

    Science.gov (United States)

    Pasch, James J.

    2018-01-02

    The present disclosure is directed to a cascaded recompression closed Brayton cycle (CRCBC) system and method of operation thereof, where the CRCBC system includes a compressor for compressing the system fluid, a separator for generating fluid feed streams for each of the system's turbines, and separate segments of a heater that heat the fluid feed streams to different feed temperatures for the system's turbines. Fluid exiting each turbine is used to preheat the fluid to the turbine. In an embodiment, the amount of heat extracted is determined by operational costs.

  6. Modeling cascading failures with the crisis of trust in social networks

    Science.gov (United States)

    Yi, Chengqi; Bao, Yuanyuan; Jiang, Jingchi; Xue, Yibo

    2015-10-01

    In social networks, some friends often post or disseminate malicious information, such as advertising messages, informal overseas purchasing messages, illegal messages, or rumors. Too much malicious information may cause a feeling of intense annoyance. When the feeling exceeds a certain threshold, it will lead social network users to distrust these friends, which we call the crisis of trust. The crisis of trust in social networks has already become a universal concern and an urgent unsolved problem. As a result of the crisis of trust, users will cut off their relationships with some of their untrustworthy friends. Once a few of these relationships are made unavailable, it is likely that other friends will decline trust, and a large portion of the social network will be influenced. The phenomenon in which the unavailability of a few relationships will trigger the failure of successive relationships is known as cascading failure dynamics. To our best knowledge, no one has formally proposed cascading failures dynamics with the crisis of trust in social networks. In this paper, we address this potential issue, quantify the trust between two users based on user similarity, and model the minimum tolerance with a nonlinear equation. Furthermore, we construct the processes of cascading failures dynamics by considering the unique features of social networks. Based on real social network datasets (Sina Weibo, Facebook and Twitter), we adopt two attack strategies (the highest trust attack (HT) and the lowest trust attack (LT)) to evaluate the proposed dynamics and to further analyze the changes of the topology, connectivity, cascading time and cascade effect under the above attacks. We numerically find that the sparse and inhomogeneous network structure in our cascading model can better improve the robustness of social networks than the dense and homogeneous structure. However, the network structure that seems like ripples is more vulnerable than the other two network

  7. Influence of non-binary effects on intranuclear cascade method

    International Nuclear Information System (INIS)

    Gomes, E.H.C.

    1985-01-01

    The importance of non binary process effects in the intranuclear cascade method is analysed. It is shown that, in the higher density steps, the non binary collisions lead to baryon density distribution and rapidity differents from the one obtained using the usual intranuclear cascade method (limited to purely binary collisions). The validity of the applications of binary intranuclear cascade method to the simulation of the thermal equilibrium, nuclear transparency and particle production, is discussed. (M.C.K.) [pt

  8. Cascade processing of wheat bran through a biorefinery approach

    International Nuclear Information System (INIS)

    Celiktas, Melih Soner; Kirsch, Christian; Smirnova, Irina

    2014-01-01

    Highlights: • About 98% of total sugars were successfully converted and recovered from wheat bran. • LHW and effective enzyme-assisted extraction method is used to obtain total sugar. • Sequential treatment of various materials can be a great value to the industry. • High pressure and LHW can be a valuable treatment for the lignocellulosic materials. • Protein separation can be done with LHW. - Abstract: Structural characteristics of wheat bran such as surface area, crystallinity, cellulose, hemicellulose, and lignin content significantly affect the yield of biorefinery products such as protein, fermentable sugar and lignin. The aim of the study was to use a sequence of high pressure extraction and hydrolysis processes in a cascade to create high potential value added products, namely, proteins, fermentable sugars and lignin. In the present study, four different sets of experiments were carried out step by step in a cascade sequence. The main experiments were the sequential extraction and hydrolysis which were optimized using design of experiments. Protein extraction from wheat bran was performed in a fixed bed reactor and was maximized to 1.976 g/L at the elicited optimum conditions which were 80 °C, pH 9.3 for a duration of 30 min. In the sequential experiment, process parameters such as temperature, flow rate and duration were optimized for liquid hot water (LHW) hydrolysis. The maximum reducing sugar concentration was 200 g/kg which corresponded to 34% per dry biomass obtained at a flow rate of 5 ml/min, temperature of 210 °C during a 45 min treatment. The following step was enzymatic hydrolysis to saccharify the cellulose under high pressure, where the independent variables were pressure, temperature and process time in order to ascertain the process conditions maximizing the reducing sugar content, where a positive correlation was observed between the solid–liquid loading ratio and reducing sugar yield. In the final step, the lignin content of

  9. Application of Enzyme Coupling Reactions to Shift Thermodynamically Limited Biocatalytic Reactions

    DEFF Research Database (Denmark)

    Abu, Rohana; Woodley, John M.

    2015-01-01

    , it can be challenging to combine several engineered enzymes in vitro for the conversion of non-natural substrates. In this mini-review we focus on enzyme coupling reactions as a tool to alleviate thermodynamic constraints in synthetically useful biocatalytic reactions. The implications of thermodynamic...... shift the equilibrium of otherwise thermodynamically unfavourable reactions to give a higher conversion of the target product. By coupling an energetically unfavourable reaction with a more favourable one, the multi-enzyme cascade mimics the approach taken in nature in metabolic pathways. Nevertheless...

  10. The comparison of extraction of energy in two-cascade and one-cascade targets

    Energy Technology Data Exchange (ETDEWEB)

    Dolgoleva, G. V., E-mail: dolgg@list.ru [National Research Tomsk State University, 36, Lenin Ave., 634050, Tomsk (Russian Federation); Ponomarev, I. V., E-mail: wingof17@mail.ru [Moscow State University, Department of Mechanics and Mathematics, 1, Vorobyovy Gory, Moscow,119961 (Russian Federation)

    2016-01-15

    The paper is devoted to numerical designing of cylindrical microtargets on the basis of shock-free compression. When designing microtargets for the controlled thermonuclear fusion, the core tasks are to select geometry and make-up of layers, and the law of energy embedding as well, which allow receiving of “burning” of deuterium- tritium mix, that is, the existence of thermonuclear reactions of working area. Yet, the energy yield as a result of thermonuclear reactions has to be more than the embedded energy (the coefficient of amplification is more than a unit). So, an important issue is the value of the embedded energy. The purpose of the present paper is to study the extraction of energy by working DT area in one-cascade and two-cascade targets. A bigger extraction of energy will contribute to a better burning of DT mix and a bigger energy yield as a result of thermonuclear reactions. The comparison of analytical results to numerical calculations is carried out. The received results show advantages of a two-cascade target compared to a one-cascade one.

  11. Optimization of the cascade with gas centrifuges for uranium enrichment

    International Nuclear Information System (INIS)

    Ozaki, N.; Harada, I.

    1976-01-01

    Computer programs to optimize the step and tapered-step cascades with gas centrifuges are developed. The 'Complex Method', one of the direct search method, is employed to find the optimum of the nonlinear function of several variables within a constrained region. The separation characteristics of the optimized step and tapered-step cascades are discussed in comparison with that of the ideal cascade. The local optima of the cascade profile, the convergence of the object function, and the stopping criterion for the optimization trial are also discussed. (author)

  12. All passive architecture for high efficiency cascaded Raman conversion

    Science.gov (United States)

    Balaswamy, V.; Arun, S.; Chayran, G.; Supradeepa, V. R.

    2018-02-01

    Cascaded Raman fiber lasers have offered a convenient method to obtain scalable, high-power sources at various wavelength regions inaccessible with rare-earth doped fiber lasers. A limitation previously was the reduced efficiency of these lasers. Recently, new architectures have been proposed to enhance efficiency, but this came at the cost of enhanced complexity, requiring an additional low-power, cascaded Raman laser. In this work, we overcome this with a new, all-passive architecture for high-efficiency cascaded Raman conversion. We demonstrate our architecture with a fifth-order cascaded Raman converter from 1117nm to 1480nm with output power of ~64W and efficiency of 60%.

  13. Gas separation performance of tapered cascade with membrane

    International Nuclear Information System (INIS)

    Ohno, Masayoshi; Morisue, Tetsuo; Ozaki, Osamu; Miyauchi, Terukatsu.

    1978-01-01

    Membrane gas separation cascades are analyzed at steady state. The method of calculating the flow rate and concentration profiles in the cascade are examined, using formulas expressing the various membrane separation cell characteristics. The method adopted is applicable to relatively high concentrations and separation factors. Considerations are further given on the steady state performance of four theoretical forms of cascade: (a) with common value of cut for all stages, (b) with symmetric separation cells, (c) with no mixing at the junction at each stage, and (d) ideal cascade. The analysis showed that, with membrane cells, the ideal cascade would have a pressure ratio varying from stage to stage. The symmetric separation cascade would provide a separation performance lower than the ideal cascade on account of the mixing at the junctions of streams possessing different concentrations, whereas the cut and separation factor of the no-mixing cascade requiring minimum membrane area exhibits zig-zag curves when plotted against stage number. Both these circumstances contribute to the lower separation performance obtained with these two forms as compared with the ideal cascade, and results in larger total membrane area; but these semi-ideal forms retain the advantage of easy practical treatment with their pressure ratio common to all stages. (auth.)

  14. A novel electrochemical sensor for lead ion based on cascade DNA and quantum dots amplification

    International Nuclear Information System (INIS)

    Tang, Shurong; Lu, Wei; Gu, Fang; Tong, Ping; Yan, Zhiming; Zhang, Lan

    2014-01-01

    A new enzyme-free and ultrasensitive electrochemical Pb 2+ biosensor was developed. By coupling the DNA-assisted cascade of hybridization reaction with the quantum dots (QDs) for signal amplification, a detection limit as low as 6.1 pM can be obtained for Pb 2+ . In this study, the “8-17” DNAzyme was used for specific recognition of Pb 2+ . In the presence of Pb 2+ , the DNAzyme was activated and cleaved the substrate strand. And then, the hybridization between the linker probe and signal probe was initiated, which resulted in formation of a long cascade DNA structure as well as assemble of numerous QDs at last. By the use of magnetic beads, the free signal probe can be easily removed by external magnetic field. After acid lysis, a great amount of redox cations can be released from the QDs and eventually result in significantly amplified electrochemical signals. This method is highly sensitive, selective and simple without the participation of any protein based enzyme (nuclease), thereby holds great potential for real sample analysis

  15. Enzymic lactose hydrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Miller, J J; Brand, J C

    1980-01-01

    Acid or enzymic hydrolysis can be used to hydrolyze lactose. Advantages of both are compared and details of enzymic hydrolysis using yeast or fungal enzymes given. The new scheme outlined involves recycling lactase. Because lactose and lactase react to ultrafiltration (UF) membranes differently separation is possible. Milk or milk products are ultrafiltered to separate a concentrate from a lactose-rich permeate which is treated with lactase in a reactor until hydrolysis reaches a required level. The lactase can be removed by UF as it does not permeate the membrane, and it is recycled back to the reactor. Permeate from the second UF stage may or may not be recombined with the concentrate from the first stage to produce a low lactose product (analysis of a typical low-lactose dried whole milk is given). Batch or continuous processes are explained and a batch process without enzyme recovery is discussed. (Refs. 4).

  16. Indicators: Sediment Enzymes

    Science.gov (United States)

    Sediment enzymes are proteins that are produced by microorganisms living in the sediment or soil. They are indicators of key ecosystem processes and can help determine which nutrients are affecting the biological community of a waterbody.

  17. Enzyme Vs. Extremozyme -32 ...

    Indian Academy of Sciences (India)

    Enzymes are biocatalytic protein molecules that enhance the rates of ... to physical forces (hydrogen bonds, hydrophobic 1, electrostatic and Van der ... conformation. In 1995 ... surface against 14.7% in Klenow poll (some of the hydrophobic.

  18. Overproduction of ligninolytic enzymes

    Science.gov (United States)

    Elisashvili, Vladimir; Kachlishvili, Eva; Torok, Tamas

    2014-06-17

    Methods, compositions, and systems for overproducing ligninolytic enzymes from the basidiomycetous fungus are described herein. As described, the method can include incubating a fungal strain of Cerrena unicolor IBB 303 in a fermentation system having growth medium which includes lignocellulosic material and then cultivating the fungal strain in the fermentation system under conditions wherein the fungus expresses the ligninolytic enzymes. In some cases, the lignocellulosic material is mandarin peel, ethanol production residue, walnut pericarp, wheat bran, wheat straw, or banana peel.

  19. Cascading walks model for human mobility patterns.

    Science.gov (United States)

    Han, Xiao-Pu; Wang, Xiang-Wen; Yan, Xiao-Yong; Wang, Bing-Hong

    2015-01-01

    Uncovering the mechanism behind the scaling laws and series of anomalies in human trajectories is of fundamental significance in understanding many spatio-temporal phenomena. Recently, several models, e.g. the explorations-returns model (Song et al., 2010) and the radiation model for intercity travels (Simini et al., 2012), have been proposed to study the origin of these anomalies and the prediction of human movements. However, an agent-based model that could reproduce most of empirical observations without priori is still lacking. In this paper, considering the empirical findings on the correlations of move-lengths and staying time in human trips, we propose a simple model which is mainly based on the cascading processes to capture the human mobility patterns. In this model, each long-range movement activates series of shorter movements that are organized by the law of localized explorations and preferential returns in prescribed region. Based on the numerical simulations and analytical studies, we show more than five statistical characters that are well consistent with the empirical observations, including several types of scaling anomalies and the ultraslow diffusion properties, implying the cascading processes associated with the localized exploration and preferential returns are indeed a key in the understanding of human mobility activities. Moreover, the model shows both of the diverse individual mobility and aggregated scaling displacements, bridging the micro and macro patterns in human mobility. In summary, our model successfully explains most of empirical findings and provides deeper understandings on the emergence of human mobility patterns.

  20. The cascad spent fuel dry storage facility

    International Nuclear Information System (INIS)

    Guay, P.; Bonnet, C.

    1991-01-01

    France has a wide variety of experimental spent fuels different from LWR spent fuel discharged from commercial reactors. Reprocessing such fuels would thus require the development and construction of special facilities. The French Atomic Energy Commission (CEA) has consequently opted for long-term interim storage of these spent fuels over a period of 50 years. Comparative studies of different storage concepts have been conducted on the basis of safety (mainly containment barriers and cooling), economic, modular design and operating flexibility criteria. These studies have shown that dry storage in a concrete vault cooled by natural convection is the best solution. A research and development program including theoretical investigations and mock-up tests confirmed the feasibility of cooling by natural convection and the validity of design rules applied for fuel storage. A facility called CASCAD was built at the CEA's Cadarache Nuclear Research Center, where it has been operational since mid-1990. This paper describes the CASCAD facility and indicates how its concept can be applied to storage of LWR fuel assemblies

  1. Frequency division using a micromechanical resonance cascade

    Energy Technology Data Exchange (ETDEWEB)

    Qalandar, K. R., E-mail: kamala@engineering.ucsb.edu; Gibson, B.; Sharma, M.; Ma, A.; Turner, K. L. [Department of Mechanical Engineering, University of California at Santa Barbara, Santa Barbara, California 93106 (United States); Strachan, B. S. [Department of Mechanical Engineering, Michigan State University, East Lansing, Michigan 48823 (United States); Department of Electrical Engineering, Michigan State University, East Lansing, Michigan 48823 (United States); Shaw, S. W. [Department of Mechanical Engineering, Michigan State University, East Lansing, Michigan 48823 (United States); Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48823 (United States)

    2014-12-15

    A coupled micromechanical resonator array demonstrates a mechanical realization of multi-stage frequency division. The mechanical structure consists of a set of N sequentially perpendicular microbeams that are connected by relatively weak elastic elements such that the system vibration modes are localized to individual microbeams and have natural frequencies with ratios close to 1:2:⋯:2{sup N}. Conservative (passive) nonlinear inter-modal coupling provides the required energy transfer between modes and is achieved by finite deformation kinematics. When the highest frequency beam is excited, this arrangement promotes a cascade of subharmonic resonances that achieve frequency division of 2{sup j} at microbeam j for j = 1, …, N. Results are shown for a capacitively driven three-stage divider in which an input signal of 824 kHz is passively divided through three modal stages, producing signals at 412 kHz, 206 kHz, and 103 kHz. The system modes are characterized and used to delineate the range of AC input voltages and frequencies over which the cascade occurs. This narrow band frequency divider has simple design rules that are scalable to higher frequencies and can be extended to a larger number of modal stages.

  2. Turbulent cascades in foreign exchange markets

    Science.gov (United States)

    Ghashghaie, S.; Breymann, W.; Peinke, J.; Talkner, P.; Dodge, Y.

    1996-06-01

    THE availability of high-frequency data for financial markets has made it possible to study market dynamics on timescales of less than a day1. For foreign exchange (FX) rates Müller et al.2 have shown that there is a net flow of information from long to short timescales: the behaviour of long-term traders (who watch the markets only from time to time) influences the behaviour of short-term traders (who watch the markets continuously). Motivated by this hierarchical feature, we have studied FX market dynamics in more detail, and report here an analogy between these dynamics and hydrodynamic turbulence3-8. Specifically, the relationship between the probability density of FX price changes (δx) and the time delay (δt) (Fig. la) is much the same as the relationship between the probability density of the velocity differences (δv) of two points in a turbulent flow and their spatial separation δr (Fig. 1b). Guided by this similarity we claim that there is an information cascade in FX market dynamics that corresponds to the energy cascade in hydrodynamic turbulence. On the basis of this analogy we can now rationalize the statistics of FX price differences at different time delays, which is important for, for example, option pricing. The analogy also provides a conceptual framework for understanding the short-term dynamics of speculative markets.

  3. Measurement of enzyme activity.

    Science.gov (United States)

    Harris, T K; Keshwani, M M

    2009-01-01

    To study and understand the nature of living cells, scientists have continually employed traditional biochemical techniques aimed to fractionate and characterize a designated network of macromolecular components required to carry out a particular cellular function. At the most rudimentary level, cellular functions ultimately entail rapid chemical transformations that otherwise would not occur in the physiological environment of the cell. The term enzyme is used to singularly designate a macromolecular gene product that specifically and greatly enhances the rate of a chemical transformation. Purification and characterization of individual and collective groups of enzymes has been and will remain essential toward advancement of the molecular biological sciences; and developing and utilizing enzyme reaction assays is central to this mission. First, basic kinetic principles are described for understanding chemical reaction rates and the catalytic effects of enzymes on such rates. Then, a number of methods are described for measuring enzyme-catalyzed reaction rates, which mainly differ with regard to techniques used to detect and quantify concentration changes of given reactants or products. Finally, short commentary is given toward formulation of reaction mixtures used to measure enzyme activity. Whereas a comprehensive treatment of enzymatic reaction assays is not within the scope of this chapter, the very core principles that are presented should enable new researchers to better understand the logic and utility of any given enzymatic assay that becomes of interest.

  4. A perpetual cascade of cytokines postirradiation leads to pulmonary fibrosis

    International Nuclear Information System (INIS)

    Rubin, Philip; Johnston, Carl J.; Williams, Jacqueline P.; McDonald, Sandra; Finkelstein, Jacob N.

    1995-01-01

    Purpose: Radiation-induced pulmonary reactions have classically been viewed as distinct phases--acute pneumonitis and, later, fibrosis--occurring at different times after irradiation and attributed to different target cell populations. We prefer to view these events as a continuum, with no clear distinction between the temporal sequence of the different pulmonary reactions; the progression is the result of an early activation of an inflammatory reaction, leading to the expression and maintenance of a cytokine cascade. In the current study, we have examined the temporal and spatial expression of cytokine and extracellular matrix messenger ribonucleic acid (mRNA) abundance in fibrosis-sensitive mice after thoracic irradiation. Methods and Materials: Radiation fibrosis-prone ((C57BL(6))) mice received thoracic irradiation of 5 and 12.5 Gy. At Day 1, and 1, 2, 8, 16 and 24 weeks after treatment, animals were killed and lung tissue processed for light microscopy and isolation of RNA. Expression of cytokine and extracellular matrix mRNA abundance was evaluated by slot-blot analysis and cellular localization by in situ hybridization and immunochemistry. Results: One of the cytokines responsible for the inflammatory phase (IL-1α) is elevated at 2 weeks, returns to normal baseline values, then increases at 8 weeks, remaining elevated until 26 weeks when lung fibrosis appears. Transforming growth factor-beta (TGFβ), a proliferative cytokine, is elevated at 2 weeks, persists until 8 weeks, and then returns to baseline values. In parallel with the cytokine cascade, the fibrogenic markers for CI/CIII/IV (collagen genes) correlate by showing a similar early and then later elevation of activity. For instance, the collagen gene expression of CI/CIII is a biphasic response with an initial increase at 1-2 weeks that remits at 8 weeks, remains inactive from 8 to 16 weeks, and then becomes elevated at 6 months when collagen deposition is recognized histopathologically. Conclusion

  5. Geographic extent and variation of a coral reef trophic cascade.

    Science.gov (United States)

    McClanahan, T R; Muthiga, N A

    2016-07-01

    Trophic cascades caused by a reduction in predators of sea urchins have been reported in Indian Ocean and Caribbean coral reefs. Previous studies have been constrained by their site-specific nature and limited spatial replication, which has produced site and species-specific understanding that can potentially preclude larger community-organization nuances and generalizations. In this study, we aimed to evaluate the extent and variability of the cascade community in response to fishing across ~23° of latitude and longitude in coral reefs in the southwestern Indian Ocean. The taxonomic composition of predators of sea urchins, the sea urchin community itself, and potential effects of changing grazer abundance on the calcifying benthic organisms were studied in 171 unique coral reef sites. We found that geography and habitat were less important than the predator-prey relationships. There were seven sea urchin community clusters that aligned with a gradient of declining fishable biomass and the abundance of a key predator, the orange-lined triggerfish (Balistapus undulatus). The orange-lined triggerfish dominated where sea urchin numbers and diversity were low but the relative abundance of wrasses and emperors increased where sea urchin numbers were high. Two-thirds of the study sites had high sea urchin biomass (>2,300 kg/ha) and could be dominated by four different sea urchin species, Echinothrix diadema, Diadema savignyi, D. setosum, and Echinometra mathaei, depending on the community of sea urchin predators, geographic location, and water depth. One-third of the sites had low sea urchin biomass and diversity and were typified by high fish biomass, predators of sea urchins, and herbivore abundance, representing lightly fished communities with generally higher cover of calcifying algae. Calcifying algal cover was associated with low urchin abundance where as noncalcifying fleshy algal cover was not clearly associated with herbivore abundance. Fishing of the orange

  6. Modeling of cascade and sub-cascade formation at high PKA energies in irradiated fusion structural materials

    International Nuclear Information System (INIS)

    Ryazanov, A.I.; Metelkin, E.V.; Semenov, E.V.

    2009-01-01

    A new theoretical model is developed for the investigations of cascade and sub-cascade formation in fusion structural materials under fast neutron irradiation at high primary knock-on atom energies. Light fusion structural materials: such as Be, C and SiC under 14 MeV neutron irradiation in fusion reactor will have the primary knock-on atoms with the energies up to 1 MeV. It is very difficult to use at such high energies the Monte-Carlo or molecular dynamic simulations [H.L. Heinisch, B.N. Singh, Philos. Mag. A67 (1993) 407; H.L. Heinisch, B.N. Singh, J. Nucl. Mater. 251 (1997) 77]. The developed model is based on the analytical consideration of elastic collisions between displaced moving atoms produced by primary knock-on atoms with some kinetic energies obtained from fast neutrons and crystal lattice atoms. The Thomas-Fermi interaction potential is used here for the description of these elastic atomic collisions. The suggested model takes into account also the electronic losses for moving atoms between elastic collisions. The self-consistent criterion for sub-cascade formation is suggested here which is based on the comparison of mean distance of primary knock-on atoms between consequent collisions of them with the target atoms and a size of sub-cascade produced by moving secondary knock-on atoms produced in such collisions. The analytical relations for the most important characteristics of cascades and sub-cascades are determined including the average number of sub-cascades per one primary knock-on atom in the dependence on its energy, the distance between sub-cascades and the average cascade and sub-cascade sizes. The developed model allows determining the total numbers, distribution functions of cascades and sub-cascades in dependence on their sizes and generation rate of cascades and sub-cascades for the different fusion neutron energy spectra. On the basis of this developed model the numerical calculations for main characteristics of cascades and sub-cascades

  7. EFSA Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids (CEF); Scientific Opinion on Flavouring Group Evaluation 17, Revision 3 (FGE.17Rev3): Pyrazine derivatives from chemical group 24

    DEFF Research Database (Denmark)

    Larsen, John Christian; Nørby, Karin Kristiane; Beltoft, Vibe Meister

    The Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids of the European Food Safety Authority was requested to evaluate 28 flavouring substances in the Flavouring Group Evaluation 17, including seven additional substances considered in this Revision 3, using the Procedure......-activity relationships, intake from current uses, toxicological threshold of concern, and available data on metabolism and toxicity. The Panel concluded that 24 substances [FL-no: 14.057, 14.081, 14.083, 14.084, 14.086, 14.087, 14.091, 14.097, 14.099, 14.101, 14.102, 14.108, 14.109, 14.111, 14.112, 14.113, 14.122, 14...... substances, the specifications for the materials of commerce have also been considered and for one substance [FL-no: 14.102], the composition of mixture has not been specified sufficiently....

  8. A coupled-enzyme equilibrium method for measuring urea in serum: optimization and evaluation of the AACC study group on urea candidate reference method.

    Science.gov (United States)

    Sampson, E J; Baird, M A; Burtis, C A; Smith, E M; Witte, D L; Bayse, D D

    1980-06-01

    We describe a coupled-enzyme equilibrium method for measuring urea in serum, which is performed on supernates prepared by treating each specimen with Ba(OH)2 and ZnSO4 (Somogyi reagent). Analytical recovery of [14C]urea added to a variety of matrices was essentially complete (mean, 100.6%) for the supernates after precipitation. Nine variables were univariately examined in arriving at the reaction conditions for the method: glutamate dehydrogenase, urease, 2-oxoglutarate, ADP, Tris . HCI, NADH, EDTA, pH, and temperature. The reagent is stable for at least 48 days at--20 degrees C and for 23 days at 4 degrees C. Mean analytical recovery of urea (14 mmol/L) added to seven different specimens (three different matrices) was 100.8%. The analytical linear range of the method extends to 30 mmol of urea per liter. Of 22 potential interferents, only bilirubin at 1 mmol/L (580 mg/L), hemoglobin at 10 g/L, and hydroxyurea at 6 mmol/L showed more than 2% interference. We discuss precision and effects of specimen dilution, and compare results for 100 human serum specimens with those measured for the same specimens with four other urea methods. We examined the effects of measuring a blank, consisting of sample and reagent without urease, with each specimen.

  9. Cascade reservoir flood control operation based on risk grading and warning in the Upper Yellow River

    Science.gov (United States)

    Xuejiao, M.; Chang, J.; Wang, Y.

    2017-12-01

    Flood risk reduction with non-engineering measures has become the main idea for flood management. It is more effective for flood risk management to take various non-engineering measures. In this paper, a flood control operation model for cascade reservoirs in the Upper Yellow River was proposed to lower the flood risk of the water system with multi-reservoir by combining the reservoir flood control operation (RFCO) and flood early warning together. Specifically, a discharge control chart was employed to build the joint RFCO simulation model for cascade reservoirs in the Upper Yellow River. And entropy-weighted fuzzy comprehensive evaluation method was adopted to establish a multi-factorial risk assessment model for flood warning grade. Furthermore, after determining the implementing mode of countermeasures with future inflow, an intelligent optimization algorithm was used to solve the optimization model for applicable water release scheme. In addition, another model without any countermeasure was set to be a comparative experiment. The results show that the model developed in this paper can further decrease the flood risk of water system with cascade reservoirs. It provides a new approach to flood risk management by coupling flood control operation and flood early warning of cascade reservoirs.

  10. Serviceability Assessment for Cascading Failures in Water Distribution Network under Seismic Scenario

    Directory of Open Access Journals (Sweden)

    Qing Shuang

    2016-01-01

    Full Text Available The stability of water service is a hot point in industrial production, public safety, and academic research. The paper establishes a service evaluation model for the water distribution network (WDN. The serviceability is measured in three aspects: (1 the functionality of structural components under disaster environment; (2 the recognition of cascading failure process; and (3 the calculation of system reliability. The node and edge failures in WDN are interrelated under seismic excitations. The cascading failure process is provided with the balance of water supply and demand. The matrix-based system reliability (MSR method is used to represent the system events and calculate the nonfailure probability. An example is used to illustrate the proposed method. The cascading failure processes with different node failures are simulated. The serviceability is analyzed. The critical node can be identified. The result shows that the aged network has a greater influence on the system service under seismic scenario. The maintenance could improve the antidisaster ability of WDN. Priority should be given to controlling the time between the initial failure and the first secondary failure, for taking postdisaster emergency measures within this time period can largely cut down the spread of cascade effect in the whole WDN.

  11. Biotechnological production of vanillin using immobilized enzymes.

    Science.gov (United States)

    Furuya, Toshiki; Kuroiwa, Mari; Kino, Kuniki

    2017-02-10

    Vanillin is an important and popular plant flavor, but the amount of this compound available from plant sources is very limited. Biotechnological methods have high potential for vanillin production as an alternative to extraction from plant sources. Here, we report a new approach using immobilized enzymes for the production of vanillin. The recently discovered oxygenase Cso2 has coenzyme-independent catalytic activity for the conversion of isoeugenol and 4-vinylguaiacol to vanillin. Immobilization of Cso2 on Sepabeads EC-EA anion-exchange carrier conferred enhanced operational stability enabling repetitive use. This immobilized Cso2 catalyst allowed 6.8mg yield of vanillin from isoeugenol through ten reaction cycles at a 1mL scale. The coenzyme-independent decarboxylase Fdc, which has catalytic activity for the conversion of ferulic acid to 4-vinylguaiacol, was also immobilized on Sepabeads EC-EA. We demonstrated that the immobilized Fdc and Cso2 enabled the cascade synthesis of vanillin from ferulic acid via 4-vinylguaiacol with repetitive use of the catalysts. This study is the first example of biotechnological production of vanillin using immobilized enzymes, a process that provides new possibilities for vanillin production. Copyright © 2016 Elsevier B.V. All rights reserved.

  12. Immobilised enzymes in biorenewables production.

    Science.gov (United States)

    Franssen, Maurice C R; Steunenberg, Peter; Scott, Elinor L; Zuilhof, Han; Sanders, Johan P M

    2013-08-07

    Oils, fats, carbohydrates, lignin, and amino acids are all important raw materials for the production of biorenewables. These compounds already play an important role in everyday life in the form of wood, fabrics, starch, paper and rubber. Enzymatic reactions do, in principle, allow the transformation of these raw materials into biorenewables under mild and sustainable conditions. There are a few examples of processes using immobilised enzymes that are already applied on an industrial scale, such as the production of High-Fructose Corn Syrup, but these are still rather rare. Fortunately, there is a rapid expansion in the research efforts that try to improve this, driven by a combination of economic and ecological reasons. This review focusses on those efforts, by looking at attempts to use fatty acids, carbohydrates, proteins and lignin (and their building blocks), as substrates in the synthesis of biorenewables using immobilised enzymes. Therefore, many examples (390 references) from the recent literature are discussed, in which we look both at the specific reactions as well as to the methods of immobilisation of the enzymes, as the latter are shown to be a crucial factor with respect to stability and reuse. The applications of the renewables produced in this way range from building blocks for the pharmaceutical and polymer industry, transport fuels, to additives for the food industry. A critical evaluation of the relevant factors that need to be improved for large-scale use of these examples is presented in the outlook of this review.

  13. Evaluation of a SUMO E2 conjugating enzyme involved in resistance to Clavibacter michiganensis subsp. michiganensis in Solanum peruvianum, through a tomato mottle virus VIGS assay

    Directory of Open Access Journals (Sweden)

    Mayra Janeth Esparza-Araiza

    2015-12-01

    Full Text Available Clavibacter michiganensis subsp. michiganensis (Cmm causes bacterial wilt and canker of tomato. Currently, no Solanum lycopersicum resistant varieties are commercially available, but some degree of Cmm resistance has been identified in Solanum peruvianum. Previous research showed up-regulation of a SUMO E2 conjugating enzyme (SCEI transcript in resistant S. peruvianum compared to susceptible S. lycopersicum following infection by Cmm. In order to test the role of SCEI in resistance to Cmm, a fragment of the gene from S. peruvianum was cloned into a novel virus-induced gene-silencing (VIGS vector based on the geminivirus Tomato Mottle Virus (ToMoV. Using biolistic inoculation, the ToMoV-based VIGS vector was shown to be effective in S. peruvianum by silencing the magnesium chelatase gene, which resulted in leaf bleaching. The ToMoV_SCEI construct resulted in approx. 61% silencing of SCEI in leaves of S. peruvianum as determined by quantitative RT-PCR. VIGS of SCEI in S. peruvianum resulted in unilateral wilting (15 dpi and subsequent death (20 dpi of the entire plant after Cmm inoculation, whereas empty vector-treated plants only showed wilting in the Cmm-inoculated leaf. SCEI-silenced plants also showed higher Cmm colonization with an average of 4.5 times more damaged tissue compared to the empty vector control plants. SCEI appears to play an important role in the innate immunity of S. peruvianum against Cmm, perhaps through the regulation of WRKY transcription factors, which may lead to expression of proteins involved in salicylic acid-dependent defense responses.

  14. Evaluation of toxic equivalency factors for induction of cytochromes P450 CYP1A1 and CYP1A2 enzyme activity by dioxin-like compounds

    International Nuclear Information System (INIS)

    Toyoshiba, Hiroyoshi; Walker, Nigel J.; Bailer, A. John; Portier, Christopher J.

    2004-01-01

    The toxic equivalency factor (TEF) method has been used to characterize the toxicity of human mixtures of dioxin-like compounds and is being considered for use with other classes of potentially toxic agents. TEFs are estimated by examining the relative potencies of the various congeners for a series of biological and toxicological effects. In this paper, we consider changes in activity for two enzymes, cytochrome P450 1A1 (CYP1A1)-associated 7-ethoxyresorufin-O-deethylase (EROD) and CYP1A2-associated acetanilide-4-hydroxylase (A4H) activity, resulting from exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), 3,3',4,4',5-pentachlorobiphenyl (PCB), 2,3,4,7,8-pentachlorodibenzofuran (PeCDF) or a mixture of these agents. The ratio of median effective dose (ED 50 ) is one way to estimate the relative potencies, especially for gene expression and protein endpoints. ED 50 's were estimated with a nonlinear regression model in which dose-related changes in mean responses are described by a Hill function. ED 50 's along with other model parameters were estimated by fitting this model to a given data set. Significant differences in estimated model parameters were tested by likelihood ratio methods. The estimated parameters indicated that congener-specific dose-response shapes were significantly different, that additivity failed for these congeners, and that the ratios of ED 50 's did not predict the response seen for the mixture. These results indicate that for some biological responses, the use of a single relative potency factor (RPF) is not appropriate for the comparison of the dose response behavior of different dioxin-like congeners

  15. AN EVALUATION STUDY OF ENZYME-LINKED IMMUNOSORBENT ASSAY (ELISA USING RECOMBINANT PROTEIN GRA1 FOR DETECTION OF IGG ANTIBODIES AGAINTS TOXOPLASMA GONDII INFECTIONS

    Directory of Open Access Journals (Sweden)

    Nina Difla Muflikhah

    2017-08-01

    Full Text Available Toxoplasmosis is an infectious disease caused by Toxoplasma gondii, an intracellular protozoan parasite that live inside the cells of the reticulo endothelial and parenchymal cells of human and animals (mammals and birds. Some cases of toxoplasmosis usually have no symptoms, but in any cases caused severe symptoms, such as hydrocephalus, microcephalus, intracranial calcification, retinal damage, brain abscess, mental retardation, lymphadenopathy, and others. Its severe symptoms usually showed a long time after first exposure, except symptoms showed by congenital transmission caused by infected mother. Early diagnosis is important to prevent the illness but methods for toxoplasmosis screening are still too expensive for developing country. Enzyme-linked immunosorbent assay (ELISA allow the testing of a large number samples within short time frame and based on antibody or antigen detection. This study aimed to know the sensitivity and specificity of recombinat protein GRA1 as antigen using ELISA methods. We tested the sensitivity and spesificity of GRA1 protein as antigen in ELISA methods to diagnose toxoplasmosis and compared with ELISA Kit Commercial. Reliable laboratory testing is important to detect Toxoplasma gondii infection, and focused to improving the low cost and easy-to-use diagnostic instrument. Seventy sera collected and tested using both indirect ELISA, commercial ELISA kit and GRA1 protein coated as antigen. Fourty eight and fifty one samples showed positive IgG antibody result of ELISA-GRA1 and ELISA kit. Negative sample tested by ELISA-GRA1 was 22 samples and 19 sample tested by ELISA Kit. The sensitivity and specificity of GRA1-based on ELISA were 100% and 86.36%, positive prediction value (ppv was 94.11%. These data indicate that the recombinant protein GRA1 is a highly immunogenic protein in human toxoplasmosis and become a promising marker for the screening of toxoplasmosis.

  16. Eruptive history of South Sister, Oregon Cascades

    Science.gov (United States)

    Fierstein, J.; Hildreth, W.; Calvert, A.T.

    2011-01-01

    South Sister is southernmost and highest of the Three Sisters, three geologically dissimilar stratovolcanoes that together form a spectacular 20km reach along the Cascade crest in Oregon. North Sister is a monotonously mafic edifice as old as middle Pleistocene, Middle Sister a basalt-andesite-dacite cone built between 48 and 14ka, and South Sister is a basalt-free edifice that alternated rhyolitic and intermediate modes from 50ka to 2ka (largely contemporaneous with Middle Sister). Detailed mapping, 330 chemical analyses, and 42 radioisotopic ages show that the oldest exposed South Sister lavas were initially rhyolitic ~50ka. By ~37ka, rhyolitic lava flows and domes (72-74% SiO2) began alternating with radially emplaced dacite (63-68% SiO2) and andesite (59-63% SiO2) lava flows. Construction of a broad cone of silicic andesite-dacite (61-64% SiO2) culminated ~30ka in a dominantly explosive sequence that began with crater-forming andesitic eruptions that left fragmental deposits at least 200m thick. This was followed at ~27ka by growth of a steeply dipping summit cone of agglutinate-dominated andesite (56-60.5% SiO2) and formation of a summit crater ~800m wide. This crater was soon filled and overtopped by a thick dacite lava flow and then by >150m of dacitic pyroclastic ejecta. Small-volume dacite lavas (63-67% SiO2) locally cap the pyroclastic pile. A final sheet of mafic agglutinate (54-56% SiO2) - the most mafic product of South Sister - erupted from and drapes the small (300-m-wide) present-day summit crater, ending a summit-building sequence that lasted until ~22ka. A 20kyr-long-hiatus was broken by rhyolite eruptions that produced (1) the Rock Mesa coulee, tephra, and satellite domelets (73.5% SiO2) and (2) the Devils Chain of ~20 domes and short coulees (72.3-72.8% SiO2) from N-S vent alignments on South Sister's flanks. The compositional reversal from mafic summit agglutinate to recent rhyolites epitomizes the frequently changing compositional modes of the

  17. Energy cascading in the beat-wave accelerator

    International Nuclear Information System (INIS)

    McKinstrie, C.J.; Batha, S.H.

    1987-01-01

    A review is given of energy cascading in the beat-wave accelerator. The properties of the electromagnetic cascade and the corresponding plasma-wave evolution are well understood within the framework of an approximate analytic model. Based on this model, idealized laser-plasma coupling efficiencies of the order of 10% do not seem unreasonable. 28 refs

  18. Time development of cascades by the binary collision approximation code

    International Nuclear Information System (INIS)

    Fukumura, A.; Ishino, S.; Sekimura, N.

    1991-01-01

    To link a molecular dynamic calculation to binary collision approximation codes to explore high energy cascade damage, time between consecutive collisions is introduced into the binary collision MARLOWE code. Calculated results for gold by the modified code show formation of sub-cascades and their spatial and time overlapping, which can affect formation of defect clusters. (orig.)

  19. Cascades for hydrogen isotope separation using metal hydrides

    International Nuclear Information System (INIS)

    Hill, F.B.; Grzetic, V.

    1982-01-01

    Designs are presented for continuous countercurrent hydrogen isotope separation cascades based on the use of metal hydrides. The cascades are made up of pressure swing adsorption (PSA) or temperature swing adsorption (TSA) stages. The designs were evolved from consideration of previously conducted studies of the separation performance of four types of PSA and TSA processes

  20. Hybrid Modulation Scheme for Cascaded H-Bridge Inverter Cells ...

    African Journals Online (AJOL)

    This work proposes a switching technique for cascaded H-Bridge (CHB) cells. Single carrier Sinusoidal PWM (SCSPWM) scheme is employed in the generation of the gating signals. A sequential switching and base PWM circulation schemes are presented for this fundamental cascaded multilevel inverter topology.