An intermediate state of T7 RNA polymerase provides another pathway of nucleotide selection

International Nuclear Information System (INIS)

Wang Zhan-Feng; Liu Yu-Ru; Wang Peng-Ye; Xie Ping

2017-01-01

Phage T7 RNA polymerase is a single-subunit transcription enzyme, transcribing template DNA to RNA. Nucleoside triphosphate (NTP) selection and translocation are two critical steps of the transcription elongation. Here, using all-atom molecular dynamics simulations, we found that between pre- and post-translocation states of T7 RNA polymerase an intermediate state exists, where the O helix C-terminal residue tyrosine 639, which plays important roles in translocation, locates between its pre- and post-translocation positions and the side chain of the next template DNA nucleotide has moved into the active site. NTP selection in this intermediate state was studied, revealing that the selection in the intermediate state can be achieved relying on the effect of Watson–Crick interaction between NTP and template DNA nucleotide, effect of stability of the components near the active site such as the nascent DNA–RNA hybrid and role of tyrosine 639. This indicates that another NTP-selection pathway can also exist besides the main pathway where NTP selection begins at the post-translocation state upon the entry of NTP. (paper)

Low temperature intermediate band metallic behavior in Ti implanted Si

Energy Technology Data Exchange (ETDEWEB)

Olea, Javier, E-mail: oleaariza@fis.ucm.es; Pastor, David; Garcia-Hemme, Eric; Garcia-Hernansanz, Rodrigo; Prado, Alvaro del; Martil, Ignacio; Gonzalez-Diaz, German

2012-08-31

Si samples implanted with very high Ti doses and subjected to Pulsed-Laser Melting (PLM) have been electrically analyzed in the scope of a two-layer model previously reported based on the Intermediate Band (IB) theory. Conductivity and Hall effect measurements using the van der Pauw technique suggest that the insulator-metal transition takes place for implantation doses in the 10{sup 14}-10{sup 16} cm{sup -2} range. Results of the sample implanted with the 10{sup 16} cm{sup -2} dose show a metallic behavior at low temperature that is explained by the formation of a p-type IB out of the Ti deep levels. This suggests that the IB would be semi-filled, which is essential for IB photovoltaic devices. - Highlights: Black-Right-Pointing-Pointer We fabricated high dose Ti implanted Si samples for intermediate band research. Black-Right-Pointing-Pointer We measured the electronic transport properties in the 7-300 K range. Black-Right-Pointing-Pointer We show an insulator to metallic transition when the intermediate band is formed. Black-Right-Pointing-Pointer The intermediate band is semi-filled and populated by holes. Black-Right-Pointing-Pointer We satisfactorily explain the electrical behavior by an intermediate band model.

Why do alpha-beta parallel proteins, like flavodoxins, form misfolded off-pathway intermediates?

NARCIS (Netherlands)

Nabuurs, S.M.

2009-01-01

The question: “Why do α-β parallel proteins, like flavodoxins, form misfolded off-pathway
intermediates?" is the main subject of this thesis. A. vinelandii apoflavodoxin is chosen as protein
of interest as it is a representative of α-β parallel proteins, which are widely prevalent in

Transient intermediates are populated in the folding pathways of single-domain two-state folding protein L

Science.gov (United States)

Maity, Hiranmay; Reddy, Govardhan

2018-04-01

Small single-domain globular proteins, which are believed to be dominantly two-state folders, played an important role in elucidating various aspects of the protein folding mechanism. However, recent single molecule fluorescence resonance energy transfer experiments [H. Y. Aviram et al. J. Chem. Phys. 148, 123303 (2018)] on a single-domain two-state folding protein L showed evidence for the population of an intermediate state and it was suggested that in this state, a β-hairpin present near the C-terminal of the native protein state is unfolded. We performed molecular dynamics simulations using a coarse-grained self-organized-polymer model with side chains to study the folding pathways of protein L. In agreement with the experiments, an intermediate is populated in the simulation folding pathways where the C-terminal β-hairpin detaches from the rest of the protein structure. The lifetime of this intermediate structure increased with the decrease in temperature. In low temperature conditions, we also observed a second intermediate state, which is globular with a significant fraction of the native-like tertiary contacts satisfying the features of a dry molten globule.

Application of NX Siemens PLM software in educational process in preparing students of engineering branch

Science.gov (United States)

Sadchikova, G. M.

2017-01-01

This article discusses the results of the introduction of computer-aided design NX by Siemens Plm Software to the classes of a higher education institution. The necessity of application of modern information technologies in teaching students of engineering profile and selection of a software product is substantiated. The author describes stages of the software module study in relation to some specific courses, considers the features of NX software, which require the creation of standard and unified product databases. The article also gives examples of research carried out by the students with the various software modules.

Greigite: a true intermediate on the polysulfide pathway to pyrite

Directory of Open Access Journals (Sweden)

Benning Liane G

2007-03-01

Full Text Available Abstract The formation of pyrite (FeS2 from iron monosulfide precursors in anoxic sediments has been suggested to proceed via mackinawite (FeS and greigite (Fe3S4. Despite decades of research, the mechanisms of pyrite formation are not sufficiently understood because solid and dissolved intermediates are oxygen-sensitive and poorly crystalline and therefore notoriously difficult to characterize and quantify. In this study, hydrothermal synchrotron-based energy dispersive X-ray diffraction (ED-XRD methods were used to investigate in situ and in real-time the transformation of mackinawite to greigite and pyrite via the polysulfide pathway. The rate of formation and disappearance of specific Bragg peaks during the reaction and the changes in morphology of the solid phases as observed with high resolution microscopy were used to derive kinetic parameters and to determine the mechanisms of the reaction from mackinawite to greigite and pyrite. The results clearly show that greigite is formed as an intermediate on the pathway from mackinawite to pyrite. The kinetics of the transformation of mackinawite to greigite and pyrite follow a zero-order rate law indicating a solid-state mechanism. The morphology of greigite and pyrite crystals formed under hydrothermal conditions supports this conclusion and furthermore implies growth of greigite and pyrite by oriented aggregation of nanoparticulate mackinawite and greigite, respectively. The activation enthalpies and entropies of the transformation of mackinawite to greigite, and of greigite to pyrite were determined from the temperature dependence of the rate constants according to the Eyring equation. Although the activation enthalpies are uncharacteristic of a solid-state mechanism, the activation entropies indicate a large increase of order in the transition state, commensurate with a solid-state mechanism.

Coat Protein Mutations That Alter the Flux of Morphogenetic Intermediates through the ϕX174 Early Assembly Pathway.

Science.gov (United States)

Blackburn, Brody J; Li, Shuaizhi; Roznowski, Aaron P; Perez, Alexis R; Villarreal, Rodrigo H; Johnson, Curtis J; Hardy, Margaret; Tuckerman, Edward C; Burch, April D; Fane, Bentley A

2017-12-15

Two scaffolding proteins orchestrate ϕX174 morphogenesis. The internal scaffolding protein B mediates the formation of pentameric assembly intermediates, whereas the external scaffolding protein D organizes 12 of these intermediates into procapsids. Aromatic amino acid side chains mediate most coat-internal scaffolding protein interactions. One residue in the internal scaffolding protein and three in the coat protein constitute the core of the B protein binding cleft. The three coat gene codons were randomized separately to ascertain the chemical requirements of the encoded amino acids and the morphogenetic consequences of mutation. The resulting mutants exhibited a wide range of recessive phenotypes, which could generally be explained within a structural context. Mutants with phenylalanine, tyrosine, and methionine substitutions were phenotypically indistinguishable from the wild type. However, tryptophan substitutions were detrimental at two sites. Charged residues were poorly tolerated, conferring extreme temperature-sensitive and lethal phenotypes. Eighteen lethal and conditional lethal mutants were genetically and biochemically characterized. The primary defect associated with the missense substitutions ranged from inefficient internal scaffolding protein B binding to faulty procapsid elongation reactions mediated by external scaffolding protein D. Elevating B protein concentrations above wild-type levels via exogenous, cloned-gene expression compensated for inefficient B protein binding, as did suppressing mutations within gene B. Similarly, elevating D protein concentrations above wild-type levels or compensatory mutations within gene D suppressed faulty elongation. Some of the parental mutations were pleiotropic, affecting multiple morphogenetic reactions. This progressively reduced the flux of intermediates through the pathway. Accordingly, multiple mechanisms, which may be unrelated, could restore viability. IMPORTANCE Genetic analyses have been

Macromolecular crowding compacts unfolded apoflavodoxin and causes severe aggregation of the off-pathway intermediate during apoflavodoxin folding

NARCIS (Netherlands)

Engel, R.; Westphal, A.H.; Huberts, D.; Nabuurs, S.M.; Lindhoud, S.; Visser, A.J.W.G.; Mierlo, van C.P.M.

2008-01-01

To understand how proteins fold in vivo, it is important to investigate the effects of macromolecular crowding on protein folding. Here, the influence of crowding on in vitro apoflavodoxin folding, which involves a relatively stable off-pathway intermediate with molten globule characteristics, is

On the characterization of intermediates in the isodesmic aggregation pathway of hen lysozyme at alkaline pH.

Directory of Open Access Journals (Sweden)

Vijay Kumar Ravi

Full Text Available Protein aggregation leading to formation of amyloid fibrils is a symptom of several diseases like Alzheimer's, type 2 diabetes and so on. Elucidating the poorly understood mechanism of such phenomena entails the difficult task of characterizing the species involved at each of the multiple steps in the aggregation pathway. It was previously shown by us that spontaneous aggregation of hen-eggwhite lysozyme (HEWL at room temperature in pH 12.2 is a good model to study aggregation. Here in this paper we investigate the growth kinetics, structure, function and dynamics of multiple intermediate species populating the aggregation pathway of HEWL at pH 12.2. The different intermediates were isolated by varying the HEWL monomer concentration in the 300 nM-0.12 mM range. The intermediates were characterized using techniques like steady-state and nanosecond time-resolved fluorescence, atomic force microscopy and dynamic light scattering. Growth kinetics of non-fibrillar HEWL aggregates were fitted to the von Bertalanffy equation to yield a HEWL concentration independent rate constant (k = (6.6 ± 0.6 × 10(-5 s(-1. Our results reveal stepwise changes in size, molecular packing and enzymatic activity among growing HEWL aggregates consistent with an isodesmic aggregation model. Formation of disulphide bonds that crosslink the monomers in the aggregate appear as a unique feature of this aggregation. AFM images of multiple amyloid fibrils emanating radially from amorphous aggregates directly confirmed that on-pathway fibril formation was feasible under isodesmic polymerization. The isolated HEWL aggregates are revealed as polycationic protein nanoparticles that are robust at neutral pH with ability to take up non-polar molecules like ANS.

Comparative techno-economic analysis and process design for indirect liquefaction pathways to distillate-range fuels via biomass-derived oxygenated intermediates upgrading: Liquid Transportation Fuel Production via Biomass-derived Oxygenated Intermediates Upgrading

Energy Technology Data Exchange (ETDEWEB)

Tan, Eric C. D. [National Renewable Energy Laboratory, Golden CO USA; Snowden-Swan, Lesley J. [Pacific Northwest National Laboratory, Richland WA USA; Talmadge, Michael [National Renewable Energy Laboratory, Golden CO USA; Dutta, Abhijit [National Renewable Energy Laboratory, Golden CO USA; Jones, Susanne [Pacific Northwest National Laboratory, Richland WA USA; Ramasamy, Karthikeyan K. [Pacific Northwest National Laboratory, Richland WA USA; Gray, Michel [Pacific Northwest National Laboratory, Richland WA USA; Dagle, Robert [Pacific Northwest National Laboratory, Richland WA USA; Padmaperuma, Asanga [Pacific Northwest National Laboratory, Richland WA USA; Gerber, Mark [Pacific Northwest National Laboratory, Richland WA USA; Sahir, Asad H. [National Renewable Energy Laboratory, Golden CO USA; Tao, Ling [National Renewable Energy Laboratory, Golden CO USA; Zhang, Yanan [National Renewable Energy Laboratory, Golden CO USA

2016-09-27

This paper presents a comparative techno-economic analysis (TEA) of five conversion pathways from biomass to gasoline-, jet-, and diesel-range hydrocarbons via indirect liquefaction with specific focus on pathways utilizing oxygenated intermediates. The four emerging pathways of interest are compared with one conventional pathway (Fischer-Tropsch) for the production of the hydrocarbon blendstocks. The processing steps of the four emerging pathways include: biomass to syngas via indirect gasification, gas cleanup, conversion of syngas to alcohols/oxygenates followed by conversion of alcohols/oxygenates to hydrocarbon blendstocks via dehydration, oligomerization, and hydrogenation. Conversion of biomass-derived syngas to oxygenated intermediates occurs via three different pathways, producing: 1) mixed alcohols over a MoS2 catalyst, 2) mixed oxygenates (a mixture of C2+ oxygenated compounds, predominantly ethanol, acetic acid, acetaldehyde, ethyl acetate) using an Rh-based catalyst, and 3) ethanol from syngas fermentation. This is followed by the conversion of oxygenates/alcohols to fuel-range olefins in two approaches: 1) mixed alcohols/ethanol to 1-butanol rich mixture via Guerbet reaction, followed by alcohol dehydration, oligomerization, and hydrogenation, and 2) mixed oxygenates/ethanol to isobutene rich mixture and followed by oligomerization and hydrogenation. The design features a processing capacity of 2,000 tonnes/day (2,205 short tons) of dry biomass. The minimum fuel selling prices (MFSPs) for the four developing pathways range from $3.40 to $5.04 per gasoline-gallon equivalent (GGE), in 2011 US dollars. Sensitivity studies show that MFSPs can be improved with co-product credits and are comparable to the commercial Fischer-Tropsch benchmark ($3.58/GGE). Overall, this comparative TEA study documents potential economics for the developmental biofuel pathways via mixed oxygenates.

Identification and characterization of monoclonal antibodies specific for macrophages at intermediate stages in the tumoricidal activation pathway

International Nuclear Information System (INIS)

Paulnock, D.M.; Lambert, L.E.

1990-01-01

Macrophage activation for tumor cell killing is a multistep pathway in which responsive macrophages interact sequentially with priming and triggering stimuli in the acquisition of full tumoricidal activity. A number of mediators have been identified which have activating capability, including in particular IFN-gamma and bacterial LPS. Although the synergistic functional response of normal macrophages to sequential incubation with these activation signals has been well-established, characterization of the intermediate stages in the activation pathway has been difficult. We have developed a model system for examination of various aspects of macrophage activation, through the use of the murine macrophage tumor cell line, RAW 264.7. These cells, like normal macrophages, exhibit a strict requirement for interaction with both IFN-gamma and LPS in the development of tumor cytolytic activity. In addition, these cells can be stably primed by the administration of gamma-radiation. In the studies reported here, we have used RAW 264.7 cells treated with IFN-gamma alone or with IFN-gamma plus LPS to stimulate the production of rat mAb probes recognizing cell surface changes occurring during the activation process. In this way we have identified three Ag associated with intermediate stages of the activation process. One Ag, TM-1, is expressed on RAW 264.7 cells primed by IFN-gamma or gamma-radiation. This surface Ag thus identifies cells at the primed cell intermediate stage of the tumoricidal activation pathway regardless of the mechanism of activation. A second Ag, TM-2, is expressed on IFN-treated RAW 264.7 cells but not on RAW 264.7 cells primed with gamma-radiation alone. Expression of this Ag can be induced by treatment of irradiated cells with IFN-gamma, but is not induced by IFN-gamma treatment of a noncytolytic cell line, WEHI-3

Structure and Functional Analysis of ClbQ, an Unusual Intermediate-Releasing Thioesterase from the Colibactin Biosynthetic Pathway.

Science.gov (United States)

Guntaka, Naga Sandhya; Healy, Alan R; Crawford, Jason M; Herzon, Seth B; Bruner, Steven D

2017-10-20

Colibactin is a genotoxic hybrid nonribosomal peptide/polyketide secondary metabolite produced by various pathogenic and probiotic bacteria residing in the human gut. The presence of colibactin metabolites has been correlated to colorectal cancer formation in several studies. The specific function of many gene products in the colibactin gene cluster can be predicted. However, the role of ClbQ, a type II editing thioesterase, has not been established. The importance of ClbQ has been demonstrated by genetic deletions that abolish colibactin cytotoxic activity, and recent studies suggest an atypical role in releasing pathway intermediates from the assembly line. Here we report the 2.0 Å crystal structure and biochemical characterization of ClbQ. Our data reveal that ClbQ exhibits greater catalytic efficiency toward acyl-thioester substrates as compared to precolibactin intermediates and does not discriminate among carrier proteins. Cyclized pyridone-containing colibactins, which are off-pathway derivatives, are not viable substrates for ClbQ, while linear precursors are, supporting a role of ClbQ in facilitating the promiscuous off-loading of premature precolibactin metabolites and novel insights into colibactin biosynthesis.

Structure and Functional Analysis of ClbQ, an Unusual Intermediate-Releasing Thioesterase from the Colibactin Biosynthetic Pathway

Energy Technology Data Exchange (ETDEWEB)

Guntaka, Naga Sandhya; Healy, Alan R.; Crawford, Jason M.; Herzon, Seth B.; Bruner, Steven D. (Yale); (Florida); (Yale-MED)

2017-09-08

Colibactin is a genotoxic hybrid nonribosomal peptide/polyketide secondary metabolite produced by various pathogenic and probiotic bacteria residing in the human gut. The presence of colibactin metabolites has been correlated to colorectal cancer formation in several studies. The specific function of many gene products in the colibactin gene cluster can be predicted. However, the role of ClbQ, a type II editing thioesterase, has not been established. The importance of ClbQ has been demonstrated by genetic deletions that abolish colibactin cytotoxic activity, and recent studies suggest an atypical role in releasing pathway intermediates from the assembly line. Here we report the 2.0 Å crystal structure and biochemical characterization of ClbQ. Our data reveal that ClbQ exhibits greater catalytic efficiency toward acyl-thioester substrates as compared to precolibactin intermediates and does not discriminate among carrier proteins. Cyclized pyridone-containing colibactins, which are off-pathway derivatives, are not viable substrates for ClbQ, while linear precursors are, supporting a role of ClbQ in facilitating the promiscuous off-loading of premature precolibactin metabolites and novel insights into colibactin biosynthesis.

Intégration d'un système de Retour d'Expériences à un PLM

OpenAIRE

Bertin, Aurélie

2012-01-01

Les travaux présentés dans cette thèse s’inscrivent dans une problématique d’amélioration continue appliquée aux produits et aux processus industriels, par la mise en place d’un système de Retour d’Expérience (REx) couplé au système PLM (Product Lifecycle Management) de gestion du cycle de vie du produit. Les développements, menés dans le cadre d’un partenarial industriel, ciblent l’établissement d’une solution de valorisation du patrimoine immatériel de l’entreprise, constitué des expérience...

Role of Intermediate Filaments in Vesicular Traffic

Directory of Open Access Journals (Sweden)

Azzurra Margiotta

2016-04-01

Full Text Available Intermediate filaments are an important component of the cellular cytoskeleton. The first established role attributed to intermediate filaments was the mechanical support to cells. However, it is now clear that intermediate filaments have many different roles affecting a variety of other biological functions, such as the organization of microtubules and microfilaments, the regulation of nuclear structure and activity, the control of cell cycle and the regulation of signal transduction pathways. Furthermore, a number of intermediate filament proteins have been involved in the acquisition of tumorigenic properties. Over the last years, a strong involvement of intermediate filament proteins in the regulation of several aspects of intracellular trafficking has strongly emerged. Here, we review the functions of intermediate filaments proteins focusing mainly on the recent knowledge gained from the discovery that intermediate filaments associate with key proteins of the vesicular membrane transport machinery. In particular, we analyze the current understanding of the contribution of intermediate filaments to the endocytic pathway.

A Western Blot-based Investigation of the Yeast Secretory Pathway Designed for an Intermediate-Level Undergraduate Cell Biology Laboratory

Science.gov (United States)

Hood-DeGrenier, Jennifer K.

2008-01-01

The movement of newly synthesized proteins through the endomembrane system of eukaryotic cells, often referred to generally as the secretory pathway, is a topic covered in most intermediate-level undergraduate cell biology courses. An article previously published in this journal described a laboratory exercise in which yeast mutants defective in…

Photo-fenton degradation of diclofenac: identification of main intermediates and degradation pathway.

Science.gov (United States)

Pérez-Estrada, Leónidas A; Malato, Sixto; Gernjak, Wolfgang; Agüera, Ana; Thurman, E Michael; Ferrer, Imma; Fernández-Alba, Amadeo R

2005-11-01

In recent years, the presence of pharmaceuticals in the aquatic environment has been of growing interest. These new contaminants are important because many of them are not degraded under the typical biological treatments applied in the wastewater treatment plants and represent a continuous input into the environment. Thus, compounds such as diclofenac are present in surface waters in all Europe and a crucial need for more enhanced technologies that can reduce its presence in the environment has become evident. In this sense, advanced oxidation processes (AOPs) represent a good choice for the treatment of hazardous nonbiodegradable pollutants. This work deals with the solar photodegradation of diclofenac, an antiinflammatory drug, in aqueous solutions by photo-Fenton reaction. A pilot-scale facility using a compound parabolic collector (CPC) reactor was used for this study. Results obtained show rapid and complete oxidation of diclofenac after 60 min, and total mineralization (disappearance of dissolved organic carbon, DOC) after 100 min of exposure to sunlight. Although diclofenac precipitates during the process at low pH, its degradation takes place in the homogeneous phase governed by a precipitation-redissolution-degradation process. Establishment of the reaction pathway was made possible by a thorough analysis of the reaction mixture identifying the main intermediate products generated. Gas chromatography-mass spectrometry (GC/ MS) and liquid chromatography coupled with time-of-flight mass spectrometry (LC/TOF-MS) were used to identify 18 intermediates, in two tentative degradation routes. The main one was based on the initial hydroxylation of the phenylacetic acid moiety in the C-4 position and subsequent formation of a quinone imine derivative that was the starting point for further multistep degradation involving hydroxylation, decarboxylation, and oxidation reactions. An alternative route was based on the transient preservation of the biphenyl amino moiety

Roles of different initial Maillard intermediates and pathways in meat flavor formation for cysteine-xylose-glycine model reaction systems.

Science.gov (United States)

Hou, Li; Xie, Jianchun; Zhao, Jian; Zhao, Mengyao; Fan, Mengdie; Xiao, Qunfei; Liang, Jingjing; Chen, Feng

2017-10-01

To explore initial Maillard reaction pathways and mechanisms for maximal formation of meaty flavors in heated cysteine-xylose-glycine systems, model reactions with synthesized initial Maillard intermediates, Gly-Amadori, TTCA (2-threityl-thiazolidine-4-carboxylic acids) and Cys-Amadori, were investigated. Relative relativities were characterized by spectrophotometrically monitoring the development of colorless degradation intermediates and browning reaction products. Aroma compounds formed were determined by solid-phase microextraction combined with GC-MS and GC-olfactometry. Gly-Amadori showed the fastest reaction followed by Cys-Amadori then TTCA. Free glycine accelerated reaction of TTCA, whereas cysteine inhibited that of Gly-Amadori due to association forming relatively stable thiazolidines. Cys-Amadori/Gly had the highest reactivity in development of both meaty flavors and brown products. TTCA/Gly favored yielding meaty flavors, whereas Gly-Amadori/Cys favored generation of brown products. Conclusively, initial formation of TTCA and pathway involving TTCA with glycine were more applicable to efficiently produce processed-meat flavorings in a cysteine-xylose-glycine system. Copyright © 2017 Elsevier Ltd. All rights reserved.

Imaging and Quantitation of a Succession of Transient Intermediates Reveal the Reversible Self-Assembly Pathway of a Simple Icosahedral Virus Capsid.

Science.gov (United States)

Medrano, María; Fuertes, Miguel Ángel; Valbuena, Alejandro; Carrillo, Pablo J P; Rodríguez-Huete, Alicia; Mateu, Mauricio G

2016-11-30

Understanding the fundamental principles underlying supramolecular self-assembly may facilitate many developments, from novel antivirals to self-organized nanodevices. Icosahedral virus particles constitute paradigms to study self-assembly using a combination of theory and experiment. Unfortunately, assembly pathways of the structurally simplest virus capsids, those more accessible to detailed theoretical studies, have been difficult to study experimentally. We have enabled the in vitro self-assembly under close to physiological conditions of one of the simplest virus particles known, the minute virus of mice (MVM) capsid, and experimentally analyzed its pathways of assembly and disassembly. A combination of electron microscopy and high-resolution atomic force microscopy was used to structurally characterize and quantify a succession of transient assembly and disassembly intermediates. The results provided an experiment-based model for the reversible self-assembly pathway of a most simple (T = 1) icosahedral protein shell. During assembly, trimeric capsid building blocks are sequentially added to the growing capsid, with pentamers of building blocks and incomplete capsids missing one building block as conspicuous intermediates. This study provided experimental verification of many features of self-assembly of a simple T = 1 capsid predicted by molecular dynamics simulations. It also demonstrated atomic force microscopy imaging and automated analysis, in combination with electron microscopy, as a powerful single-particle approach to characterize at high resolution and quantify transient intermediates during supramolecular self-assembly/disassembly reactions. Finally, the efficient in vitro self-assembly achieved for the oncotropic, cell nucleus-targeted MVM capsid may facilitate its development as a drug-encapsidating nanoparticle for anticancer targeted drug delivery.

Oxidative degradation of atenolol by heat-activated persulfate: Kinetics, degradation pathways and distribution of transformation intermediates.

Science.gov (United States)

Miao, Dong; Peng, Jianbiao; Zhou, Xiaohuan; Qian, Li; Wang, Mengjie; Zhai, Li; Gao, Shixiang

2018-05-17

Atenolol (ATL) has been widely detected in wastewater and aquatic environment. Although satisfactory removal of ATL from wastewater could be achieved, the mineralization ratio is usually low, which may result in the accumulation of its transformation products in the effluent and cause additional ecological risk to the environment. The aim of this study is to explore the effectiveness of heat activated persulfate (PS) in the removal of ATL from wastewater. Influencing factors including temperature, PS dosage, solution pH, existence of NO 3 - , Cl - , HCO 3 - and Suwannee river fulvic acid (SRFA) were examined. Complete removal of ATL was achieved within 40 min at pH 7.0 and 70 °C by using 0.5 mM PS. Inhibitive effects of HCO 3 - and FA had been observed on ATL oxidation, which was increased with the increase of their concentration. Sulfate radical (SO 4 - ) was determined as the main reactive species by quenching experiment. Eight intermediates produced in ATL degradation were identified, and four degradation pathways were proposed based on the analysis of mass spectrum and frontier electron densities. The distribution of major intermediates was influenced by reaction temperature. Hydroxylation intermediates and deamidation intermediate were the most prominent at 50 °C and 60 °C, respectively. All intermediates were completely degraded in 40 min except P134 at 70 °C. Effective removal of TOC (74.12%) was achieved with 0.5 mM PS, pH 7.0 and 70 °C after 240 min. The results proved that heat activation of PS is a promising method to remove organic pollutants in wastewater. Copyright © 2018 Elsevier Ltd. All rights reserved.

Delineating neurotrophin-3 dependent signaling pathways underlying sympathetic axon growth along intermediate targets.

Science.gov (United States)

Keeler, Austin B; Suo, Dong; Park, Juyeon; Deppmann, Christopher D

2017-07-01

Postganglionic sympathetic neurons detect vascular derived neurotrophin 3 (NT3) via the axonally expressed receptor tyrosine kinase, TrkA, to promote chemo-attraction along intermediate targets. Once axons arrive to their final target, a structurally related neurotrophic factor, nerve growth factor (NGF), also acts through TrkA to promote final target innervation. Does TrkA signal differently at these different locales? We previously found that Coronin-1 is upregulated in sympathetic neurons upon exposure to NGF, thereby endowing the NGF-TrkA complex with new signaling capabilities (i.e. calcium signaling), which dampens axon growth and branching. Based on the notion that axons do not express functional levels of Coronin-1 prior to final target innervation, we developed an in vitro model for axon growth and branching along intermediate targets using Coro1a -/- neurons grown in NT3. We found that, similar to NGF-TrkA, NT3-TrkA is capable of inducing MAPK and PI3K in the presence or absence of Coronin-1. However, unlike NGF, NT3 does not induce calcium release from intracellular stores. Using a combination of pharmacology, knockout neurons and in vitro functional assays, we suggest that the NT3-TrkA complex uses Ras/MAPK and/or PI3K-AKT signaling to induce axon growth and inhibit axon branching along intermediate targets. However, in the presence of Coronin-1, these signaling pathways lose their ability to impact NT3 dependent axon growth or branching. This is consistent with a role for Coronin-1 as a molecular switch for axon behavior and suggests that Coronin-1 suppresses NT3 dependent axon behavior. Copyright © 2017 Elsevier Inc. All rights reserved.

A Western blot-based investigation of the yeast secretory pathway designed for an intermediate-level undergraduate cell biology laboratory.

Science.gov (United States)

Hood-Degrenier, Jennifer K

2008-01-01

The movement of newly synthesized proteins through the endomembrane system of eukaryotic cells, often referred to generally as the secretory pathway, is a topic covered in most intermediate-level undergraduate cell biology courses. An article previously published in this journal described a laboratory exercise in which yeast mutants defective in two distinct steps of protein secretion were differentiated using a genetic reporter designed specifically to identify defects in the first step of the pathway, the insertion of proteins into the endoplasmic reticulum (Vallen, 2002). We have developed two versions of a Western blotting assay that serves as a second way of distinguishing the two secretory mutants, which we pair with the genetic assay in a 3-wk laboratory module. A quiz administered before and after students participated in the lab activities revealed significant postlab gains in their understanding of the secretory pathway and experimental techniques used to study it. A second survey administered at the end of the lab module assessed student perceptions of the efficacy of the lab activities; the results of this survey indicated that the experiments were successful in meeting a set of educational goals defined by the instructor.

Photocatalytic mineralization of codeine by UV-A/TiO{sub 2}—Kinetics, intermediates, and pathways

Energy Technology Data Exchange (ETDEWEB)

Kuo, Chin-Sheng [Graduate Institute of Environmental Engineering, National Taiwan University, Taipei 106, Taiwan, ROC (China); Lin, Cheng-Fang, E-mail: cflin@ntu.edu.tw [Graduate Institute of Environmental Engineering, National Taiwan University, Taipei 106, Taiwan, ROC (China); Hong, Pui-Kwan Andy [Department of Civil and Environmental Engineering, University of Utah, Salt Lake City, UT 84112 (United States)

2016-01-15

Highlights: • Codeine was completely removed in 30 min under irradiated UV-A/TiO{sub 2}. • Codeine was mineralized in 90 min with near complete N conversion to NH{sub 4}{sup +} and NO{sub 3}{sup −}. • Morphine was authenticated and four others were identified as intermediates. • Degradation proceeded via ipso-substitution and hydroxylation of the aromatic ring. - Abstract: This study investigated the photocatalytic degradation of codeine by UV-irradiated TiO{sub 2}. The degradation kinetics was determined under varied conditions including the TiO{sub 2} loading, codeine concentration, and pH. Codeine and several reaction intermediates including morphine were identified and tracked during degradation using HPLC/MS–MS technique, along with TOC and IC measurements. Specifically, removal of 100 μg/L of spike codeine was complete in 3 min by contact with a 0.1 g/L suspension of TiO{sub 2} under UV irradiation at pH 7. The degradation kinetics of codeine was first-order with respect to both the catalyst TiO{sub 2} and the reactant codeine, with enhanced reaction rates with increasing pH up to pH 9. Mineralization of codeine was possible upon prolonged contact; near complete mineralization of 10 mg/L of codeine was achieved in 90 min with 0.1 g/L TiO{sub 2} under irradiation at pH 5, during which the organic nitrogen was converted to NH{sub 3}-N (74%) and NO{sub 3}-N (22%). Based on the identified intermediates, two degradation pathways were proposed of which one involved ipso-substitution followed by cleavage of the aromatic ring and another involved repeated hydroxylation of the codeine molecule followed by its fragmentation.

Photocatalytic degradation of metoprolol tartrate in suspensions of two TiO2-based photocatalysts with different surface area. Identification of intermediates and proposal of degradation pathways

International Nuclear Information System (INIS)

Abramović, Biljana; Kler, Sanja; Šojić, Daniela; Laušević, Mila; Radović, Tanja; Vione, Davide

2011-01-01

Highlights: ► Kinetics and efficiency of photocatalytic degradation of the β 1 -blocker metoprolol tartrate (MET). ► Two TiO 2 specimens employed. ► Faster degradation of MET, but slower mineralization, obtained with the TiO 2 specimen having lower surface area. ► Photocatalytic transformation pathways of MET including mineralization. - Abstract: This study investigates the efficiency of the photocatalytic degradation of metoprolol tartrate (MET), a widely used β 1 -blocker, in TiO 2 suspensions of Wackherr's “Oxyde de titane standard” and Degussa P25. The study encompasses transformation kinetics and efficiency, identification of intermediates and reaction pathways. In the investigated range of initial concentrations (0.01–0.1 mM), the photocatalytic degradation of MET in the first stage of the reaction followed approximately a pseudo-first order kinetics. The TiO 2 Wackherr induced a significantly faster MET degradation compared to TiO 2 Degussa P25 when relatively high substrate concentrations were used. By examining the effect of ethanol as a scavenger of hydroxyl radicals (·OH), it was shown that the reaction with ·OH played the main role in the photocatalytic degradation of MET. After 240 min of irradiation the reaction intermediates were almost completely mineralized to CO 2 and H 2 O, while the nitrogen was predominantly present as NH 4 + . Reaction intermediates were studied in detail and a number of them were identified using LC–MS/MS (ESI+), which allowed the proposal of a tentative pathway for the photocatalytic transformation of MET as a function of the TiO 2 specimen.

An NPF transporter exports a central monoterpene indole alkaloid intermediate from the vacuole

DEFF Research Database (Denmark)

Payne, Richard; Xu, Deyang; Foureau, Emilien

2017-01-01

Plants sequester intermediates of metabolic pathways into different cellular compartments, but the mechanisms by which these molecules are transported remain poorly understood. Monoterpene indole alkaloids, a class of specialized metabolites that includes the anticancer agent vincristine, antimal......Plants sequester intermediates of metabolic pathways into different cellular compartments, but the mechanisms by which these molecules are transported remain poorly understood. Monoterpene indole alkaloids, a class of specialized metabolites that includes the anticancer agent vincristine...

Double Ion Implantation and Pulsed Laser Melting Processes for Third Generation Solar Cells

Directory of Open Access Journals (Sweden)

Eric García-Hemme

2013-01-01

Full Text Available In the framework of the third generation of photovoltaic devices, the intermediate band solar cell is one of the possible candidates to reach higher efficiencies with a lower processing cost. In this work, we introduce a novel processing method based on a double ion implantation and, subsequently, a pulsed laser melting (PLM process to obtain thicker layers of Ti supersaturated Si. We perform ab initio theoretical calculations of Si impurified with Ti showing that Ti in Si is a good candidate to theoretically form an intermediate band material in the Ti supersaturated Si. From time-of-flight secondary ion mass spectroscopy measurements, we confirm that we have obtained a Ti implanted and PLM thicker layer of 135 nm. Transmission electron microscopy reveals a single crystalline structure whilst the electrical characterization confirms the transport properties of an intermediate band material/Si substrate junction. High subbandgap absorption has been measured, obtaining an approximate value of 104 cm−1 in the photons energy range from 1.1 to 0.6 eV.

Photocatalytic degradation of metoprolol tartrate in suspensions of two TiO{sub 2}-based photocatalysts with different surface area. Identification of intermediates and proposal of degradation pathways

Energy Technology Data Exchange (ETDEWEB)

Abramovic, Biljana, E-mail: biljana.abramovic@dh.uns.ac.rs [Department of Chemistry, Biochemistry and Environmental Protection, Faculty of Sciences, University of Novi Sad, Trg D. Obradovica 3, 21000 Novi Sad (Serbia); Kler, Sanja, E-mail: sanja.kler@dh.uns.ac.rs [Department of Chemistry, Biochemistry and Environmental Protection, Faculty of Sciences, University of Novi Sad, Trg D. Obradovica 3, 21000 Novi Sad (Serbia); Sojic, Daniela, E-mail: daniela.sojic@dh.uns.ac.rs [Department of Chemistry, Biochemistry and Environmental Protection, Faculty of Sciences, University of Novi Sad, Trg D. Obradovica 3, 21000 Novi Sad (Serbia); Lausevic, Mila, E-mail: milal@tmf.bg.ac.rs [Faculty of Technology and Metallurgy, University of Belgrade, Karnegijeva 4, 11120 Belgrade (Serbia); Radovic, Tanja, E-mail: tradovic@tmf.bg.ac.rs [Faculty of Technology and Metallurgy, University of Belgrade, Karnegijeva 4, 11120 Belgrade (Serbia); Vione, Davide, E-mail: davide.vione@unito.it [Dipartimento di Chimica Analitica, Universita di Torino, Via Pietro Giuria 5, 10125 Torino (Italy)

2011-12-30

Highlights: Black-Right-Pointing-Pointer Kinetics and efficiency of photocatalytic degradation of the {beta}{sub 1}-blocker metoprolol tartrate (MET). Black-Right-Pointing-Pointer Two TiO{sub 2} specimens employed. Black-Right-Pointing-Pointer Faster degradation of MET, but slower mineralization, obtained with the TiO{sub 2} specimen having lower surface area. Black-Right-Pointing-Pointer Photocatalytic transformation pathways of MET including mineralization. - Abstract: This study investigates the efficiency of the photocatalytic degradation of metoprolol tartrate (MET), a widely used {beta}{sub 1}-blocker, in TiO{sub 2} suspensions of Wackherr's 'Oxyde de titane standard' and Degussa P25. The study encompasses transformation kinetics and efficiency, identification of intermediates and reaction pathways. In the investigated range of initial concentrations (0.01-0.1 mM), the photocatalytic degradation of MET in the first stage of the reaction followed approximately a pseudo-first order kinetics. The TiO{sub 2} Wackherr induced a significantly faster MET degradation compared to TiO{sub 2} Degussa P25 when relatively high substrate concentrations were used. By examining the effect of ethanol as a scavenger of hydroxyl radicals ({center_dot}OH), it was shown that the reaction with {center_dot}OH played the main role in the photocatalytic degradation of MET. After 240 min of irradiation the reaction intermediates were almost completely mineralized to CO{sub 2} and H{sub 2}O, while the nitrogen was predominantly present as NH{sub 4}{sup +}. Reaction intermediates were studied in detail and a number of them were identified using LC-MS/MS (ESI+), which allowed the proposal of a tentative pathway for the photocatalytic transformation of MET as a function of the TiO{sub 2} specimen.

Dexter energy transfer pathways.

Science.gov (United States)

Skourtis, Spiros S; Liu, Chaoren; Antoniou, Panayiotis; Virshup, Aaron M; Beratan, David N

2016-07-19

Energy transfer with an associated spin change of the donor and acceptor, Dexter energy transfer, is critically important in solar energy harvesting assemblies, damage protection schemes of photobiology, and organometallic opto-electronic materials. Dexter transfer between chemically linked donors and acceptors is bridge mediated, presenting an enticing analogy with bridge-mediated electron and hole transfer. However, Dexter coupling pathways must convey both an electron and a hole from donor to acceptor, and this adds considerable richness to the mediation process. We dissect the bridge-mediated Dexter coupling mechanisms and formulate a theory for triplet energy transfer coupling pathways. Virtual donor-acceptor charge-transfer exciton intermediates dominate at shorter distances or higher tunneling energy gaps, whereas virtual intermediates with an electron and a hole both on the bridge (virtual bridge excitons) dominate for longer distances or lower energy gaps. The effects of virtual bridge excitons were neglected in earlier treatments. The two-particle pathway framework developed here shows how Dexter energy-transfer rates depend on donor, bridge, and acceptor energetics, as well as on orbital symmetry and quantum interference among pathways.

Investigation of the O+allyl addition/elimination reaction pathways from the OCH2CHCH2 radical intermediate

International Nuclear Information System (INIS)

FitzPatrick, Benjamin L.; Lau, K.-C.; Butler, Laurie J.; Lee, S.-H.; Lin, Jim Jr-Min

2008-01-01

These experiments study the preparation of and product channels resulting from OCH 2 CHCH 2 , a key radical intermediate in the O+allyl bimolecular reaction. The data include velocity map imaging and molecular beam scattering results to probe the photolytic generation of the radical intermediate and the subsequent pathways by which the radicals access the energetically allowed product channels of the bimolecular reaction. The photodissociation of epichlorohydrin at 193.3 nm produces chlorine atoms and c-OCH 2 CHCH 2 radicals; these undergo a facile ring opening to the OCH 2 CHCH 2 radical intermediate. State-selective resonance-enhanced multiphoton ionization (REMPI) detection resolves the velocity distributions of ground and spin-orbit excited state chlorine independently, allowing for a more accurate determination of the internal energy distribution of the nascent radicals. We obtain good agreement detecting the velocity distributions of the Cl atoms with REMPI, vacuum ultraviolet (VUV) photoionization at 13.8 eV, and electron bombardment ionization; all show a bimodal distribution of recoil kinetic energies. The dominant high recoil kinetic energy feature peaks near 33 kcal/mol. To elucidate the product channels resulting from the OCH 2 CHCH 2 radical intermediate, the crossed laser-molecular beam experiment uses VUV photoionization and detects the velocity distribution of the possible products. The data identify the three dominant product channels as C 3 H 4 O (acrolein)+H, C 2 H 4 +HCO (formyl radical), and H 2 CO (formaldehyde)+C 2 H 3 . A small signal from C 2 H 2 O (ketene) product is also detected. The measured velocity distributions and relative signal intensities at m/e=27, 28, and 29 at two photoionization energies show that the most exothermic product channel, C 2 H 5 +CO, does not contribute significantly to the product branching. The higher internal energy onset of the acrolein+H product channel is consistent with the relative barriers en route to

Investigation of the O+allyl addition/elimination reaction pathways from the OCH2CHCH2 radical intermediate

Science.gov (United States)

Fitzpatrick, Benjamin L.; Lau, Kai-Chung; Butler, Laurie J.; Lee, Shih-Huang; Lin, Jim-Min, Jr.

2008-08-01

These experiments study the preparation of and product channels resulting from OCH2CHCH2, a key radical intermediate in the O+allyl bimolecular reaction. The data include velocity map imaging and molecular beam scattering results to probe the photolytic generation of the radical intermediate and the subsequent pathways by which the radicals access the energetically allowed product channels of the bimolecular reaction. The photodissociation of epichlorohydrin at 193.3 nm produces chlorine atoms and c-OCH2CHCH2 radicals; these undergo a facile ring opening to the OCH2CHCH2 radical intermediate. State-selective resonance-enhanced multiphoton ionization (REMPI) detection resolves the velocity distributions of ground and spin-orbit excited state chlorine independently, allowing for a more accurate determination of the internal energy distribution of the nascent radicals. We obtain good agreement detecting the velocity distributions of the Cl atoms with REMPI, vacuum ultraviolet (VUV) photoionization at 13.8 eV, and electron bombardment ionization; all show a bimodal distribution of recoil kinetic energies. The dominant high recoil kinetic energy feature peaks near 33 kcal/mol. To elucidate the product channels resulting from the OCH2CHCH2 radical intermediate, the crossed laser-molecular beam experiment uses VUV photoionization and detects the velocity distribution of the possible products. The data identify the three dominant product channels as C3H4O (acrolein)+H, C2H4+HCO (formyl radical), and H2CO (formaldehyde)+C2H3. A small signal from C2H2O (ketene) product is also detected. The measured velocity distributions and relative signal intensities at m/e=27, 28, and 29 at two photoionization energies show that the most exothermic product channel, C2H5+CO, does not contribute significantly to the product branching. The higher internal energy onset of the acrolein+H product channel is consistent with the relative barriers en route to each of these product channels

Synthetic routes to some isotopically labelled intermediates for diterpenoid biosynthesis

International Nuclear Information System (INIS)

Dawson, R.M.; Godfrey, I.M.; Hogg, R.W.; Knox, J.R.

1989-01-01

The exo-15-hydrogen of ent-kaurene can be exchanged through a reversible ene reaction in a convenient and efficient procedure which has the potential for giving high specific activity 3 H-labelling. Copalol, the (Z)-double bond stereoisomer, and the allylic alcohol isomers ent-manool and ent-epimanool have been obtained through divergent synthetic pathways involving a 15,16-bisnor ketone intermediate. These pathways have also allowed the four compounds to be obtained with 14 C-labelling. A method, involving a Wittig reaction to form a vinyl bromide intermediate, has been developed for obtaining copalol, as the trityl ether derivative, with stereospecific isotopic labelling of one or the other of the hydrogens of the exocyclic methylene group. 27 refs., figs

Synthesized TiO{sub 2}/ZSM-5 composites used for the photocatalytic degradation of azo dye: Intermediates, reaction pathway, mechanism and bio-toxicity

Energy Technology Data Exchange (ETDEWEB)

Zhou, Kefu; Hu, Xin-Yan [College of the Environment and Ecology, Xiamen University, Xiamen (China); Chen, Bor-Yann; Hsueh, Chung-Chuan [Department of Chemical and Materials Engineering, National I-Lan University, I-Lan, Taiwan (China); Zhang, Qian [Department of Environmental Engineering, National Taiwan University, Taipei, Taiwan (China); Wang, Jiajie; Lin, Yu-Jung [College of the Environment and Ecology, Xiamen University, Xiamen (China); Chang, Chang-Tang, E-mail: ctchang73222@gmail.com [Department of Environmental Engineering, National I-Lan University, I-Lan, Taiwan (China)

2016-10-15

Highlights: • The major photo-catalytic degradation pathway of azo-dye was elaborated according to the identification of by-products from GC–MS and IC analysis. • Comparative assessment on characteristics of abiotic and biotic dye decolorization was analyzed. • EDTA (hole scavengers) and t-BuOH (radical scavengers) were used to determine the main active oxidative species in the system. • The toxicity effects of degradation intermediates of Reactive Black 5 (RB5) on the cellular respiratory activity were assessed. - Abstract: In this study, a one-step solid dispersion method was used to synthesize titanium dioxide (TiO{sub 2})/Zeolite Socony Mobil-5 (ZSM-5) composites with substantially reduced time and energy consumption. A degradation efficiency of more than 95% was achieved within 10 min using 50% PTZ (synthesized TiO{sub 2}/ZSM-5 composites with TiO{sub 2} contents of 50 wt% loaded on ZSM-5) at pH 7 and 25 °C. The possible degradation pathway of azo-dye Reactive Black 5 (RB5) was investigated using gas chromatography–mass spectrometry and ion chromatography (IC). The bonds between the N atoms and naphthalene groups are likely attacked first and cleaved by hydroxyl radicals, ultimately resulting in the decolorization and mineralization of the azo dye. A comparative assessment of the characteristics of abiotic and biotic dye decolorization was completed. In addition, the toxicity effects of the degradation intermediates of azo-dye RB5 on cellular respiratory activity were analyzed. The bio-toxicity results showed that the decay rate constants of CO{sub 2} production from the azo-dye RB5 samples at different degradation times increased initially and subsequently decreased, indicating that intermediates of higher toxicity could adhere to the catalyst surface and gradually destroyed by further photocatalytic oxidation. Additionally, EDTA (hole scavengers) and t-BuOH (radical scavengers) were used to detect the main active oxidative species in the system

Adsorption and Photocatalytic Decomposition of the β-Blocker Metoprolol in Aqueous Titanium Dioxide Suspensions: Kinetics, Intermediates, and Degradation Pathways

Directory of Open Access Journals (Sweden)

Violette Romero

2013-01-01

Full Text Available This study reports the photocatalytic degradation of the β-blocker metoprolol (MET using TiO2 suspended as catalyst. A series of photoexperiments were carried out by a UV lamp, emitting in the 250–400 nm range, providing information about the absorption of radiation in the photoreactor wall. The influence of the radiation wavelength on the MET photooxidation rate was investigated using a filter cutting out wavelengths shorter than 280 nm. Effects of photolysis and adsorption at different initial pH were studied to evaluate noncatalytic degradation for this pharmaceutical. MET adsorption onto titania was fitted to two-parameter Langmuir isotherm. From adsorption results it appears that the photocatalytic degradation can occur mainly on the surface of TiO2. MET removed by photocatalysis was 100% conditions within 300 min, while only 26% was achieved by photolysis at the same time. TiO2 photocatalysis degradation of MET in the first stage of the reaction followed approximately a pseudo-first-order model. The major reaction intermediates were identified by LC/MS analysis such as 3-(propan-2-ylaminopropane-1,2-diol or 3-aminoprop-1-en-2-ol. Based on the identified intermediates, a photocatalytic degradation pathway was proposed, including the cleavage of side chain and the hydroxylation addition to the parent compounds.

Modular pathway rewiring of Saccharomyces cerevisiae enables high-level production of L-ornithine

DEFF Research Database (Denmark)

Qin, Jiufu; Zhou, Yongjin J.; Krivoruchko, Anastasia

2015-01-01

intermediates can serve as platform cell factories for production of such products. Here we implement a modular pathway rewiring (MPR) strategy and demonstrate its use for pathway optimization resulting in high-level production of L-ornithine, an intermediate of L-arginine biosynthesis and a precursor...

Photodegradation of lambda-cyhalothrin and cypermethrin in aqueous solution as affected by humic acid and/or copper: intermediates and degradation pathways.

Science.gov (United States)

Xie, Jimin; Wang, Pingli; Liu, Jun; Lv, Xiaomeng; Jiang, Deli; Sun, Cheng

2011-11-01

The influence of coexisting humic acids (HA) or Cu²⁺ on the photodegradation of pesticides lambda-cyhalothrin (λ-CHT) and cypermethrin (CPM) in aqueous solution was studied under xenon lamp irradiation. The removal efficiency of pesticides λ-CHT and CPM were enhanced in the presence of either Cu²⁺ or HA but restrained in the presence of both Cu²⁺ and HA. The photodegradation of λ-CHT and CPM followed first-order reaction kinetics. The photodegradation intermediates of λ-CHT and CPM were determined using gas chromatography/mass spectrometry. Possible photodegradation pathways included decarboxylation, ester bond cleavage, dechlorination, and phenyl group removal. Copyright © 2011 SETAC.

Indirect Liquefaction of Biomass to Transportation Fuels Via Mixed Oxygenated Intermediates

Energy Technology Data Exchange (ETDEWEB)

Tan, Eric C.D.

2016-11-14

This paper presents a comparative techno-economic analysis of four emerging conversion pathways from biomass to gasoline-, jet-, and diesel-range hydrocarbons via indirect liquefaction with specific focus on pathways utilizing oxygenated intermediates. The processing steps include: biomass-to-syngas via indirect gasification, gas cleanup, conversion of syngas to alcohols/oxygenates followed by conversion of alcohols/oxygenates to hydrocarbon blendstocks via dehydration, oligomerization, and hydrogenation.

Origin and pathways of Winter Intermediate Water in the Northwestern Mediterranean Sea using observations and numerical simulation

Science.gov (United States)

Juza, Mélanie; Renault, Lionel; Ruiz, Simon; Tintoré, Joaquin

2013-12-01

The study of water masses worldwide (their formation, spreading, mixing, and impact on general circulation) is essential for a better understanding of the ocean circulation and variability. In this paper, the formation and main pathways of Winter Intermediate Water (WIW) in the Northwestern Mediterranean Sea (NWMED) are investigated during the winter-spring 2011 using observations and numerical simulation. The main results show that the WIW, formed along the continental shelves of the Gulf of Lion and Balearic Sea, circulates southward following five preferential pathways depending on the WIW formation site location and the oceanic conditions. WIW joins the northeastern part of the Balearic Sea, or flows along the continental shelves until joining the Balearic Current (maximum of 0.33 Sv in early-April) or further south until the Ibiza Channel entrance. Two additional trajectories, contributing to water mass exchanges with the southern part of the Western Mediterranean Sea, bring the WIW through the Ibiza and Mallorca Channels (maxima of 0.26 Sv in late-March and 0.1 Sv in early-April, respectively). The circulation of WIW over the NWMED at 50-200 m depth, its mixing and spreading over the Western Mediterranean Sea (reaching the south of the Balearic Islands, the Algero-Provencal basin, the Ligurian and the Alboran Seas) suggest that the WIW may have an impact on the ocean circulation by eddy blocking effect, exchange of water masses between north and south subbasins of Western Mediterranean Sea through the Ibiza Channel or modification of the ocean stratification.

Graph-representation of oxidative folding pathways

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Kaján László

2005-01-01

Full Text Available Abstract Background The process of oxidative folding combines the formation of native disulfide bond with conformational folding resulting in the native three-dimensional fold. Oxidative folding pathways can be described in terms of disulfide intermediate species (DIS which can also be isolated and characterized. Each DIS corresponds to a family of folding states (conformations that the given DIS can adopt in three dimensions. Results The oxidative folding space can be represented as a network of DIS states interconnected by disulfide interchange reactions that can either create/abolish or rearrange disulfide bridges. We propose a simple 3D representation wherein the states having the same number of disulfide bridges are placed on separate planes. In this representation, the shuffling transitions are within the planes, and the redox edges connect adjacent planes. In a number of experimentally studied cases (bovine pancreatic trypsin inhibitor, insulin-like growth factor and epidermal growth factor, the observed intermediates appear as part of contiguous oxidative folding pathways. Conclusions Such networks can be used to visualize folding pathways in terms of the experimentally observed intermediates. A simple visualization template written for the Tulip package http://www.tulip-software.org/ can be obtained from V.A.

Identification and Spectroscopic Characterization of Nonheme Iron(III) Hypochlorite Intermediates**

Science.gov (United States)

Draksharapu, Apparao; Angelone, Davide; Quesne, Matthew G; Padamati, Sandeep K; Gómez, Laura; Hage, Ronald; Costas, Miquel; Browne, Wesley R; de Visser, Sam P

2015-01-01

FeIII–hypohalite complexes have been implicated in a wide range of important enzyme-catalyzed halogenation reactions including the biosynthesis of natural products and antibiotics and post-translational modification of proteins. The absence of spectroscopic data on such species precludes their identification. Herein, we report the generation and spectroscopic characterization of nonheme FeIII–hypohalite intermediates of possible relevance to iron halogenases. We show that FeIII-OCl polypyridylamine complexes can be sufficiently stable at room temperature to be characterized by UV/Vis absorption, resonance Raman and EPR spectroscopies, and cryo-ESIMS. DFT methods rationalize the pathways to the formation of the FeIII-OCl, and ultimately FeIV=O, species and provide indirect evidence for a short-lived FeII-OCl intermediate. The species observed and the pathways involved offer insight into and, importantly, a spectroscopic database for the investigation of iron halogenases. PMID:25663379

Novel Fragmentation Pathways of Anionic Adducts of Steroids Formed by Electrospray Anion Attachment Involving Regioselective Attachment, Regiospecific Decompositions, Charge-Induced Pathways, and Ion-Dipole Complex Intermediates

Science.gov (United States)

Rannulu, Nalaka S.; Cole, Richard B.

2012-09-01

The analysis of several bifunctional neutral steroids, 5-α-pregnane diol (5-α-pregnane-3α-20βdiol), estradiol (3,17α-dihydroxy-1,3,5(10)-estratriene), progesterone (4-pregnene-3,20-dione), lupeol (3β-hydroxy-20(29)-lupene), pregnenolone (5-pregnen-3β-ol-20-one), and pregnenolone acetate (5-pregnen-3β-ol-20-one acetate) was accomplished by negative ion electrospray mass spectrometry (ESI-MS) employing adduct formation with various anions: fluoride, bicarbonate, acetate, and chloride. Fluoride yielded higher abundances of anionic adducts and more substantial abundances of deprotonated molecules compared with other investigated anions. Collision-induced dissociation (CID) of precursor [M + anion]- adducts of these steroids revealed that fluoride adduct [M + F]- precursors first lose HF to produce [M - H]- and then undergo consecutive decompositions to yield higher abundances of structurally-informative product ions than the other tested anions. In addition to charge-remote fragmentations, the majority of CID pathways of estradiol are deduced to occur via charge-induced fragmentation. Most interestingly, certain anions exhibit preferential attachment to a specific site on these bifunctional steroid molecules, which we are calling "regioselective anion attachment." Regioselective anion attachment is evidenced by subsequent regiospecific decomposition. Regioselective attachment of fluoride (and acetate) anions to low (and moderate) acidity functional groups of pregnenolone, respectively, is demonstrated using deuterated compounds. Moreover, the formation of unique intermediate ion-dipole complexes leading to novel fragmentation pathways of fluoride adducts of pregnenolone acetate, and bicarbonate adducts of d4-pregnenolone, are also discussed.

Comparative study of ion conducting pathways in borate glasses

International Nuclear Information System (INIS)

Hall, Andreas; Swenson, Jan; Adams, Stefan

2006-01-01

The conduction pathways in metal-halide doped silver, lithium, and sodium diborate glasses have been examined by bond valence analysis of reverse Monte Carlo (RMC) produced structural models of the glasses. Although all glass compositions have basically the same short-range structure of the boron-oxygen network, it is evident that the intermediate-range structure is strongly dependent on the type of mobile ion. The topography of the pathways and the coordination of the pathway sites differ distinctly between the three glass systems. The mobile silver ions in the AgI-doped glass tend to be mainly iodine-coordinated and travel in homogeneously distributed pathways located in salt-rich channels of the borate network. In the NaCl-doped glass, there is an inhomogeneous spatial distribution of pathways that reflects the inhomogeneous introduction of salt ions into the glass. However, since the salt clusters are not connected, no long-range conduction pathways are formed without including also oxygen-rich regions. The pathways in the LiCl-doped glass are slightly more evenly distributed compared to the NaCl-doped glass (but not as ordered as in the AgI-doped glass), and the regions of mainly oxygen-coordinated pathway sites are of higher importance for the long-range migration. In order to more accurately investigate how these differences in the intermediate-range order of the glasses affect the ionic conductivity, we have compared the realistic structure models to more or less randomized structures. An important conclusion from this comparison is that we find no evidence that a pronounced intermediate-range order in the atomic structure or in the network of conduction pathways, as in the AgI-doped glass, is beneficial for the dc conductivity

A genetic and pharmacological analysis of isoprenoid pathway by LC-MS/MS in fission yeast.

Directory of Open Access Journals (Sweden)

Tomonori Takami

Full Text Available Currently, statins are the only drugs acting on the mammalian isoprenoid pathway. The mammalian genes in this pathway are not easily amenable to genetic manipulation. Thus, it is difficult to study the effects of the inhibition of various enzymes on the intermediate and final products in the isoprenoid pathway. In fission yeast, antifungal compounds such as azoles and terbinafine are available as inhibitors of the pathway in addition to statins, and various isoprenoid pathway mutants are also available. Here in these mutants, treated with statins or antifungals, we quantified the final and intermediate products of the fission yeast isoprenoid pathway using liquid chromatography-mass spectrometry/mass spectrometry. In hmg1-1, a mutant of the gene encoding 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGR, ergosterol (a final sterol product, and squalene (an intermediate pathway product, were decreased to approximately 80% and 10%, respectively, compared with that of wild-type cells. Consistently in wild-type cells, pravastatin, an HMGR inhibitor decreased ergosterol and squalene, and the effect was more pronounced on squalene. In hmg1-1 mutant and in wild-type cells treated with pravastatin, the decrease in the levels of farnesyl pyrophosphate and geranylgeranyl pyrophosphate respectively was larger than that of ergosterol but was smaller than that of squalene. In Δerg6 or Δsts1 cells, mutants of the genes involved in the last step of the pathway, ergosterol was not detected, and the changes of intermediate product levels were distinct from that of hmg1-1 mutant. Notably, in wild-type cells miconazole and terbinafine only slightly decreased ergosterol level. Altogether, these studies suggest that the pleiotropic phenotypes caused by the hmg1-1 mutation and pravastatin might be due to decreased levels of isoprenoid pyrophosphates or other isoprenoid pathway intermediate products rather than due to a decreased ergosterol level.

Sterol partitioning by HMGR and DXR for routing intermediates toward withanolide biosynthesis.

Science.gov (United States)

Singh, Shefali; Pal, Shaifali; Shanker, Karuna; Chanotiya, Chandan Singh; Gupta, Madan Mohan; Dwivedi, Upendra Nath; Shasany, Ajit Kumar

2014-12-01

Withanolides biosynthesis in the plant Withania somnifera (L.) Dunal is hypothesized to be diverged from sterol pathway at the level of 24-methylene cholesterol. The conversion and translocation of intermediates for sterols and withanolides are yet to be characterized in this plant. To understand the influence of mevalonate (MVA) and 2-C-methyl-d-erythritol-4-phosphate (MEP) pathways on sterols and withanolides biosynthesis in planta, we overexpressed the WsHMGR2 and WsDXR2 in tobacco, analyzed the effect of transient suppression through RNAi, inhibited MVA and MEP pathways and fed the leaf tissue with different sterols. Overexpression of WsHMGR2 increased cycloartenol, sitosterol, stigmasterol and campesterol compared to WsDXR2 transgene lines. Increase in cholesterol was, however, marginally higher in WsDXR2 transgenic lines. This was further validated through transient suppression analysis, and pathway inhibition where cholesterol reduction was found higher due to WsDXR2 suppression and all other sterols were affected predominantly by WsHMGR2 suppression in leaf. The transcript abundance and enzyme analysis data also correlate with sterol accumulation. Cholesterol feeding did not increase the withanolide content compared to cycloartenol, sitosterol, stigmasterol and campesterol. Hence, a preferential translocation of carbon from MVA and MEP pathways was found differentiating the sterols types. Overall results suggested that MVA pathway was predominant in contributing intermediates for withanolides synthesis mainly through the campesterol/stigmasterol route in planta. © 2014 Scandinavian Plant Physiology Society.

Balanced activation of IspG and IspH to eliminate MEP intermediate accumulation and improve isoprenoids production in Escherichia coli.

Science.gov (United States)

Li, Qingyan; Fan, Feiyu; Gao, Xiang; Yang, Chen; Bi, Changhao; Tang, Jinlei; Liu, Tao; Zhang, Xueli

2017-11-01

The MEP pathway genes were modulated to investigate whether there were new rate-limiting steps and toxic intermediates in this pathway. Activating IspG led to significant decrease of cell growth and β-carotene production. It was found that ispG overexpression led to accumulation of intermediate HMBPP, which seriously interfered with synthesis machinery of nucleotide and protein in Escherichia coli. Activation of the downstream enzyme IspH could solve HMBPP accumulation problem and eliminate the negative effects of ispG overexpression. In addition, intermediate MECPP accumulated in the starting strain, while balanced activation of IspG and IspH could push the carbon flux away from MECPP and led to 73% and 77% increase of β-carotene and lycopene titer respectively. Our work for the first time identified HMBPP to be a cytotoxic intermediate in MEP pathway and demonstrated that balanced activation of IspG and IspH could eliminate accumulation of HMBPP and MECPP and improve isoprenoids production. Copyright © 2017 International Metabolic Engineering Society. Published by Elsevier Inc. All rights reserved.

Mining the Human Phenome Using Allelic Scores That Index Biological Intermediates

DEFF Research Database (Denmark)

Evans, David M; Brion, Marie Jo A; Paternoster, Lavinia

2013-01-01

It is common practice in genome-wide association studies (GWAS) to focus on the relationship between disease risk and genetic variants one marker at a time. When relevant genes are identified it is often possible to implicate biological intermediates and pathways likely to be involved in disease...... aetiology. However, single genetic variants typically explain small amounts of disease risk. Our idea is to construct allelic scores that explain greater proportions of the variance in biological intermediates, and subsequently use these scores to data mine GWAS. To investigate the approach's properties, we...

The MHD intermediate shock interaction with an intermediate wave: Are intermediate shocks physical?

International Nuclear Information System (INIS)

Wu, C.C.

1988-01-01

Contrary to the usual belief that MHD intermediate shocks are extraneous, the authors have recently shown by numerical solutions of dissipative MHD equations that intermediate shocks are admissible and can be formed through nonlinear steepening from a continuous wave. In this paper, he clarifies the differences between the conventional view and the results by studying the interaction of an MHD intermediate shock with an intermediate wave. The study reaffirms his results. In addition, the study shows that there exists a larger class of shocklike solutions in the time-dependent dissiaptive MHD equations than are given by the MHD Rankine-Hugoniot relations. it also suggests a mechanism for forming rotational discontinuities through the interaction of an intermediate shock with an intermediate wave. The results are of importance not only to the MHD shock theory but also to studies such as magnetic field reconnection models

A board game to assist pharmacy students in learning metabolic pathways.

Science.gov (United States)

Rose, Tyler M

2011-11-10

To develop and evaluate a board game designed to increase students' enjoyment of learning metabolic pathways; their familiarity with pathway reactions, intermediates, and regulation; and, their understanding of how pathways relate to one another and to selected biological conditions. The board game, entitled Race to Glucose, was created as a team activity for first-year pharmacy students in the biochemistry curriculum. A majority of respondents agreed that the game was helpful for learning regulation, intermediates, and interpathway relationships but not for learning reactions, formation of energetic molecules, or relationships, to biological conditions. There was a significant increase in students' scores on game-related examination questions (68.8% pretest vs. 81.3% posttest), but the improvement was no greater than that for examination questions not related to the game (12.5% vs. 10.9%). First-year pharmacy students considered Race to Glucose to be an enjoyable and helpful tool for learning intermediates, regulation, and interpathway relationships.

Photocatalytic oxidation of polycyclic aromatic hydrocarbons: Intermediates identification and toxicity testing

International Nuclear Information System (INIS)

Woo, O.T.; Chung, W.K.; Wong, K.H.; Chow, Alex T.; Wong, P.K.

2009-01-01

Polycyclic aromatic hydrocarbons (PAHs) are hydrophobic pollutants and their low water solubility limits their degradation in aqueous solution. The presence of water-miscible solvent such as acetone can increase the water solubility of PAHs, however acetone will also affect the degradation of PAH. In this study the effects of acetone on the photocatalytic degradation efficiency and pathways of 5 selected PAHs, namely naphthalene (2 rings), acenaphthylene (3 rings), phenanthrene (3 rings), anthracene (3 rings) and benzo[a]anthracene (4 rings) were investigated. The Microtox toxicity test was used to determine whether the PCO system can completely detoxify the parental PAHs and its intermediates. The addition of 16% acetone can greatly alter the degradation pathway of naphthalene and anthracene. Based on intermediates identified from degradation of the 5 PAHs, the location of parental PAHs attacked by reactive free radicals can be correlated with the localization energies of different positions of the compound. For toxicity analysis, irradiation by UV light was found to induce acute toxicity by generating intermediates/degradation products from PAHs and possibly acetone. Lastly, all PAHs (10 mg l -1 ) can be completely detoxified by titanium dioxide (100 mg l -1 ) within 24 h under UVA irradiation (3.9 mW cm -2 ).

Mining the human phenome using allelic scores that index biological intermediates

NARCIS (Netherlands)

Evans, David M; Brion, Marie Jo A; Paternoster, Lavinia; Kemp, John P; McMahon, George; Munafò, Marcus; Whitfield, John B; Medland, Sarah E; Montgomery, Grant W; Timpson, Nicholas J; St Pourcain, Beate; Lawlor, Debbie A; Martin, Nicholas G; Dehghan, Abbas; Hirschhorn, Joel; Smith, George Davey; Alizadeh, Behrooz

2013-01-01

It is common practice in genome-wide association studies (GWAS) to focus on the relationship between disease risk and genetic variants one marker at a time. When relevant genes are identified it is often possible to implicate biological intermediates and pathways likely to be involved in disease

Inhibition of the isoprenoid biosynthesis pathway; detection of intermediates by UPLC-MS/MS

NARCIS (Netherlands)

Henneman, Linda; van Cruchten, Arno G.; Kulik, Willem; Waterham, Hans R.

2011-01-01

The isoprenoid biosynthesis pathway provides the cell with a variety of compounds which are involved in multiple cellular processes. Inhibition of this pathway with statins and bisphosphonates is widely applied in the treatment of hypercholesterolemia and metabolic bone disease, respectively. In

Discovery of new enzymes and metabolic pathways using structure and genome context

Science.gov (United States)

Zhao, Suwen; Kumar, Ritesh; Sakai, Ayano; Vetting, Matthew W.; Wood, B. McKay; Brown, Shoshana; Bonanno, Jeffery B.; Hillerich, Brandan S.; Seidel, Ronald D.; Babbitt, Patricia C.; Almo, Steven C.; Sweedler, Jonathan V.; Gerlt, John A.; Cronan, John E.; Jacobson, Matthew P.

2014-01-01

Assigning valid functions to proteins identified in genome projects is challenging, with over-prediction and database annotation errors major concerns1. We, and others2, are developing computation-guided strategies for functional discovery using “metabolite docking” to experimentally derived3 or homology-based4 three-dimensional structures. Bacterial metabolic pathways often are encoded by “genome neighborhoods” (gene clusters and/or operons), which can provide important clues for functional assignment. We recently demonstrated the synergy of docking and pathway context by “predicting” the intermediates in the glycolytic pathway in E. coli5. Metabolite docking to multiple binding proteins/enzymes in the same pathway increases the reliability of in silico predictions of substrate specificities because the pathway intermediates are structurally similar. We report that structure-guided approaches for predicting the substrate specificities of several enzymes encoded by a bacterial gene cluster allowed i) the correct prediction of the in vitro activity of a structurally characterized enzyme of unknown function (PDB 2PMQ), 2-epimerization of trans-4-hydroxy-L-proline betaine (tHyp-B) and cis-4-hydroxy-D-proline betaine (cHyp-B), and ii) the correct identification of the catabolic pathway in which Hyp-B 2-epimerase participates. The substrate-liganded pose predicted by virtual library screening (docking) was confirmed experimentally. The enzymatic activities in the predicted pathway were confirmed by in vitro assays and genetic analyses; the intermediates were identified by metabolomics; and repression of the genes encoding the pathway by high salt was established by transcriptomics, confirming the osmolyte role of tHyp-B. This study establishes the utility of structure-guide functional predictions to enable the discovery of new metabolic pathways. PMID:24056934

Two-Electron Transfer Pathways.

Science.gov (United States)

Lin, Jiaxing; Balamurugan, D; Zhang, Peng; Skourtis, Spiros S; Beratan, David N

2015-06-18

The frontiers of electron-transfer chemistry demand that we develop theoretical frameworks to describe the delivery of multiple electrons, atoms, and ions in molecular systems. When electrons move over long distances through high barriers, where the probability for thermal population of oxidized or reduced bridge-localized states is very small, the electrons will tunnel from the donor (D) to acceptor (A), facilitated by bridge-mediated superexchange interactions. If the stable donor and acceptor redox states on D and A differ by two electrons, it is possible that the electrons will propagate coherently from D to A. While structure-function relations for single-electron superexchange in molecules are well established, strategies to manipulate the coherent flow of multiple electrons are largely unknown. In contrast to one-electron superexchange, two-electron superexchange involves both one- and two-electron virtual intermediate states, the number of virtual intermediates increases very rapidly with system size, and multiple classes of pathways interfere with one another. In the study described here, we developed simple superexchange models for two-electron transfer. We explored how the bridge structure and energetics influence multielectron superexchange, and we compared two-electron superexchange interactions to single-electron superexchange. Multielectron superexchange introduces interference between singly and doubly oxidized (or reduced) bridge virtual states, so that even simple linear donor-bridge-acceptor systems have pathway topologies that resemble those seen for one-electron superexchange through bridges with multiple parallel pathways. The simple model systems studied here exhibit a richness that is amenable to experimental exploration by manipulating the multiple pathways, pathway crosstalk, and changes in the number of donor and acceptor species. The features that emerge from these studies may assist in developing new strategies to deliver multiple

The most prevalent genetic cause of ALS-FTD, C9orf72 synergizes the toxicity of ATXN2 intermediate polyglutamine repeats through the autophagy pathway.

Science.gov (United States)

Ciura, Sorana; Sellier, Chantal; Campanari, Maria-Letizia; Charlet-Berguerand, Nicolas; Kabashi, Edor

2016-08-02

The most common genetic cause for amyotrophic lateral sclerosis and frontotemporal dementia (ALS-FTD) is repeat expansion of a hexanucleotide sequence (GGGGCC) within the C9orf72 genomic sequence. To elucidate the functional role of C9orf72 in disease pathogenesis, we identified certain molecular interactors of this factor. We determined that C9orf72 exists in a complex with SMCR8 and WDR41 and that this complex acts as a GDP/GTP exchange factor for RAB8 and RAB39, 2 RAB GTPases involved in macroautophagy/autophagy. Consequently, C9orf72 depletion in neuronal cultures leads to accumulation of unresolved aggregates of SQSTM1/p62 and phosphorylated TARDBP/TDP-43. However, C9orf72 reduction does not lead to major neuronal toxicity, suggesting that a second stress may be required to induce neuronal cell death. An intermediate size of polyglutamine repeats within ATXN2 is an important genetic modifier of ALS-FTD. We found that coexpression of intermediate polyglutamine repeats (30Q) of ATXN2 combined with C9orf72 depletion increases the aggregation of ATXN2 and neuronal toxicity. These results were confirmed in zebrafish embryos where partial C9orf72 knockdown along with intermediate (but not normal) repeat expansions in ATXN2 causes locomotion deficits and abnormal axonal projections from spinal motor neurons. These results demonstrate that C9orf72 plays an important role in the autophagy pathway while genetically interacting with another major genetic risk factor, ATXN2, to contribute to ALS-FTD pathogenesis.

Process Design and Economics for the Conversion of Lignocellulosic Biomass to High Octane Gasoline: Thermochemical Research Pathway with Indirect Gasification and Methanol Intermediate

Energy Technology Data Exchange (ETDEWEB)

Tan, Eric [National Renewable Energy Lab. (NREL), Golden, CO (United States); Talmadge, M. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Dutta, Abhijit [National Renewable Energy Lab. (NREL), Golden, CO (United States); Hensley, Jesse [National Renewable Energy Lab. (NREL), Golden, CO (United States); Schaidle, Josh [National Renewable Energy Lab. (NREL), Golden, CO (United States); Biddy, Mary J. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Humbird, David [DWH Process Consulting, Denver, CO (United States); Snowden-Swan, Lesley J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Ross, Jeff [Harris Group, Inc., Seattle, WA (United States); Sexton, Danielle [Harris Group, Inc., Seattle, WA (United States); Yap, Raymond [Harris Group, Inc., Seattle, WA (United States); Lukas, John [Harris Group, Inc., Seattle, WA (United States)

2015-03-01

The U.S. Department of Energy (DOE) promotes research for enabling cost-competitive liquid fuels production from lignocellulosic biomass feedstocks. The research is geared to advance the state of technology (SOT) of biomass feedstock supply and logistics, conversion, and overall system sustainability. As part of their involvement in this program, the National Renewable Energy Laboratory (NREL) and the Pacific Northwest National Laboratory (PNNL) investigate the economics of conversion pathways through the development of conceptual biorefinery process models. This report describes in detail one potential conversion process for the production of high octane gasoline blendstock via indirect liquefaction (IDL). The steps involve the conversion of biomass to syngas via indirect gasification followed by gas cleanup and catalytic syngas conversion to a methanol intermediate; methanol is then further catalytically converted to high octane hydrocarbons. The conversion process model leverages technologies previously advanced by research funded by the Bioenergy Technologies Office (BETO) and demonstrated in 2012 with the production of mixed alcohols from biomass. Biomass-derived syngas cleanup via tar and hydrocarbons reforming was one of the key technology advancements as part of that research. The process described in this report evaluates a new technology area with downstream utilization of clean biomass-syngas for the production of high octane hydrocarbon products through a methanol intermediate, i.e., dehydration of methanol to dimethyl ether (DME) which subsequently undergoes homologation to high octane hydrocarbon products.

A Springloaded Metal-Ligand Mesocate Allows Access to Trapped Intermediates of Self-Assembly.

Science.gov (United States)

Bogie, Paul M; Holloway, Lauren R; Lyon, Yana; Onishi, Nicole C; Beran, Gregory J O; Julian, Ryan R; Hooley, Richard J

2018-04-02

A strained, "springloaded" Fe 2 L 3 iminopyridine mesocate shows highly variable reactivity upon postassembly reaction with competitive diamines. The strained assembly is reactive toward transimination in minutes at ambient temperature and allows observation of kinetically trapped intermediates in the self-assembly pathway. When diamines are used that can only form less favored cage products upon full equilibration, trapped ML 3 fragments with pendant, "hanging" NH 2 groups are selectively formed instead. Slight variations in diamine structure have large effects on the product outcome: less rigid diamines convert the mesocate to more favored self-assembled cage complexes under mild conditions and allow observation of heterocomplex intermediates in the displacement pathway. The mesocate allows control of equilibrium processes and direction of product outcomes via small, iterative changes in added subcomponent structure and provides a method of accessing metal-ligand cage structures not normally observed in multicomponent Fe-iminopyridine self-assembly.

Primary photodissociation pathways of epichlorohydrin and analysis of the C-C bond fission channels from an O(3P)+allyl radical intermediate

International Nuclear Information System (INIS)

FitzPatrick, Benjamin L.; Alligood, Bridget W.; Butler, Laurie J.; Lee, Shih-Huang; Lin, Jim Jr-Min

2010-01-01

This study initially characterizes the primary photodissociation processes of epichlorohydrin, c-(H 2 COCH)CH 2 Cl. The three dominant photoproduct channels analyzed are c-(H 2 COCH)CH 2 +Cl, c-(H 2 COCH)+CH 2 Cl, and C 3 H 4 O+HCl. In the second channel, the c-(H 2 COCH) photofission product is a higher energy intermediate on C 2 H 3 O global potential energy surface and has a small isomerization barrier to vinoxy. The resulting highly vibrationally excited vinoxy radicals likely dissociate to give the observed signal at the mass corresponding to ketene, H 2 CCO. The final primary photodissociation pathway HCl+C 3 H 4 O evidences a recoil kinetic energy distribution similar to that of four-center HCl elimination in chlorinated alkenes, so is assigned to production of c-(H 2 COC)=CH 2 ; the epoxide product is formed with enough vibrational energy to isomerize to acrolein and dissociate. The paper then analyzes the dynamics of the C 3 H 5 O radical produced from C-Cl bond photofission. When the epoxide radical photoproduct undergoes facile ring opening, it is the radical intermediate formed in the O( 3 P)+allyl bimolecular reaction when the O atom adds to an end C atom. We focus on the HCO+C 2 H 4 and H 2 CO+C 2 H 3 product channels from this radical intermediate in this report. Analysis of the velocity distribution of the momentum-matched signals from the HCO+C 2 H 4 products at m/e=29 and 28 shows that the dissociation of the radical intermediate imparts a high relative kinetic energy, peaking near 20 kcal/mol, between the products. Similarly, the energy imparted to relative kinetic energy in the H 2 CO+C 2 H 3 product channel of the O( 3 P)+allyl radical intermediate also peaks at high-recoil kinetic energies, near 18 kcal/mol. The strongly forward-backward peaked angular distributions and the high kinetic energy release result from tangential recoil during the dissociation of highly rotationally excited nascent radicals formed photolytically in this experiment

Primary photodissociation pathways of epichlorohydrin and analysis of the C-C bond fission channels from an O(3P)+allyl radical intermediate

Science.gov (United States)

FitzPatrick, Benjamin L.; Alligood, Bridget W.; Butler, Laurie J.; Lee, Shih-Huang; Lin, Jim-Min, Jr.

2010-09-01

This study initially characterizes the primary photodissociation processes of epichlorohydrin, c-(H2COCH)CH2Cl. The three dominant photoproduct channels analyzed are c-(H2COCH)CH2+Cl, c-(H2COCH)+CH2Cl, and C3H4O+HCl. In the second channel, the c-(H2COCH) photofission product is a higher energy intermediate on C2H3O global potential energy surface and has a small isomerization barrier to vinoxy. The resulting highly vibrationally excited vinoxy radicals likely dissociate to give the observed signal at the mass corresponding to ketene, H2CCO. The final primary photodissociation pathway HCl+C3H4O evidences a recoil kinetic energy distribution similar to that of four-center HCl elimination in chlorinated alkenes, so is assigned to production of c-(H2COC)=CH2; the epoxide product is formed with enough vibrational energy to isomerize to acrolein and dissociate. The paper then analyzes the dynamics of the C3H5O radical produced from C-Cl bond photofission. When the epoxide radical photoproduct undergoes facile ring opening, it is the radical intermediate formed in the O(P3)+allyl bimolecular reaction when the O atom adds to an end C atom. We focus on the HCO+C2H4 and H2CO+C2H3 product channels from this radical intermediate in this report. Analysis of the velocity distribution of the momentum-matched signals from the HCO+C2H4 products at m/e=29 and 28 shows that the dissociation of the radical intermediate imparts a high relative kinetic energy, peaking near 20 kcal/mol, between the products. Similarly, the energy imparted to relative kinetic energy in the H2CO+C2H3 product channel of the O(P3)+allyl radical intermediate also peaks at high-recoil kinetic energies, near 18 kcal/mol. The strongly forward-backward peaked angular distributions and the high kinetic energy release result from tangential recoil during the dissociation of highly rotationally excited nascent radicals formed photolytically in this experiment. The data also reveal substantial branching to an HCCH+H3

Intermediates and the folding of proteins L and G

Energy Technology Data Exchange (ETDEWEB)

Brown, Scott; Head-Gordon, Teresa

2003-07-01

We use a minimalist protein model, in combination with a sequence design strategy, to determine differences in primary structure for proteins L and G that are responsible for the two proteins folding through distinctly different folding mechanisms. We find that the folding of proteins L and G are consistent with a nucleation-condensation mechanism, each of which is described as helix-assisted {beta}-1 and {beta}-2 hairpin formation, respectively. We determine that the model for protein G exhibits an early intermediate that precedes the rate-limiting barrier of folding and which draws together misaligned secondary structure elements that are stabilized by hydrophobic core contacts involving the third {beta}-strand, and presages the later transition state in which the correct strand alignment of these same secondary structure elements is restored. Finally the validity of the targeted intermediate ensemble for protein G was analyzed by fitting the kinetic data to a two-step first order reversible reaction, proving that protein G folding involves an on-pathway early intermediate, and should be populated and therefore observable by experiment.

Binding mechanism and dynamic conformational change of C subunit of PKA with different pathways.

Science.gov (United States)

Chu, Wen-Ting; Chu, Xiakun; Wang, Jin

2017-09-19

The catalytic subunit of PKA (PKAc) exhibits three major conformational states (open, intermediate, and closed) during the biocatalysis process. Both ATP and substrate/inhibitor can effectively induce the conformational changes of PKAc from open to closed states. Aiming to explore the mechanism of this allosteric regulation, we developed a coarse-grained model and analyzed the dynamics of conformational changes of PKAc during binding by performing molecular dynamics simulations for apo PKAc, binary PKAc (PKAc with ATP, PKAc with PKI), and ternary PKAc (PKAc with ATP and PKI). Our results suggest a mixed binding mechanism of induced fit and conformational selection, with the induced fit dominant. The ligands can drive the movements of Gly-rich loop as well as some regions distal to the active site in PKAc and stabilize them at complex state. In addition, there are two parallel pathways (pathway with PKAc-ATP as an intermediate and pathway PKAc-PKI as an intermediate) during the transition from open to closed states. By molecular dynamics simulations and rate constant analyses, we find that the pathway through PKAc-ATP intermediate is the main binding route from open to closed state because of the fact that the bound PKI will hamper ATP from successful binding and significantly increase the barrier for the second binding subprocess. These findings will provide fundamental insights of the mechanisms of PKAc conformational change upon binding.

Chemical Exchange Saturation Transfer in Chemical Reactions: A Mechanistic Tool for NMR Detection and Characterization of Transient Intermediates.

Science.gov (United States)

Lokesh, N; Seegerer, Andreas; Hioe, Johnny; Gschwind, Ruth M

2018-02-07

The low sensitivity of NMR and transient key intermediates below detection limit are the central problems studying reaction mechanisms by NMR. Sensitivity can be enhanced by hyperpolarization techniques such as dynamic nuclear polarization or the incorporation/interaction of special hyperpolarized molecules. However, all of these techniques require special equipment, are restricted to selective reactions, or undesirably influence the reaction pathways. Here, we apply the chemical exchange saturation transfer (CEST) technique for the first time to NMR detect and characterize previously unobserved transient reaction intermediates in organocatalysis. The higher sensitivity of CEST and chemical equilibria present in the reaction pathway are exploited to access population and kinetics information on low populated intermediates. The potential of the method is demonstrated on the proline-catalyzed enamine formation for unprecedented in situ detection of a DPU stabilized zwitterionic iminium species, the elusive key intermediate between enamine and oxazolidinones. The quantitative analysis of CEST data at 250 K revealed the population ratio of [Z-iminium]/[exo-oxazolidinone] 0.02, relative free energy +8.1 kJ/mol (calculated +7.3 kJ/mol), and free energy barrier of +45.9 kJ/mol (ΔG ⧧ calc. (268 K) = +42.2 kJ/mol) for Z-iminium → exo-oxazolidinone. The findings underpin the iminium ion participation in enamine formation pathway corroborating our earlier theoretical prediction and help in better understanding. The reliability of CEST is validated using 1D EXSY-build-up techniques at low temperature (213 K). The CEST method thus serves as a new tool for mechanistic investigations in organocatalysis to access key information, such as chemical shifts, populations, and reaction kinetics of intermediates below the standard NMR detection limit.

Mediterranean intermediate circulation estimated from Argo data in 2003–2010

Directory of Open Access Journals (Sweden)

M. Menna

2010-03-01

Full Text Available Data from 38 Argo profiling floats are used to describe the intermediate Mediterranean currents for the period October 2003–January 2010. These floats were programmed to execute 5-day cycles, to drift at a neutral parking depth of 350 m and measure temperature and salinity profiles from either 700 or 2000 m up to the surface. At the end of each cycle the floats remained at the sea surface for about 6 h, enough time to be localised and transmit the data to the Argos satellite system. The Argos positions were used to determine the float surface and intermediate displacements. At the surface, the float motion was approximated by a linear displacement and inertial motion. Intermediate velocities estimates were used to investigate the Mediterranean circulation at 350 m, to compute the pseudo-Eulerian statistics and to study the influence of bathymetry on the intermediate currents. Maximum speeds, as large as 33 cm/s, were found northeast of the Balearic Islands (western basin and in the Ierapetra eddy (eastern basin. Typical speeds in the main along-slope currents (Liguro-Provençal-Catalan, Algerian and Libyo-Egyptian Currents were ~20 cm/s. In the central and western part of Mediterranean basin, the pseudo-Eulerian statistics show typical intermediate circulation pathways which can be related to the motion of Levantine Intermediate Water. In general our results agree with the qualitative intermediate circulation schemes proposed in the literature, except in the southern Ionian where we found westward-flowing intermediate currents. Fluctuating currents appeared to be usually larger than the mean flow. Intermediate currents were found to be essentially parallel to the isobaths over most of the areas characterized by strong bathymetry gradients, in particular, in the vicinity of the continental slopes.

Structure Sensitivity in Pt Nanoparticle Catalysts for Hydrogenation of 1,3-Butadiene: In Situ Study of Reaction Intermediates Using SFG Vibrational Spectroscopy

KAUST Repository

Michalak, William D.

2013-01-31

The product selectivity during 1,3-butadiene hydrogenation on monodisperse, colloidally synthesized, Pt nanoparticles was studied under reaction conditions with kinetic measurements and in situ sum frequency generation (SFG) vibrational spectroscopy. SFG was performed with the capping ligands intact in order to maintain nanoparticle size by reduced sintering. Four products are formed at 75 C: 1-butene, cis-2-butene, trans-2-butene, and n-butane. Ensembles of Pt nanoparticles with average diameters of 0.9 and 1.8 nm exhibit a ∼30% and ∼20% increase in the full hydrogenation products, respectively, as compared to Pt nanoparticles with average diameters of 4.6 and 6.7 nm. Methyl and methylene vibrational stretches of reaction intermediates observed under working conditions using SFG were used to correlate the stable reaction intermediates with the product distribution. Kinetic and SFG results correlate with previous DFT predictions for two parallel reaction pathways of 1,3-butadiene hydrogenation. Hydrogenation of 1,3-butadiene can initiate with H-addition at internal or terminal carbons leading to the formation of 1-buten-4-yl radical (metallocycle) and 2-buten-1-yl radical intermediates, respectively. Small (0.9 and 1.8 nm) nanoparticles exhibited vibrational resonances originating from both intermediates, while the large (4.6 and 6.7 nm) particles exhibited vibrational resonances originating predominately from the 2-buten-1-yl radical. This suggests each reaction pathway competes for partial and full hydrogenation and the nanoparticle size affects the kinetic preference for the two pathways. The reaction pathway through the metallocycle intermediate on the small nanoparticles is likely due to the presence of low-coordinated sites. © 2012 American Chemical Society.

Structure Sensitivity in Pt Nanoparticle Catalysts for Hydrogenation of 1,3-Butadiene: In Situ Study of Reaction Intermediates Using SFG Vibrational Spectroscopy

KAUST Repository

Michalak, William D.; Krier, James M.; Komvopoulos, Kyriakos; Somorjai, Gabor A.

2013-01-01

hydrogenation and the nanoparticle size affects the kinetic preference for the two pathways. The reaction pathway through the metallocycle intermediate on the small nanoparticles is likely due to the presence of low-coordinated sites. © 2012 American Chemical

Product lifecycle management

CERN Document Server

Stark, John

2016-01-01

This third edition updates and adds to the successful second edition and gives the reader a thorough description of PLM, providing them with a full understanding of the theory and the practical skills to implement PLM within their own business environment. This new and expanded edition is fully updated to reflect the many technological and management advances made in PLM since the release of the second edition. Describing the environment in which products are developed, manufactured and supported, before addressing the Five Pillars of PLM: business processes, product data, PLM applications, Organisational Change Management (OCM) and Project Management, this book explains what Product Lifecycle Management is, and why it’s needed. The final part of the book addresses the PLM timeline, showing the typical steps and activities of a PLM project or initiative. “Product Lifecycle Management” will broaden the reader’s understanding of PLM, nurturing the skills needed to implement PLM successfully and to achi...

Reaction Intermediate Analogues as Bisubstrate Inhibitors of Pantothenate Synthetase

OpenAIRE

Xu, Zhixiang; Yin, Wei; Martinelli, Leonardo K.; Evans, Joanna; Chen, Jinglei; Yu, Yang; Wilson, Daniel J.; Mizrahi, Valerie; Qiao, Chunhua; Aldrich, Courtney C.

2014-01-01

The biosynthesis of pantothenate, the core of coenzyme A (CoA), has been considered an attractive target for the development of antimicrobial agents since this pathway is essential in prokaryotes, but absent in mammals. Pantothenate synthetase, encoded by the gene panC, catalyzes the final condensation of pantoic acid with β–alanine to afford pantothenate via an intermediate pantoyl adenylate. We describe the synthesis and biochemical characterization of five PanC inhibitors that mimic the in...

Species associations among larval helminths in an amphipod intermediate host.

Science.gov (United States)

Dezfuli, B S; Giari, L; Poulin, R

2000-10-01

Larval helminths that share the same intermediate host may or may not also share the same definitive hosts. If one or more of these helminth species can manipulate the phenotype of the intermediate host, there can be great advantages or severe costs for other helminths resulting from co-occurring with a manipulator, depending on whether they have the same definitive host or not. Among 2372 specimens of the amphipod Echinogammarus stammeri collected from the river Brenta, northern Italy, there was a positive association between two acanthocephalan species with the same fish definitive hosts, the relatively common Pomphorhynchus laevis and the much less prevalent Acanthocephalus clavula. The number of cystacanths of P. laevis per infected amphipod, which ranged from one to five, did not influence the likelihood that the amphipod would also host A. clavula. A third acanthocephalan species, Polymorphus minutus,which matures in birds, showed no association with either of the two other species. These results show that associations among helminth species in intermediate hosts are not random, and are instead the product of selection favouring certain pathways of transmission.

Kinetic and mechanistic studies of reactive intermediates in photochemical and transition metal-assisted oxidation, decarboxylation and alkyl transfer reactions

Energy Technology Data Exchange (ETDEWEB)

Carraher, Jack McCaslin [Iowa State Univ., Ames, IA (United States)

2014-01-01

Reactive species like high-valent metal-oxo complexes and carbon and oxygen centered radicals are important intermediates in enzymatic systems, atmospheric chemistry, and industrial processes. Understanding the pathways by which these intermediates form, their relative reactivity, and their fate after reactions is of the utmost importance. Herein are described the mechanistic detail for the generation of several reactive intermediates, synthesis of precursors, characterization of precursors, and methods to direct the chemistry to more desirable outcomes yielding ‘greener’ sources of commodity chemicals and fuels.

Normal mode-guided transition pathway generation in proteins.

Directory of Open Access Journals (Sweden)

Byung Ho Lee

Full Text Available The biological function of proteins is closely related to its structural motion. For instance, structurally misfolded proteins do not function properly. Although we are able to experimentally obtain structural information on proteins, it is still challenging to capture their dynamics, such as transition processes. Therefore, we need a simulation method to predict the transition pathways of a protein in order to understand and study large functional deformations. Here, we present a new simulation method called normal mode-guided elastic network interpolation (NGENI that performs normal modes analysis iteratively to predict transition pathways of proteins. To be more specific, NGENI obtains displacement vectors that determine intermediate structures by interpolating the distance between two end-point conformations, similar to a morphing method called elastic network interpolation. However, the displacement vector is regarded as a linear combination of the normal mode vectors of each intermediate structure, in order to enhance the physical sense of the proposed pathways. As a result, we can generate more reasonable transition pathways geometrically and thermodynamically. By using not only all normal modes, but also in part using only the lowest normal modes, NGENI can still generate reasonable pathways for large deformations in proteins. This study shows that global protein transitions are dominated by collective motion, which means that a few lowest normal modes play an important role in this process. NGENI has considerable merit in terms of computational cost because it is possible to generate transition pathways by partial degrees of freedom, while conventional methods are not capable of this.

Aspartate aminotransferase: the kinetic barriers facing the covalent intermediates on the reaction pathway

International Nuclear Information System (INIS)

Kirsch, J.F.; Julin, D.A.; McLeish, M.; Wiesinger, H.

1986-01-01

The intermediates, aldimine (A), quinonoid (Q) and ketimine (K), along the transaminase reaction coordinate were probed by isotope transfer and solvent exchange kinetics. Less than 0.003% of 3 H is transferred from C/sub α/[ 3 H]-aspartate to pyridoxamine phosphate in the cytoplasmic aspartate aminotransferase (cAATase) reaction implying either that Q does not exist as a kinetically competent intermediate or that there is a rapid exchange of isotope with solvent. The ratio of the rate constants for C/sub α/ hydrogen exchange vs keto acid product formation (k/sub exge//k/sub prod/) are 2.5 and 0.5 for the reactions of cAATase with C/sub α/ [ 2 H]-aspartate and mitochondrial (m) AATase with C/sub α/[ 2 H]-glutamate respectively. The latter reaction was also probed from the α-keto-glutarate side with carbonyl 0-18 enriched keto acid. This experiment gave k/sub exge//k/sub prod/ = 1.0 for oxygen-18 exchange in α-ketoglutarate versus amino acid formation. The two exchange experiments with mAATase are interpreted in terms of a model in which the rate constant for diffusion of water from the active site is comparable with those for product forming steps

Structure and Mechanism of PhnP, a Phosphodiesterase of the Carbon-Phosphorus Lyase Pathway

DEFF Research Database (Denmark)

He, Shu-Mei; Wathier, Matthew; Podzelinska, Kateryna

2011-01-01

PhnP is a phosphodiesterase that plays an important role within the bacterial carbon-phosphorus lyase (CP-lyase) pathway by recycling a "dead-end" intermediate, 5-phospho-α-d-ribosyl 1,2-cyclic phosphate, that is formed during organophosphonate catabolism. As a member of the metallo-β-lactamase s......PhnP is a phosphodiesterase that plays an important role within the bacterial carbon-phosphorus lyase (CP-lyase) pathway by recycling a "dead-end" intermediate, 5-phospho-α-d-ribosyl 1,2-cyclic phosphate, that is formed during organophosphonate catabolism. As a member of the metallo...

Phospholemman is not required for the acute stimulation of Na+-K+-ATPase α2-activity during skeletal muscle fatigue

Science.gov (United States)

Manoharan, Palanikumar; Radzyukevich, Tatiana L.; Hakim Javadi, Hesamedin; Stiner, Cory A.; Landero Figueroa, Julio A.; Lingrel, Jerry B

2015-01-01

The Na+-K+-ATPase α2-isoform in skeletal muscle is rapidly stimulated during muscle use and plays a critical role in fatigue resistance. The acute mechanisms that stimulate α2-activity are not completely known. This study examines whether phosphorylation of phospholemman (PLM/FXYD1), a regulatory subunit of Na+-K+-ATPase, plays a role in the acute stimulation of α2 in working muscles. Mice lacking PLM (PLM KO) have a normal content of the α2-subunit and show normal exercise capacity, in contrast to the greatly reduced exercise capacity of mice that lack α2 in the skeletal muscles. Nerve-evoked contractions in vivo did not induce a change in total PLM or PLM phosphorylated at Ser63 or Ser68, in either WT or PLM KO. Isolated muscles of PLM KO mice maintain contraction and resist fatigue as well as wild type (WT). Rb+ transport by the α2-Na+-K+-ATPase is stimulated to the same extent in contracting WT and contracting PLM KO muscles. Phosphorylation of sarcolemmal membranes prepared from WT but not PLM KO skeletal muscles stimulates the activity of both α1 and α2 in a PLM-dependent manner. The stimulation occurs by an increase in Na+ affinity without significant change in Vmax and is more effective for α1 than α2. These results demonstrate that phosphorylation of PLM is capable of stimulating the activity of both isozymes in skeletal muscle; however, contractile activity alone is not sufficient to induce PLM phosphorylation. Importantly, acute stimulation of α2, sufficient to support exercise and oppose fatigue, does not require PLM or its phosphorylation. PMID:26468207

Mechanisms for the inversion of chirality: Global reaction route mapping of stereochemical pathways in a probable chiral extraterrestrial molecule, 2-aminopropionitrile

International Nuclear Information System (INIS)

Kaur, Ramanpreet; Vikas

2015-01-01

2-Aminopropionitrile (APN), a probable candidate as a chiral astrophysical molecule, is a precursor to amino-acid alanine. Stereochemical pathways in 2-APN are explored using Global Reaction Route Mapping (GRRM) method employing high-level quantum-mechanical computations. Besides predicting the conventional mechanism for chiral inversion that proceeds through an achiral intermediate, a counterintuitive flipping mechanism is revealed for 2-APN through chiral intermediates explored using the GRRM. The feasibility of the proposed stereochemical pathways, in terms of the Gibbs free-energy change, is analyzed at the temperature conditions akin to the interstellar medium. Notably, the stereoinversion in 2-APN is observed to be more feasible than the dissociation of 2-APN and intermediates involved along the stereochemical pathways, and the flipping barrier is observed to be as low as 3.68 kJ/mol along one of the pathways. The pathways proposed for the inversion of chirality in 2-APN may provide significant insight into the extraterrestrial origin of life

Lifetime assessment and lifetime management for key components of nuclear power plants

International Nuclear Information System (INIS)

Dou Yikang; Sun Hanhong; Qu Jiadi

2000-01-01

On the bases of investigation on recent development of plant lifetime management in the world, the author gives some points of view on how to establish plant lifetime assessment (PLA) and management (PLM) systems for Chinese nuclear power plants. The main points lie in: 1) safety regulatory organizations, utilities and R and D institutes work cooperatively for PLA and PLM; 2) PLA and PLM make a interdependent cycle, which means that a good PLM system ensures authentic input for PLA, while veritable PLA provides valuable feedback for PLM improvement; 3) PLA and PLM should be initiated for some key components. The author also analyzes some important problems to be tackled in PLA and PLM from the view angle of a R and D institute

Coarsely resolved topography along protein folding pathways

Science.gov (United States)

Fernández, Ariel; Kostov, Konstantin S.; Berry, R. Stephen

2000-03-01

The kinetic data from the coarse representation of polypeptide torsional dynamics described in the preceding paper [Fernandez and Berry, J. Chem. Phys. 112, 5212 (2000), preceding paper] is inverted by using detailed balance to obtain a topographic description of the potential-energy surface (PES) along the dominant folding pathway of the bovine pancreatic trypsin inhibitor (BPTI). The topography is represented as a sequence of minima and effective saddle points. The dominant folding pathway displays an overall monotonic decrease in energy with a large number of staircaselike steps, a clear signature of a good structure-seeker. The diversity and availability of alternative folding pathways is analyzed in terms of the Shannon entropy σ(t) associated with the time-dependent probability distribution over the kinetic ensemble of contact patterns. Several stages in the folding process are evident. Initially misfolded states form and dismantle revealing no definite pattern in the topography and exhibiting high Shannon entropy. Passage down a sequence of staircase steps then leads to the formation of a nativelike intermediate, for which σ(t) is much lower and fairly constant. Finally, the structure of the intermediate is refined to produce the native state of BPTI. We also examine how different levels of tolerance to mismatches of side chain contacts influence the folding kinetics, the topography of the dominant folding pathway, and the Shannon entropy. This analysis yields upper and lower bounds of the frustration tolerance required for the expeditious and robust folding of BPTI.

Aerobic degradation of 4-nitroaniline (4-NA) via novel degradation intermediates by Rhodococcus sp. strain FK48

Energy Technology Data Exchange (ETDEWEB)

Khan, Fazlurrahman; Pandey, Janmejay; Vikram, Surendra; Pal, Deepika; Cameotra, Swaranjit Singh, E-mail: ssc@imtech.res.in

2013-06-15

Highlights: • This study reports isolation of a novel bacterium capable of mineralizing 4-nitroaniline (4-NA). • This bacterium has been identified as Rhodococcus sp. strain FK48. • Strain FK48 degrades 4-NA via a novel aerobic degradation pathway that involves 4-AP and 1,2,4-BT. • Subsequent degradation proceeds via ring fission and formation of maleylacetate. • This is the first report showing elucidation of catabolic pathway for microbial degradation 4-NA. -- Abstract: An aerobic strain, Rhodococcus sp. strain FK48, capable of growing on 4-nitroaniline (4-NA) as the sole source of carbon, nitrogen, and energy has been isolated from enrichment cultures originating from contaminated soil samples. During growth studies with non- induced cells of FK48 catalyzed sequential denitrification (release of NO{sub 2} substituent) and deamination (release of NH{sub 2} substituent) of 4-NA. However, none of the degradation intermediates could be identified with growth studies. During resting cell studies, 4-NA-induced cells of strain FK48 transformed 4-NA via a previously unknown pathway which involved oxidative hydroxylation leading to formation of 4-aminophenol (4-AP). Subsequent degradation involved oxidated deamination of 4-AP and formation of 1,2,4-benzenetriol (BT) as the major identified terminal aromatic intermediate. Identification of these intermediates was ascertained by HPLC, and GC–MS analyses of the culture supernatants. 4-NA-induced cells of strain FK48 showed positive activity for 1,2,4-benzenetriol dioxygenase in spectrophotometric assay. This is the first conclusive study on aerobic microbial degradation of 4-NA and elucidation of corresponding metabolic pathway.

Aerobic degradation of 4-nitroaniline (4-NA) via novel degradation intermediates by Rhodococcus sp. strain FK48

International Nuclear Information System (INIS)

Khan, Fazlurrahman; Pandey, Janmejay; Vikram, Surendra; Pal, Deepika; Cameotra, Swaranjit Singh

2013-01-01

Highlights: • This study reports isolation of a novel bacterium capable of mineralizing 4-nitroaniline (4-NA). • This bacterium has been identified as Rhodococcus sp. strain FK48. • Strain FK48 degrades 4-NA via a novel aerobic degradation pathway that involves 4-AP and 1,2,4-BT. • Subsequent degradation proceeds via ring fission and formation of maleylacetate. • This is the first report showing elucidation of catabolic pathway for microbial degradation 4-NA. -- Abstract: An aerobic strain, Rhodococcus sp. strain FK48, capable of growing on 4-nitroaniline (4-NA) as the sole source of carbon, nitrogen, and energy has been isolated from enrichment cultures originating from contaminated soil samples. During growth studies with non- induced cells of FK48 catalyzed sequential denitrification (release of NO 2 substituent) and deamination (release of NH 2 substituent) of 4-NA. However, none of the degradation intermediates could be identified with growth studies. During resting cell studies, 4-NA-induced cells of strain FK48 transformed 4-NA via a previously unknown pathway which involved oxidative hydroxylation leading to formation of 4-aminophenol (4-AP). Subsequent degradation involved oxidated deamination of 4-AP and formation of 1,2,4-benzenetriol (BT) as the major identified terminal aromatic intermediate. Identification of these intermediates was ascertained by HPLC, and GC–MS analyses of the culture supernatants. 4-NA-induced cells of strain FK48 showed positive activity for 1,2,4-benzenetriol dioxygenase in spectrophotometric assay. This is the first conclusive study on aerobic microbial degradation of 4-NA and elucidation of corresponding metabolic pathway

PROCESS OF INNOVATION IN PRODUCT LIFECYCLE MANAGEMENT BUSINESS STRATEGY

OpenAIRE

VALENTINA GECEVSKA; FRANC CUS; RADMIL POLENAKOVIC; PAOLO CHABERT

2011-01-01

This article proposes a scenario of Product Lifecycle Management (PLM), as a innovative business strategy based on the analysis of business drivers, industry requirements, limit of current solution, and recent state-of-the-art review in the domain related to PLM. Potential industrial impact of the developed PLM technology solutions is analyzed. It is hoped that the proposed PLM technology solutions will form the frontier basis for further research, development, and application of PLM systems ...

Process Design and Economics for the Conversion of Lignocellulosic Biomass to Hydrocarbons via Indirect Liquefaction. Thermochemical Research Pathway to High-Octane Gasoline Blendstock Through Methanol/Dimethyl Ether Intermediates

Energy Technology Data Exchange (ETDEWEB)

Tan, E. C. D.; Talmadge, M.; Dutta, A.; Hensley, J.; Schaidle, J.; Biddy, M.; Humbird, D.; Snowden-Swan, L. J.; Ross, J.; Sexton, D.; Yap, R.; Lukas, J.

2015-03-01

This report was developed as part of the U.S. Department of Energy’s Bioenergy Technologies Office’s (BETO’s) efforts to enable the development of technologies for the production of infrastructure-compatible, cost-competitive liquid hydrocarbon fuels from lignocellulosic biomass feedstocks. The research funded by BETO is designed to advance the state of technology of biomass feedstock supply and logistics, conversion, and overall system sustainability. It is expected that these research improvements will be made within the 2022 timeframe. As part of their involvement in this research and development effort, the National Renewable Energy Laboratory and the Pacific Northwest National Laboratory investigate the economics of conversion pathways through the development of conceptual biorefinery process models and techno-economic analysis models. This report describes in detail one potential conversion process for the production of high-octane gasoline blendstock via indirect liquefaction of biomass. The processing steps of this pathway include the conversion of biomass to synthesis gas or syngas via indirect gasification, gas cleanup, catalytic conversion of syngas to methanol intermediate, methanol dehydration to dimethyl ether (DME), and catalytic conversion of DME to high-octane, gasoline-range hydrocarbon blendstock product. The conversion process configuration leverages technologies previously advanced by research funded by BETO and demonstrated in 2012 with the production of mixed alcohols from biomass. Biomass-derived syngas cleanup via reforming of tars and other hydrocarbons is one of the key technology advancements realized as part of this prior research and 2012 demonstrations. The process described in this report evaluates a new technology area for the downstream utilization of clean biomass-derived syngas for the production of high-octane hydrocarbon products through methanol and DME intermediates. In this process, methanol undergoes dehydration to

Microbial mineralization of ring-substituted anilines through an ortho-cleavage pathway.

Science.gov (United States)

Zeyer, J; Wasserfallen, A; Timmis, K N

1985-08-01

Moraxella sp. strain G is able to utilize as sole source of carbon and nitrogen aniline, 4-fluoroaniline, 2-chloroaniline, 3-chloroaniline, 4-chloroaniline (PCA), and 4-bromoaniline but not 4-iodoaniline, 4-methylaniline, 4-methoxyaniline, or 3,4-dichloroaniline. The generation time on PCA was 6 h. The pathway for the degradation of PCA was investigated by analysis of catabolic intermediates and enzyme activities. Mutants of strain G were isolated to enhance the accumulation of specific pathway intermediates. PCA was converted by an aniline oxygenase to 4-chlorocatechol, which in turn was degraded via a modified ortho-cleavage pathway. Synthesis of the aniline oxygenase was inducible by various anilines. This enzyme exhibited a broad substrate specificity. Its specific activity towards substituted anilines seemed to be correlated more with the size than with the electron-withdrawing effect of the substituent and was very low towards anilines having substituents larger than iodine or a methyl group. The initial enzyme of the modified ortho-cleavage pathway, catechol 1,2-dioxygenase, had similar characteristics to those of corresponding enzymes of pathways for the degradation of chlorobenzoic acid and chlorophenol, that is, a broad substrate specificity and high activity towards chlorinated and methylated catechols.

Intermediate treatments

Science.gov (United States)

John R. Jones; Wayne D. Shepperd

1985-01-01

Intermediate treatments are those applied after a new stand is successfully established and before the final harvest. These include not only intermediate cuttings - primarily thinning - but also fertilization, irrigation, and protection of the stand from damaging agents.

Metabolic Engineering of the Shikimate Pathway for Production of Aromatics and Derived Compounds—Present and Future Strain Construction Strategies

Directory of Open Access Journals (Sweden)

Nils J. H. Averesch

2018-03-01

Full Text Available The aromatic nature of shikimate pathway intermediates gives rise to a wealth of potential bio-replacements for commonly fossil fuel-derived aromatics, as well as naturally produced secondary metabolites. Through metabolic engineering, the abundance of certain intermediates may be increased, while draining flux from other branches off the pathway. Often targets for genetic engineering lie beyond the shikimate pathway, altering flux deep in central metabolism. This has been extensively used to develop microbial production systems for a variety of compounds valuable in chemical industry, including aromatic and non-aromatic acids like muconic acid, para-hydroxybenzoic acid, and para-coumaric acid, as well as aminobenzoic acids and aromatic α-amino acids. Further, many natural products and secondary metabolites that are valuable in food- and pharma-industry are formed outgoing from shikimate pathway intermediates. (Reconstruction of such routes has been shown by de novo production of resveratrol, reticuline, opioids, and vanillin. In this review, strain construction strategies are compared across organisms and put into perspective with requirements by industry for commercial viability. Focus is put on enhancing flux to and through shikimate pathway, and engineering strategies are assessed in order to provide a guideline for future optimizations.

Identification of the para-nitrophenol catabolic pathway, and characterization of three enzymes involved in the hydroquinone pathway, in pseudomonas sp. 1-7

Directory of Open Access Journals (Sweden)

Zhang Shuangyu

2012-03-01

Full Text Available Abstract Background para-Nitrophenol (PNP, a priority environmental pollutant, is hazardous to humans and animals. However, the information relating to the PNP degradation pathways and their enzymes remain limited. Results Pseudomonas sp.1-7 was isolated from methyl parathion (MP-polluted activated sludge and was shown to degrade PNP. Two different intermediates, hydroquinone (HQ and 4-nitrocatechol (4-NC were detected in the catabolism of PNP. This indicated that Pseudomonas sp.1-7 degraded PNP by two different pathways, namely the HQ pathway, and the hydroxyquinol (BT pathway (also referred to as the 4-NC pathway. A gene cluster (pdcEDGFCBA was identified in a 10.6 kb DNA fragment of a fosmid library, which cluster encoded the following enzymes involved in PNP degradation: PNP 4-monooxygenase (PdcA, p-benzoquinone (BQ reductase (PdcB, hydroxyquinol (BT 1,2-dioxygenase (PdcC, maleylacetate (MA reductase (PdcF, 4-hydroxymuconic semialdehyde (4-HS dehydrogenase (PdcG, and hydroquinone (HQ 1,2-dioxygenase (PdcDE. Four genes (pdcDEFG were expressed in E. coli and the purified pdcDE, pdcG and pdcF gene products were shown to convert HQ to 4-HS, 4-HS to MA and MA to β-ketoadipate respectively by in vitro activity assays. Conclusions The cloning, sequencing, and characterization of these genes along with the functional PNP degradation studies identified 4-NC, HQ, 4-HS, and MA as intermediates in the degradation pathway of PNP by Pseudomonas sp.1-7. This is the first conclusive report for both 4-NC and HQ- mediated degradation of PNP by one microorganism.

Kinetic and reaction pathways of methanol oxidation on platinum

International Nuclear Information System (INIS)

McCabe, R.W.; McCready, D.F.

1986-01-01

Methanol oxidation kinetics were measured on Pt wires in a flow reactor at pressures between 30 and 130 Pa. The kinetics were measured as a function of oxygen-to-methanol equivalence ratio phi and wire temperature. In methanol-lean feeds (phi 2 CO, CO 2 , and H 2 O were the only products; in methanol-rich feeds (phi > 1), CO, H 2 , H 2 CO, CO 2 , and H 2 O were observed. Experiments with 18 O 2 showed that the principal methanol oxidation pathway does not involve C-O bond dissociation. However, the 18 O 2 experiments, together with other features of the methanol oxidation data, also provided evidence for a minor oxidation pathway (accounting for less than 1% of the product CO 2 ) which proceeds through a carbon intermediate. A mathematical model is presented which describes the principal CH 3 OH oxidation pathway as a series reaction involving adsorbed H 2 CO and CO intermediates. Consistent with experimental results, the model predicts that inhibition by adsorbed CO should be weaker for CH 3 OH and H 2 CO oxidation than for CO oxidation. 34 references, 10 figures, 2 tables

Photolysis of nonylphenol ethoxylates: the determination of the degradation kinetics and the intermediate products.

Science.gov (United States)

Chen, Ling; Zhou, Hai-Yun; Deng, Qin-Ying

2007-06-01

The photolysis of nonylphenol ethoxylates with an average oligomers length of ten ethoxylate units (NPEO(10)) in aqueous solution under UV, as well as the influence of humic acid (HA) on the photolysis was studied. A 125W high-pressure mercury lamp was employed as the light source. The intermediate products from the photolysis were determined by LC-MS. The results indicated that NPEO(10) underwent direct photolysis upon exposed to UV. The degradation pathway was complex. Besides the generally proposed degradation pathway of ethylene oxide (EO) side chains shortening, the oxidation of alkyl chain and EO chain led to intermediates having both a carboxylated (as well as carbonylated) ethoxylate and alkyl chain of varying lengths. The hydrogenation of benzene ring was also detected. The kinetics data showed that the first order reaction kinetics could be well used to describe the kinetics of NPEO(10) degradation. In the presence of dissolved organic matter by HA addition, the performance of NPEO(10) photodegradation was reduced. The photolysis rate decreased with increased HA concentration.

Intermediate-field transport of contaminants

International Nuclear Information System (INIS)

Ahn, J.; Kim, C.L.; Chambre, P.L.; Pigford, T.H.; Lee, W.W.L.

1989-06-01

This report is about ''intermediate-field'' transport or the migration of contaminants from arrays of discrete waste packages or sources. In constructing nuclear waste repositories in rock, it may be necessary to place a waste package across a rock fracture, or a rock fracture may develop some time after waste packages have been emplaced. To predict the spatial and temporal distribution of contaminant species from a line of waste packages facing a rock fracture may be important, because such fractures may now be considered a preferential pathway for released radionuclides to re-enter the biosphere. In land disposal of hazardous wastes, individual barrels may contain especially toxic material whose dispersion special attention. We have published analytic solutions for the multidimensional advective transport of contaminants from arrays of waste packages and multiple areal sources into a planar fracture. The results show a near region in which the concentrations vary greatly in the direction transverse to ground-water flow, an intermediate region in which the array can be treated as an infinite plane source of dissolving species, and a far-field region in which the array can be treated as a plane source of finite extent. The array equations have been developed for both porous and fractured media. In this paper we summarize and compare the work with multiple areal sources facing a planar fracture and an array of point sources in porous media. 5 refs., 5 figs

Tat proteins as novel thylakoid membrane anchors organize a biosynthetic pathway in chloroplasts and increase product yield 5-fold

DEFF Research Database (Denmark)

Henriques de Jesus, Maria Perestrello Ramos; Nielsen, Agnieszka Janina Zygadlo; Mellor, Silas Busck

2017-01-01

to their complex structures. Some of the crucial enzymes catalyzing their biosynthesis are the cytochromes P450 (P450s) situated in the endoplasmic reticulum (ER), powered by electron transfers from NADPH. Dhurrin is a cyanogenic glucoside and its biosynthesis involves a dynamic metabolon formed by two P450s....... Nevertheless, translocation of the pathway from the ER to the chloroplast creates other difficulties, such as the loss of metabolon formation and intermediate diversion into other metabolic pathways. We show here that co-localization of these enzymes in the thylakoid membrane leads to a significant increase...... in product formation, with a concomitant decrease in off-pathway intermediates. This was achieved by exchanging the membrane anchors of the dhurrin pathway enzymes to components of the Twin-arginine translocation pathway, TatB and TatC, which have self-assembly properties. Consequently, we show 5-fold...

Effects of Metal Ions, Temperature, and a Denaturant on the Oxidative Folding Pathways of Bovine α-Lactalbumin

Directory of Open Access Journals (Sweden)

Reina Shinozaki

2017-09-01

Full Text Available Bovine α-lactalbumin (αLA has four disulfide (SS bonds in the native form (N. On the oxidative folding pathways of this protein, two specific SS folding intermediates, i.e., (61–77, 73–91 and des[6–120], which have two and three native SS bonds, respectively, accumulate predominantly in the presence of Ca2+. In this study, we reinvestigated the pathways using a water-soluble cyclic selenoxide reagent, trans-3,4-dihydroxyselenolane oxide (DHSox, as a strong and quantitative oxidant to oxidize the fully reduced form (R. In the presence of ethylenediaminetetraacetic acid (EDTA (under a metal-free condition, SS formation randomly proceeded, and N did not regenerate. On the other hand, two specific SS intermediates transiently generated in the presence of Ca2+. These intermediates could be assigned to (61–77, 73–91 and des[6–120] having two common SS bonds, i.e., Cys61-Cys77 and Cys73-Cys91, near the calcium binding pocket of the β-sheet domain. Much faster folding to N was observed in the presence of Mn2+, whereas Na+, K+, Mg2+, and Zn2+ did not affect the pathways. The two key intermediates were susceptible to temperature and a denaturant. The oxidative folding pathways revealed were significantly different from those of hen egg white lysozyme, which has the same SS-bonding pattern as αLA, suggesting that the folding pathways of SS-containing proteins can alter depending on the amino acid sequence and other factors, even when the SS-bond topologies are similar to each other.

Biodegradation of nicotine by a novel nicotine-degrading bacterium, Pseudomonas plecoglossicida TND35 and its new biotransformation intermediates.

Science.gov (United States)

Raman, Gurusamy; Mohan, KasiNadar; Manohar, Venkat; Sakthivel, Natarajan

2014-02-01

Tobacco wastes that contain nicotine alkaloids are harmful to human health and the environment. In the investigation, a novel nicotine-biodegrading bacterium TND35 was isolated and identified as Pseudomonas plecoglossicida on the basis of phenotypic, biochemical characteristics and 16S rRNA sequence homology. We have studied the nicotine biodegradation potential of strain TND35 by detecting the intermediate metabolites using an array of approaches such as HPLC, GC-MS, NMR and FT-IR. Biotransformation metabolites, N-methylmyosmine, 4-hydroxy-1-(3-pyridyl)-1-butanone (HPB) and other three new intermediate metabolites namely, 3,5-bis (1-methylpyrrolidin-2-yl) pyridine, 2,3-dihydro-1-methyl-5-(pyridin-3-yl)-1H-pyrrol-2-ol and 5-(pyridin-3-yl)-1H-pyrrol-2(3H)-one have been identified. Interestingly, these intermediate metabolites suggest that the strain TND35 employs a novel nicotine biodegradation pathway, which is different from the reported pathways of Aspergillus oryzae 112822, Arthrobacter nicotinovorans pAO1, Agrobacterium tumefaciens S33 and other species of Pseudomonas. The metabolite, HPB reported in this study can also be used as biochemical marker for tobacco related cancer studies.

Early Events, Kinetic Intermediates and the Mechanism of Protein Folding in Cytochrome c

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David S. Kliger

2009-04-01

Full Text Available Kinetic studies of the early events in cytochrome c folding are reviewed with a focus on the evidence for folding intermediates on the submillisecond timescale. Evidence from time-resolved absorption, circular dichroism, magnetic circular dichroism, fluorescence energy and electron transfer, small-angle X-ray scattering and amide hydrogen exchange studies on the t £ 1 ms timescale reveals a picture of cytochrome c folding that starts with the ~ 1-ms conformational diffusion dynamics of the unfolded chains. A fractional population of the unfolded chains collapses on the 1 – 100 ms timescale to a compact intermediate IC containing some native-like secondary structure. Although the existence and nature of IC as a discrete folding intermediate remains controversial, there is extensive high time-resolution kinetic evidence for the rapid formation of IC as a true intermediate, i.e., a metastable state separated from the unfolded state by a discrete free energy barrier. Final folding to the native state takes place on millisecond and longer timescales, depending on the presence of kinetic traps such as heme misligation and proline mis-isomerization. The high folding rates observed in equilibrium molten globule models suggest that IC may be a productive folding intermediate. Whether it is an obligatory step on the pathway to the high free energy barrier associated with millisecond timescale folding to the native state, however, remains to be determined.

Characterization of a structural intermediate of flavivirus membrane fusion.

Directory of Open Access Journals (Sweden)

Karin Stiasny

2007-02-01

Full Text Available Viral membrane fusion proceeds through a sequence of steps that are driven by triggered conformational changes of viral envelope glycoproteins, so-called fusion proteins. Although high-resolution structural snapshots of viral fusion proteins in their prefusion and postfusion conformations are available, it has been difficult to define intermediate structures of the fusion pathway because of their transient nature. Flaviviruses possess a class II viral fusion protein (E mediating fusion at acidic pH that is converted from a dimer to a trimer with a hairpin-like structure during the fusion process. Here we show for tick-borne encephalitis virus that exposure of virions to alkaline instead of acidic pH traps the particles in an intermediate conformation in which the E dimers dissociate and interact with target membranes via the fusion peptide without proceeding to the merger of the membranes. Further treatment to low pH, however, leads to fusion, suggesting that these monomers correspond to an as-yet-elusive intermediate required to convert the prefusion dimer into the postfusion trimer. Thus, the use of nonphysiological conditions allows a dissection of the flavivirus fusion process and the identification of two separate steps, in which membrane insertion of multiple copies of E monomers precedes the formation of hairpin-like trimers. This sequence of events provides important new insights for understanding the dynamic process of viral membrane fusion.

Integrative Analysis of Gene Expression Data Including an Assessment of Pathway Enrichment for Predicting Prostate Cancer

Directory of Open Access Journals (Sweden)

Pingzhao Hu

2006-01-01

Full Text Available Background: Microarray technology has been previously used to identify genes that are differentially expressed between tumour and normal samples in a single study, as well as in syntheses involving multiple studies. When integrating results from several Affymetrix microarray datasets, previous studies summarized probeset-level data, which may potentially lead to a loss of information available at the probe-level. In this paper, we present an approach for integrating results across studies while taking probe-level data into account. Additionally, we follow a new direction in the analysis of microarray expression data, namely to focus on the variation of expression phenotypes in predefined gene sets, such as pathways. This targeted approach can be helpful for revealing information that is not easily visible from the changes in the individual genes. Results: We used a recently developed method to integrate Affymetrix expression data across studies. The idea is based on a probe-level based test statistic developed for testing for differentially expressed genes in individual studies. We incorporated this test statistic into a classic random-effects model for integrating data across studies. Subsequently, we used a gene set enrichment test to evaluate the significance of enriched biological pathways in the differentially expressed genes identified from the integrative analysis. We compared statistical and biological significance of the prognostic gene expression signatures and pathways identified in the probe-level model (PLM with those in the probeset-level model (PSLM. Our integrative analysis of Affymetrix microarray data from 110 prostate cancer samples obtained from three studies reveals thousands of genes significantly correlated with tumour cell differentiation. The bioinformatics analysis, mapping these genes to the publicly available KEGG database, reveals evidence that tumour cell differentiation is significantly associated with many

Cluster Analysis of Time-Dependent Crystallographic Data: Direct Identification of Time-Independent Structural Intermediates

Science.gov (United States)

Kostov, Konstantin S.; Moffat, Keith

2011-01-01

The initial output of a time-resolved macromolecular crystallography experiment is a time-dependent series of difference electron density maps that displays the time-dependent changes in underlying structure as a reaction progresses. The goal is to interpret such data in terms of a small number of crystallographically refinable, time-independent structures, each associated with a reaction intermediate; to establish the pathways and rate coefficients by which these intermediates interconvert; and thereby to elucidate a chemical kinetic mechanism. One strategy toward achieving this goal is to use cluster analysis, a statistical method that groups objects based on their similarity. If the difference electron density at a particular voxel in the time-dependent difference electron density (TDED) maps is sensitive to the presence of one and only one intermediate, then its temporal evolution will exactly parallel the concentration profile of that intermediate with time. The rationale is therefore to cluster voxels with respect to the shapes of their TDEDs, so that each group or cluster of voxels corresponds to one structural intermediate. Clusters of voxels whose TDEDs reflect the presence of two or more specific intermediates can also be identified. From such groupings one can then infer the number of intermediates, obtain their time-independent difference density characteristics, and refine the structure of each intermediate. We review the principles of cluster analysis and clustering algorithms in a crystallographic context, and describe the application of the method to simulated and experimental time-resolved crystallographic data for the photocycle of photoactive yellow protein. PMID:21244840

Quantitative trait loci and metabolic pathways

Science.gov (United States)

McMullen, M. D.; Byrne, P. F.; Snook, M. E.; Wiseman, B. R.; Lee, E. A.; Widstrom, N. W.; Coe, E. H.

1998-01-01

The interpretation of quantitative trait locus (QTL) studies is limited by the lack of information on metabolic pathways leading to most economic traits. Inferences about the roles of the underlying genes with a pathway or the nature of their interaction with other loci are generally not possible. An exception is resistance to the corn earworm Helicoverpa zea (Boddie) in maize (Zea mays L.) because of maysin, a C-glycosyl flavone synthesized in silks via a branch of the well characterized flavonoid pathway. Our results using flavone synthesis as a model QTL system indicate: (i) the importance of regulatory loci as QTLs, (ii) the importance of interconnecting biochemical pathways on product levels, (iii) evidence for “channeling” of intermediates, allowing independent synthesis of related compounds, (iv) the utility of QTL analysis in clarifying the role of specific genes in a biochemical pathway, and (v) identification of a previously unknown locus on chromosome 9S affecting flavone level. A greater understanding of the genetic basis of maysin synthesis and associated corn earworm resistance should lead to improved breeding strategies. More broadly, the insights gained in relating a defined genetic and biochemical pathway affecting a quantitative trait should enhance interpretation of the biological basis of variation for other quantitative traits. PMID:9482823

Maturation Pathways of Cross-Reactive HIV-1 Neutralizing Antibodies

Directory of Open Access Journals (Sweden)

Dimiter S. Dimitrov

2009-11-01

Full Text Available Several human monoclonal antibodies (hmAbs and antibody fragments, including the best characterized in terms of structure-function b12 and Fab X5, exhibit relatively potent and broad HIV-1 neutralizing activity. However, the elicitation of b12 or b12-like antibodies in vivo by vaccine immunogens based on the HIV-1 envelope glycoprotein (Env has not been successful. B12 is highly divergent from the closest corresponding germline antibody while X5 is less divergent. We have hypothesized that the relatively high degree of specific somatic hypermutations may preclude binding of the HIV-1 envelope glycoprotein (Env to closest germline antibodies, and that identifying antibodies that are intermediates in the pathways to maturation could help design novel vaccine immunogens to guide the immune system for their enhanced elicitation. In support of this hypothesis we have previously found that a germline-like b12 (monovalent and bivalent scFv as an Fc fusion protein or IgG lacks measurable binding to an Env as measured by ELISA with a sensitivity in the μM range [1]; here we present evidence confirming and expanding these findings for a panel of Envs. In contrast, a germline-like scFv X5 bound Env with high (nM affinity. To begin to explore the maturation pathways of these antibodies we identified several possible b12 intermediate antibodies and tested their neutralizing activity. These intermediate antibodies neutralized only some HIV-1 isolates and with relatively weak potency. In contrast, germline-like scFv X5 neutralized a subset of the tested HIV-1 isolates with comparable efficiencies to that of the mature X5. These results could help explain the relatively high immunogenicity of the coreceptor binding site on gp120 and the abundance of CD4-induced (CD4i antibodies in HIV-1-infected patients (X5 is a CD4i antibody as well as the maturation pathway of X5. They also can help identify antigens that can bind specifically to b12 germline and

Intermediate neutron spectrum problems and the intermediate neutron spectrum experiment

International Nuclear Information System (INIS)

Jaegers, P.J.; Sanchez, R.G.

1996-01-01

Criticality benchmark data for intermediate energy spectrum systems does not exist. These systems are dominated by scattering and fission events induced by neutrons with energies between 1 eV and 1 MeV. Nuclear data uncertainties have been reported for such systems which can not be resolved without benchmark critical experiments. Intermediate energy spectrum systems have been proposed for the geological disposition of surplus fissile materials. Without the proper benchmarking of the nuclear data in the intermediate energy spectrum, adequate criticality safety margins can not be guaranteed. The Zeus critical experiment now under construction will provide this necessary benchmark data

Osmolyte Effects on the Unfolding Pathway of β-Lactoglobulin

International Nuclear Information System (INIS)

Meng Wei; Pan Hai; Qin Meng; Cao Yi; Wang Wei

2013-01-01

There are large amounts of osmolytes inside cells, which impact many physiological processes by complicated mechanisms. The osmolyte effects on the stability and folding of proteins have been studied in detail using simple two-state folding proteins. However, many important functional proteins fold in complex pathways involving various intermediates. Little is known about the osmolyte effects on the folding and unfolding of these proteins. It is noted that β-lactoglobulin (BLG) is an example of such proteins, whose unfolding involves an obvious intermediate state. Using equilibrium chemical denaturation and stopped-flow kinetics, we investigate the unfolding of BLG in the presence of different osmolytes, e.g., glycerol, ethylene glycol (EG) and poly(ethylene glycol)400 (PEG400). It is found that all these osmolytes can stabilize the unfolding intermediate by modulating the relative unfolding kinetics of the native and the intermediate states. The stabilization effects are similar for EG and PEG400 but distinct for glycerol. Since the unfolding intermediates of many proteins are directly related to protein misfolding diseases, evaluation of the osmolyte effects for the unfolding of these proteins in vitro should be beneficial for the understanding of the occurrence of the related diseases in vivo

Tools and Strategies for Product Life Cycle Management ñ A Case Study in Foundry

Science.gov (United States)

Patil, Rajashekar; Kumar, S. Mohan; Abhilash, E.

2012-08-01

Advances in information and communication technology (ICT) have opened new possibilities of collaborations among the customers, suppliers, manufactures and partners to effectively tackle various business challenges. Product Life Cycle Management(PLM) has been a proven approach for Original Equipment Manufacturers (OEMs) to increase their productivity, improve their product quality, speed up delivery, and increase their profit and to become more efficient. However, their Tier 2 and Tier 3 suppliers like foundry industries are still in their infancy without adopting PLM. Hence to enhance their understanding, the basic concepts, the tools and strategies for PLM are presented is this paper. By selecting and implementing appropriate PLM strategies in a small foundry, an attempt was also made to understand the immediate benefits of using PLM tools (commercial PLM software and digital manufacturing tools). This study indicated a reduction in lead time and improved utilization of organizational resources in the production of automobile impeller. These observations may be further extrapolated to other multiproduct, multi-discipline and multi-customer companies to realize the advantages of using PLM technology

Tetracycline degradation by ozonation in the aqueous phase: Proposed degradation intermediates and pathway

International Nuclear Information System (INIS)

Khan, M. Hammad; Bae, Hyokwan; Jung, Jin-Young

2010-01-01

During the ozonation of tetracycline (TC) in aqueous media at pHs 2.2 and 7.0, the effects of pH variations, protonation and dissociation of functional groups and variation in free radical exposure were investigated to elucidate the transformation pathway. Liquid chromatography-triple quadrupole mass spectrometry detected around 15 ozonation products, and uncovered their production and subsequent degradation patterns. During ozonation at pH 2.2, the TC degradation pathway was proposed on the basis of the structure, ozonation chemistry and mass spectrometry data of TC. Ozonation of TC at the C11a-C12 and C2-C3 double bonds, aromatic ring and amino group generated products of m/z 461, 477, 509 and 416, respectively. Further ozonation at the above mentioned sites gave products of m/z 432, 480, 448, 525 and 496. The removal of TOC reached a maximum of ∼40% after 2 h of ozonation, while TC was completely removed within 4-6 min at both pHs. The low TOC removal efficiency might be due to the generation of recalcitrant products and the low ozone supply for high TC concentration. Ozonation decreased the acute toxicity of TC faster at pH 7.0 than pH 2.2, but the maximum decrease was only about 40% at both pHs after 2 h of ozonation. In this study, attempts were made to understand the correlation between the transformation products, pathway, acute toxicity and quantity of residual organics in solution. Overall, ozonation was found to be a promising process for removing TC and the products initially generated.

Unraveling the structure and chemical mechanisms of highly oxygenated intermediates in oxidation of organic compounds

KAUST Repository

Wang, Zhandong

2017-11-28

Decades of research on the autooxidation of organic compounds have provided fundamental and practical insights into these processes; however, the structure of many key autooxidation intermediates and the reactions leading to their formation still remain unclear. This work provides additional experimental evidence that highly oxygenated intermediates with one or more hydroperoxy groups are prevalent in the autooxidation of various oxygenated (e.g., alcohol, aldehyde, keto compounds, ether, and ester) and nonoxygenated (e.g., normal alkane, branched alkane, and cycloalkane) organic compounds. These findings improve our understanding of autooxidation reaction mechanisms that are routinely used to predict fuel ignition and oxidative stability of liquid hydrocarbons, while also providing insights relevant to the formation mechanisms of tropospheric aerosol building blocks. The direct observation of highly oxygenated intermediates for the autooxidation of alkanes at 500–600 K builds upon prior observations made in atmospheric conditions for the autooxidation of terpenes and other unsaturated hydrocarbons; it shows that highly oxygenated intermediates are stable at conditions above room temperature. These results further reveal that highly oxygenated intermediates are not only accessible by chemical activation but also by thermal activation. Theoretical calculations on H-atom migration reactions are presented to rationalize the relationship between the organic compound’s molecular structure (n-alkane, branched alkane, and cycloalkane) and its propensity to produce highly oxygenated intermediates via extensive autooxidation of hydroperoxyalkylperoxy radicals. Finally, detailed chemical kinetic simulations demonstrate the influence of these additional reaction pathways on the ignition of practical fuels.

Unraveling the structure and chemical mechanisms of highly oxygenated intermediates in oxidation of organic compounds

KAUST Repository

Wang, Zhandong; Popolan-Vaida, Denisia M.; Chen, Bingjie; Moshammer, Kai; Mohamed, Samah; Wang, Heng; Sioud, Salim; Raji, Misjudeen; Kohse-Hö inghaus, Katharina; Hansen, Nils; Dagaut, Philippe; Leone, Stephen R.; Sarathy, Mani

2017-01-01

Decades of research on the autooxidation of organic compounds have provided fundamental and practical insights into these processes; however, the structure of many key autooxidation intermediates and the reactions leading to their formation still remain unclear. This work provides additional experimental evidence that highly oxygenated intermediates with one or more hydroperoxy groups are prevalent in the autooxidation of various oxygenated (e.g., alcohol, aldehyde, keto compounds, ether, and ester) and nonoxygenated (e.g., normal alkane, branched alkane, and cycloalkane) organic compounds. These findings improve our understanding of autooxidation reaction mechanisms that are routinely used to predict fuel ignition and oxidative stability of liquid hydrocarbons, while also providing insights relevant to the formation mechanisms of tropospheric aerosol building blocks. The direct observation of highly oxygenated intermediates for the autooxidation of alkanes at 500–600 K builds upon prior observations made in atmospheric conditions for the autooxidation of terpenes and other unsaturated hydrocarbons; it shows that highly oxygenated intermediates are stable at conditions above room temperature. These results further reveal that highly oxygenated intermediates are not only accessible by chemical activation but also by thermal activation. Theoretical calculations on H-atom migration reactions are presented to rationalize the relationship between the organic compound’s molecular structure (n-alkane, branched alkane, and cycloalkane) and its propensity to produce highly oxygenated intermediates via extensive autooxidation of hydroperoxyalkylperoxy radicals. Finally, detailed chemical kinetic simulations demonstrate the influence of these additional reaction pathways on the ignition of practical fuels.

Can Morphing Methods Predict Intermediate Structures?

Science.gov (United States)

Weiss, Dahlia R.; Levitt, Michael

2009-01-01

Movement is crucial to the biological function of many proteins, yet crystallographic structures of proteins can give us only a static snapshot. The protein dynamics that are important to biological function often happen on a timescale that is unattainable through detailed simulation methods such as molecular dynamics as they often involve crossing high-energy barriers. To address this coarse-grained motion, several methods have been implemented as web servers in which a set of coordinates is usually linearly interpolated from an initial crystallographic structure to a final crystallographic structure. We present a new morphing method that does not extrapolate linearly and can therefore go around high-energy barriers and which can produce different trajectories between the same two starting points. In this work, we evaluate our method and other established coarse-grained methods according to an objective measure: how close a coarse-grained dynamics method comes to a crystallographically determined intermediate structure when calculating a trajectory between the initial and final crystal protein structure. We test this with a set of five proteins with at least three crystallographically determined on-pathway high-resolution intermediate structures from the Protein Data Bank. For simple hinging motions involving a small conformational change, segmentation of the protein into two rigid sections outperforms other more computationally involved methods. However, large-scale conformational change is best addressed using a nonlinear approach and we suggest that there is merit in further developing such methods. PMID:18996395

Effect of changes in periodic limb movements under cpap on adherence and long term compliance in obstructive sleep apnea.

Science.gov (United States)

Mwenge, Gimbada B; Rougui, Ihsan; Rodenstein, Daniel

2017-11-20

Purpose of the study Periodic leg movements (PLMs) are found in 30% of patients suffering from OSA. Under CPAP, we observed that PLMs can increase, decrease, or remain unchanged. The predictors of these changes are not well established. Objective To determine the predictors of PLMs change under CPAP and its impact on long-term adherence. Materials and method The patients were referred to the sleep laboratory for snoring or sleepiness. A single PSG night has been performed before and after CPAP treatment. Data on medication used, comorbidities and ferritin level were collected. Results A total of 160 patients were recruited with a severe OSA. About 32.5% (52/160) patients had emerging PLM i.e. that appeared after the disappearance of respiratory events. By comparing patients with emerging-PLMs to others, we found that only the blood ferritin level was significantly different between groups. Moreover, after one-year follow-up, a significant difference in adherence and long-term compliance was observed between patients without PLM at both screening and CPAP polysomnographies or emerging PLM at the second study (56%) vs. patients with baseline PLM, whether PLM remained stable or decreased under CPAP treatment (75%) (p-value 0.028). Serum ferritin and presence of diabetes mellitus predicted the evolution of PLM observed. Patients with low ferritin levels demonstrated an increase of PLM after initiation of nasal CPAP treatment. Conclusion The emergence of PLM negatively impacts long-term adherence to nasal CPAP treatment in OSA. Blood ferritin level is a predictor of the evolution of PLM under CPAP therapy.

Psychological Perspectives on Pathways Linking Socioeconomic Status and Physical Health

Science.gov (United States)

Matthews, Karen A.; Gallo, Linda C.

2011-01-01

Low socioeconomic status (SES) is a reliable correlate of poor physical health. Rather than treat SES as a covariate, health psychology has increasingly focused on the psychobiological pathways that inform understanding why SES is related to physical health. This review assesses the status of research that has examined stress and its associated distress, and social and personal resources as pathways. It highlights work on biomarkers and biological pathways related to SES that can serve as intermediate outcomes in future studies. Recent emphasis on the accumulation of psychobiological risks across the life course is summarized and represents an important direction for future research. Studies that test pathways from SES to candidate psychosocial pathways to health outcomes are few in number but promising. Future research should test integrated models rather than taking piecemeal approaches to evidence. Much work remains to be done, but the questions are of great health significance. PMID:20636127

Analysis of acyl CoA ester intermediates of the mevalonate pathway in Saccharomyces cerevisiae

DEFF Research Database (Denmark)

Seker, Tamay; Møller, Kasper; Nielsen, Jens

2005-01-01

The mevalonate pathway plays an important role in providing the cell with a number of essential precursors for the synthesis of biomass constituents. With respect to their chemical structure, the metabolites of this pathway can be divided into two groups: acyl esters [acetoacetyl CoA, acetyl Co......A, hydroxymethylglutaryl (HMG) CoA] and phosphorylated metabolites (isopentenyl pyrophosphate, dimethylallyl pyrophosphate, geranyl pyrophosphate, farnesyl pyrophosphate). In this study, we developed a method for the precise analysis of the intracellular concentration of acetoacetyl CoA, acetyl CoA and HMG CoA; and we...... used this method for quantification of these metabolites in Saccharomyces cerevisiae, both during batch growth on glucose and on galactose and in glucose-limited chemostat cultures operated at three different dilution rates. The level of the metabolites changed depending on the growth phase...

ApoE4-specific Misfolded Intermediate Identified by Molecular Dynamics Simulations.

Directory of Open Access Journals (Sweden)

Benfeard Williams

2015-10-01

Full Text Available The increased risk of developing Alzheimer's disease (AD is associated with the APOE gene, which encodes for three variants of Apolipoprotein E, namely E2, E3, E4, differing only by two amino acids at positions 112 and 158. ApoE4 is known to be the strongest risk factor for AD onset, while ApoE3 and ApoE2 are considered to be the AD-neutral and AD-protective isoforms, respectively. It has been hypothesized that the ApoE isoforms may contribute to the development of AD by modifying the homeostasis of ApoE physiological partners and AD-related proteins in an isoform-specific fashion. Here we find that, despite the high sequence similarity among the three ApoE variants, only ApoE4 exhibits a misfolded intermediate state characterized by isoform-specific domain-domain interactions in molecular dynamics simulations. The existence of an ApoE4-specific intermediate state can contribute to the onset of AD by altering multiple cellular pathways involved in ApoE-dependent lipid transport efficiency or in AD-related protein aggregation and clearance. We present what we believe to be the first structural model of an ApoE4 misfolded intermediate state, which may serve to elucidate the molecular mechanism underlying the role of ApoE4 in AD pathogenesis. The knowledge of the structure for the ApoE4 folding intermediate provides a new platform for the rational design of alternative therapeutic strategies to fight AD.

Probing the Catalytic Mechanism of S-Ribosylhomocysteinase (LuxS) with Catalytic Intermediates and Substrate Analogues

Energy Technology Data Exchange (ETDEWEB)

Gopishetty, Bhaskar; Zhu, Jinge; Rajan, Rakhi; Sobczak, Adam J.; Wnuk, Stanislaw F.; Bell, Charles E.; Pei, Dehua; (OSU); (FIU)

2009-05-12

S-Ribosylhomocysteinase (LuxS) cleaves the thioether bond in S-ribosylhomocysteine (SRH) to produce homocysteine (Hcys) and 4,5-dihydroxy-2,3-pentanedione (DPD), the precursor of the type II bacterial quorum sensing molecule (AI-2). The catalytic mechanism of LuxS comprises three distinct reaction steps. The first step involves carbonyl migration from the C1 carbon of ribose to C2 and the formation of a 2-ketone intermediate. The second step shifts the C=O group from the C2 to C3 position to produce a 3-ketone intermediate. In the final step, the 3-ketone intermediate undergoes a {beta}-elimination reaction resulting in the cleavage of the thioether bond. In this work, the 3-ketone intermediate was chemically synthesized and shown to be chemically and kinetically competent in the LuxS catalytic pathway. Substrate analogues halogenated at the C3 position of ribose were synthesized and reacted as time-dependent inhibitors of LuxS. The time dependence was caused by enzyme-catalyzed elimination of halide ions. Examination of the kinetics of halide release and decay of the 3-ketone intermediate catalyzed by wild-type and mutant LuxS enzymes revealed that Cys-84 is the general base responsible for proton abstraction in the three reaction steps, whereas Glu-57 likely facilitates substrate binding and proton transfer during catalysis.

Formation of RNA Granule-Derived Capsid Assembly Intermediates Appears To Be Conserved between Human Immunodeficiency Virus Type 1 and the Nonprimate Lentivirus Feline Immunodeficiency Virus.

Science.gov (United States)

Reed, Jonathan C; Westergreen, Nick; Barajas, Brook C; Ressler, Dylan T B; Phuong, Daryl J; Swain, John V; Lingappa, Vishwanath R; Lingappa, Jaisri R

2018-05-01

During immature capsid assembly in cells, human immunodeficiency virus type 1 (HIV-1) Gag co-opts a host RNA granule, forming a pathway of intracellular assembly intermediates containing host components, including two cellular facilitators of assembly, ABCE1 and DDX6. A similar assembly pathway has been observed for other primate lentiviruses. Here we asked whether feline immunodeficiency virus (FIV), a nonprimate lentivirus, also forms RNA granule-derived capsid assembly intermediates. First, we showed that the released FIV immature capsid and a large FIV Gag-containing intracellular complex are unstable during analysis, unlike for HIV-1. We identified harvest conditions, including in situ cross-linking, that overcame this problem, revealing a series of FIV Gag-containing complexes corresponding in size to HIV-1 assembly intermediates. Previously, we showed that assembly-defective HIV-1 Gag mutants are arrested at specific assembly intermediates; here we identified four assembly-defective FIV Gag mutants, including three not previously studied, and demonstrated that they appear to be arrested at the same intermediate as the cognate HIV-1 mutants. Further evidence that these FIV Gag-containing complexes correspond to assembly intermediates came from coimmunoprecipitations demonstrating that endogenous ABCE1 and the RNA granule protein DDX6 are associated with FIV Gag, as shown previously for HIV-1 Gag, but are not associated with a ribosomal protein, at steady state. Additionally, we showed that FIV Gag associates with another RNA granule protein, DCP2. Finally, we validated the FIV Gag-ABCE1 and FIV Gag-DCP2 interactions with proximity ligation assays demonstrating colocalization in situ Together, these data support a model in which primate and nonprimate lentiviruses form intracellular capsid assembly intermediates derived from nontranslating host RNA granules. IMPORTANCE Like HIV-1 Gag, FIV Gag assembles into immature capsids; however, it is not known whether

L-myo-inosose-1 as a probable intermediate in the reaction catalyzed by myo-inositol oxygenase

International Nuclear Information System (INIS)

Naber, N.I.; Swan, J.S.; Hamilton, G.A.

1986-01-01

In previous investigations, it was necessary to have Fe(II) and cysteine present in order to assay the catalytic activity of purified hog kidney myo-inositol oxygenase. In the present study it was found that, if this purified nonheme iron enzyme is slowly frozen in solution with glutathione and stored at -20 degrees C, it is fully active in the absence of activators if catalase is present to remove adventitious H 2 O 2 . With this simpler assay system it was possible to clarify the effects of several variables on the enzymic reaction. Thus, the maximum velocity is pH-dependent with a maximum around pH 9.5, but the apparent Km for myo-inositol (air atmosphere) remains constant at 5.0 mM throughout a broad pH range. The enzyme is quite specific for its substrate myo-inositol, is very sensitive to oxidants and reductants, but is not affected by a variety of complexing agents, nucleotides, sulfhydryl reagents, etc. In other experiments it was found that L-myo-inosose-1, a potential intermediate in the enzymic reaction, is a potent competitive inhibitor (Ki = 62 microM), while other inososes and a solution thought to contain D-glucodialdehyde, another potential intermediate, are weak inhibitors. Also, both a kinetic deuterium isotope effect (kH/kD = 2.1) and a tritium isotope effect (kH/kT = 7.5) are observed for the enzymic reaction when [1-2H]- and [1-3H]-myo-inositol are used as reactants. These latter results are considered strong evidence that the oxygenase reaction proceeds by a pathway involving L-myo-inosose-1 as an intermediate rather than by an alternative pathway that would have D-glucodialdehyde as the intermediate

Intermediality and media change

OpenAIRE

2012-01-01

This book is about intermediality as an approach to analysing and understanding media change. Intermediality and Media Change is critical of technological determinism that characterises 'new media discourse' about the ongoing digitalization, framed as a revolution and creating sharp contrasts between old and new media. Intermediality instead emphasises paying attention to continuities between media of all types and privileges a comparative perspective on technological changes in media over ti...

Intermediate Fragment

DEFF Research Database (Denmark)

Kruse Aagaard, Anders

2015-01-01

This text and its connected exhibition are aiming to reflect both on the thoughts, the processes and the outcome of the design and production of the artefact ‘Intermediate Fragment’ and making as a contemporary architectural tool in general. Intermediate Fragment was made for the exhibition ‘Enga...... of realising an exhibition object was conceived, but expanded, refined and concretised through this process. The context of the work shown here is an interest in a tighter, deeper connection between experimentally obtained material knowledge and architectural design....

Governance-Default Risk Relationship and the Demand for Intermediated and Non-Intermediated Debt

Directory of Open Access Journals (Sweden)

Husam Aldamen

2012-09-01

Full Text Available This paper explores the impact of corporate governance on the demand for intermediated debt (asset finance, bank debt, non-bank private debt and non-intermediated debt (public debt in the Australian debt market. Relative to other countries the Australian debt market is characterised by higher proportions of intermediated or private debt with a lower inherent level of information asymmetry in that private lenders have greater access to financial information (Gray, Koh & Tong 2009. Our firm level, cross-sectional evidence suggests that higher corporate governance impacts demand for debt via the mitigation of default risk. However, this relationship is not uniform across all debt types. Intermediated debt such as bank and asset finance debt are more responsive to changes in governance-default risk relationship than non-bank and non-intermediated debt. The implication is that a firm’s demand for different debt types will reflect its governance-default risk profile.

Risks assessment associated with the possibility of intrusion into the low and intermediate level waste disposal facility

International Nuclear Information System (INIS)

Didita, L.; Ilie, P.; Pavelescu, M.

1997-01-01

In post-closure performance assessment of low and intermediate level waste disposal facilities it is necessary to assess the individual risks associated with the possibility of intrusion into repository. Intruder induced disruptive events can potentially compromise the integrity of the disposal unit and result in exhumation of the waste and radionuclides migration into environment. In this way, the main routes of exposure are: -inhalation of radioactive materials by the intruder; - external gamma irradiation of the intruder, - long-term pathways resulting from the transfer of radioactive materials to the surface of the site. This paper describes the evaluation of conditional and absolute risks associated with each route of exposure as a function of time. To evaluate the risks, it is necessary to calculate the time-dependent activities of each nuclide considered. This is achieved by employing an analytic solution to the Bateman equation at specified times of evaluation. Conditional risks by inhalation, external exposure and long-term pathways and different modes of intrusion are evaluated on the basis of an annual probability of intrusion of unity. Absolute risks are calculated by scaling the user-supplied probabilities of intrusion at various times of evaluation. The evaluation of absolute risks by long-term exposure pathways involves an interpolation procedure in time. The calculations have been performed for the most important radionuclides present in low and intermediate wastes. (authors)

Dimethylsulfoniopropionate biosynthesis in Spartina alterniflora: evidence that S-methylmethionine and dimethylsulfoniopropylamine are intermediates

International Nuclear Information System (INIS)

Kocsis, M.G.; Nolte, K.D.; Rhodes, D.; Shen, T.L.; Gage, D.A.; Hanson, A.D.

1998-01-01

The osmoprotectant 3-dimethylsulfoniopropionate (DMSP) occurs in Gramineae and Compositae, but its synthesis has been studied only in the latter. The DMSP synthesis pathway was therefore investigated in the salt marsh grass Spartina alterniflora Loisel. Leaf tissue metabolized supplied [35S]methionine (Met) to S-methyl-L-Met (SMM), 3-dimethylsulfoniopropylamine (DMSP-amine), and DMSP. The 35S-labeling kinetics of SMM and DMSP-amine indicated that they were intermediates and, consistent with this, the dimethylsulfonium moiety of SMM was shown by stable isotope labeling to be incorporated as a unit into DMSP. The identity of DMSP-amine, a novel natural product, was confirmed by both chemical and mass-spectral methods. S. alterniflora readily converted supplied [35S]SMM to DMSP-amine and DMSP, and also readily converted supplied [35S]DMSP-amine to DMSP; grasses that lack DMSP did neither. A small amount of label was detected in 3-dimethylsulfoniopropionaldehyde (DMSP-ald) when [35S]SMM or [35S]DMSP-amine was given. These results are consistent with the operation of the pathway Met leads to SMM leads to DMSP-amine leads to DMSP-ald leads to DMSP, which differs from that found in Compositae by the presence of a free DMSP-amine intermediate. This dissimilarity suggests that DMSP synthesis evolved independently in Gramineae and Compositae

Novel key metabolites reveal further branching of the roquefortine/meleagrin biosynthetic pathway.

Science.gov (United States)

Ries, Marco I; Ali, Hazrat; Lankhorst, Peter P; Hankemeier, Thomas; Bovenberg, Roel A L; Driessen, Arnold J M; Vreeken, Rob J

2013-12-27

Metabolic profiling and structural elucidation of novel secondary metabolites obtained from derived deletion strains of the filamentous fungus Penicillium chrysogenum were used to reassign various previously ascribed synthetase genes of the roquefortine/meleagrin pathway to their corresponding products. Next to the structural characterization of roquefortine F and neoxaline, which are for the first time reported for P. chrysogenum, we identified the novel metabolite roquefortine L, including its degradation products, harboring remarkable chemical structures. Their biosynthesis is discussed, questioning the exclusive role of glandicoline A as key intermediate in the pathway. The results reveal that further enzymes of this pathway are rather unspecific and catalyze more than one reaction, leading to excessive branching in the pathway with meleagrin and neoxaline as end products of two branches.

MHD intermediate shock discontinuities: Pt. 1

International Nuclear Information System (INIS)

Kennel, C.F.; Blandford, R.D.; Coppi, P.

1989-01-01

Recent numerical investigations have focused attention once more on the role of intermediate shocks in MHD. Four types of intermediate shock are identified using a graphical representation of the MHD Rankine-Hugoniot conditions. This same representation can be used to exhibit the close relationship of intermediate shocks to switch-on shocks and rotational discontinuities. The conditions under which intermediate discontinuities can be found are elucidated. The variations in velocity, pressure, entropy and magnetic-field jumps with upstream parameters in intermediate shocks are exhibited graphically. The evolutionary arguments traditionally advanced against intermediate shocks may fail because the equations of classical MHD are not strictly hyperbolic. (author)

DCEO Biotechnology: Tools To Design, Construct, Evaluate, and Optimize the Metabolic Pathway for Biosynthesis of Chemicals

DEFF Research Database (Denmark)

Chen, Xiulai; Gao, Cong; Guo, Liang

2018-01-01

, and pathway optimization at the systems level, offers a conceptual and technological framework to exploit potential pathways, modify existing pathways and create new pathways for the optimal production of desired chemicals. Here, we summarize recent progress of DCEO biotechnology and examples of its......Chemical synthesis is a well established route for producing many chemicals on a large scale, but some drawbacks still exist in this process, such as unstable intermediates, multistep reactions, complex process control, etc. Biobased production provides an attractive alternative to these challenges......, but how to make cells into efficient factories is challenging. As a key enabling technology to develop efficient cell factories, design-construction-evaluation-optimization (DCEO) biotechnology, which incorporates the concepts and techniques of pathway design, pathway construction, pathway evaluation...

Pentose pathway in human liver

International Nuclear Information System (INIS)

Magnusson, I.; Chandramouli, V.; Schumann, W.C.; Kumaran, K.; Wahren, J.; Landau, B.R.

1988-01-01

[1- 14 C]Ribose and [1- 14 C]glucose were given to normal subjects along with glucose loads (1 g per kg of body weight) after administration of diflunisal and acetaminophen, drugs that are excreted in urine as glucuronides. Distributions of 14 C were determined in the carbons of the excreted glucoronides and in the glucose from blood samples drawn from hepatic veins before and after glucagon administration. Eighty percent or more of the 14 C from [1- 14 C]ribose incorporated into the glucuronic acid moiety of the glucuronides was in carbons 1 and 3, with less than 8% in carbon 2. In glucuronic acid from glucuronide excreted when [2- 14 C]glucose was given, 3.5-8.1% of the 14 C was in carbon 1, 2.5-4.3% in carbon 3, and more than 70% in carbon 2. These distributions are in accord with the glucuronides sampling the glucose unit of the glucose 6-phosphate pool that is a component of the pentose pathway and is intermediate in glycogen formation. It is concluded that the glucuronic acid conjugates of the drugs can serve as a noninvasive means of sampling hepatic glucose 6-phosphate. In human liver, as in animal liver, the classical pentose pathway functions, not the L-type pathway, and only a small percentage of the glucose is metabolized via the pathway

Mapping intermediate degradation products of poly(lactic-co-glycolic acid) in vitro.

Science.gov (United States)

Li, Jian; Nemes, Peter; Guo, Ji

2018-04-01

There is widespread interest in using absorbable polymers, such as poly(lactic-co-glycolic acid) (PLGA), as components in the design and manufacture of new-generation drug eluting stents (DES). PLGA undergoes hydrolysis to progressively degrade through intermediate chemical entities to simple organic acids that are ultimately absorbed by the human body. Understanding the composition and structure of these intermediate degradation products is critical not only to elucidate polymer degradation pathways accurately, but also to assess the safety and performance of absorbable cardiovascular implants. However, analytical approaches to determining the intermediate degradation products have yet to be established and evaluated in a standard or regulatory setting. Hence, we developed a methodology using electrospray ionization mass spectrometry to qualitatively and quantitatively describe intermediate degradation products generated in vitro from two PLGA formulations commonly used in DES. Furthermore, we assessed the temporal evolution of these degradation products using time-lapse experiments. Our data demonstrated that PLGA degradation products via heterogeneous cleavage of ester bonds are modulated by multiple intrinsic and environmental factors, including polymer chemical composition, degradants solubility in water, and polymer synthesis process. We anticipate the methodologies and outcomes presented in this work will elevate the mechanistic understanding of comprehensive degradation profiles of absorbable polymeric devices, and facilitate the design and regulation of cardiovascular implants by supporting the assessments of the associated biological response to degradation products. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 1129-1137, 2018. © 2017 Wiley Periodicals, Inc.

Probing force-induced unfolding intermediates of a single staphylococcal nuclease molecule and the effect of ligand binding

International Nuclear Information System (INIS)

Ishii, Takaaki; Murayama, Yoshihiro; Katano, Atsuto; Maki, Kosuke; Kuwajima, Kunihiro; Sano, Masaki

2008-01-01

Single-molecule manipulation techniques have given experimental access to unfolding intermediates of proteins that are inaccessible in conventional experiments. A detailed characterization of the intermediates is a challenging problem that provides new possibilities for directly probing the energy landscape of proteins. We investigated single-molecule mechanical unfolding of a small globular protein, staphylococcal nuclease (SNase), using atomic force microscopy. The unfolding trajectories of the protein displayed sub-molecular and stochastic behavior with typical lengths corresponding to the size of the unfolded substructures. Our results support the view that the single protein unfolds along multiple pathways as suggested in recent theoretical studies. Moreover, we found the drastic change, caused by the ligand and inhibitor bindings, in the mechanical unfolding dynamics

Designing of a technological line in the context of controlling with the use of integration of the virtual controller with the mechatronics concept designer module of the PLM Siemens NX software

Science.gov (United States)

Herbuś, K.; Ociepka, P.

2017-08-01

In the work is examined the sequential control system of a technological line in the form of the final part of a system of an internal transport. The process of designing this technological line using the computer-aided approach ran concurrently in two different program environments. In the Mechatronics Concept Designer module of the PLM Siemens NX software was developed the 3D model of the technological line prepared for verification the logic interrelations implemented in the control system. For this purpose, from the whole system of the technological line, it was distinguished the sub-system of actuators and sensors, because their correct operation determines the correct operation of the whole system. Whereas in the application of the virtual controller have been implemented the algorithms of work of the planned line. Then both program environments have been integrated using the OPC server, which enables the exchange of data between the considered systems. The data on the state of the object and the data defining the way and sequence of operation of the technological line are exchanged between the virtual controller and the 3D model of the technological line in real time.

Prognostic impact of the lymph node metastatic ratio on 5-year survival of patients with rectal cancer not submitted to preoperative chemoradiation

Directory of Open Access Journals (Sweden)

Alfredo Luiz Jacomo

2011-12-01

Full Text Available Lymph node metastases are a major prognostic factor in colorectal cancer. Inadequate lymph node resection is related to shorter survival. The lymph nodes ratio (LNR has been used as a prognostic factor in patients with colon cancer. Few studies have evaluated the impact of LNR on the 5-year survival of patients with rectal cancer. OBJECTIVE: To evaluate the impact of LNR on the survival of patients with rectal cancer not submitted to preoperative chemoradiotherapy. METHODS: Ninety patients with rectal cancer excluding colon tumors, synchronous tumors, hereditary colorectal cancer and those undergoing preoperative chemoradiation. The patients were divided into three groups according t Metástases linfonodais representam um dos principais fatores prognósticos no câncer colorretal. A ressecção linfonodal inadequada relaciona-se à menor sobrevida. A proporção entre linfonodos metastáticos (PLM vem sendo utilizada como fator prognóstico em doentes com câncer de cólon. Poucos estudos avaliaram o impacto da PLM na sobrevida de doentes com câncer retal. OBJETIVO: Avaliar o impacto da PLM na sobrevida de doentes com câncer de reto não submetidos à quimioradioterapia pré-operatória. MÉTODOS: Foram incluídos 90 doentes com adenocarcinoma retal excluindo-se tumores de cólon, tumores sincrônicos, câncer colorretal hereditário e aqueles submetidos a tratamento radioquimioterápico pré-operatório. Os doentes foram divididos em três grupos segundo a PLM: PLM-0, sem linfonodos comprometidos; PLM-1, 1 a 20% dos linfonodos comprometidos; e PLM-2, mais de 21% dos linfonodos comprometidos. A identificação do ponto de corte da amostra selecionada foi obtida a partir da curva de características de operação do receptor (curva ROC. A sobrevida foi avaliada pelo teste de Kaplan-Meier, a diferença entre os grupos pelo teste de Cox-Mantel e a correlação entre as variáveis pelo teste de Pearson, adotando-se um nível de significância de 5

Engineering the spatial organization of metabolic pathways

DEFF Research Database (Denmark)

Albertsen, Line; Maury, Jerome; Bach, Lars Stougaard

One of the goals of metabolic engineering is to optimize the production of valuable metabolites in cell factories. In this context, modulating the gene expression and activity of enzymes are tools that have been extensively used. Another approach that is gaining interest is the engineering...... of the spatial organization of biosynthetic pathways. Several natural systems for ensuring optimal spatial arrangement of biosynthetic enzymes exist. Sequentially acting enzymes can for example be positioned in close proximity by attachment to cellular structures, up-concentration in membrane enclosed organelles...... or assembly into large complexes. The vision is that by positioning sequentially acting enzymes in close proximity, the cell can accelerate reaction rates and thereby prevent loss of intermediates through diffusion, degradation or competing pathways. The production of valuable metabolites in cell factories...

The return of metabolism: biochemistry and physiology of the pentose phosphate pathway

Science.gov (United States)

Stincone, Anna; Prigione, Alessandro; Cramer, Thorsten; Wamelink, Mirjam M. C.; Campbell, Kate; Cheung, Eric; Olin-Sandoval, Viridiana; Grüning, Nana-Maria; Krüger, Antje; Alam, Mohammad Tauqeer; Keller, Markus A.; Breitenbach, Michael; Brindle, Kevin M.; Rabinowitz, Joshua D.; Ralser, Markus

2015-01-01

The pentose phosphate pathway (PPP) is a fundamental component of cellular metabolism. The PPP is important to maintain carbon homoeostasis, to provide precursors for nucleotide and amino acid biosynthesis, to provide reducing molecules for anabolism, and to defeat oxidative stress. The PPP shares reactions with the Entner–Doudoroff pathway and Calvin cycle and divides into an oxidative and non-oxidative branch. The oxidative branch is highly active in most eukaryotes and converts glucose 6-phosphate into carbon dioxide, ribulose 5-phosphate and NADPH. The latter function is critical to maintain redox balance under stress situations, when cells proliferate rapidly, in ageing, and for the ‘Warburg effect’ of cancer cells. The non-oxidative branch instead is virtually ubiquitous, and metabolizes the glycolytic intermediates fructose 6-phosphate and glyceraldehyde 3-phosphate as well as sedoheptulose sugars, yielding ribose 5-phosphate for the synthesis of nucleic acids and sugar phosphate precursors for the synthesis of amino acids. Whereas the oxidative PPP is considered unidirectional, the non-oxidative branch can supply glycolysis with intermediates derived from ribose 5-phosphate and vice versa, depending on the biochemical demand. These functions require dynamic regulation of the PPP pathway that is achieved through hierarchical interactions between transcriptome, proteome and metabolome. Consequently, the biochemistry and regulation of this pathway, while still unresolved in many cases, are archetypal for the dynamics of the metabolic network of the cell. In this comprehensive article we review seminal work that led to the discovery and description of the pathway that date back now for 80 years, and address recent results about genetic and metabolic mechanisms that regulate its activity. These biochemical principles are discussed in the context of PPP deficiencies causing metabolic disease and the role of this pathway in biotechnology, bacterial and

Information acquisition and financial intermediation

OpenAIRE

Boyarchenko, Nina

2012-01-01

This paper considers the problem of information acquisition in an intermediated market, where the specialists have access to superior technology for acquiring information. These informational advantages of specialists relative to households lead to disagreement between the two groups, changing the shape of the intermediation-constrained region of the economy and increasing the frequency of periods when the intermediation constraint binds. Acquiring the additional information is, however, cost...

Traumatic Brain Injury Pathophysiology and Treatments: Early, Intermediate, and Late Phases Post-Injury

Science.gov (United States)

Algattas, Hanna; Huang, Jason H.

2014-01-01

Traumatic Brain Injury (TBI) affects a large proportion and extensive array of individuals in the population. While precise pathological mechanisms are lacking, the growing base of knowledge concerning TBI has put increased emphasis on its understanding and treatment. Most treatments of TBI are aimed at ameliorating secondary insults arising from the injury; these insults can be characterized with respect to time post-injury, including early, intermediate, and late pathological changes. Early pathological responses are due to energy depletion and cell death secondary to excitotoxicity, the intermediate phase is characterized by neuroinflammation and the late stage by increased susceptibility to seizures and epilepsy. Current treatments of TBI have been tailored to these distinct pathological stages with some overlap. Many prophylactic, pharmacologic, and surgical treatments are used post-TBI to halt the progression of these pathologic reactions. In the present review, we discuss the mechanisms of the pathological hallmarks of TBI and both current and novel treatments which target the respective pathways. PMID:24381049

Electrochemical mineralization pathway of quinoline by boron-doped diamond anodes.

Science.gov (United States)

Wang, Chunrong; Ma, Keke; Wu, Tingting; Ye, Min; Tan, Peng; Yan, Kecheng

2016-04-01

Boron-doped diamond anodes were selected for quinoline mineralization, and the resulting intermediates, phenylpropyl aldehyde, phenylpropionic acid, and nonanal were identified and followed during quinoline oxidation by gas chromatography-mass spectrometry and high-performance liquid chromatography. The evolutions of formic acid, acetic acid, oxalic acid, NO2(-), NO3(-), and NH4(+) were quantified. A new reaction pathway for quinoline mineralization by boron-doped diamond anodes has been proposed, where the pyridine ring in quinoline is cleaved by a hydroxyl radical giving phenylpropyl aldehyde and NH4(+). Phenylpropyl aldehyde is quickly oxidized into phenylpropionic acid, and the benzene ring is cleaved giving nonanal. This is further oxidized to formic acid, acetic acid, and oxalic acid. Finally, these organic intermediates are mineralized to CO2 and H2O. NH4(+) is also oxidized to NO2(-) and on to NO3(-). The results will help to gain basic reference for clearing intermediates and their toxicity. Copyright © 2016 Elsevier Ltd. All rights reserved.

Product Lifecycle Management Architecture: A Model Based Systems Engineering Analysis.

Energy Technology Data Exchange (ETDEWEB)

Noonan, Nicholas James [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

2015-07-01

This report is an analysis of the Product Lifecycle Management (PLM) program. The analysis is centered on a need statement generated by a Nuclear Weapons (NW) customer. The need statement captured in this report creates an opportunity for the PLM to provide a robust service as a solution. Lifecycles for both the NW and PLM are analyzed using Model Based System Engineering (MBSE).

Interaction of the Faroe Bank Channel overflow with Iceland Basin intermediate waters

Science.gov (United States)

Ullgren, Jenny E.; Fer, Ilker; Darelius, Elin; Beaird, Nicholas

2014-01-01

The narrow and deep Faroe Bank Channel (FBC) is an important pathway for cold, dense waters from the Nordic Seas to flow across the Iceland-Scotland ridge into the North Atlantic. The swift, turbulent FBC overflow is associated with strong vertical mixing. Hydrographic profiles from a shipboard survey and two Slocum electric gliders deployed during a cruise in May-June 2012 show an intermediate water mass characterized by low salinity and low oxygen concentration between the upper waters of Atlantic origin and the dense overflow water. A weak low-salinity signal originating north-east of Iceland is discernible at the exit of the FBC, but smeared out by intense mixing. Further west (downstream) marked salinity and oxygen minima are found, which we hypothesize are indicators of a mixture of Labrador Sea Water and Intermediate Water from the Iceland Basin. Water mass characteristics vary strongly on short time scales. Low-salinity, low-oxygen water in the stratified interface above the overflow plume is shown to move along isopycnals toward the Iceland-Faroe Front as a result of eddy stirring and a secondary, transverse circulation in the plume interface. The interaction of low-salinity, low-oxygen intermediate waters with the overflow plume already at a short distance downstream of the sill, here reported for the first time, affects the final properties of the overflow waters through entrainment and mixing.

Polarization control of multi-photon absorption under intermediate femtosecond laser field

International Nuclear Information System (INIS)

Cheng Wenjing; Liang Guo; Wu Ping; Liu Pei; Jia Tianqing; Sun Zhenrong; Zhang Shian

2017-01-01

It has been shown that the femtosecond laser polarization modulation is a very simple and well-established method to control the multi-photon absorption process by the light–matter interaction. Previous studies mainly focused on the multi-photon absorption control in the weak field. In this paper, we further explore the polarization control behavior of multi-photon absorption process in the intermediate femtosecond laser field. In the weak femtosecond laser field, the second-order perturbation theory can well describe the non-resonant two-photon absorption process. However, the higher order nonlinear effect (e.g., four-photon absorption) can occur in the intermediate femtosecond laser field, and thus it is necessary to establish new theoretical model to describe the multi-photon absorption process, which includes the two-photon and four-photon transitions. Here, we construct a fourth-order perturbation theory to study the polarization control behavior of this multi-photon absorption under the intermediate femtosecond laser field excitation, and our theoretical results show that the two-photon and four-photon excitation pathways can induce a coherent interference, while the coherent interference is constructive or destructive that depends on the femtosecond laser center frequency. Moreover, the two-photon and four-photon transitions have the different polarization control efficiency, and the four-photon absorption can obtain the higher polarization control efficiency. Thus, the polarization control efficiency of the whole excitation process can be increased or decreased by properly designing the femtosecond laser field intensity and laser center frequency. These studies can provide a clear physical picture for understanding and controlling the multi-photon absorption process in the intermediate femtosecond laser field, and also can provide a theoretical guidance for the future experimental realization. (paper)

Photofragment imaging study of the CH2CCH2OH radical intermediate of the OH+allene reaction

International Nuclear Information System (INIS)

Raman, Arjun S.; Justine Bell, M.; Lau, K.-C.; Butler, Laurie J.

2007-01-01

These velocity map imaging experiments characterize the photolytic generation of one of the two radical intermediates formed when OH reacts via an addition mechanism with allene. The CH 2 CCH 2 OH radical intermediate is generated photolytically from the photodissociation of 2-chloro-2-propen-1-ol at 193 nm. Detecting the Cl atoms using [2+1] resonance-enhanced multiphoton ionization evidences an isotropic angular distribution for the Cl+CH 2 CCH 2 OH photofragments, a spin-orbit branching ratio for Cl( 2 P 1/2 ):Cl( 2 P 3/2 ) of 0.28, and a bimodal recoil kinetic energy distribution. Conservation of momentum and energy allows us to determine from this data the internal energy distribution of the nascent CH 2 CCH 2 OH radical cofragment. To assess the possible subsequent decomposition pathways of this highly vibrationally excited radical intermediate, we include electronic structure calculations at the G3//B3LYP level of theory. They predict the isomerization and dissociation transition states en route from the initial CH 2 CCH 2 OH radical intermediate to the three most important product channels for the OH+allene reaction expected from this radical intermediate: formaldehyde+C 2 H 3 , H+acrolein, and ethene+CHO. We also calculate the intermediates and transition states en route from the other radical adduct, formed by addition of the OH to the center carbon of allene, to the ketene+CH 3 product channel. We compare our results to a previous theoretical study of the O+allyl reaction conducted at the CBS-QB3 level of theory, as the two reactions include several common intermediates

Photofragment imaging study of the CH2CCH2OH radical intermediate of the OH +allene reaction

Science.gov (United States)

Raman, Arjun S.; Justine Bell, M.; Lau, Kai-Chung; Butler, Laurie J.

2007-10-01

These velocity map imaging experiments characterize the photolytic generation of one of the two radical intermediates formed when OH reacts via an addition mechanism with allene. The CH2CCH2OH radical intermediate is generated photolytically from the photodissociation of 2-chloro-2-propen-1-ol at 193nm. Detecting the Cl atoms using [2+1] resonance-enhanced multiphoton ionization evidences an isotropic angular distribution for the Cl +CH2CCH2OH photofragments, a spin-orbit branching ratio for Cl(P1/22):Cl(P3/22) of 0.28, and a bimodal recoil kinetic energy distribution. Conservation of momentum and energy allows us to determine from this data the internal energy distribution of the nascent CH2CCH2OH radical cofragment. To assess the possible subsequent decomposition pathways of this highly vibrationally excited radical intermediate, we include electronic structure calculations at the G3//B3LYP level of theory. They predict the isomerization and dissociation transition states en route from the initial CH2CCH2OH radical intermediate to the three most important product channels for the OH +allene reaction expected from this radical intermediate: formaldehyde+C2H3, H +acrolein, and ethene+CHO. We also calculate the intermediates and transition states en route from the other radical adduct, formed by addition of the OH to the center carbon of allene, to the ketene+CH3 product channel. We compare our results to a previous theoretical study of the O +allyl reaction conducted at the CBS-QB3 level of theory, as the two reactions include several common intermediates.

Identification of the intermediates of in vivo oxidation of 1 ,4-dioxane by monooxygenase-containing bacteria.

Science.gov (United States)

Mahendra, Shaily; Petzold, Christopher J; Baidoo, Edward E; Keasling, Jay D; Alvarez-Cohen, Lisa

2007-11-01

1,4-dioxane is a probable human carcinogen and an emerging water contaminant. Monooxygenase-expressing bacteria have been shown to degrade dioxane via growth-supporting as well as cometabolic mechanisms. In this study, the intermediates of dioxane degradation by monooxygenase-expressing bacteria were determined by triple quadrupole-mass spectrometry and Fourier transform ion cyclotron resonance-mass spectrometry. The major intermediates were identified as 2-hydroxyethoxyacetic acid (HEAA), ethylene glycol, glycolate, and oxalate. Studies with uniformly labeled 14C dioxane showed that over 50% of the dioxane was mineralized to CO2 by CB1190, while 5% became biomass-associated after 48 h. Volatile organic acids and non-volatiles, respectively, accounted for 20 and 11% of the radiolabeled carbon. Although strains cometabolizing dioxane exhibited limited transformation capacities, nearly half of the initial dioxane was recovered as CO2. On the basis of these analytical results, we propose a pathway for dioxane oxidation by monooxygenase-expressing cells in which dioxane is first converted to 2-hydroxy-1,4-dioxane, which is spontaneously oxidized to HEAA. During a second monooxygenation step, HEAA is further hydroxylated, resulting in a mixture of dihydroxyethoxyacetic acids with a hydroxyl group at the ortho or para position. After cleavage of the second ether bond, small organic molecules such as ethylene glycol, glycolate, glyoxalate, and oxalate are progressively formed, which are then mineralized to CO2 via common cellular metabolic pathways. Bioremediation of dioxane via this pathway is not expected to cause an accumulation of toxic compounds in the environment.

Comparison between dopaminergic agents and physical exercise as treatment for periodic limb movements in patients with spinal cord injury.

Science.gov (United States)

De Mello, M T; Esteves, A M; Tufik, S

2004-04-01

Randomized controlled trial of physical exercise and dopaminergic agonist in persons with spinal cord injury and periodic leg movement (PLM). The objective of the present study was to compare the effectiveness of physical exercise and of a dopaminergic agonist in reducing the frequency of PLM. Centro de Estudos em Psicobiologia e Exercício. Universidade Federal de São Paulo, Brazil. A total of 13 volunteers (mean age: 31.6+/-8.3 years) received L-DOPA (200 mg) and benserazide (50 mg) 1 h before sleeping time for 30 days and were then submitted to a physical exercise program on a manual bicycle ergometer for 45 days (3 times a week). Both L-DOPA administration (35.11-19.87 PLM/h, P<0.03) and physical exercise (35.11-18.53 PLM/h, P<0.012) significantly reduced PLM; however, no significant difference was observed between the two types of treatment. The two types of treatment were found to be effective in the reduction of PLM; however, physical exercise is indicated as the first treatment approach, while dopaminergic agonists or other drugs should only be recommended for patients who do not respond to this type of treatment.

The Prevalence of Palmaris longus agenesis among the Ghanaian population

Directory of Open Access Journals (Sweden)

Osonuga A

2012-10-01

Full Text Available Objective: Background: Studies have documented the agenesis of Palmaris longus muscle in different populations but none has included the Ghanaian population. Methods: The study involved 226 subjects (130 females and 96 males who are students of the University of Cape Coast, Cape Coast, Ghana. The presence of the PLM was clinically determined using the Schaeffer’s test. Subjects in which the tendon was not visualized or palpable, two other tests were performed to confirm the absence. Results: The total prevalence of absence of PLM was 3.1%; absence on the left hand was commoner than on the right hand. The frequency of PLM absence was also slightly higher in females than in males representing 1.8% and 1.3% respectively. One female had the PLM absent bilaterally whiles a male subject had a trifid tendon on the right forearm with a bifid on the left. Conclusion: The prevalence of PLM agenesis in the Ghanaian population is lower compared to values coated in standard textbook on surgery. PLM is not diminishing as fast as observed in some population hence it is can be readily used as donor tendon by Ghanaian surgeons.

Discourses and Models of Intermediality

OpenAIRE

Schröter, Jens

2011-01-01

In his article "Discourses and Models of Intermediality" Jens Schröter discusses the question as to what relations do different discourses pose between different "media." Schröter identifies four models of discourse: 1) synthetic intermediality: a "fusion" of different media to super-media, a model with roots in the Wagnerian concept of Gesamtkunstwerk with political connotations, 2) formal (or transmedial) intermediality: a concept based on formal structures not "specific" to one medium but ...

Reconstruction of the biosynthetic pathway for the core fungal polyketide scaffold rubrofusarin in Saccharomyces cerevisiae

DEFF Research Database (Denmark)

Rugbjerg, Peter; Naesby, Michael; Mortensen, Uffe Hasbro

2013-01-01

production in easily fermentable and genetically engineerable organisms, such as Saccharomyces cerevisiae and Escherichia coli are desirable. Rubrofusarin is an orange polyketide pigment that is a common intermediate in many different fungal biosynthetic pathways. RESULTS: In this study, we established...

Kinetics of a Criegee intermediate that would survive high humidity and may oxidize atmospheric SO2.

Science.gov (United States)

Huang, Hao-Li; Chao, Wen; Lin, Jim Jr-Min

2015-09-01

Criegee intermediates are thought to play a role in atmospheric chemistry, in particular, the oxidation of SO2, which produces SO3 and subsequently H2SO4, an important constituent of aerosols and acid rain. However, the impact of such oxidation reactions is affected by the reactions of Criegee intermediates with water vapor, because of high water concentrations in the troposphere. In this work, the kinetics of the reactions of dimethyl substituted Criegee intermediate (CH3)2COO with water vapor and with SO2 were directly measured via UV absorption of (CH3)2COO under near-atmospheric conditions. The results indicate that (i) the water reaction with (CH3)2COO is not fast enough (kH2O SO2 at a near-gas-kinetic-limit rate (kSO2 = 1.3 × 10(-10) cm(3) s(-1)). These observations imply a significant fraction of atmospheric (CH3)2COO may survive under humid conditions and react with SO2, very different from the case of the simplest Criegee intermediate CH2OO, in which the reaction with water dimer predominates in the CH2OO decay under typical tropospheric conditions. In addition, a significant pressure dependence was observed for the reaction of (CH3)2COO with SO2, suggesting the use of low pressure rate may underestimate the impact of this reaction. This work demonstrates that the reactivity of a Criegee intermediate toward water vapor strongly depends on its structure, which will influence the main decay pathways and steady-state concentrations for various Criegee intermediates in the atmosphere.

Metabolic and functional diversity of saponins, biosynthetic intermediates and semi-synthetic derivatives

Science.gov (United States)

Moses, Tessa; Papadopoulou, Kalliope K.

2014-01-01

Saponins are widely distributed plant natural products with vast structural and functional diversity. They are typically composed of a hydrophobic aglycone, which is extensively decorated with functional groups prior to the addition of hydrophilic sugar moieties, to result in surface-active amphipathic compounds. The saponins are broadly classified as triterpenoids, steroids or steroidal glycoalkaloids, based on the aglycone structure from which they are derived. The saponins and their biosynthetic intermediates display a variety of biological activities of interest to the pharmaceutical, cosmetic and food sectors. Although their relevance in industrial applications has long been recognized, their role in plants is underexplored. Recent research on modulating native pathway flux in saponin biosynthesis has demonstrated the roles of saponins and their biosynthetic intermediates in plant growth and development. Here, we review the literature on the effects of these molecules on plant physiology, which collectively implicate them in plant primary processes. The industrial uses and potential of saponins are discussed with respect to structure and activity, highlighting the undoubted value of these molecules as therapeutics. PMID:25286183

Time-resolved resonance Raman spectroscopy of intermediates of bacteriorhodopsin: The bK(590) intermediate.

Science.gov (United States)

Terner, J; Hsieh, C L; Burns, A R; El-Sayed, M A

1979-07-01

We have combined microbeam and flow techniques with computer subtraction methods to obtain the resonance Raman spectrum of the short lived batho-intermediate (bK(590)) of bacteriorhodopsin. Comparison of the spectra obtained in (1)H(2)O and (2)H(2)O, as well as the fact that the bK(590) intermediate shows large optical red shifts, suggests that the Schiff base linkage of this intermediate is protonated. The fingerprint region of the spectrum of bK(590), sensitive to the isomeric configuration of the retinal chromophore, does not resemble the corresponding region of the parent bR(570) form. The resonance Raman spectrum of bK(590) as well as the spectra of all of the other main intermediates in the photoreaction cycle of bacteriorhodopsin are discussed and compared with resonance Raman spectra of published model compounds.

Intermediality: Bridge to Critical Media Literacy.

Science.gov (United States)

Pailliotet, Ann Watts; Semali, Ladislaus; Rodenberg, Rita K.; Giles, Jackie K.; Macaul, Sherry L.

2000-01-01

Defines "intermediality" as the ability to critically read and write with and across varied symbol systems. Relates it to critical media literacy. Offers rationales for teaching critical media literacy in general, and intermedial instruction in particular. Identifies seven guiding intermedial elements: theory, texts, processes, contexts,…

Bonding pathways of high-pressure chemical transformations

International Nuclear Information System (INIS)

Hu Anguang; Zhang Fan

2013-01-01

A three-stage bonding pathway towards high-pressure chemical transformations from molecular precursors or intermediate states has been identified by first-principles simulations. With the evolution of principal stress tensor components in the response of chemical bonding to compressive loading, the three stages can be defined as the van der Waals bonding destruction, a bond breaking and forming reaction, and equilibrium of new bonds. The three-stage bonding pathway leads to the establishment of a fundamental principle of chemical bonding under compression. It reveals that during high-pressure chemical transformation, electrons moving away from functional groups follow anti-addition, collision-free paths to form new bonds in counteracting the local stress confinement. In applying this principle, a large number of molecular precursors were identified for high-pressure chemical transformations, resulting in new materials. (fast track communication)

Elucidation of the pathways of catabolic glutamate conversion in three thermophilic anaerobic bacteria.

Science.gov (United States)

Plugge, C M; van Leeuwen, J M; Hummelen, T; Balk, M; Stams, A J

2001-07-01

The glutamate catabolism of three thermophilic syntrophic anaerobes was compared based on the combined use of [(13)C] glutamate NMR measurements and enzyme activity determinations. In some cases the uptake of intermediates from different pathways was studied. The three organisms, Caloramator coolhaasii, Thermanaerovibrio acidaminovorans and strain TGO, had a different stoichiometry of glutamate conversion and were dependent on the presence of a hydrogen scavenger (Methanobacterium thermoautotrophicum Z245) to a different degree for their growth. C. coolhaasii formed acetate, CO(2), NH(4)(+) and H(2) from glutamate. Acetate was found to be formed through the beta-methylaspartate pathway in pure culture as well as in coculture. T. acidaminovorans converted glutamate to acetate, propionate, CO(2), NH(4)(+) and H(2). Most likely, this organism uses the beta-methylaspartate pathway for acetate formation. Propionate formation occurred through a direct oxidation of glutamate via succinyl-CoA and methylmalonyl-CoA. The metabolism of T. acidaminovorans shifted in favour of propionate formation when grown in coculture with the methanogen, but this did not lead to the use of a different glutamate degradation pathway. Strain TGO, an obligate syntrophic glutamate-degrading organism, formed propionate, traces of succinate, CO(2), NH(4)(+) and H(2). Glutamate was converted to propionate oxidatively via the intermediates succinyl-CoA and methylmalonyl-CoA. A minor part of the succinyl-CoA was converted to succinate and excreted.

Signal Transduction Pathways that Regulate CAB Gene Expression

Energy Technology Data Exchange (ETDEWEB)

Chory, Joanne

2004-12-31

The process of chloroplast differentiation, involves the coordinate regulation of many nuclear and chloroplast genes. The cues for the initiation of this developmental program are both extrinsic (e.g., light) and intrinsic (cell-type and plastid signals). During this project period, we utilized a molecular genetic approach to select for Arabidopsis mutants that did not respond properly to environmental light conditions, as well as mutants that were unable to perceive plastid damage. These latter mutants, called gun mutants, define two retrograde signaling pathways that regulate nuclear gene expression in response to chloroplasts. A major finding was to identify a signal from chloroplasts that regulates nuclear gene transcription. This signal is the build-up of Mg-Protoporphyrin IX, a key intermediate of the chlorophyll biosynthetic pathway. The signaling pathways downstream of this signal are currently being studied. Completion of this project has provided an increased understanding of the input signals and retrograde signaling pathways that control nuclear gene expression in response to the functional state of chloroplasts. These studies should ultimately influence our abilities to manipulate plant growth and development, and will aid in the understanding of the developmental control of photosynthesis.

Signal Transduction Pathways that Regulate CAB Gene Expression

Energy Technology Data Exchange (ETDEWEB)

Chory, Joanne

2006-01-16

The process of chloroplast differentiation, involves the coordinate regulation of many nuclear and chloroplast genes. The cues for the initiation of this developmental program are both extrinsic (e.g., light) and intrinsic (cell-type and plastid signals). During this project period, we utilized a molecular genetic approach to select for Arabidopsis mutants that did not respond properly to environmental light conditions, as well as mutants that were unable to perceive plastid damage. These latter mutants, called gun mutants, define two retrograde signaling pathways that regulate nuclear gene expression in response to chloroplasts. A major finding was to identify a signal from chloroplasts that regulates nuclear gene transcription. This signal is the build-up of Mg-Protoporphyrin IX, a key intermediate of the chlorophyll biosynthetic pathway. The signaling pathways downstream of this signal are currently being studied. Completion of this project has provided an increased understanding of the input signals and retrograde signaling pathways that control nuclear gene expression in response to the functional state of chloroplasts. These studies should ultimately influence our abilities to manipulate plant growth and development, and will aid in the understanding of the developmental control of photosynthesis.

Aligning institutional priorities: engaging house staff in a quality improvement and safety initiative to fulfill Clinical Learning Environment Review objectives and electronic medical record Meaningful Use requirements.

Science.gov (United States)

Flanagan, Meghan R; Foster, Carolyn C; Schleyer, Anneliese; Peterson, Gene N; Mandell, Samuel P; Rudd, Kristina E; Joyner, Byron D; Payne, Thomas H

2016-02-01

House staff quality improvement projects are often not aligned with training institution priorities. House staff are the primary users of inpatient problem lists in academic medical centers, and list maintenance has significant patient safety and financial implications. Improvement of the problem list is an important objective for hospitals with electronic health records under the Meaningful Use program. House staff surveys were used to create an electronic problem list manager (PLM) tool enabling efficient problem list updating. Number of new problems added and house staff perceptions of the problem list were compared before and after PLM intervention. The PLM was used by 654 house staff after release. Surveys demonstrated increased problem list updating (P = .002; response rate 47%). Mean new problems added per day increased from 64 pre-PLM to 125 post-PLM (P house staff in institutional quality and safety initiatives with tangible institutional benefits. Copyright © 2016 Elsevier Inc. All rights reserved.

Dilute ferromagnetic semiconductors prepared by the combination of ion implantation with pulse laser melting

International Nuclear Information System (INIS)

Zhou, Shengqiang

2015-01-01

Combining semiconducting and ferromagnetic properties, dilute ferromagnetic semiconductors (DFS) have been under intensive investigation for more than two decades. Mn doped III–V compound semiconductors have been regarded as the prototype of DFS from both experimental and theoretic investigations. The magnetic properties of III–V:Mn can be controlled by manipulating free carriers via electrical gating, as for controlling the electrical properties in conventional semiconductors. However, the preparation of DFS presents a big challenge due to the low solubility of Mn in semiconductors. Ion implantation followed by pulsed laser melting (II-PLM) provides an alternative to the widely used low-temperature molecular beam epitaxy (LT-MBE) approach. Both ion implantation and pulsed-laser melting occur far enough from thermodynamic equilibrium conditions. Ion implantation introduces enough dopants and the subsequent laser pulse deposit energy in the near-surface region to drive a rapid liquid-phase epitaxial growth. Here, we review the experimental study on preparation of III–V:Mn using II-PLM. We start with a brief description about the development of DFS and the physics behind II-PLM. Then we show that ferromagnetic GaMnAs and InMnAs films can be prepared by II-PLM and they show the same characteristics of LT-MBE grown samples. Going beyond LT-MBE, II-PLM is successful to bring two new members, GaMnP and InMnP, into the family of III–V:Mn DFS. Both GaMnP and InMnP films show the signature of DFS and an insulating behavior. At the end, we summarize the work done for Ge:Mn and Si:Mn using II-PLM and present suggestions for future investigations. The remarkable advantage of II-PLM approach is its versatility. In general, II-PLM can be utilized to prepare supersaturated alloys with mismatched components. (topical review)

Nucleic acid binding properties and intermediates of HCV core protein multimerization in Pichia pastoris

International Nuclear Information System (INIS)

Acosta-Rivero, Nelson; Rodriguez, Armando; Musacchio, Alexis; Falcon, Viviana; Suarez, Viana M.; Chavez, Liudmila; Morales-Grillo, Juan; Duenas-Carrera, Santiago

2004-01-01

Little is known about the in vivo assembly pathway or structure of the hepatitis C virus nucleocapsid. In this work the intermediates of HCcAg multimerization in Pichia pastoris cells and the nucleic acid binding properties of structured nucleocapsid-like particles (NLPs) were studied. Extensive cross-linking was observed for HCcAg after glutaraldehyde treatment. Data suggest that HCcAg exists in dimeric forms probably representing P21-P21, P21-P23, and P23-P23 dimers. In addition, the presence of HCcAg species that might represent trimers and multimers was observed. After sucrose equilibrium density gradient purification and nuclease digestion, NLPs were shown to contain both RNA and DNA molecules. Finally, the analysis by electron microscopy indicated that native NLPs were resistant to nuclease treatment. These results indicated that HCcAg assembles through dimers, trimers, and multimers' intermediates into capsids in P. pastoris cells. Assembly of NLPs in its natural environment might confer stability to these particles by adopting a compact structure

Predicting protein folding pathways at the mesoscopic level based on native interactions between secondary structure elements

Directory of Open Access Journals (Sweden)

Sze Sing-Hoi

2008-07-01

Full Text Available Abstract Background Since experimental determination of protein folding pathways remains difficult, computational techniques are often used to simulate protein folding. Most current techniques to predict protein folding pathways are computationally intensive and are suitable only for small proteins. Results By assuming that the native structure of a protein is known and representing each intermediate conformation as a collection of fully folded structures in which each of them contains a set of interacting secondary structure elements, we show that it is possible to significantly reduce the conformation space while still being able to predict the most energetically favorable folding pathway of large proteins with hundreds of residues at the mesoscopic level, including the pig muscle phosphoglycerate kinase with 416 residues. The model is detailed enough to distinguish between different folding pathways of structurally very similar proteins, including the streptococcal protein G and the peptostreptococcal protein L. The model is also able to recognize the differences between the folding pathways of protein G and its two structurally similar variants NuG1 and NuG2, which are even harder to distinguish. We show that this strategy can produce accurate predictions on many other proteins with experimentally determined intermediate folding states. Conclusion Our technique is efficient enough to predict folding pathways for both large and small proteins at the mesoscopic level. Such a strategy is often the only feasible choice for large proteins. A software program implementing this strategy (SSFold is available at http://faculty.cs.tamu.edu/shsze/ssfold.

Electron-atom scattering at intermediate energies

International Nuclear Information System (INIS)

Kingston, A.E.; Walters, H.R.J.

1982-01-01

The problems of intermediate energy scattering are approached from the low and high energy ends. At low intermediate energies difficulties associated with the use of pseudostates and correlation terms are discussed, special consideration being given to nonphysical pseudoresonances. Perturbation methods appropriate to high intermediate energies are described and attempts to extend these high energy approximations down to low intermediate energies are studied. It is shown how the importance of electron exchange effects develops with decreasing energy. The problem of assessing the 'effective completeness' of pseudostate sets at intermediate energies is mentioned and an instructive analysis of a 2p pseudostate approximation to elastic e - -H scattering is given. It is suggested that at low energies the Pauli Exclusion Principle can act to hide short range defects in pseudostate approximations. (author)

The intermediate state in Patd

African Journals Online (AJOL)

) Jesus had assumed. (concerning the 'intermediate state') as existing, anything which does not exist. Three basic things about the intermediate state emerge from the parable: (a) Jesus recognizes that at the moment of death, in ipso articulo.

Higher order antibunching in intermediate states

International Nuclear Information System (INIS)

Verma, Amit; Sharma, Navneet K.; Pathak, Anirban

2008-01-01

Since the introduction of binomial state as an intermediate state, different intermediate states have been proposed. Different nonclassical effects have also been reported in these intermediate states. But till now higher order antibunching is predicted in only one type of intermediate state, which is known as shadowed negative binomial state. Recently we have shown that the higher order antibunching is not a rare phenomenon [P. Gupta, P. Pandey, A. Pathak, J. Phys. B 39 (2006) 1137]. To establish our earlier claim further, here we have shown that the higher order antibunching can be seen in different intermediate states, such as binomial state, reciprocal binomial state, hypergeometric state, generalized binomial state, negative binomial state and photon added coherent state. We have studied the possibility of observing the higher order subpoissonian photon statistics in different limits of intermediate states. The effects of different control parameters on the depth of non classicality have also been studied in this connection and it has been shown that the depth of nonclassicality can be tuned by controlling various physical parameters

Prokaryotic Heme Biosynthesis: Multiple Pathways to a Common Essential Product.

Science.gov (United States)

Dailey, Harry A; Dailey, Tamara A; Gerdes, Svetlana; Jahn, Dieter; Jahn, Martina; O'Brian, Mark R; Warren, Martin J

2017-03-01

The advent of heme during evolution allowed organisms possessing this compound to safely and efficiently carry out a variety of chemical reactions that otherwise were difficult or impossible. While it was long assumed that a single heme biosynthetic pathway existed in nature, over the past decade, it has become clear that there are three distinct pathways among prokaryotes, although all three pathways utilize a common initial core of three enzymes to produce the intermediate uroporphyrinogen III. The most ancient pathway and the only one found in the Archaea converts siroheme to protoheme via an oxygen-independent four-enzyme-step process. Bacteria utilize the initial core pathway but then add one additional common step to produce coproporphyrinogen III. Following this step, Gram-positive organisms oxidize coproporphyrinogen III to coproporphyrin III, insert iron to make coproheme, and finally decarboxylate coproheme to protoheme, whereas Gram-negative bacteria first decarboxylate coproporphyrinogen III to protoporphyrinogen IX and then oxidize this to protoporphyrin IX prior to metal insertion to make protoheme. In order to adapt to oxygen-deficient conditions, two steps in the bacterial pathways have multiple forms to accommodate oxidative reactions in an anaerobic environment. The regulation of these pathways reflects the diversity of bacterial metabolism. This diversity, along with the late recognition that three pathways exist, has significantly slowed advances in this field such that no single organism's heme synthesis pathway regulation is currently completely characterized. Copyright © 2017 American Society for Microbiology.

Mechanical unfolding reveals stable 3-helix intermediates in talin and α-catenin.

Directory of Open Access Journals (Sweden)

Vasyl V Mykuliak

2018-04-01

Full Text Available Mechanical stability is a key feature in the regulation of structural scaffolding proteins and their functions. Despite the abundance of α-helical structures among the human proteome and their undisputed importance in health and disease, the fundamental principles of their behavior under mechanical load are poorly understood. Talin and α-catenin are two key molecules in focal adhesions and adherens junctions, respectively. In this study, we used a combination of atomistic steered molecular dynamics (SMD simulations, polyprotein engineering, and single-molecule atomic force microscopy (smAFM to investigate unfolding of these proteins. SMD simulations revealed that talin rod α-helix bundles as well as α-catenin α-helix domains unfold through stable 3-helix intermediates. While the 5-helix bundles were found to be mechanically stable, a second stable conformation corresponding to the 3-helix state was revealed. Mechanically weaker 4-helix bundles easily unfolded into a stable 3-helix conformation. The results of smAFM experiments were in agreement with the findings of the computational simulations. The disulfide clamp mutants, designed to protect the stable state, support the 3-helix intermediate model in both experimental and computational setups. As a result, multiple discrete unfolding intermediate states in the talin and α-catenin unfolding pathway were discovered. Better understanding of the mechanical unfolding mechanism of α-helix proteins is a key step towards comprehensive models describing the mechanoregulation of proteins.

Carbon isotope composition of intermediates of the starch-malate sequence and level of the crassulacean acid metabolism in leaves of Kalanchoe blossfeldiana Tom Thumb.

Science.gov (United States)

Deleens, E; Garnier-Dardart, J; Queiroz, O

1979-09-01

Isotype analyses were performed on biochemical fractions isolated from leaves of Kalanchoe blossfeldiana Tom Thumb. during aging under long days or short days. Irrespective of the age or photoperiodic conditions, the intermediates of the starch-malate sequence (starch, phosphorylated compounds and organic acids) have a level of (13)C higher than that of soluble sugars, cellulose and hemicellulose. In short days, the activity of the crassulacean acid metabolism pathway is predominant as compared to that of C3 pathway: leaves accumulate organic acids, rich in (13)C. In long days, the activity of the crassulacean acid metabolism pathway increases as the leaves age, remaining, however, relatively low as compared to that of C3 pathway: leaves accumulate soluble sugars, poor in (13)C. After photoperiodic change (long days→short days), isotopic modifications of starch and organic acids suggest evidence for a lag phase in the establishment of the crassulacean acid metabolism pathway specific to short days. The relative proportions of carbon from a C3-origin (RuBPC acitivity as strong discriminating step, isotope discrimination in vivo=20‰) or C4-origin (PEPC activity as weak discriminating step, isotope discrimination in vivo=4‰) present in the biochemical fractions were calculated from their δ(13)C values. Under long days, 30 to 70% versus 80 to 100% under short days, of the carbon of the intermediates linked to the starch-malate sequence, or CAM pathway (starch, phosphorylated compounds and organic acids), have a C4-origin. Products connected to the C3 pathway (free sugars, cellulose, hemicellulose) have 0 to 50% of their carbon, arising from reuptake of the C4 from malate, under long days versus 30 to 70% under short days.

NPP Design Basis Handover and Knowledge Preservation from Subcontractors, Vendors and EPC

International Nuclear Information System (INIS)

Freeland, Kent

2013-01-01

Using PLM-based Workflow for Configuration Management (CM) in the Nuclear Power Industry Advantages – some work to do! • NPP’s must adapt to using PLM-based solutions to support CM and to synchronize design changes to asset or product changes, and reduce “slipstreaming”. In the NPP world, this often appears as events that circumvent CM – for example, non-approved parts substitutions and “temporary” plant modifications that are never removed. • PLM serves as the method for unifying the application of requirements to design changes, processes and workflow. In NPP’s, requirements are generally considered only relevant to designs – not process and workflow. • PLM supports Configuration Management and Design Basis in Regulator Action Tracking for NPP’s, and application of PLM-based CM to regulator action and compliance systems. This is a poorly-understood application of CM in NPP’s, yet these elements control large parts of the NPP design basis. • Suppliers, EPC’s and Technology Vendors must also understand the role of CM, SE and PLM in construction of new standards-driven NPP designs (like EPR and Westinghouse AP-1000 NPP designs), as well as understanding the role and handling of Knowledge Systems

The use of phospholipid modified column for the determination of lipophilic properties in high performance liquid chromatography.

Science.gov (United States)

Godard, Tal; Grushka, Eli

2011-03-04

A new chromatographic stationary phase obtained by coating a reversed phase amide column with phosphatidylcholine based liposomes solution to yield a phospholipid modified column (PLM). The modification is achieved by the dynamic coating method which recycles the coating solution through the column in a closed loop for a period of 24 h. The chromatographic properties of the new column have changed significantly as compared to the original amide column due to the phospholipid coating. A good correlation was observed between n-octanol/water logP values and the logarithm of the retention factor obtained on the PLM column for a large number of solutes. In addition the PLM column was characterized using the linear solvation energy relationship (LSER). The values of the LSER system constants for the PLM column were calculated and were found to be very close to those of the n-octanol/water extraction system thus suggesting that the PLM column can be used for the estimation of n-octanol/water partition coefficient and serve as a possible alternative to the shake-flask method for lipophilicity determination. In addition, the results suggest that the PLM column can provide an alternative to other phospholipid-based column such as the IAM and the DPC columns. Copyright © 2011 Elsevier B.V. All rights reserved.

Nitrate ammonification by Nautilia profundicola AmH: experimental evidence consistent with a free hydroxylamine intermediate.

Directory of Open Access Journals (Sweden)

Thomas E Hanson

2013-07-01

Full Text Available The process of nitrate reduction via nitrite controls the fate and bioavailability of mineral nitrogen within ecosystems; i.e. whether it is retained as ammonium (ammonification or lost as nitrous oxide or dinitrogen (denitrification. Here, we present experimental evidence for a novel pathway of microbial nitrate reduction, the reverse hydroxylamine:ubiquinone reductase module (reverse-HURM pathway. Instead of a classical ammonia-forming nitrite reductase that performs a 6 electron-transfer process, the pathway is thought to employ two catalytic redox modules operating in sequence: the reverse-HURM reducing nitrite to hydroxylamine followed by a hydroxylamine reductase that converts hydroxylamine to ammonium. Experiments were performed on Nautilia profundicola strain AmH, whose genome sequence led to the reverse-HURM pathway proposal. N. profundicola produced ammonium from nitrate, which was assimilated into biomass. Furthermore, genes encoding the catalysts of the reverse-HURM pathway were preferentially expressed during growth of N. profundicola on nitrate as an electron acceptor relative to cultures grown on polysulfide as an electron acceptor. Finally, nitrate-grown cells of N. profundicola were able to rapidly and stoichiometrically convert high concentrations of hydroxylamine to ammonium in resting cell assays. These experiments are consistent with the reverse-HURM pathway and a free hydroxylamine intermediate, but could not definitively exclude direct nitrite reduction to ammonium by the reverse-HURM with hydroxylamine as an off-pathway product. N. profundicola and related organisms are models for a new pathway of nitrate ammonification that may have global impact due to the wide distribution of these organisms in hypoxic environments and symbiotic or pathogenic associations with animal hosts.

Stabilization of the second oxyanion intermediate by 1,4-dihydroxy-2-naphthoyl-coenzyme A synthase of the menaquinone pathway: spectroscopic evidence of the involvement of a conserved aspartic acid.

Science.gov (United States)

Chen, Minjiao; Jiang, Ming; Sun, Yueru; Guo, Zu-Feng; Guo, Zhihong

2011-07-05

1,4-Dihydroxy-2-naphthoyl-coenzyme A (DHNA-CoA) synthase, or MenB, catalyzes an intramolecular Claisen condensation involving two oxyanion intermediates in the biosynthetic pathway of menaquinone, an essential respiration electron transporter in many microorganisms. Here we report the finding that the DHNA-CoA product and its analogues bind and inhibit the synthase from Escherichia coli with significant ultraviolet--visible spectral changes, which are similar to the changes induced by deprotonation of the free inhibitors in a basic solution. Dissection of the structure--affinity relationships of the inhibitors identifies the hydroxyl groups at positions 1 (C1-OH) and 4 (C4-OH) of DHNA-CoA or their equivalents as the dominant and minor sites, respectively, for the enzyme--ligand interaction that polarizes or deprotonates the bound ligands to cause the observed spectral changes. In the meantime, spectroscopic studies with active site mutants indicate that C4-OH of the enzyme-bound DHNA-CoA interacts with conserved polar residues Arg-91, Tyr-97, and Tyr-258 likely through a hydrogen bonding network that also includes Ser-161. In addition, site-directed mutation of the conserved Asp-163 to alanine causes a complete loss of the ligand binding ability of the protein, suggesting that the Asp-163 side chain is most likely hydrogen-bonded to C1-OH of DHNA-CoA to provide the dominant polarizing effect. Moreover, this mutation also completely eliminates the enzyme activity, strongly supporting the possibility that the Asp-163 side chain provides a strong stabilizing hydrogen bond to the tetrahedral oxyanion, which takes a position similar to that of C1-OH of the enzyme-bound DHNA-CoA and is the second high-energy intermediate in the intracellular Claisen condensation reaction. Interestingly, both Arg-91 and Tyr-97 are located in a disordered loop forming part of the active site of all available DHNA-CoA synthase structures. Their involvement in the interaction with the small

[Therapy of intermediate uveitis].

Science.gov (United States)

Doycheva, D; Deuter, C; Zierhut, M

2014-12-01

Intermediate uveitis is a form of intraocular inflammation in which the vitreous body is the major site of inflammation. Intermediate uveitis is primarily treated medicinally and systemic corticosteroids are the mainstay of therapy. When recurrence of uveitis or side effects occur during corticosteroid therapy an immunosuppressive treatment is required. Cyclosporine A is the only immunosuppressive agent that is approved for therapy of uveitis in Germany; however, other immunosuppressive drugs have also been shown to be effective and well-tolerated in patients with intermediate uveitis. In severe therapy-refractory cases when conventional immunosuppressive therapy has failed, biologics can be used. In patients with unilateral uveitis or when the systemic therapy is contraindicated because of side effects, an intravitreal steroid treatment can be carried out. In certain cases a vitrectomy may be used.

Product Lifecycle Management and the Quest for Sustainable Space Exploration Solutions

Science.gov (United States)

Caruso, Pamela W.; Dumbacher, Daniel L.; Grieves, Michael

2011-01-01

Product Lifecycle Management (PLM) is an outcome of lean thinking to eliminate waste and increase productivity. PLM is inextricably tied to the systems engineering business philosophy, coupled with a methodology by which personnel, processes and practices, and information technology combine to form an architecture platform for product design, development, manufacturing, operations, and decommissioning. In this model, which is being implemented by the Marshall Space Flight Center (MSFC) Engineering Directorate, total lifecycle costs are important variables for critical decision-making. With the ultimate goal to deliver quality products that meet or exceed requirements on time and within budget, PLM is a powerful concept to shape everything from engineering trade studies and testing goals, to integrated vehicle operations and retirement scenarios. This briefing will demonstrate how the MSFC Engineering Directorate is implementing PLM as part of an overall strategy to deliver safe, reliable, and affordable space exploration solutions and how that strategy aligns with the Agency and Center systems engineering policies and processes. Sustainable space exploration solutions demand that all lifecycle phases be optimized, and engineering the next generation space transportation system requires a paradigm shift such that digital tools and knowledge management, which are central elements of PLM, are used consistently to maximum effect. Adopting PLM, which has been used by the aerospace and automotive industry for many years, for spacecraft applications provides a foundation for strong, disciplined systems engineering and accountable return on investment. PLM enables better solutions using fewer resources by making lifecycle considerations in an integrative decision-making process.

PLMD: An updated data resource of protein lysine modifications.

Science.gov (United States)

Xu, Haodong; Zhou, Jiaqi; Lin, Shaofeng; Deng, Wankun; Zhang, Ying; Xue, Yu

2017-05-20

Post-translational modifications (PTMs) occurring at protein lysine residues, or protein lysine modifications (PLMs), play critical roles in regulating biological processes. Due to the explosive expansion of the amount of PLM substrates and the discovery of novel PLM types, here we greatly updated our previous studies, and presented a much more integrative resource of protein lysine modification database (PLMD). In PLMD, we totally collected and integrated 284,780 modification events in 53,501 proteins across 176 eukaryotes and prokaryotes for up to 20 types of PLMs, including ubiquitination, acetylation, sumoylation, methylation, succinylation, malonylation, glutarylation, glycation, formylation, hydroxylation, butyrylation, propionylation, crotonylation, pupylation, neddylation, 2-hydroxyisobutyrylation, phosphoglycerylation, carboxylation, lipoylation and biotinylation. Using the data set, a motif-based analysis was performed for each PLM type, and the results demonstrated that different PLM types preferentially recognize distinct sequence motifs for the modifications. Moreover, various PLMs synergistically orchestrate specific cellular biological processes by mutual crosstalks with each other, and we totally found 65,297 PLM events involved in 90 types of PLM co-occurrences on the same lysine residues. Finally, various options were provided for accessing the data, while original references and other annotations were also present for each PLM substrate. Taken together, we anticipated the PLMD database can serve as a useful resource for further researches of PLMs. PLMD 3.0 was implemented in PHP + MySQL and freely available at http://plmd.biocuckoo.org. Copyright © 2017 Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, and Genetics Society of China. Published by Elsevier Ltd. All rights reserved.

High-throughput enzyme screening platform for the IPP-bypass mevalonate pathway for isopentenol production

DEFF Research Database (Denmark)

Kang, Aram; Meadows, Corey W.; Canu, Nicolas

2017-01-01

Isopentenol (or isoprenol, 3-methyl-3-buten-1-ol) is a drop-in biofuel and a precursor for commodity chemicals such as isoprene. Biological production of isopentenol via the mevalonate pathway has been optimized extensively in Escherichia coli, yielding 70% of its theoretical maximum. However, high...... ATP requirements and isopentenyl diphosphate (IPP) toxicity pose immediate challenges for engineering bacterial strains to overproduce commodities utilizing IPP as an intermediate. To overcome these limitations, we developed an “IPP-bypass� isopentenol pathway using the promiscuous activity...

Effect of Intermediate Hosts on Emerging Zoonoses.

Science.gov (United States)

Cui, Jing-An; Chen, Fangyuan; Fan, Shengjie

2017-08-01

Most emerging zoonotic pathogens originate from animals. They can directly infect humans through natural reservoirs or indirectly through intermediate hosts. As a bridge, an intermediate host plays different roles in the transmission of zoonotic pathogens. In this study, we present three types of pathogen transmission to evaluate the effect of intermediate hosts on emerging zoonotic diseases in human epidemics. These types are identified as follows: TYPE 1, pathogen transmission without an intermediate host for comparison; TYPE 2, pathogen transmission with an intermediate host as an amplifier; and TYPE 3, pathogen transmission with an intermediate host as a vessel for genetic variation. In addition, we established three mathematical models to elucidate the mechanisms underlying zoonotic disease transmission according to these three types. Stability analysis indicated that the existence of intermediate hosts increased the difficulty of controlling zoonotic diseases because of more difficult conditions to satisfy for the disease to die out. The human epidemic would die out under the following conditions: TYPE 1: [Formula: see text] and [Formula: see text]; TYPE 2: [Formula: see text], [Formula: see text], and [Formula: see text]; and TYPE 3: [Formula: see text], [Formula: see text], [Formula: see text], and [Formula: see text] Simulation with similar parameters demonstrated that intermediate hosts could change the peak time and number of infected humans during a human epidemic; intermediate hosts also exerted different effects on controlling the prevalence of a human epidemic with natural reservoirs in different periods, which is important in addressing problems in public health. Monitoring and controlling the number of natural reservoirs and intermediate hosts at the right time would successfully manage and prevent the prevalence of emerging zoonoses in humans.

Biomarkers of intermediate endpoints in environmental and occupational health

DEFF Research Database (Denmark)

Knudsen, Lisbeth E; Hansen, Ase M

2007-01-01

The use of biomarkers in environmental and occupational health is increasing due to increasing demands on information about health risks from unfavourable exposures. Biomarkers provide information about individual loads. Biomarkers of intermediate endpoints benefit in comparison with biomarkers...... of exposure from the fact that they are closer to the adverse outcome in the pathway from exposure to health effects and may provide powerful information for intervention. Some biomarkers are specific, e.g., DNA and protein adducts, while others are unspecific like the cytogenetic biomarkers of chromosomal...... health effect from the result of the measurement has been performed for the cytogenetic biomarkers showing a predictive value of high levels of CA and increased risk of cancer. The use of CA in future studies is, however, limited by the laborious and sensitive procedure of the test and lack of trained...

Intermediate structure and threshold phenomena

International Nuclear Information System (INIS)

Hategan, Cornel

2004-01-01

The Intermediate Structure, evidenced through microstructures of the neutron strength function, is reflected in open reaction channels as fluctuations in excitation function of nuclear threshold effects. The intermediate state supporting both neutron strength function and nuclear threshold effect is a micro-giant neutron threshold state. (author)

Curation and Computational Design of Bioenergy-Related Metabolic Pathways

Energy Technology Data Exchange (ETDEWEB)

Karp, Peter D. [SRI International, Menlo Park, CA (United States)

2014-09-12

Pathway Tools is a systems-biology software package written by SRI International (SRI) that produces Pathway/Genome Databases (PGDBs) for organisms with a sequenced genome. Pathway Tools also provides a wide range of capabilities for analyzing predicted metabolic networks and user-generated omics data. More than 5,000 academic, industrial, and government groups have licensed Pathway Tools. This user community includes researchers at all three DOE bioenergy centers, as well as academic and industrial metabolic engineering (ME) groups. An integral part of the Pathway Tools software is MetaCyc, a large, multiorganism database of metabolic pathways and enzymes that SRI and its academic collaborators manually curate. This project included two main goals: I. Enhance the MetaCyc content of bioenergy-related enzymes and pathways. II. Develop computational tools for engineering metabolic pathways that satisfy specified design goals, in particular for bioenergy-related pathways. In part I, SRI proposed to significantly expand the coverage of bioenergy-related metabolic information in MetaCyc, followed by the generation of organism-specific PGDBs for all energy-relevant organisms sequenced at the DOE Joint Genome Institute (JGI). Part I objectives included: 1: Expand the content of MetaCyc to include bioenergy-related enzymes and pathways. 2: Enhance the Pathway Tools software to enable display of complex polymer degradation processes. 3: Create new PGDBs for the energy-related organisms sequenced by JGI, update existing PGDBs with new MetaCyc content, and make these data available to JBEI via the BioCyc website. In part II, SRI proposed to develop an efficient computational tool for the engineering of metabolic pathways. Part II objectives included: 4: Develop computational tools for generating metabolic pathways that satisfy specified design goals, enabling users to specify parameters such as starting and ending compounds, and preferred or disallowed intermediate compounds

Intermediate algebra & analytic geometry

CERN Document Server

Gondin, William R

1967-01-01

Intermediate Algebra & Analytic Geometry Made Simple focuses on the principles, processes, calculations, and methodologies involved in intermediate algebra and analytic geometry. The publication first offers information on linear equations in two unknowns and variables, functions, and graphs. Discussions focus on graphic interpretations, explicit and implicit functions, first quadrant graphs, variables and functions, determinate and indeterminate systems, independent and dependent equations, and defective and redundant systems. The text then examines quadratic equations in one variable, system

Regularities of intermediate adsorption complex relaxation

International Nuclear Information System (INIS)

Manukova, L.A.

1982-01-01

The experimental data, characterizing the regularities of intermediate adsorption complex relaxation in the polycrystalline Mo-N 2 system at 77 K are given. The method of molecular beam has been used in the investigation. The analytical expressions of change regularity in the relaxation process of full and specific rates - of transition from intermediate state into ''non-reversible'', of desorption into the gas phase and accumUlation of the particles in the intermediate state are obtained

FINANCIAL INTERMEDIATION, ENTREPRENEURSHIP AND ECONOMIC GROWTH

OpenAIRE

Wenli Cheng

2007-01-01

This paper presents a simple general equilibrium model of financial intermediation, entrepreneurship and economic growth. In this model, the role of financial intermediation is to pool savings and to lend the pooled funds to an entrepreneur, who in turn invests the funds in a new production technology. The adoption of the new production technology improves individual real income. Thus financial intermediation promotes economic growth through affecting individuals’ saving behaviour and enabl...

Quantum Chemical Investigation of the Transition States and Intermediates for the Reaction of the Nitrosonium Ion with the Pentaammineazidocobalt(III) Ion.

Science.gov (United States)

Rotzinger, François P

2016-12-19

The water exchange reaction on Co(NH 3 ) 5 OH 2 3+ was investigated with various density functionals and basis sets. A Gibbs activation energy (ΔG ⧧ ) agreeing with experiment was obtained with the long-range-corrected functionals ωB97X-D3 and LC-BOP-LRD, SMD hydration, and modified Karlsruhe def2-TZVP basis sets. This computational technique was then applied to the reaction of NO + with Co(NH 3 ) 5 N 3 2+ . All of the possible pathways were investigated, NO + attack at the terminal N of Co(NH 3 ) 5 N 3 2+ via the E and the Z isomers of the transition states, and NO + attack at the bound N of azide, also via both isomers. The most favorable pathway proceeds via the attack at the bound N via the Z isomer. This leads to the intermediate with an oxatetrazole ligand bound to Co(III) at the N in the 3-position, Co(NH 3 ) 5 (cycl-N 4 O) 3+ , which undergoes N 2 elimination to yield the Co(NH 3 ) 5 N 2 O 3+ intermediate. The subsequent substitution of N 2 O by water follows the I d mechanism with retention of the configuration. No evidence for the existence of the square-pyramidal pentacoordinated intermediate Co(NH 3 ) 5 3+ was found. All of the investigated intermediates, Co(NH 3 ) 5 N 2 3+ , Co(NH 3 ) 5 [E-N(N 2 )(NO)] 3+ , Co(NH 3 ) 5 (E-ON 4 ) 3+ , Co(NH 3 ) 5 ON 2 3+ , Co(NH 3 ) 5 (cycl-N 4 O) 3+ , and Co(NH 3 ) 5 N 2 O 3+ , exhibit short lifetimes of less than ∼60 μs and react via the I d mechanism.

Some Intermediate-Level Violin Concertos.

Science.gov (United States)

Abramson, Michael

1997-01-01

Contends that many violin students attempt difficult concertos before they are technically or musically prepared. Identifies a variety of concertos at the intermediate and advanced intermediate-level for students to study and master before attempting the advanced works by Bach and Mozart. Includes concertos by Vivaldi, Leclair, Viotti, Haydn,…

Adaptation of red cell enzymes and intermediates in metabolic disorders.

Science.gov (United States)

Goebel, K M; Goebel, F D; Neitzert, A; Hausmann, L; Schneider, J

1975-01-01

The metabolic activity of the red cell glycolytic pathway hexose monophosphate shunt (HMP) with dependent glutathione system was studied in patients with hyperthyroidism (n = 10), hyperlipoproteinemia (n = 16), hypoglycemia (n = 25) and hyperglycemia (n = 23). In uncontrolled diabetics and patients with hyperthyroidism the mean value of glucose phosphate isomerase (GPI), glucose-6-phosphate dehydrogenase (G-6-PD), glutathione reductase (GR) was increased, whereas these enzyme activities were reduced in patients with hypoglycemia. Apart from a few values of hexokinase (HK) which were lower than normal the results in hyperlipoproteinemia patients remained essentially unchanged, including the intermediates such as 2,3-diphosphoglycerate (2,3-DPG), adenosine triphosphate (ATP) and reduced glutathione (GSH). While increased rates of 2,3-DPG and ATP in hypoglycemia patients were obtained, these substrates were markedly reduced in diabetics.

Quantitative importance of the pentose phosphate pathway determined by incorporation of 13C from [2-13C]- and [3-13C]glucose into TCA cycle intermediates and neurotransmitter amino acids in functionally intact neurons.

Science.gov (United States)

Brekke, Eva M F; Walls, Anne B; Schousboe, Arne; Waagepetersen, Helle S; Sonnewald, Ursula

2012-09-01

The brain is highly susceptible to oxidative injury, and the pentose phosphate pathway (PPP) has been shown to be affected by pathological conditions, such as Alzheimer's disease and traumatic brain injury. While this pathway has been investigated in the intact brain and in astrocytes, little is known about the PPP in neurons. The activity of the PPP was quantified in cultured cerebral cortical and cerebellar neurons after incubation in the presence of [2-(13)C]glucose or [3-(13)C]glucose. The activity of the PPP was several fold lower than glycolysis in both types of neurons. While metabolism of (13)C-labeled glucose via the PPP does not appear to contribute to the production of releasable lactate, it contributes to labeling of tricarboxylic acid (TCA) cycle intermediates and related amino acids. Based on glutamate isotopomers, it was calculated that PPP activity accounts for ~6% of glucose metabolism in cortical neurons and ~4% in cerebellar neurons. This is the first demonstration that pyruvate generated from glucose via the PPP contributes to the synthesis of acetyl CoA for oxidation in the TCA cycle. Moreover, the fact that (13)C labeling from glucose is incorporated into glutamate proves that both the oxidative and the nonoxidative stages of the PPP are active in neurons.

Photonic intermediate layer for silicon tandem solar cells

Energy Technology Data Exchange (ETDEWEB)

Bielawny, Andreas; Miclea, Paul-Tiberiu; Wehrspohn, Ralf [Martin-Luther Universitaet Halle-Wittenberg (Germany). Inst. fuer Physik, Mikro-MD; Lee, Seuong-Mo; Knez, Mato [Max-Planck-Inst. fuer Mikrostrukturphysik, Halle (Germany); Carius, Reinhard [Forschungszentrum Juelich (DE). Inst. fuer Photovoltaik (IEF-5); Lisca, Marian; Rockstuhl, Carsten; Lederer, Falk [Universitaet Jena (Germany). Dept. Physik

2008-07-01

The concept of incorporation of a 3D photonic crystal as diffractive spectral filter within a-Si/mc-Si tandem solar cells has been investigated as a promising application. Our intermediate reflective filter enhances the pathway of spectrally selected light within an amorphous silicon top cell in its spectral region of low absorption. From our previous work, we expect a significant improvement of the tandem's efficiency of about 1.2%(absolute). This increases efficiency for a typical silicon tandem cell from 11.2% to 12.4%, as a result of the optical current-matching of the two junctions. Our wavelength-selective optical element is a 3D-structured optical thin-film - prepared by self-organized artificial opal templates and finalized with atomic layer deposition techniques. The resulting samples are highly periodical thin-film inverted opals made of zinc-oxide. We compare recent experimental data on the optical properties with our simulations and photonic bandstructure calculations.

Welding. Performance Objectives. Intermediate Course.

Science.gov (United States)

Vincent, Kenneth

Several intermediate performance objectives and corresponding criterion measures are listed for each of nine terminal objectives for an intermediate welding course. The materials were developed for a 36-week (3 hours daily) course designed to prepare the student for employment in the field of welding. Electric welding and specialized (TIG & MIG)…

Synthetic lethality between gene defects affecting a single non-essential molecular pathway with reversible steps.

Directory of Open Access Journals (Sweden)

Andrei Zinovyev

2013-04-01

Full Text Available Systematic analysis of synthetic lethality (SL constitutes a critical tool for systems biology to decipher molecular pathways. The most accepted mechanistic explanation of SL is that the two genes function in parallel, mutually compensatory pathways, known as between-pathway SL. However, recent genome-wide analyses in yeast identified a significant number of within-pathway negative genetic interactions. The molecular mechanisms leading to within-pathway SL are not fully understood. Here, we propose a novel mechanism leading to within-pathway SL involving two genes functioning in a single non-essential pathway. This type of SL termed within-reversible-pathway SL involves reversible pathway steps, catalyzed by different enzymes in the forward and backward directions, and kinetic trapping of a potentially toxic intermediate. Experimental data with recombinational DNA repair genes validate the concept. Mathematical modeling recapitulates the possibility of kinetic trapping and revealed the potential contributions of synthetic, dosage-lethal interactions in such a genetic system as well as the possibility of within-pathway positive masking interactions. Analysis of yeast gene interaction and pathway data suggests broad applicability of this novel concept. These observations extend the canonical interpretation of synthetic-lethal or synthetic-sick interactions with direct implications to reconstruct molecular pathways and improve therapeutic approaches to diseases such as cancer.

A STUDY OF INTERMEDIATES INVOLVED IN THE FOLDING PATHWAY FOR RECOMBINANT HUMAN MACROPHAGE COLONY-STIMULATING FACTOR (M-CSF) - EVIDENCE FOR 2 DISTINCT FOLDING PATHWAYS

NARCIS (Netherlands)

WILKINS, JA; CONE, J; RANDHAWA, ZI; WOOD, D; WARREN, MK; WITKOWSKA, HE

The folding pathway for a 150-amino acid recombinant form of the dimeric cytokine human macrophage colony-stimulating factor (M-CSF) has been studied. All 14 cysteine residues in the biologically active homodimer are involved in disulfide linkages. The structural characteristics of folding

Metal-Free α-C(sp3–H Functionalized Oxidative Cyclization of Tertiary N,N-Diaryl Amino Alcohols: Theoretical Approach for Mechanistic Pathway

Directory of Open Access Journals (Sweden)

Zakir Ullah

2017-03-01

Full Text Available The mechanistic pathway of TEMPO/I2-mediated oxidative cyclization of N,N-diaryl amino alcohols 1 was investigated. Based on direct empirical experiments, three key intermediates (aminium radical cation 3, α-aminoalkyl radical 4, and iminium 5, four types of reactive species (radical TEMPO, cationic TEMPO, TEMPO-I, and iodo radical, and three types of pathways ((1 SET/PCET mechanism; (2 HAT/1,6-H transfer mechanism; (3 ionic mechanism were assumed. Under the assumption, nine free energy diagrams were acquired through density functional theory calculations. From the comparison of solution-phase free energy, some possible mechanisms were excluded, and then the chosen plausible mechanisms were concretized using the more stable intermediate 7.

Money distribution with intermediation

OpenAIRE

Teles, Caio Augusto Colnago

2013-01-01

This pap er analyzes the distribution of money holdings in a commo dity money search-based mo del with intermediation. Intro ducing heterogeneity of costs to the Kiyotaki e Wright ( 1989 ) mo del, Cavalcanti e Puzzello ( 2010) gives rise to a non-degenerated distribution of money. We extend further this mo del intro ducing intermediation in the trading pro cess. We show that the distribution of money matters for savings decisions. This gives rises to a xed p oint problem for the ...

Pyrite formation and mineral transformation pathways upon sulfidation of ferric hydroxides depend on mineral type and sulfide concentration

NARCIS (Netherlands)

Peiffer, Stefan; Behrends, Thilo; Hellige, Katrin; Larese-Casanova, Philip; Wan, Moli; Pollok, Kilian

2015-01-01

The reaction of ferric (hydr)oxides with dissolved sulfide does not lead to the instantaneous production of thermodynamically stable products but can induce a variety of mineral transformations including the formation of metastable intermediates. The importance of the various transformation pathways

Search for intermediate vector bosons

International Nuclear Information System (INIS)

Klajn, D.B.; Rubbia, K.; Meer, S.

1983-01-01

Problem of registration and search for intermediate vector bosons is discussed. According to weak-current theory there are three intermediate vector bosons with +1(W + )-1(W - ) and zero (Z 0 ) electric charges. It was suggested to conduct the investigation into particles in 1976 by cline, Rubbia and Makintair using proton-antiproton beams. Major difficulties of the experiment are related to the necessity of formation of sufficient amount of antiparticles and the method of antiproton beam ''cooling'' for the purpose of reduction of its random movements. The stochastic method was suggested by van der Meer in 1968 as one of possible cooling methods. Several large detectors were designed for searching intermediate vector bosons

Validation of intermediate end points in cancer research.

Science.gov (United States)

Schatzkin, A; Freedman, L S; Schiffman, M H; Dawsey, S M

1990-11-21

Investigations using intermediate end points as cancer surrogates are quicker, smaller, and less expensive than studies that use malignancy as the end point. We present a strategy for determining whether a given biomarker is a valid intermediate end point between an exposure and incidence of cancer. Candidate intermediate end points may be selected from case series, ecologic studies, and animal experiments. Prospective cohort and sometimes case-control studies may be used to quantify the intermediate end point-cancer association. The most appropriate measure of this association is the attributable proportion. The intermediate end point is a valid cancer surrogate if the attributable proportion is close to 1.0, but not if it is close to 0. Usually, the attributable proportion is close to neither 1.0 nor 0; in this case, valid surrogacy requires that the intermediate end point mediate an established exposure-cancer relation. This would in turn imply that the exposure effect would vanish if adjusted for the intermediate end point. We discuss the relative advantages of intervention and observational studies for the validation of intermediate end points. This validation strategy also may be applied to intermediate end points for adverse reproductive outcomes and chronic diseases other than cancer.

A Single Enzyme Transforms a Carboxylic Acid into a Nitrile through an Amide Intermediate.

Science.gov (United States)

Nelp, Micah T; Bandarian, Vahe

2015-09-01

The biosynthesis of nitriles is known to occur through specialized pathways involving multiple enzymes; however, in bacterial and archeal biosynthesis of 7-deazapurines, a single enzyme, ToyM, catalyzes the conversion of the carboxylic acid containing 7-carboxy-7-deazaguanine (CDG) into its corresponding nitrile, 7-cyano-7-deazaguanine (preQ0 ). The mechanism of this unusual direct transformation was shown to proceed via the adenylation of CDG, which activates it to form the newly discovered amide intermediate 7-amido-7-deazaguanine (ADG). This is subsequently dehydrated to form the nitrile in a process that consumes a second equivalent of ATP. The authentic amide intermediate is shown to be chemically and kinetically competent. The ability of ToyM to activate two different substrates, an acid and an amide, accounts for this unprecedented one-enzyme catalysis of nitrile synthesis, and the differential rates of these two half reactions suggest that this catalytic ability is derived from an amide synthetase that gained a new function. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Biocatalytic Synthesis of Chiral Pharmaceutical Intermediates

Directory of Open Access Journals (Sweden)

Ramesh N. Patel

2004-01-01

Full Text Available The production of single enantiomers of drug intermediates has become increasingly important in the pharmaceutical industry. Chiral intermediates and fine chemicals are in high demand from both the pharmaceutical and agrochemical industries for the preparation of bulk drug substances and agricultural products. The enormous potential of microorganisms and enzymes for the transformation of synthetic chemicals with high chemo-, regio- and enantioselectivities has been demonstrated. In this article, biocatalytic processes are described for the synthesis of chiral pharmaceutical intermediates.

Simplifying biochemical models with intermediate species

DEFF Research Database (Denmark)

Feliu, Elisenda; Wiuf, Carsten

2013-01-01

techniques, we study systematically the effects of intermediate, or transient, species in biochemical systems and provide a simple, yet rigorous mathematical classification of all models obtained from a core model by including intermediates. Main examples include enzymatic and post-translational modification...... systems, where intermediates often are considered insignificant and neglected in a model, or they are not included because we are unaware of their existence. All possible models obtained from the core model are classified into a finite number of classes. Each class is defined by a mathematically simple...... canonical model that characterizes crucial dynamical properties, such as mono- and multistationarity and stability of steady states, of all models in the class. We show that if the core model does not have conservation laws, then the introduction of intermediates does not change the steady...

Combined quantum mechanical and molecular mechanical reaction pathway calculation for aromatic hydroxylation by p-hydroxybenzoate-3-hydroxylase

NARCIS (Netherlands)

Ridder, L.; Mulholland, A.; Rietjens, I.M.C.M.; Vervoort, J.

1999-01-01

The reaction pathway for the aromatic 3-hydroxylation of p-hydroxybenzoate by the reactive C4a-hydroperoxyflavin cofactor intermediate in p-hydroxybenzoate hydroxylase (PHBH) has been investigated by a combined quantum mechanical and molecular mechanical (QM/MM) method. A structural model for the

Reactions of stabilized Criegee Intermediates

Science.gov (United States)

Vereecken, Luc; Harder, Hartwig; Novelli, Anna

2014-05-01

Carbonyl oxides (Criegee intermediates) were proposed as key intermediates in the gas phase ozonolysis of alkenes in 1975 by Rudolf Criegee. Despite the importance of ozonolysis in atmospheric chemistry, direct observation of these intermediates remained elusive, with only indirect experimental evidence for their role in the oxidation of hydrocarbons, e.g. through scavenging experiments. Direct experimental observation of stabilized CI has only been achieved since 2008. Since then, a concerted effort using experimental and theoretical means is in motion to characterize the chemistry and kinetics of these reactive intermediates. We present the results of theoretical investigations of the chemistry of Criegee intermediates with a series of coreactants which may be of importance in the atmosphere, in experimental setups, or both. This includes the CI+CI cross-reaction, which proceeds with a rate coefficient near the collision limit and can be important in experimental conditions. The CI + alkene reactions show strong dependence of the rate coefficient depending on the coreactants, but is generally found to be rather slow. The CI + ozone reaction is sufficiently fast to occur both in experiment and the free troposphere, and acts as a sink for CI. The reaction of CI with hydroperoxides, ROOH, is complex, and leads both to the formation of oligomers, as to the formation of reactive etheroxides, with a moderately fast rate coefficient. The importance of these reactions is placed in the context of the reaction conditions in different atmospheric environments ranging from unpolluted to highly polluted.

The intermediate endpoint effect in logistic and probit regression

Science.gov (United States)

MacKinnon, DP; Lockwood, CM; Brown, CH; Wang, W; Hoffman, JM

2010-01-01

Background An intermediate endpoint is hypothesized to be in the middle of the causal sequence relating an independent variable to a dependent variable. The intermediate variable is also called a surrogate or mediating variable and the corresponding effect is called the mediated, surrogate endpoint, or intermediate endpoint effect. Clinical studies are often designed to change an intermediate or surrogate endpoint and through this intermediate change influence the ultimate endpoint. In many intermediate endpoint clinical studies the dependent variable is binary, and logistic or probit regression is used. Purpose The purpose of this study is to describe a limitation of a widely used approach to assessing intermediate endpoint effects and to propose an alternative method, based on products of coefficients, that yields more accurate results. Methods The intermediate endpoint model for a binary outcome is described for a true binary outcome and for a dichotomization of a latent continuous outcome. Plots of true values and a simulation study are used to evaluate the different methods. Results Distorted estimates of the intermediate endpoint effect and incorrect conclusions can result from the application of widely used methods to assess the intermediate endpoint effect. The same problem occurs for the proportion of an effect explained by an intermediate endpoint, which has been suggested as a useful measure for identifying intermediate endpoints. A solution to this problem is given based on the relationship between latent variable modeling and logistic or probit regression. Limitations More complicated intermediate variable models are not addressed in the study, although the methods described in the article can be extended to these more complicated models. Conclusions Researchers are encouraged to use an intermediate endpoint method based on the product of regression coefficients. A common method based on difference in coefficient methods can lead to distorted

Density Functional Theory Study of Competitive Reaction Pathways of Ti+ with Fluorinated Acetone in the Gas Phase

International Nuclear Information System (INIS)

Hong, Kiryong; Kim, Tae Kyu

2012-01-01

We investigate the doublet and quartet potential energy surfaces associated with the gas-phase reaction between Ti + and CF 3 COCH 3 for two plausible reaction pathways, TiF 2 + and TiO + formation pathways by using the density functional theory (DFT) method. The molecular structures of intermediates and transition states involved in these reaction pathways are optimized at the DFT level by using the PBE0 functional. All transition states are identified by using the intrinsic reaction coordinate (IRC) method, and the resulting reaction coordinates describe how Ti + activates CF 3 COCH 3 and produces TiF 2 + and TiO + as products. On the basis of presented results, we propose the most favorable reaction pathway in the reaction between Ti + and CF 3 COCH 3

Photosynthetic carbon metabolism in seagrasses C-labeling evidence for the c(3) pathway.

Science.gov (United States)

Andrews, T J; Abel, K M

1979-04-01

The delta(13)C values of several seagrasses were considerably less negative than those of terrestrial C(3) plants and tended toward those of terrestrial C(4) plants. However, for Thalassia hemprichii (Ehrenb.) Aschers and Halophila spinulosa (R. Br.) Aschers, phosphoglycerate and other C(3) cycle intermediates predominated among the early labeled products of photosynthesis in (14)C-labeled seawater (more than 90% at the earliest times) and the labeling pattern at longer times was brought about by the operation of the C(3) pathway. Malate and aspartate together accounted for only a minor fraction of the total fixed label at all times and the kinetic data of this labeling were not at all consistent with these compounds being early intermediates in seagrass photosynthesis. Pulse-chase (14)C-labeling studies further substantiated these conclusions. Significant labeling of photorespiratory intermediates was observed in all experiments. The kinetics of total fixation of label during some steady-state and pulse-chase experiments suggested that there may be an intermediate pool of inorganic carbon of variable size closely associated with the leaves, either externally or internally. Such a pool may be one cause for the C(4)-like carbon isotope ratios of seagrasses.

Chemically activated formation of organic acids in reactions of the Criegee intermediate with aldehydes and ketones.

Science.gov (United States)

Jalan, Amrit; Allen, Joshua W; Green, William H

2013-10-21

Reactions of the Criegee intermediate (CI, ˙CH2OO˙) are important in atmospheric ozonolysis models. In this work, we compute the rates for reactions between ˙CH2OO˙ and HCHO, CH3CHO and CH3COCH3 leading to the formation of secondary ozonides (SOZ) and organic acids. Relative to infinitely separated reactants, the SOZ in all three cases is found to be 48-51 kcal mol(-1) lower in energy, formed via 1,3-cycloaddition of ˙CH2OO˙ across the C=O bond. The lowest energy pathway found for SOZ decomposition is intramolecular disproportionation of the singlet biradical intermediate formed from cleavage of the O-O bond to form hydroxyalkyl esters. These hydroxyalkyl esters undergo concerted decomposition providing a low energy pathway from SOZ to acids. Geometries and frequencies of all stationary points were obtained using the B3LYP/MG3S DFT model chemistry, and energies were refined using RCCSD(T)-F12a/cc-pVTZ-F12 single-point calculations. RRKM calculations were used to obtain microcanonical rate coefficients (k(E)) and the reservoir state method was used to obtain temperature and pressure dependent rate coefficients (k(T, P)) and product branching ratios. At atmospheric pressure, the yield of collisionally stabilized SOZ was found to increase in the order HCHO reactions were found to be the most sensitive parameters determining SOZ and organic acid yield.

Gravity with Intermediate Goods Trade

Directory of Open Access Journals (Sweden)

Sujin Jang

2017-12-01

Full Text Available This paper derives the gravity equation with intermediate goods trade. We extend a standard monopolistic competition model to incorporate intermediate goods trade, and show that the gravity equation with intermediates trade is identical to the one without it except in that gross output should be used as the output measure instead of value added. We also show that the output elasticity of trade is significantly underestimated when value added is used as the output measure. This implies that with the conventional gravity equation, the contribution of output growth can be substantially underestimated and the role of trade costs reduction can be exaggerated in explaining trade expansion, as we demonstrate for the case of Korea's trade growth between 1995 and 2007.

Electronic patient information systems and care pathways: the organisational challenges of implementation and integration.

Science.gov (United States)

Dent, Mike; Tutt, Dylan

2014-09-01

Our interest here is with the 'marriage' of e-patient information systems with care pathways in order to deliver integrated care. We report on the development and implementation of four such pathways within two National Health Service primary care trusts in England: (a) frail elderly care, (b) stroke care, (c) diabetic retinopathy screening and (d) intermediate care. The pathways were selected because each represents a different type of information and data 'couplings', in terms of task interdependency with some pathways/systems reflecting more complex coordinating patterns than others. Our aim here is identify and explain how health professionals and information specialists in two organisational National Health Service primary care trusts organisationally construct and use such systems and, in particular, the implications this has for issues of professional and managerial control and autonomy. The article is informed by an institutionalist analysis. © The Author(s) 2013.

First-principles calculated decomposition pathways for LiBH4 nanoclusters

Science.gov (United States)

Huang, Zhi-Quan; Chen, Wei-Chih; Chuang, Feng-Chuan; Majzoub, Eric H.; Ozoliņš, Vidvuds

2016-05-01

We analyze thermodynamic stability and decomposition pathways of LiBH4 nanoclusters using grand-canonical free-energy minimization based on total energies and vibrational frequencies obtained from density-functional theory (DFT) calculations. We consider (LiBH4)n nanoclusters with n = 2 to 12 as reactants, while the possible products include (Li)n, (B)n, (LiB)n, (LiH)n, and Li2BnHn; off-stoichiometric LinBnHm (m ≤ 4n) clusters were considered for n = 2, 3, and 6. Cluster ground-state configurations have been predicted using prototype electrostatic ground-state (PEGS) and genetic algorithm (GA) based structural optimizations. Free-energy calculations show hydrogen release pathways markedly differ from those in bulk LiBH4. While experiments have found that the bulk material decomposes into LiH and B, with Li2B12H12 as a kinetically inhibited intermediate phase, (LiBH4)n nanoclusters with n ≤ 12 are predicted to decompose into mixed LinBn clusters via a series of intermediate clusters of LinBnHm (m ≤ 4n). The calculated pressure-composition isotherms and temperature-pressure isobars exhibit sloping plateaus due to finite size effects on reaction thermodynamics. Generally, decomposition temperatures of free-standing clusters are found to increase with decreasing cluster size due to thermodynamic destabilization of reaction products.

Mobile communication and intermediality

DEFF Research Database (Denmark)

Helles, Rasmus

2013-01-01

communicative affordances of mobile devices in order to understand how people choose between them for different purposes. It is argued that mobile communication makes intermediality especially central, as the choice of medium is detached from the location of stationary media and begins to follow the user across......The article argues the importance of intermediality as a concept for research in mobile communication and media. The constant availability of several, partially overlapping channels for communication (texting, calls, email, Facebook, etc.) requires that we adopt an integrated view of the various...

RNase MRP is required for entry of 35S precursor rRNA into the canonical processing pathway.

Science.gov (United States)

Lindahl, Lasse; Bommankanti, Ananth; Li, Xing; Hayden, Lauren; Jones, Adrienne; Khan, Miriam; Oni, Tolulope; Zengel, Janice M

2009-07-01

RNase MRP is a nucleolar RNA-protein enzyme that participates in the processing of rRNA during ribosome biogenesis. Previous experiments suggested that RNase MRP makes a nonessential cleavage in the first internal transcribed spacer. Here we report experiments with new temperature-sensitive RNase MRP mutants in Saccharomyces cerevisiae that show that the abundance of all early intermediates in the processing pathway is severely reduced upon inactivation of RNase MRP. Transcription of rRNA continues unabated as determined by RNA polymerase run-on transcription, but the precursor rRNA transcript does not accumulate, and appears to be unstable. Taken together, these observations suggest that inactivation of RNase MRP blocks cleavage at sites A0, A1, A2, and A3, which in turn, prevents precursor rRNA from entering the canonical processing pathway (35S > 20S + 27S > 18S + 25S + 5.8S rRNA). Nevertheless, at least some cleavage at the processing site in the second internal transcribed spacer takes place to form an unusual 24S intermediate, suggesting that cleavage at C2 is not blocked. Furthermore, the long form of 5.8S rRNA is made in the absence of RNase MRP activity, but only in the presence of Xrn1p (exonuclease 1), an enzyme not required for the canonical pathway. We conclude that RNase MRP is a key enzyme for initiating the canonical processing of precursor rRNA transcripts, but alternative pathway(s) might provide a backup for production of small amounts of rRNA.

Hyperthermophilic Archaeon Thermococcus kodakarensis Utilizes a Four-Step Pathway for NAD+ Salvage through Nicotinamide Deamination.

Science.gov (United States)

Hachisuka, Shin-Ichi; Sato, Takaaki; Atomi, Haruyuki

2018-06-01

hyperthermophilic archaeon Thermococcus kodakarensis The organism utilizes a four-step pathway that initially hydrolyzes the amide bond of Nm to generate nicotinic acid (Na), followed by phosphoribosylation, adenylylation, and amidation. Although the two-step pathway, consisting of only phosphoribosylation of Nm and adenylylation, seems to be more efficient, Nm mononucleotide in the two-step pathway is much more thermolabile than Na mononucleotide, the corresponding intermediate in the four-step pathway. Although NAD + itself is thermolabile, this may represent an example of a metabolism that has evolved to avoid the use of thermolabile intermediates. Copyright © 2018 American Society for Microbiology.

Characterization of 16S rRNA Processing with Pre-30S Subunit Assembly Intermediates from E. coli.

Science.gov (United States)

Smith, Brian A; Gupta, Neha; Denny, Kevin; Culver, Gloria M

2018-06-08

Ribosomal RNA (rRNA) is a major component of ribosomes and is fundamental to the process of translation. In bacteria, 16S rRNA is a component of the small ribosomal subunit and plays a critical role in mRNA decoding. rRNA maturation entails the removal of intervening spacer sequences contained within the pre-rRNA transcript by nucleolytic enzymes. Enzymatic activities involved in maturation of the 5'-end of 16S rRNA have been identified, but those involved in 3'-end maturation of 16S rRNA are more enigmatic. Here, we investigate molecular details of 16S rRNA maturation using purified in vivo-formed small subunit (SSU) assembly intermediates (pre-SSUs) from wild-type Escherichia coli that contain precursor 16S rRNA (17S rRNA). Upon incubation of pre-SSUs with E. coli S100 cell extracts or purified enzymes implicated in 16S rRNA processing, the 17S rRNA is processed into additional intermediates and mature 16S rRNA. These results illustrate that exonucleases RNase R, RNase II, PNPase, and RNase PH can process the 3'-end of pre-SSUs in vitro. However, the endonuclease YbeY did not exhibit nucleolytic activity with pre-SSUs under these conditions. Furthermore, these data demonstrate that multiple pathways facilitate 16S rRNA maturation with pre-SSUs in vitro, with the dominant pathways entailing complete processing of the 5'-end of 17S rRNA prior to 3'-end maturation or partial processing of the 5'-end with concomitant processing of the 3'-end. These results reveal the multifaceted nature of SSU biogenesis and suggest that E. coli may be able to escape inactivation of any one enzyme by using an existing complementary pathway. Copyright © 2018 Elsevier Ltd. All rights reserved.

Classical model of intermediate statistics

International Nuclear Information System (INIS)

Kaniadakis, G.

1994-01-01

In this work we present a classical kinetic model of intermediate statistics. In the case of Brownian particles we show that the Fermi-Dirac (FD) and Bose-Einstein (BE) distributions can be obtained, just as the Maxwell-Boltzmann (MD) distribution, as steady states of a classical kinetic equation that intrinsically takes into account an exclusion-inclusion principle. In our model the intermediate statistics are obtained as steady states of a system of coupled nonlinear kinetic equations, where the coupling constants are the transmutational potentials η κκ' . We show that, besides the FD-BE intermediate statistics extensively studied from the quantum point of view, we can also study the MB-FD and MB-BE ones. Moreover, our model allows us to treat the three-state mixing FD-MB-BE intermediate statistics. For boson and fermion mixing in a D-dimensional space, we obtain a family of FD-BE intermediate statistics by varying the transmutational potential η BF . This family contains, as a particular case when η BF =0, the quantum statistics recently proposed by L. Wu, Z. Wu, and J. Sun [Phys. Lett. A 170, 280 (1992)]. When we consider the two-dimensional FD-BE statistics, we derive an analytic expression of the fraction of fermions. When the temperature T→∞, the system is composed by an equal number of bosons and fermions, regardless of the value of η BF . On the contrary, when T=0, η BF becomes important and, according to its value, the system can be completely bosonic or fermionic, or composed both by bosons and fermions

Hydrogen sulfide oxidation without oxygen - oxidation products and pathways

International Nuclear Information System (INIS)

Fossing, H.

1992-01-01

Hydrogen sulfide oxidation was studied in anoxic marine sediments-both in undisturbed sediment cores and in sediment slurries. The turn over of hydrogen sulfide was followed using 35 S-radiolabeled hydrogen sulfide which was injected into the sediment. However, isotope exchange reactions between the reduced sulfur compounds, in particular between elemental sulfur and hydrogen sulfide, influenced on the specific radioactivity of these pools. It was, therefore, not possible to measure the turn over rates of the reduced sulfur pools by the radiotracer technique but merely to use the radioisotope to demonstrate some of the oxidation products. Thiosulfate was one important intermediate in the anoxic oxidation of hydrogen sulfide and was continuously turned over by reduction, oxidation and disproportionation. The author discusses the importance of isotope exchange and also presents the results from experiments in which both 35 S-radiolabeled elemental sulfur, radiolabeled hydrogen sulfide and radiolabeled thiosulfate were used to study the intermediates in the oxidative pathways of the sulfur cycle

Using Peephole Optimization on Intermediate Code

NARCIS (Netherlands)

Tanenbaum, A.S.; van Staveren, H.; Stevenson, J.W.

1982-01-01

Many portable compilers generate an intermediate code that is subsequently translated into the target machine's assembly language. In this paper a stack-machine-based intermediate code suitable for algebraic languages (e.g., PASCAL, C, FORTRAN) and most byte-addressed mini- and microcomputers is

Pair production of intermediate vector bosons

International Nuclear Information System (INIS)

Mikaelian, K.O.

1979-01-01

The production of intermediate vector boson pairs W + W - , Z 0 Z 0 , W +- Z 0 and W +- γ in pp and p anti p collisions is discussed. The motivation is to detect the self-interactions among the four intermediate vector bosons

Exploring the Unfolding Pathway of Maltose Binding Proteins: An Integrated Computational Approach

KAUST Repository

Guardiani, Carlo; Marino, Daniele Di; Tramontano, Anna; Chinappi, Mauro; Cecconi, Fabio

2014-01-01

© 2014 American Chemical Society. Recent single-molecule force spectroscopy experiments on the Maltose Binding Proteins (MBPs) identified four stable structural units, termed unfoldons, that resist mechanical stress and determine the intermediates of the unfolding pathway. In this work, we analyze the topological origin and the dynamical role of the unfoldons using an integrated approach which combines a graph-theoretical analysis of the interaction network of the MBP native-state with steered molecular dynamics simulations. The topological analysis of the native state, while revealing the structural nature of the unfoldons, provides a framework to interpret the MBP mechanical unfolding pathway. Indeed, the experimental pathway can be effectively predicted by means of molecular dynamics simulations with a simple topology-based and low-resolution model of the MBP. The results obtained from the coarse-grained approach are confirmed and further refined by all-atom molecular dynamics.

Exploring the Unfolding Pathway of Maltose Binding Proteins: An Integrated Computational Approach

KAUST Repository

Guardiani, Carlo

2014-09-09

© 2014 American Chemical Society. Recent single-molecule force spectroscopy experiments on the Maltose Binding Proteins (MBPs) identified four stable structural units, termed unfoldons, that resist mechanical stress and determine the intermediates of the unfolding pathway. In this work, we analyze the topological origin and the dynamical role of the unfoldons using an integrated approach which combines a graph-theoretical analysis of the interaction network of the MBP native-state with steered molecular dynamics simulations. The topological analysis of the native state, while revealing the structural nature of the unfoldons, provides a framework to interpret the MBP mechanical unfolding pathway. Indeed, the experimental pathway can be effectively predicted by means of molecular dynamics simulations with a simple topology-based and low-resolution model of the MBP. The results obtained from the coarse-grained approach are confirmed and further refined by all-atom molecular dynamics.

Kinetic analysis of human CYP24A1 metabolism of vitamin D via the C24-oxidation pathway.

Science.gov (United States)

Tieu, Elaine W; Tang, Edith K Y; Tuckey, Robert C

2014-07-01

CYP24A1 is the multicatalytic cytochrome P450 responsible for the catabolism of vitamin D via the C23- and C24-oxidation pathways. We successfully expressed the labile human enzyme in Escherichia coli and partially purified it in an active state that permitted detailed characterization of its metabolism of 1,25-dihydroxyvitamin D3 [1,25(OH)2 D3] and the intermediates of the C24-oxidation pathway in a phospholipid-vesicle reconstituted system. The C24-oxidation pathway intermediates, 1,24,25-trihydroxyvitamin D3, 24-oxo-1,25-dihydroxyvitamin D3, 24-oxo-1,23,25-trihydroxyvitamin D3 and tetranor-1,23-dihydroxyvitamin D3, were enzymatically produced from 1,25(OH)2 D3 using rat CYP24A1. Both 1,25(OH)2 D3 and 1,23-dihydroxy-24,25,26,27-tetranorvitamin D3 were found to partition strongly into the phospholipid bilayer when in aqueous medium. Changes to the phospholipid concentration did not affect the kinetic parameters for the metabolism of 1,25(OH)2 D3 by CYP24A1, indicating that it is the concentration of substrates in the membrane phase (mol substrate·mol phospholipid(-1) ) that determines their rate of metabolism. CYP24A1 exhibited Km values for the different C24-intermediates ranging from 0.34 to 15 mmol·mol phospholipid(-1) , with 24-oxo-1,23,25-trihydroxyvitamin D3 [24-oxo-1,23,25(OH)3 D3] displaying the lowest and 1,24,25-trihydroxyvitamin D3 [1,24,25(OH)3 D3] displaying the highest. The kcat values varied by up to 3.8-fold, with 1,24,25(OH)3 D3 displaying the highest kcat (34 min(-1) ) and 24-oxo-1,23,25(OH)3 D3 the lowest. The data show that the cleavage of the side chain of 24-oxo-1,23,25(OH)3 D3 occurs with the highest catalytic efficiency (kcat /Km ) and produces 1-hydroxy-23-oxo-24,25,26,27-tetranorvitamin D3 and not 1,23-dihydroxy-24,25,26,27-tetranorvitamin D3, as the primary product. These kinetic analyses also show that intermediates of the C24-oxidation pathway effectively compete with precursor substrates for binding to the active site of the

Language in use intermediate : classroom book

CERN Document Server

Doff, Adrian

1995-01-01

ach of the four levels comprises about 80 hours of class work, with additional time for the self-study work. The Teacher's Book contains all the pages from the Classroom Book, with interleaved teaching notes including optional activities to cater for different abilities. There is a video to accompany the Beginner, Pre-intermediate and Intermediate levels. Each video contains eight stimulating and entertaining short programmes, as well as a booklet of photocopiable activities. Free test material is available in booklet and web format for Beginner and Pre-intermediate levels. Visit www.cambridge.org/elt/liu or contact your local Cambridge University Press representative.

Language in use intermediate : teacher's book

CERN Document Server

Doff, Adrian

1998-01-01

Each of the four levels comprises about 80 hours of class work, with additional time for the self-study work. The Teacher's Book contains all the pages from the Classroom Book, with interleaved teaching notes including optional activities to cater for different abilities. There is a video to accompany the Beginner, Pre-intermediate and Intermediate levels. Each video contains eight stimulating and entertaining short programmes, as well as a booklet of photocopiable activities. Free test material is available in booklet and web format for Beginner and Pre-intermediate levels. Visit www.cambridge.org/elt/liu or contact your local Cambridge University Press representative.

Product Lifecycle Management and Sustainable Space Exploration

Science.gov (United States)

Caruso, Pamela W.; Dumbacher, Daniel L.; Grieves, Michael

2011-01-01

This slide presentation reviews the use of product lifecycle management (PLM) in the general aerospace industry, its use and development at NASA and at Marshall Space Flight Center, and how the use of PLM can lead to sustainable space exploration.

Interpretation and code generation based on intermediate languages

DEFF Research Database (Denmark)

Kornerup, Peter; Kristensen, Bent Bruun; Madsen, Ole Lehrmann

1980-01-01

The possibility of supporting high level languages through intermediate languages to be used for direct interpretation and as intermediate forms in compilers is investigated. An accomplished project in the construction of an interpreter and a code generator using one common intermediate form...

Novel pathway of SO2 oxidation in the atmosphere: reactions with monoterpene ozonolysis intermediates and secondary organic aerosol

Science.gov (United States)

Ye, Jianhuai; Abbatt, Jonathan P. D.; Chan, Arthur W. H.

2018-04-01

Ozonolysis of monoterpenes is an important source of atmospheric biogenic secondary organic aerosol (BSOA). While enhanced BSOA formation has been associated with sulfate-rich conditions, the underlying mechanisms remain poorly understood. In this work, the interactions between SO2 and reactive intermediates from monoterpene ozonolysis were investigated under different humidity conditions (10 % vs. 50 %). Chamber experiments were conducted with ozonolysis of α-pinene or limonene in the presence of SO2. Limonene SOA formation was enhanced in the presence of SO2, while no significant changes in SOA yields were observed during α-pinene ozonolysis. Under dry conditions, SO2 primarily reacted with stabilized Criegee intermediates (sCIs) produced from ozonolysis, but at 50 % RH heterogeneous uptake of SO2 onto organic aerosol was found to be the dominant sink of SO2, likely owing to reactions between SO2 and organic peroxides. This SO2 loss mechanism to organic peroxides in SOA has not previously been identified in experimental chamber studies. Organosulfates were detected and identified using an electrospray ionization-ion mobility spectrometry-high-resolution time-of-flight mass spectrometer (ESI-IMS-TOF) when SO2 was present in the experiments. Our results demonstrate the synergistic effects between BSOA formation and SO2 oxidation through sCI chemistry and SO2 uptake onto organic aerosol and illustrate the importance of considering the chemistry of organic and sulfur-containing compounds holistically to properly account for their reactive sinks.

Targeted Molecular Dynamics to determine Focal Adhesion Targeting Domain Folding Intermediates

Directory of Open Access Journals (Sweden)

Pallavi Mohanty

2017-10-01

Full Text Available The Focal adhesion kinase (FAT domain of Focal Adhesion Kinase is a four helical bundle known for conformational plasticity. FAT adopts two distinctly different conformations i.e., close (cFAT and arm-exchanged (aeFAT states under native conditions [1]. The slow transition from cFAT to aeFAT is likely to proceed through an open intermediate state that allows YENV motif to attain β-turn conformation and phosphorylation of Y925 by Src kinases [2]. The two end states of FAT are known to interact with Paxillin and are responsible for maintaining steady state in Heart while intermediate conformation interacts with Grb2-SH2 leading to Pathological Cardiac Hypertrophy (PAH [2]. 10ns Targeted Molecular Dynamics (TMD was done between c- and aeFAT in order to explore the conformational transition and to capture pathologically relevant oFAT. Cluster and dynamic cross correlation analysis (DCCA of TMD generated trajectory was done and the selected FAT intermediate was docked with Grb2-SH2 using HADDOCK v2.2 docking followed by molecular dynamics. Conservation analysis of FAT-Grb2 binding site was done using CONSURF [3]. A Pharmacophore FAT-Grb2 complex was generated using SPARKv1.2 and submitted for Virtual screening using BLAZE v4. Drug likeliness and ADMET properties were calculated using MOLINSPIRATION tool. TMD reveals six clusters and DCCA showed positively and negatively correlated region along the transition pathway. Intermediates with competence for Grb2 interaction were docked with Grb2 and best binding complex was further refined. MMPBSA binding energy calculations revealed the best binding pose where the phosphorylated YENV motif of Human FAT interacted with a charged and hydrophobic pocket of Grb2. The conservation analysis showed that the charged pocket was more conserved in comparison with the hydrophobic pocket, hence providing useful insights on binding and specificity determining residues in Grb2. Virtual screening using the pharmacophore

Disposal of high level and intermediate level radioactive wastes

International Nuclear Information System (INIS)

Flowers, R.H.

1991-01-01

The waste products from the nuclear industry are relatively small in volume. Apart from a few minor gaseous and liquid waste streams, containing readily dispersible elements of low radiotoxicity, all these products are processed into stable solid packages for disposal in underground repositories. Because the volumes are small, and because radioactive wastes are latecomers on the industrial scene, a whole new industry with a world-wide technological infrastructure has grown up alongside the nuclear power industry to carry out the waste processing and disposal to very high standards. Some of the technical approaches used, and the Regulatory controls which have been developed, will undoubtedly find application in the future to the management of non-radioactive toxic wastes. The repository site outlined would contain even high-level radioactive wastes and spent fuels being contained without significant radiation dose rates to the public. Water pathway dose rates are likely to be lowest for vitrified high-level wastes with spent PWR fuel and intermediate level wastes being somewhat higher. (author)

Unprecedented Carbonato Intermediates in Cyclic Carbonate Synthesis Catalysed by Bimetallic Aluminium(Salen) Complexes.

Science.gov (United States)

Castro-Osma, José A; North, Michael; Offermans, Willem K; Leitner, Walter; Müller, Thomas E

2016-04-21

The mechanism by which [Al(salen)]2 O complexes catalyse the synthesis of cyclic carbonates from epoxides and carbon dioxide in the absence of a halide cocatalyst has been investigated. Density functional theory (DFT) studies, mass spectrometry and (1) H NMR, (13) C NMR and infrared spectroscopies provide evidence for the formation of an unprecedented carbonato bridged bimetallic aluminium complex which is shown to be a key intermediate for the halide-free synthesis of cyclic carbonates from epoxides and carbon dioxide. Deuterated and enantiomerically-pure epoxides were used to study the reaction pathway. Based on the experimental and theoretical results, a catalytic cycle is proposed. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Altered dopamine levels induced by the parasite Profilicollis antarcticus on its intermediate host, the crab Hemigrapsus crenulatus

Directory of Open Access Journals (Sweden)

JOSÉ MIGUEL ROJAS

2005-01-01

Full Text Available A serotonergic pathway is apparently involved in parasite-host interactions. Previous studies conducted in our laboratory showed increased rates in oxygen consumption and alterations in body posture in the crab Hemigrapsus crenulatus parasitized by the acanthocephalan, Profilicollis antarcticus. Such changes may be related to the functions described for biogenic amines in crustaceans. During the infective stage the acanthocephalans live freely in the hemocelomic cavity, suggesting that the possible alteration induced by biogenic amines may be related to their neurohormonal function in crustaceans. To test whether the presence of P. antarcticus produced neurohormonal changes in its intermediate host, H. crenulatus, we analyzed serotonin and dopamine levels in the host using HPLC with electrochemical detection. Two groups of 11 female crabs were studied; one group was artificially inoculated with two cystacanths while the other was used as the control. Our results show a dramatic increase in hemolymph dopamine, but not serotonin in H. crenulatus parasitized by the acanthocephalan P. antarcticus. Our results, along with those reported by Maynard (1996, suggest a parasite-specific strategy involved in the behavior alteration caused by the acanthocephalans on their intermediate host. The use of a biogenic amine as a mechanism of interaction by the parasites gives them an endless number of alternative potential actions on their intermediate hosts

Altered dopamine levels induced by the parasite Profilicollis antarcticus on its intermediate host, the crab Hemigrapsus crenulatus.

Science.gov (United States)

Rojas, José Miguel; Ojeda, F Patricio

2005-01-01

A serotonergic pathway is apparently involved in parasite-host interactions. Previous studies conducted in our laboratory showed increased rates in oxygen consumption and alterations in body posture in the crab Hemigrapsus crenulatus parasitized by the acanthocephalan, Profilicollis antarcticus. Such changes may be related to the functions described for biogenic amines in crustaceans. During the infective stage the acanthocephalans live freely in the hemocelomic cavity, suggesting that the possible alteration induced by biogenic amines may be related to their neurohormonal function in crustaceans. To test whether the presence of P. antarcticus produced neurohormonal changes in its intermediate host, H. crenulatus, we analyzed serotonin and dopamine levels in the host using HPLC with electrochemical detection. Two groups of 11 female crabs were studied; one group was artificially inoculated with two cystacanths while the other was used as the control. Our results show a dramatic increase in hemolymph dopamine, but not serotonin in H. crenulatus parasitized by the acanthocephalan P. antarcticus. Our results, along with those reported by Maynard (1996), suggest a parasite-specific strategy involved in the behavior alteration caused by the acanthocephalans on their intermediate host. The use of a biogenic amine as a mechanism of interaction by the parasites gives them an endless number of alternative potential actions on their intermediate hosts.

Search for intermediate vector bosons

International Nuclear Information System (INIS)

Cline, D.B.; Rubbia, C.; van der Meer, S.

1982-01-01

Over the past 15 years a new class of unified theories has been developed to describe the forces acting between elementary particles. The most successful of the new theories establishes a link between electromagnetism and the weak force. A crucial prediction of this unified electroweak theory is the existence of three massive particles called intermediate vector bosons. If these intermediate vector bosons exist and if they have properties attributed to them by electroweak theory, they should soon be detected, as the world's first particle accelerator with enough energy to create such particles has recently been completed at the European Organization for Nuclear Research (CERN) in Geneva. The accelerator has been converted to a colliding beam machine in which protons and antiprotons collide head on. According to electroweak theory, intermediate vector bosons can be created in proton-antiproton collisions. (SC)

39 CFR 3001.39 - Intermediate decisions.

Science.gov (United States)

2010-07-01

... 39 Postal Service 1 2010-07-01 2010-07-01 false Intermediate decisions. 3001.39 Section 3001.39 Postal Service POSTAL REGULATORY COMMISSION PERSONNEL RULES OF PRACTICE AND PROCEDURE Rules of General Applicability § 3001.39 Intermediate decisions. (a) Initial decision by presiding officer. In any proceedings in...

42 CFR 54.12 - Treatment of intermediate organizations.

Science.gov (United States)

2010-10-01

... 42 Public Health 1 2010-10-01 2010-10-01 false Treatment of intermediate organizations. 54.12... intermediate organizations. If a nongovernmental organization (referred to here as an “intermediate organization”), acting under a contract or other agreement with the Federal Government or a State or local...

Formation, structure, and stability of MHD intermediate shocks

International Nuclear Information System (INIS)

Wu, C.C.

1990-01-01

Contrary to the usual belief that MHD intermediate shocks are extraneous, the author has recently shown by numerical solutions of dissipative MHD equations that intermediate shocks are admissible and can be formed through nonlinear wave steepening from continuous waves. In this paper, the formation, structure and stability of intermediate shocks in dissipative MHD are considered in detail. The differences between the conventional theory and his are pointed out and clarified. He shows that all four types of intermediate shocks can be formed from smooth waves. He also shows that there are free parameters in the structure of the intermediate shocks, and that these parameters are related to the shock stability. In addition, he shows that a rotational discontinuity can not exist with finite width, indicate how this is related to the existence of time-dependent intermediate shocks, and show why the conventional theory is not a good approximation to dissipative MHD solutions whenever there is rotation in magnetic field

Product Lifecycle Management: CERN to host an important international conference

CERN Multimedia

CERN Bulletin

2011-01-01

CERN designs, builds and operates machines that contain millions of items of many types, such as software, electronics, and electrical, mechanical and chemical components. It is a challenge to maintain a coherent configuration of everything that has been developed and installed. To do this, CERN developed the EDMS system – an integrated Product Lifecycle Management (PLM) platform that enables management of all the information related to the entire lifecycle of each single component. On 5 and 6 September CERN will host an international PLM conference at which participants will exchange experience and address how best to apply PLM in their organisations.   Pictogram representation of a typical product lifecycle. Picture by the National Institute of Standards and Technology’s Manufacturing Engineering via Wikimedia Commons [Public domain]. PLM is the activity of managing, in the most effective way, an organisation’s products all the way through their lifecycles: from th...

A novel pathway for nicotine degradation by Aspergillus oryzae 112822 isolated from tobacco leaves.

Science.gov (United States)

Meng, Xiang Jing; Lu, Li Li; Gu, Guo Feng; Xiao, Min

2010-09-01

An efficient nicotine-degrading fungus was isolated from tobacco leaves and identified as Aspergillus oryzae 112822 based on morphological characteristics and sequence analysis of 18S rDNA, 5.8S rDNA and the internal transcribed spacer (5.8S-ITS region). When the strain was cultured in a medium with tobacco leaf extract for 40 h, the maximum amount of cell growth was 3.6 g l(-1) and nicotine degradation was 2.19 g l(-1). The intermediates of nicotine degradation by resting cells were isolated by preparative TLC or semi-preparative HPLC, and identified by TLC, MS, NMR, Fourier-transform (FT)-IR and GC-MS analysis. The pathway for nicotine degradation in A. oryzae 112822 was proposed to be from nicotine to 2,3-dihydroxypyridine through the intermediates nornicotine, myosmine, N-methylnicotinamide and 2-hydroxy-N-methylnicotinamide. The ring of 2,3-dihydroxypyridine was opened between the 2- and 3-hydroxy positions to yield succinic acid. N-methylnicotinamide and 2,3-dihydroxypyridine were satisfactorily verified as metabolites of nicotine degradation. This is the first elucidation of a pathway for nicotine degradation in fungi. Copyright 2010 Elsevier Masson SAS. All rights reserved.

Partially folded intermediates during trypsinogen denaturation

Directory of Open Access Journals (Sweden)

Martins N.F.

1999-01-01

Full Text Available The equilibrium unfolding of bovine trypsinogen was studied by circular dichroism, differential spectra and size exclusion HPLC. The change in free energy of denaturation was = 6.99 ± 1.40 kcal/mol for guanidine hydrochloride and = 6.37 ± 0.57 kcal/mol for urea. Satisfactory fits of equilibrium unfolding transitions required a three-state model involving an intermediate in addition to the native and unfolded forms. Size exclusion HPLC allowed the detection of an intermediate population of trypsinogen whose Stokes radii varied from 24.1 ± 0.4 Å to 26.0 ± 0.3 Å for 1.5 M and 2.5 M guanidine hydrochloride, respectively. During urea denaturation, the range of Stokes radii varied from 23.9 ± 0.3 Å to 25.7 ± 0.6 Å for 4.0 M and 6.0 M urea, respectively. Maximal intrinsic fluorescence was observed at about 3.8 M urea with 8-aniline-1-naphthalene sulfonate (ANS binding. These experimental data indicate that the unfolding of bovine trypsinogen is not a simple transition and suggest that the equilibrium intermediate population comprises one intermediate that may be characterized as a molten globule. To obtain further insight by studying intermediates representing different stages of unfolding, we hope to gain a better understanding of the complex interrelations between protein conformation and energetics.

Bacterial intermediate filaments

DEFF Research Database (Denmark)

Charbon, Godefroid; Cabeen, M.; Jacobs-Wagner, C.

2009-01-01

Crescentin, which is the founding member of a rapidly growing family of bacterial cytoskeletal proteins, was previously proposed to resemble eukaryotic intermediate filament (IF) proteins based on structural prediction and in vitro polymerization properties. Here, we demonstrate that crescentin...

Critical Roles of the Direct GABAergic Pallido-cortical Pathway in Controlling Absence Seizures

Science.gov (United States)

Li, Min; Ma, Tao; Wu, Shengdun; Ma, Jingling; Cui, Yan; Xia, Yang; Xu, Peng; Yao, Dezhong

2015-01-01

The basal ganglia (BG), serving as an intermediate bridge between the cerebral cortex and thalamus, are believed to play crucial roles in controlling absence seizure activities generated by the pathological corticothalamic system. Inspired by recent experiments, here we systematically investigate the contribution of a novel identified GABAergic pallido-cortical pathway, projecting from the globus pallidus externa (GPe) in the BG to the cerebral cortex, to the control of absence seizures. By computational modelling, we find that both increasing the activation of GPe neurons and enhancing the coupling strength of the inhibitory pallido-cortical pathway can suppress the bilaterally synchronous 2–4 Hz spike and wave discharges (SWDs) during absence seizures. Appropriate tuning of several GPe-related pathways may also trigger the SWD suppression, through modulating the activation level of GPe neurons. Furthermore, we show that the previously discovered bidirectional control of absence seizures due to the competition between other two BG output pathways also exists in our established model. Importantly, such bidirectional control is shaped by the coupling strength of this direct GABAergic pallido-cortical pathway. Our work suggests that the novel identified pallido-cortical pathway has a functional role in controlling absence seizures and the presented results might provide testable hypotheses for future experimental studies. PMID:26496656

Modeling optical behavior of birefringent biological tissues for evaluation of quantitative polarized light microscopy

NARCIS (Netherlands)

Turnhout, van M.C.; Kranenbarg, S.; Leeuwen, van J.L.

2009-01-01

Quantitative polarized light microscopy (qPLM) is a popular tool for the investigation of birefringent architectures in biological tissues. Collagen, the most abundant protein in mammals, is such a birefringent material. Interpretation of results of qPLM in terms of collagen network architecture and

Integrated interpretation of helicopter and ground-based geophysical data recorded within the Okavango Delta, Botswana

DEFF Research Database (Denmark)

Podgorski, Joel E.; Green, Alan G.; Kalscheuer, Thomas

2015-01-01

resistivities and very low to low P-wave velocities. Except for images of several buried abandoned river channels, it is non-reflective. The laterally extensive underlying unit of low resistivities, low P-wave velocity, and subhorizontal reflectors very likely contains saline-water-saturated sands and clays...... deposited in the huge Paleo Lake Makgadikgadi (PLM), which once covered a 90,000km2 area that encompassed the delta, Lake Ngami, the Mababe Depression, and the Makgadikgadi Basin. Examples of PLM sediments are intersected in many boreholes. Low permeability clay within the PLM unit seems to be a barrier...

Protein Loop Structure Prediction Using Conformational Space Annealing.

Science.gov (United States)

Heo, Seungryong; Lee, Juyong; Joo, Keehyoung; Shin, Hang-Cheol; Lee, Jooyoung

2017-05-22

We have developed a protein loop structure prediction method by combining a new energy function, which we call E PLM (energy for protein loop modeling), with the conformational space annealing (CSA) global optimization algorithm. The energy function includes stereochemistry, dynamic fragment assembly, distance-scaled finite ideal gas reference (DFIRE), and generalized orientation- and distance-dependent terms. For the conformational search of loop structures, we used the CSA algorithm, which has been quite successful in dealing with various hard global optimization problems. We assessed the performance of E PLM with two widely used loop-decoy sets, Jacobson and RAPPER, and compared the results against the DFIRE potential. The accuracy of model selection from a pool of loop decoys as well as de novo loop modeling starting from randomly generated structures was examined separately. For the selection of a nativelike structure from a decoy set, E PLM was more accurate than DFIRE in the case of the Jacobson set and had similar accuracy in the case of the RAPPER set. In terms of sampling more nativelike loop structures, E PLM outperformed E DFIRE for both decoy sets. This new approach equipped with E PLM and CSA can serve as the state-of-the-art de novo loop modeling method.

In vivo kinetic analysis of the penicillin biosynthesis pathway using PAA stimulus response experiments.

Science.gov (United States)

Deshmukh, Amit T; Verheijen, Peter J T; Maleki Seifar, Reza; Heijnen, Joseph J; van Gulik, Walter M

2015-11-01

In this study we combined experimentation with mathematical modeling to unravel the in vivo kinetic properties of the enzymes and transporters of the penicillin biosynthesis pathway in a high yielding Penicillium chrysogenum strain. The experiment consisted of a step response experiment with the side chain precursor phenyl acetic acid (PAA) in a glucose-limited chemostat. The metabolite data showed that in the absence of PAA all penicillin pathway enzymes were expressed, leading to the production of a significant amount of 6-aminopenicillanic acid (6APA) as end product. After the stepwise perturbation with PAA, the pathway produced PenG within seconds. From the extra- and intracellular metabolite measurements, hypotheses for the secretion mechanisms of penicillin pathway metabolites were derived. A dynamic model of the penicillin biosynthesis pathway was then constructed that included the formation and transport over the cytoplasmic membrane of pathway intermediates, PAA and the product penicillin-G (PenG). The model parameters and changes in the enzyme levels of the penicillin biosynthesis pathway under in vivo conditions were simultaneously estimated using experimental data obtained at three different timescales (seconds, minutes, hours). The model was applied to determine changes in the penicillin pathway enzymes in time, calculate fluxes and analyze the flux control of the pathway. This led to a reassessment of the in vivo behavior of the pathway enzymes and in particular Acyl-CoA:Isopenicillin N Acyltransferase (AT). Copyright © 2015 International Metabolic Engineering Society. Published by Elsevier Inc. All rights reserved.

Present status of intermediate band solar cell research

International Nuclear Information System (INIS)

Cuadra, L.; Marti, A.; Luque, A.

2004-01-01

The intermediate band solar cell is a theoretical concept with the potential for exceeding the performance of conventional single-gap solar cells. This novel photovoltaic converter bases its superior theoretical efficiency over single-gap solar cells by enhancing its photogenerated current, via the two-step absorption of sub-band gap photons, without reducing its output voltage. This is achieved through a material with an electrically isolated and partially filled intermediate band located within a higher forbidden gap. This material is commonly named intermediate band material. This paper centres on summarising the present status of intermediate band solar cell research. A number of attempts, which aim to implement the intermediate band concept, are being followed: the direct engineering of the intermediate band material, its implementation by means of quantum dots and the highly porous material approach. Among other sub-band gap absorbing proposals, there is a renewed interest on the impurity photovoltaic effect, the quantum well solar cells and the particularly promising proposal for the use of up- and down-converters

Thermodynamics of metabolic pathways for penicillin production: Analysis of thermodynamic feasibility and free energy changes during fed-batch cultivation

DEFF Research Database (Denmark)

Pissarra, P.D.; Nielsen, Jens Bredal

1997-01-01

This paper describes the thermodynamic analysis of pathways related to penicillin production in Penicillium chrysogenum. First a thermodynamic feasibility analysis is performed of the L-lysine pathway of which one of the precursors for penicillin biosynthesis (alpha-aminoadipic acid......) is an intermediate. It is found that the L-lysine pathway in P. chrysogenum is thermodynamically feasible and that the calculated standard Gibbs free energy values of the two enzymes controlling the pathway flux indicate that they operate far from equilibrium. It is therefore proposed that the regulation of alpha......-aminoadipate reductase by lysine is important to maintain a high concentration of alpha-aminoadipate in order to direct the carbon flux to penicillin production. Secondly the changes in Gibbs free energy in the penicillin biosynthetic pathway during fed-batch cultivation were studied. The analysis showed that all...

An LL-diaminopimelate aminotransferase defines a novel variant of the lysine biosynthesis pathway in plants.

Science.gov (United States)

Hudson, André O; Singh, Bijay K; Leustek, Thomas; Gilvarg, Charles

2006-01-01

Although lysine (Lys) biosynthesis in plants is known to occur by way of a pathway that utilizes diaminopimelic acid (DAP) as a central intermediate, the available evidence suggests that none of the known DAP-pathway variants found in nature occur in plants. A new Lys biosynthesis pathway has been identified in Arabidopsis (Arabidopsis thaliana) that utilizes a novel transaminase that specifically catalyzes the interconversion of tetrahydrodipicolinate and LL-diaminopimelate, a reaction requiring three enzymes in the DAP-pathway variant found in Escherichia coli. The LL-DAP aminotransferase encoded by locus At4g33680 was able to complement the dapD and dapE mutants of E. coli. This result, in conjunction with the kinetic properties and substrate specificity of the enzyme, indicated that LL-DAP aminotransferase functions in the Lys biosynthetic direction under in vivo conditions. Orthologs of At4g33680 were identified in all the cyanobacterial species whose genomes have been sequenced. The Synechocystis sp. ortholog encoded by locus sll0480 showed the same functional properties as At4g33680. These results demonstrate that the Lys biosynthesis pathway in plants and cyanobacteria is distinct from the pathways that have so far been defined in microorganisms.

Associations of Systemic Diseases with Intermediate Uveitis.

Science.gov (United States)

Shoughy, Samir S; Kozak, Igor; Tabbara, Khalid F

2016-01-01

To determine the associations of systemic diseases with intermediate uveitis. The medical records of 50 consecutive cases with intermediate uveitis referred to The Eye Center in Riyadh, Saudi Arabia, were reviewed. Age- and sex-matched patients without uveitis served as controls. Patients had complete ophthalmic and medical examinations. There were 27 male and 23 female patients. Mean age was 29 years with a range of 5-62 years. Overall, 21 cases (42%) had systemic disorders associated with intermediate uveitis and 29 cases (58%) had no associated systemic disease. A total of 11 patients (22%) had asthma, 4 (8%) had multiple sclerosis, 3 (6%) had presumed ocular tuberculosis, 1 (2%) had inflammatory bowel disease, 1 (2%) had non-Hodgkin lymphoma and 1 (2%) had sarcoidosis. Evidence of systemic disease was found in 50 (5%) of the 1,000 control subjects. Bronchial asthma was found in 37 patients (3.7 %), multiple sclerosis in 9 patients (0.9%), inflammatory bowel disease in 3 patients (0.3%), and tuberculosis in 1 patient (0.1%). None of the control patients had sarcoidosis or lymphoma. There were statistically significant associations between intermediate uveitis and bronchial asthma (p = 0.0001), multiple sclerosis (p = 0.003) and tuberculosis (p = 0.0005). Bronchial asthma and multiple sclerosis were the most frequently encountered systemic diseases associated with intermediate uveitis in our patient population. Patients with intermediate uveitis should undergo careful history-taking and investigations to rule out associated systemic illness.

Bio-inspired piezoelectric linear motor driven by a single-phase harmonic wave with an asymmetric stator.

Science.gov (United States)

Pan, Qiaosheng; Miao, Enming; Wu, Bingxuan; Chen, Weikang; Lei, Xiujun; He, Liangguo

2017-07-01

A novel, bio-inspired, single-phase driven piezoelectric linear motor (PLM) using an asymmetric stator was designed, fabricated, and tested to avoid mode degeneracy and to simplify the drive mechanism of a piezoelectric motor. A piezoelectric transducer composed of two piezoelectric stacks and a displacement amplifier was used as the driving element of the PLM. Two simple and specially designed claws performed elliptical motion. A numerical simulation was performed to design the stator and determine the feasibility of the design mechanism of the PLM. Moreover, an experimental setup was built to validate the working principles, as well as to evaluate the performance, of the PLM. The prototype motor outputs a no-load speed of 233.7 mm/s at a voltage of 180 V p-p and a maximum thrust force of 2.3 N under a preload of 10 N. This study verified the feasibility of the proposed design and provided a method to simplify the driving harmonic signal and structure of PLMs.

The Deoxygenation Pathways of Palmitic Acid into Hydrocarbons on Silica-Supported Ni12P5 and Ni2P Catalysts

Directory of Open Access Journals (Sweden)

Wenjun Zhou

2018-04-01

Full Text Available Pure Ni12P5/SiO2 and pure Ni2P/SiO2 catalysts were obtained by adjusting the Ni and P molar ratios, while Ni/SiO2 catalyst was prepared as a reference against which the deoxygenation pathways of palmitic acid were investigated. The catalysts were characterized by N2 adsorption, X-ray diffraction (XRD, X-ray photoelectron spectroscopy (XPS, transmission election microscopy (TEM, infrared spectroscopy of pyridine adsorption (Py-IR, H2-adsorption and temperature-programmed desorption of hydrogen (H2-TPD. The crystallographic planes of Ni(111, Ni12P5(400, Ni2P(111 were found mainly exposed on the above three catalysts, respectively. It was found that the deoxygenation pathway of palmitic acid mainly proceeded via direct decarboxylation (DCO2 to form C15 on Ni/SiO2. In contrast, on the Ni12P5/SiO2 catalyst, there were two main competitive pathways producing C15 and C16, one of which mainly proceeded via the decarbonylation (DCO to form C15 accompanying water formation, and the other pathway produced C16 via the dehydration of hexadecanol intermediate, and the yield of C15 was approximately twofold that of C16. Over the Ni2P/SiO2 catalyst, two main deoxygenation pathways formed C15, one of which was mainly the DCO pathway and the other was dehydration accompanying the hexadecanal intermediate and then direct decarbonylation without water formation. The turn over frequency (TOF followed the order: Ni12P5/SiO2 > Ni/SiO2 > Ni2P/SiO2.

Metabolic pathways of decabromodiphenyl ether (BDE209) in rainbow trout (Oncorhynchus mykiss) via intraperitoneal injection.

Science.gov (United States)

Feng, Chenglian; Xu, Yiping; Zha, Jinmiao; Li, Jian; Wu, Fengchang; Wang, Zijian

2015-03-01

Decabromodiphenyl ether (BDE209) was of great concern due to its biotransformation in different organisms. However, most studies devoted to the metabolic intermediates of BDE209, less has been done on the metabolic pathways in vivo, especially on the relationships among debrominated-BDEs, OH-BDEs and MeO-BDEs. In this study, the metabolic pathways and intermediates of BDE209 in rainbow trout (Oncorhynchus mykiss) were investigated, and the time-dependent transformations of the metabolites were also examined. The primary debrominated metabolites were BDE47, 49, 99, 197, 207; the main MeO-BDEs were MeO-BDE47, MeO-BDE68 and MeO-BDE100; OH-BDEs were primarily composed of OH-BDE28 and OH-BDE42. From the time-dependent and dose-effect relationships, the debromination should be followed by hydroxylation, and then by methoxylation. The increasing in body burden of MeO-BDEs corresponded to the decreasing of OH-BDEs, which could indirectly prove the inter-conversion between OH-BDEs and MeO-BDEs. This study would motivate the future research of toxicological mechanisms of BDEs. Copyright © 2015 Elsevier B.V. All rights reserved.

Pesticide Leaching Models in a Brazilian Agricultural Field Scenario

NARCIS (Netherlands)

Scorza, R.P.; Oliveira Rigitano, de R.L.; Boesten, J.J.T.I.

2011-01-01

The use of Pesticide Leaching Models (PLM) for risk assessment may be an efficient and attractive way of assessing solutions to some agricultural and environmental problems. Many countries of the European Union and the USA have been using PLM for risk assessment already for a few decades. This

Photochemical transformation of phenylurea herbicides in surface waters: a model assessment of persistence, and implications for the possible generation of hazardous intermediates.

Science.gov (United States)

Fabbri, Debora; Minella, Marco; Maurino, Valter; Minero, Claudio; Vione, Davide

2015-01-01

This work models the phototransformation kinetics in surface waters of five phenylurea herbicides (diuron, fenuron, isoproturon, metoxuron and chlortoluron), for which important photochemical parameters are available in the literature (direct photolysis quantum yields and reaction rate constants with ·OH, CO3(-·) and the triplet states of chromophoric dissolved organic matter, (3)CDOM*). Model calculations suggest that isoproturon and metoxuron would be the least photochemically persistent and diuron the most persistent compound. Reactions with ·OH and (3)CDOM* would be the main phototransformation pathways for all compounds in the majority of environmental conditions. Reaction with CO3(-) could be important in waters with low dissolved organic carbon (DOC), while direct photolysis would be negligible for fenuron, quite important for chlortoluron, and somewhat significant for the other compounds. The direct photolysis of metoxuron and diuron is known to increase toxicity, and such a photoreaction pathway would be enhanced at intermediate DOC values (1-4 mg C L(1)). The reaction between phenylureas and ·OH is known to produce toxic intermediates, differently from (3)CDOM*. Therefore, the shift of reactivity from ·OH to (3)CDOM* with increasing DOC could reduce the environmental impact of photochemical transformation. Copyright © 2014 Elsevier Ltd. All rights reserved.

BioBoost. Biomass based energy intermediates boosting bio-fuel production

Energy Technology Data Exchange (ETDEWEB)

Niebel, Andreas [Karlsruher Institut fuer Technologie (KIT), Karlsruhe (Germany). Institut fuer Katalyseforschung und -technologie (IKFT)

2013-10-01

To increase the share of biomass for renewable energy in Europe conversion pathways which are economic, flexible in feedstock and energy efficient are needed. The BioBoost project concentrates on dry and wet residual biomass and wastes as feedstock for de-central conversion by fast pyrolysis, catalytic pyrolysis and hydrothermal carbonization to the intermediate energy carriers oil, coal or slurry. Based on straw the energy density increases from 2 to 20-30 GJ/m{sup 3}, enabling central GW scale gasification plants for bio-fuel production. A logistic model for feedstock supply and connection of de-central with central conversion is set up and validated allowing the determination of costs, the number and location of de-central and central sites. Techno/economic and environmental assessment of the value chain supports the optimization of products and processes. The utilization of energy carriers is investigated in existing and coming applications of heat and power production and synthetic fuels and chemicals. (orig.)

Directing folding pathways for multi-component DNA origami nanostructures with complex topology

International Nuclear Information System (INIS)

Marras, A E; Zhou, L; Su, H-J; Castro, C E; Kolliopoulos, V

2016-01-01

Molecular self-assembly has become a well-established technique to design complex nanostructures and hierarchical mesoscale assemblies. The typical approach is to design binding complementarity into nucleotide or amino acid sequences to achieve the desired final geometry. However, with an increasing interest in dynamic nanodevices, the need to design structures with motion has necessitated the development of multi-component structures. While this has been achieved through hierarchical assembly of similar structural units, here we focus on the assembly of topologically complex structures, specifically with concentric components, where post-folding assembly is not feasible. We exploit the ability to direct folding pathways to program the sequence of assembly and present a novel approach of designing the strand topology of intermediate folding states to program the topology of the final structure, in this case a DNA origami slider structure that functions much like a piston-cylinder assembly in an engine. The ability to program the sequence and control orientation and topology of multi-component DNA origami nanostructures provides a foundation for a new class of structures with internal and external moving parts and complex scaffold topology. Furthermore, this work provides critical insight to guide the design of intermediate states along a DNA origami folding pathway and to further understand the details of DNA origami self-assembly to more broadly control folding states and landscapes. (paper)

Directing folding pathways for multi-component DNA origami nanostructures with complex topology

Science.gov (United States)

Marras, A. E.; Zhou, L.; Kolliopoulos, V.; Su, H.-J.; Castro, C. E.

2016-05-01

Molecular self-assembly has become a well-established technique to design complex nanostructures and hierarchical mesoscale assemblies. The typical approach is to design binding complementarity into nucleotide or amino acid sequences to achieve the desired final geometry. However, with an increasing interest in dynamic nanodevices, the need to design structures with motion has necessitated the development of multi-component structures. While this has been achieved through hierarchical assembly of similar structural units, here we focus on the assembly of topologically complex structures, specifically with concentric components, where post-folding assembly is not feasible. We exploit the ability to direct folding pathways to program the sequence of assembly and present a novel approach of designing the strand topology of intermediate folding states to program the topology of the final structure, in this case a DNA origami slider structure that functions much like a piston-cylinder assembly in an engine. The ability to program the sequence and control orientation and topology of multi-component DNA origami nanostructures provides a foundation for a new class of structures with internal and external moving parts and complex scaffold topology. Furthermore, this work provides critical insight to guide the design of intermediate states along a DNA origami folding pathway and to further understand the details of DNA origami self-assembly to more broadly control folding states and landscapes.

Photoreceptor layer map using spectral-domain optical coherence tomography.

Science.gov (United States)

Lee, Ji Eun; Lim, Dae Won; Bae, Han Yong; Park, Hyun Jin

2009-12-01

To develop a novel method for analysis of the photoreceptor layer map (PLM) generated using spectral-domain optical coherence tomography (OCT). OCT scans were obtained from 20 eyes, 10 with macular holes (MH) and 10 with central serous chorioretinopathy (CSC) using the Macular Cube (512 x 128) protocol of the Cirrus HD-OCT (Carl Zeiss). The scanned data were processed using embedded tools of the advanced visualization. A partial thickness OCT fundus image of the photoreceptor layer was generated by setting the region of interest to a 50-microm thick layer that was parallel and adjacent to the retinal pigment epithelium. The resulting image depicted the photoreceptor layer as a map of the reflectivity in OCT. The PLM was compared with fundus photography, auto-fluorescence, tomography, and retinal thickness map. The signal from the photoreceptor layer of every OCT scan in each case was demonstrated as a single image of PLM in a fundus photograph fashion. In PLM images, detachment of the sensory retina is depicted as a hypo-reflective area, which represents the base of MH and serous detachment in CSC. Relative hypo-reflectivity, which was also noted at closed MH and at recently reattached retina in CSC, was associated with reduced signal from the junction between the inner and outer segments of photoreceptors in OCT images. Using PLM, changes in the area of detachment and reflectivity of the photoreceptor layer could be efficiently monitored. The photoreceptor layer can be analyzed as a map using spectral-domain OCT. In the treatment of both MH and CSC, PLM may provide new pathological information about the photoreceptor layer to expand our understanding of these diseases.

Periodic Limb Movements and White Matter Hyperintensities in First-Ever Minor Stroke or High-Risk Transient Ischemic Attack.

Science.gov (United States)

Boulos, Mark I; Murray, Brian J; Muir, Ryan T; Gao, Fuqiang; Szilagyi, Gregory M; Huroy, Menal; Kiss, Alexander; Walters, Arthur S; Black, Sandra E; Lim, Andrew S; Swartz, Richard H

2017-03-01

Emerging evidence suggests that periodic limb movements (PLMs) may contribute to the development of cerebrovascular disease. White matter hyperintensities (WMHs), a widely accepted biomarker for cerebral small vessel disease, are associated with incident stroke and death. We evaluated the association between increased PLM indices and WMH burden in patients presenting with stroke or transient ischemic attack (TIA), while controlling for vascular risk factors and stroke severity. Thirty patients presenting within 2 weeks of a first-ever minor stroke or high-risk TIA were prospectively recruited. PLM severity was measured with polysomnography. WMH burden was quantified using the Age Related White Matter Changes (ARWMC) scale based on neuroimaging. Partial Spearman's rank-order correlations and multiple linear regression models tested the association between WMH burden and PLM severity. Greater WMH burden was correlated with elevated PLM index and stroke volume. Partial Spearman's rank-order correlations demonstrated that the relationship between WMH burden and PLM index persisted despite controlling for vascular risk factors. Multivariate linear regression models revealed that PLM index was a significant predictor of an elevated ARWMC score while controlling for age, stroke volume, stroke severity, hypertension, and apnea-hypopnea index. The quantity of PLMs was associated with WMH burden in patients with first-ever minor stroke or TIA. PLMs may be a risk factor for or marker of WMH burden, even after considering vascular risk factors and stroke severity. These results invite further investigation of PLMs as a potentially useful target to reduce WMH and stroke burden. © Sleep Research Society (SRS) 2016. All rights reserved. For permissions, please email: journals.permissions@oup.com

Isoporphyrin Intermediate in Heme Oxygenase Catalysis

Science.gov (United States)

Evans, John P.; Niemevz, Fernando; Buldain, Graciela; de Montellano, Paul Ortiz

2008-01-01

Human heme oxygenase-1 (hHO-1) catalyzes the O2- and NADPH-dependent oxidation of heme to biliverdin, CO, and free iron. The first step involves regiospecific insertion of an oxygen atom at the α-meso carbon by a ferric hydroperoxide and is predicted to proceed via an isoporphyrin π-cation intermediate. Here we report spectroscopic detection of a transient intermediate during oxidation by hHO-1 of α-meso-phenylheme-IX, α-meso-(p-methylphenyl)-mesoheme-III, and α-meso-(p-trifluoromethylphenyl)-mesoheme-III. In agreement with previous experiments (Wang, J., Niemevz, F., Lad, L., Huang, L., Alvarez, D. E., Buldain, G., Poulos, T. L., and Ortiz de Montellano, P. R. (2004) J. Biol. Chem. 279, 42593–42604), only the α-biliverdin isomer is produced with concomitant formation of the corresponding benzoic acid. The transient intermediate observed in the NADPH-P450 reductase-catalyzed reaction accumulated when the reaction was supported by H2O2 and exhibited the absorption maxima at 435 and 930 nm characteristic of an isoporphyrin. Product analysis by reversed phase high performance liquid chromatography and liquid chromatography electrospray ionization mass spectrometry of the product generated with H2O2 identified it as an isoporphyrin that, on quenching, decayed to benzoylbiliverdin. In the presence of H218O2, one labeled oxygen atom was incorporated into these products. The hHO-1-isoporphyrin complexes were found to have half-lives of 1.7 and 2.4 h for the p-trifluoromethyl- and p-methyl-substituted phenylhemes, respectively. The addition of NADPH-P450 reductase to the H2O2-generated hHO-1-isoporphyrin complex produced α-biliverdin, confirming its role as a reaction intermediate. Identification of an isoporphyrin intermediate in the catalytic sequence of hHO-1, the first such intermediate observed in hemoprotein catalysis, completes our understanding of the critical first step of heme oxidation. PMID:18487208

One-Pot Conversion of Carbohydrates into Furan Derivatives via Furfural and 5-Hydroxylmethylfurfural as Intermediates.

Science.gov (United States)

Liu, Bing; Zhang, Zehui

2016-08-23

Recently, there has been growing interest in the transformation of renewable biomass into value-added fuels and chemicals. The catalytic conversion of naturally abundant carbohydrates can generate two-important furan chemicals: 5-hydroxymethylfurfural (HMF) from C6 carbohydrates and furfural from C5 carbohydrates. Both HMF and furfural have received great interest as precursors in the synthesis of commodity chemicals and liquid fuels. In recent years, a trend has emerged to integrate sequential catalytic processes involving multistep reactions for the direct one-pot transformation of carbohydrates into the aimed fuels and chemicals. One-pot reactions have remarkably unique and environmentally friendly benefits, including the fact that isolation and purification of intermediate compounds can be avoided. Herein, the present article aims to review recent advances in the one-pot conversion of carbohydrates into furan derivatives via furfural and HMF as intermediates. Special attention will be paid to the catalytic systems, mechanistic insight, reaction pathways, and catalyst stability. It is expected that this review will guide researchers to develop effective catalytic systems for the one-pot transformation of carbohydrates into furan derivatives. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Reaction between peroxynitrite and boronates: EPR spin-trapping, HPLC analyses, and quantum mechanical study of the free radical pathway

Science.gov (United States)

Sikora, Adam; Zielonka, Jacek; Lopez, Marcos; Dybala-Defratyka, Agnieszka; Joseph, Joy; Marcinek, Andrzej; Kalyanaraman, Balaraman

2013-01-01

Recently we showed that peroxynitrite (ONOO−) reacts directly and rapidly with aromatic and aliphatic boronic acids (k ≈ 106 M−1s−1). Product analyses and substrate consumption data indicated that ONOO− reacts stoichiometrically with boronates, yielding the corresponding phenols as the major product (~85–90%), and the remaining products (10–15%) were proposed to originate from free radical intermediates (phenyl and phenoxyl radicals). Here we investigated in detail the minor, free radical pathway of boronate reaction with ONOO−. The electron paramagnetic resonance (EPR) spin-trapping technique was used to characterize the free radical intermediates formed from the reaction between boronates and ONOO−. Using 2-methyl-2-nitrosopropane (MNP) and 5-diethoxyphosphoryl-5-methyl-1-pyrroline-N-oxide (DEPMPO) spin traps, phenyl radicals were trapped and detected. Although phenoxyl radicals were not detected, the positive effects of molecular oxygen, and inhibitory effects of hydrogen atom donors (acetonitrile, and 2-propanol) and general radical scavengers (GSH, NADH, ascorbic acid and tyrosine) on the formation of phenoxyl radical-derived nitrated product, suggest that phenoxyl radical was formed as the secondary species. We propose that the initial step of the reaction involves the addition of ONOO− to the boron atom in boronates. The anionic intermediate undergoes both heterolytic (major pathway) and homolytic (minor pathway) cleavage of the peroxy (O-O) bond to form phenol and nitrite as a major product (via a non-radical mechanism), or a radical pair PhB(OH)2O•−…•NO2 as a minor product. It is conceivable that phenyl radicals are formed by the fragmentation of PhB(OH)2O•− radical anion. According to the DFT quantum mechanical calculations, the energy barrier for the dissociation of PhB(OH)2O•− radical anion to form phenyl radicals is only a few kcal/mol, suggesting rapid and spontaneous fragmentation of PhB(OH)2O•− radical anion

Language in use intermediate : self-study workbook

CERN Document Server

Doff, Adrian

1994-01-01

Each of the four levels comprises about 80 hours of class work, with additional time for the self-study work. The Teacher's Book contains all the pages from the Classroom Book, with interleaved teaching notes including optional activities to cater for different abilities. There is a video to accompany the Beginner, Pre-intermediate and Intermediate levels. Each video contains eight stimulating and entertaining short programmes, as well as a booklet of photocopiable activities. Free test material is available in booklet and web format for Beginner and Pre-intermediate levels. Visit www.cambridge.org/elt/liu or contact your local Cambridge University Press representative.

Nitrite and hydroxylamine as nitrogenase substrates: mechanistic implications for the pathway of N₂ reduction.

Science.gov (United States)

Shaw, Sudipta; Lukoyanov, Dmitriy; Danyal, Karamatullah; Dean, Dennis R; Hoffman, Brian M; Seefeldt, Lance C

2014-09-10

Investigations of reduction of nitrite (NO2(-)) to ammonia (NH3) by nitrogenase indicate a limiting stoichiometry, NO2(-) + 6e(-) + 12ATP + 7H(+) → NH3 + 2H2O + 12ADP + 12Pi. Two intermediates freeze-trapped during NO2(-) turnover by nitrogenase variants and investigated by Q-band ENDOR/ESEEM are identical to states, denoted H and I, formed on the pathway of N2 reduction. The proposed NO2(-) reduction intermediate hydroxylamine (NH2OH) is a nitrogenase substrate for which the H and I reduction intermediates also can be trapped. Viewing N2 and NO2(-) reductions in light of their common reduction intermediates and of NO2(-) reduction by multiheme cytochrome c nitrite reductase (ccNIR) leads us to propose that NO2(-) reduction by nitrogenase begins with the generation of NO2H bound to a state in which the active-site FeMo-co (M) has accumulated two [e(-)/H(+)] (E2), stored as a (bridging) hydride and proton. Proton transfer to NO2H and H2O loss leaves M-[NO(+)]; transfer of the E2 hydride to the [NO(+)] directly to form HNO bound to FeMo-co is one of two alternative means for avoiding formation of a terminal M-[NO] thermodynamic "sink". The N2 and NO2(-) reduction pathways converge upon reduction of NH2NH2 and NH2OH bound states to form state H with [-NH2] bound to M. Final reduction converts H to I, with NH3 bound to M. The results presented here, combined with the parallels with ccNIR, support a N2 fixation mechanism in which liberation of the first NH3 occurs upon delivery of five [e(-)/H(+)] to N2, but a total of seven [e(-)/H(+)] to FeMo-co when obligate H2 evolution is considered, and not earlier in the reduction process.

an intermediate moisture meat

African Journals Online (AJOL)

STORAGESEVER

2008-07-04

Jul 4, 2008 ... traditional SM muscle without compromising quality. ... technique is intermediate moisture food processing. ... Traditionally, most tsire suya producers use ..... quality of Chinese purebred and European X Chinese crossbred ...

Understanding the Contribution of Zinc Transporters in the Function of the Early Secretory Pathway.

Science.gov (United States)

Kambe, Taiho; Matsunaga, Mayu; Takeda, Taka-Aki

2017-10-19

More than one-third of newly synthesized proteins are targeted to the early secretory pathway, which is comprised of the endoplasmic reticulum (ER), Golgi apparatus, and other intermediate compartments. The early secretory pathway plays a key role in controlling the folding, assembly, maturation, modification, trafficking, and degradation of such proteins. A considerable proportion of the secretome requires zinc as an essential factor for its structural and catalytic functions, and recent findings reveal that zinc plays a pivotal role in the function of the early secretory pathway. Hence, a disruption of zinc homeostasis and metabolism involving the early secretory pathway will lead to pathway dysregulation, resulting in various defects, including an exacerbation of homeostatic ER stress. The accumulated evidence indicates that specific members of the family of Zn transporters (ZNTs) and Zrt- and Irt-like proteins (ZIPs), which operate in the early secretory pathway, play indispensable roles in maintaining zinc homeostasis by regulating the influx and efflux of zinc. In this review, the biological functions of these transporters are discussed, focusing on recent aspects of their roles. In particular, we discuss in depth how specific ZNT transporters are employed in the activation of zinc-requiring ectoenzymes. The means by which early secretory pathway functions are controlled by zinc, mediated by specific ZNT and ZIP transporters, are also subjects of this review.

Pathway Distiller - multisource biological pathway consolidation.

Science.gov (United States)

Doderer, Mark S; Anguiano, Zachry; Suresh, Uthra; Dashnamoorthy, Ravi; Bishop, Alexander J R; Chen, Yidong

2012-01-01

One method to understand and evaluate an experiment that produces a large set of genes, such as a gene expression microarray analysis, is to identify overrepresentation or enrichment for biological pathways. Because pathways are able to functionally describe the set of genes, much effort has been made to collect curated biological pathways into publicly accessible databases. When combining disparate databases, highly related or redundant pathways exist, making their consolidation into pathway concepts essential. This will facilitate unbiased, comprehensive yet streamlined analysis of experiments that result in large gene sets. After gene set enrichment finds representative pathways for large gene sets, pathways are consolidated into representative pathway concepts. Three complementary, but different methods of pathway consolidation are explored. Enrichment Consolidation combines the set of the pathways enriched for the signature gene list through iterative combining of enriched pathways with other pathways with similar signature gene sets; Weighted Consolidation utilizes a Protein-Protein Interaction network based gene-weighting approach that finds clusters of both enriched and non-enriched pathways limited to the experiments' resultant gene list; and finally the de novo Consolidation method uses several measurements of pathway similarity, that finds static pathway clusters independent of any given experiment. We demonstrate that the three consolidation methods provide unified yet different functional insights of a resultant gene set derived from a genome-wide profiling experiment. Results from the methods are presented, demonstrating their applications in biological studies and comparing with a pathway web-based framework that also combines several pathway databases. Additionally a web-based consolidation framework that encompasses all three methods discussed in this paper, Pathway Distiller (http://cbbiweb.uthscsa.edu/PathwayDistiller), is established to allow

Orthorhombic Intermediate State in the Zinc Blende to Rocksalt Transformation Path of SiC at High Pressure

International Nuclear Information System (INIS)

Catti, Michele

2001-01-01

The mechanism of the B3/B1 phase transition of SiC has been investigated by periodic LCAO-DFT least-enthalpy calculations. A new transformation pathway, based on a Pmm2 orthorhombic intermediate state with two SiC units per cell, is found to be energetically favored over the traditional R3m mechanism. The computed activation enthalpy is 0.75eV/SiC unit at the predicted transition pressure of 92GPa (B3LYP functional). Activation enthalpy and activation volume vs pressure are analyzed to characterize the kinetic aspects of the transformation

Fenton degradation of Cartap hydrochloride: identification of the main intermediates and the degradation pathway.

Science.gov (United States)

Tian, Kaixun; Ming, Cuixiang; Dai, Youzhi; Honore Ake, Kouassi Marius

2015-01-01

The advanced oxidation of Cartap hydrochloride (Cartap) promoted by the Fenton system in an aqueous medium was investigated. Based on total organic carbon, chemical oxygen demand and high-performance liquid chromatography, the oxidation of Cartap is quite efficient by the Fenton system. Its long chain is easily destroyed, but the reaction does not proceed to complete mineralization. Ion chromatography detection indicated the formation of acetic acid, propionic acid, formic acid, nitrous acid and sulfuric acid in the reaction mixtures. Further evidence of nitrogen monoxide and sulfur dioxide formation was obtained by using a flue gas analyzer. Monitoring by gas chromatograph-mass spectrometer demonstrated the formation of oxalic acid, ethanol, carbon dioxide, and L-alanine ethylamide. Based on these experimental results, plausible degradation pathways for Cartap mineralization in an aqueous medium by the Fenton system are proposed.

Taxation of Financial Intermediation Activities in Hong Kong

OpenAIRE

Jack M. Mintz; Stephen R. Richardson

2001-01-01

This paper discusses issues related to the taxation of financial intermediation in Hong Kong in the context of Hong Kong's position as a major regional financial centre. It first provides some background analysis as to the definition of financial intermediation and identification of the providers of financial services. This is then followed by a discussion of the principles of taxation applicable to financial intermediation, including a comparison of income taxes to consumption taxes. Some sp...

Theoretical study of the decomposition pathways and products of C5- perfluorinated ketone (C5 PFK)

Energy Technology Data Exchange (ETDEWEB)

Fu, Yuwei; Wang, Xiaohua, E-mail: xhw@mail.xjtu.edu.cn, E-mail: mzrong@mail.xjtu.edu.cn; Li, Xi; Yang, Aijun; Wu, Yi; Rong, Mingzhe, E-mail: xhw@mail.xjtu.edu.cn, E-mail: mzrong@mail.xjtu.edu.cn [State Key Laboratory of Electrical Insulation and Power Equipment, Xi’an Jiaotong University, No. 28 XianNing West Road, Xi’an, Shaanxi Province 710049 (China); Han, Guohui; Lu, Yanhui [Pinggao Group Co. Ltd., Pingdingshan, Henan Province 467001 (China)

2016-08-15

Due to the high global warming potential (GWP) and increasing environmental concerns, efforts on searching the alternative gases to SF{sub 6}, which is predominantly used as insulating and interrupting medium in high-voltage equipment, have become a hot topic in recent decades. Overcoming the drawbacks of the existing candidate gases, C5- perfluorinated ketone (C5 PFK) was reported as a promising gas with remarkable insulation capacity and the low GWP of approximately 1. Experimental measurements of the dielectric strength of this novel gas and its mixtures have been carried out, but the chemical decomposition pathways and products of C5 PFK during breakdown are still unknown, which are the essential factors in evaluating the electric strength of this gas in high-voltage equipment. Therefore, this paper is devoted to exploring all the possible decomposition pathways and species of C5 PFK by density functional theory (DFT). The structural optimizations, vibrational frequency calculations and energy calculations of the species involved in a considered pathway were carried out with DFT-(U)B3LYP/6-311G(d,p) method. Detailed potential energy surface was then investigated thoroughly by the same method. Lastly, six decomposition pathways of C5 PFK decomposition involving fission reactions and the reactions with a transition states were obtained. Important intermediate products were also determined. Among all the pathways studied, the favorable decomposition reactions of C5 PFK were found, involving C-C bond ruptures producing Ia and Ib in pathway I, followed by subsequent C-C bond ruptures and internal F atom transfers in the decomposition of Ia and Ib presented in pathways II + III and IV + V, respectively. Possible routes were pointed out in pathway III and lead to the decomposition of IIa, which is the main intermediate product found in pathway II of Ia decomposition. We also investigated the decomposition of Ib, which can undergo unimolecular reactions to give the

Two pedigrees with restless legs syndrome in Brazil

Directory of Open Access Journals (Sweden)

A.M. Esteves

2008-02-01

Full Text Available Numerous studies have suggested a substantial genetic contribution in the etiology of the primary form of restless legs syndrome (RLS and periodic leg movements (PLM. We describe the symptoms, the sleep profiles and physiological parameters of two families in which several members present RLS/PLM. The proband of family 1 is a 70-year-old woman and the proband of family 2 is a 57-year-old woman; both have exhibited the symptoms since the age of 20 years. All patients in both families were diagnosed with RLS according to the criteria of the International RLS Study Group. Polysomnographic recordings were performed to quantify and to describe PLM during sleep. Sleep parameters showed decreased sleep efficiency, increased sleep latency in the arousal index and the presence of PLM in all subjects. One of the families showed an exact profile of dominant inheritance with anticipation of age at onset. In the other family, the founders were blood relatives and there was no affected member in the third generation suggesting a recessive mode of inheritance. RLS/PLM is a prevalent sleep disorder affecting about 5 to 15% of the population and one that substantially impairs healthy sleep patterns. Efforts to understand the underlying pathophysiology will contribute to improve the sleep and life quality of these patients.

Parallel pathways of ethoxylated alcohol biodegradation under aerobic conditions

International Nuclear Information System (INIS)

Zembrzuska, Joanna; Budnik, Irena; Lukaszewski, Zenon

2016-01-01

Non-ionic surfactants (NS) are a major component of the surfactant flux discharged into surface water, and alcohol ethoxylates (AE) are the major component of this flux. Therefore, biodegradation pathways of AE deserve more thorough investigation. The aim of this work was to investigate the stages of biodegradation of homogeneous oxyethylated dodecanol C_1_2E_9 having 9 oxyethylene subunits, under aerobic conditions. Enterobacter strain Z3 bacteria were chosen as biodegrading organisms under conditions with C_1_2E_9 as the sole source of organic carbon. Bacterial consortia of river water were used in a parallel test as an inoculum for comparison. The LC-MS technique was used to identify the products of biodegradation. Liquid-liquid extraction with ethyl acetate was selected for the isolation of C_1_2E_9 and metabolites from the biodegradation broth. The LC-MS/MS technique operating in the multiple reaction monitoring (MRM) mode was used for quantitative determination of C_1_2E_9, C_1_2E_8, C_1_2E_7 and C_1_2E_6. Apart from the substrate, the homologues C_1_2E_8, C_1_2E_7 and C_1_2E_6, being metabolites of C_1_2E_9 biodegradation by shortening of the oxyethylene chain, as well as intermediate metabolites having a carboxyl end group in the oxyethylene chain (C_1_2E_8COOH, C_1_2E_7COOH, C_1_2E_6COOH and C_1_2E_5COOH), were identified. Poly(ethylene glycols) (E) having 9, 8 and 7 oxyethylene subunits were also identified, indicating parallel central fission of C_1_2E_9 and its metabolites. Similar results were obtained with river water as inoculum. It is concluded that AE, under aerobic conditions, are biodegraded via two parallel pathways: by central fission with the formation of PEG, and by Ω-oxidation of the oxyethylene chain with the formation of carboxylated AE and subsequent shortening of the oxyethylene chain by a single unit. - Highlights: • Two parallel biodegradation pathways of alcohol ethoxylates have been discovered. • Apart from central fission

Plectin isoforms as organizers of intermediate filament cytoarchitecture.

Science.gov (United States)

Wiche, Gerhard; Winter, Lilli

2011-01-01

Intermediate filaments (IFs) form cytoplamic and nuclear networks that provide cells with mechanical strength. Perturbation of this structural support causes cell and tissue fragility and accounts for a number of human genetic diseases. In recent years, important additional roles, nonmechanical in nature, were ascribed to IFs, including regulation of signaling pathways that control survival and growth of the cells, and vectorial processes such as protein targeting in polarized cellular settings. The cytolinker protein plectin anchors IF networks to junctional complexes, the nuclear envelope and cytoplasmic organelles and it mediates their cross talk with the actin and tubulin cytoskeleton. These functions empower plectin to wield significant influence over IF network cytoarchitecture. Moreover, the unusual diversity of plectin isoforms with different N termini and a common IF-binding (C-terminal) domain enables these isoforms to specifically associate with and thereby bridge IF networks to distinct cellular structures. Here we review the evidence for IF cytoarchitecture being controlled by specific plectin isoforms in different cell systems, including fibroblasts, endothelial cells, lens fibers, lymphocytes, myocytes, keratinocytes, neurons and astrocytes, and discuss what impact the absence of these isoforms has on IF cytoarchitecture-dependent cellular functions.

Intermediate-energy nuclear chemistry workshop

International Nuclear Information System (INIS)

Butler, G.W.; Giesler, G.C.; Liu, L.C.; Dropesky, B.J.; Knight, J.D.; Lucero, F.; Orth, C.J.

1981-05-01

This report contains the proceedings of the LAMPF Intermediate-Energy Nuclear Chemistry Workshop held in Los Alamos, New Mexico, June 23-27, 1980. The first two days of the Workshop were devoted to invited review talks highlighting current experimental and theoretical research activities in intermediate-energy nuclear chemistry and physics. Working panels representing major topic areas carried out indepth appraisals of present research and formulated recommendations for future research directions. The major topic areas were Pion-Nucleus Reactions, Nucleon-Nucleus Reactions and Nuclei Far from Stability, Mesonic Atoms, Exotic Interactions, New Theoretical Approaches, and New Experimental Techniques and New Nuclear Chemistry Facilities

Intermediate-energy nuclear chemistry workshop

Energy Technology Data Exchange (ETDEWEB)

Butler, G.W.; Giesler, G.C.; Liu, L.C.; Dropesky, B.J.; Knight, J.D.; Lucero, F.; Orth, C.J.

1981-05-01

This report contains the proceedings of the LAMPF Intermediate-Energy Nuclear Chemistry Workshop held in Los Alamos, New Mexico, June 23-27, 1980. The first two days of the Workshop were devoted to invited review talks highlighting current experimental and theoretical research activities in intermediate-energy nuclear chemistry and physics. Working panels representing major topic areas carried out indepth appraisals of present research and formulated recommendations for future research directions. The major topic areas were Pion-Nucleus Reactions, Nucleon-Nucleus Reactions and Nuclei Far from Stability, Mesonic Atoms, Exotic Interactions, New Theoretical Approaches, and New Experimental Techniques and New Nuclear Chemistry Facilities.

The ARES High-level Intermediate Representation

Energy Technology Data Exchange (ETDEWEB)

Moss, Nicholas David [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2017-03-03

The LLVM intermediate representation (IR) lacks semantic constructs for depicting common high-performance operations such as parallel and concurrent execution, communication and synchronization. Currently, representing such semantics in LLVM requires either extending the intermediate form (a signi cant undertaking) or the use of ad hoc indirect means such as encoding them as intrinsics and/or the use of metadata constructs. In this paper we discuss a work in progress to explore the design and implementation of a new compilation stage and associated high-level intermediate form that is placed between the abstract syntax tree and when it is lowered to LLVM's IR. This highlevel representation is a superset of LLVM IR and supports the direct representation of these common parallel computing constructs along with the infrastructure for supporting analysis and transformation passes on this representation.

Enriched pathways for major depressive disorder identified from a genome-wide association study.

Science.gov (United States)

Kao, Chung-Feng; Jia, Peilin; Zhao, Zhongming; Kuo, Po-Hsiu

2012-11-01

Major depressive disorder (MDD) has caused a substantial burden of disease worldwide with moderate heritability. Despite efforts through conducting numerous association studies and now, genome-wide association (GWA) studies, the success of identifying susceptibility loci for MDD has been limited, which is partially attributed to the complex nature of depression pathogenesis. A pathway-based analytic strategy to investigate the joint effects of various genes within specific biological pathways has emerged as a powerful tool for complex traits. The present study aimed to identify enriched pathways for depression using a GWA dataset for MDD. For each gene, we estimated its gene-wise p value using combined and minimum p value, separately. Canonical pathways from the Kyoto Encyclopedia of Genes and Genomes (KEGG) and BioCarta were used. We employed four pathway-based analytic approaches (gene set enrichment analysis, hypergeometric test, sum-square statistic, sum-statistic). We adjusted for multiple testing using Benjamini & Hochberg's method to report significant pathways. We found 17 significantly enriched pathways for depression, which presented low-to-intermediate crosstalk. The top four pathways were long-term depression (p⩽1×10-5), calcium signalling (p⩽6×10-5), arrhythmogenic right ventricular cardiomyopathy (p⩽1.6×10-4) and cell adhesion molecules (p⩽2.2×10-4). In conclusion, our comprehensive pathway analyses identified promising pathways for depression that are related to neurotransmitter and neuronal systems, immune system and inflammatory response, which may be involved in the pathophysiological mechanisms underlying depression. We demonstrated that pathway enrichment analysis is promising to facilitate our understanding of complex traits through a deeper interpretation of GWA data. Application of this comprehensive analytic strategy in upcoming GWA data for depression could validate the findings reported in this study.

Gasoline Engine Mechanics. Performance Objectives. Intermediate Course.

Science.gov (United States)

Jones, Marion

Several intermediate performance objectives and corresponding criterion measures are listed for each of six terminal objectives presented in this curriculum guide for an intermediate gasoline engine mechanics course at the secondary level. (For the beginning course guide see CE 010 947.) The materials were developed for a two-semester (2 hour…

Computed tomographic characteristics of collateral venous pathways in dogs with caudal vena cava obstruction.

Science.gov (United States)

Specchi, Swan; d'Anjou, Marc-André; Carmel, Eric Norman; Bertolini, Giovanna

2014-01-01

Collateral venous pathways develop in dogs with obstruction or increased blood flow resistance at any level of the caudal vena cava in order to maintain venous drainage to the right atrium. The purpose of this retrospective study was to describe the sites, causes of obstruction, and configurations of venous collateral pathways for a group of dogs with caudal vena cava obstruction. Computed tomography databases from two veterinary hospitals were searched for dogs with a diagnosis of caudal vena cava obstruction and multidetector row computed tomographic angiographic (CTA) scans that included the entire caudal vena cava. Images for each included dog were retrieved and collateral venous pathways were characterized using image postprocessing and a classification system previously reported for humans. A total of nine dogs met inclusion criteria and four major collateral venous pathways were identified: deep (n = 2), portal (n = 2), intermediate (n = 7), and superficial (n = 5). More than one collateral venous pathway was present in 5 dogs. An alternative pathway consisting of renal subcapsular collateral veins, arising mainly from the caudal pole of both kidneys, was found in three dogs. In conclusion, findings indicated that collateral venous pathway patterns similar to those described in humans are also present in dogs with caudal vena cava obstruction. These collateral pathways need to be distinguished from other vascular anomalies in dogs. Postprocessing of multidetector-row CTA images allowed delineation of the course of these complicated venous pathways and may be a helpful adjunct for treatment planning in future cases. © 2014 American College of Veterinary Radiology.

Tyrosine kinase signalling in breast cancer: Modulation of tyrosine kinase signalling in human breast cancer through altered expression of signalling intermediates

International Nuclear Information System (INIS)

Kairouz, Rania; Daly, Roger J

2000-01-01

The past decade has seen the definition of key signalling pathways downstream of receptor tyrosine kinases (RTKs) in terms of their components and the protein-protein interactions that facilitate signal transduction. Given the strong evidence that links signalling by certain families of RTKs to the progression of breast cancer, it is not surprising that the expression profile of key downstream signalling intermediates in this disease has also come under scrutiny, particularly because some exhibit transforming potential or amplify mitogenic signalling pathways when they are overexpressed. Reflecting the diverse cellular processes regulated by RTKs, it is now clear that altered expression of such signalling proteins in breast cancer may influence not only cellular proliferation (eg Grb2) but also the invasive properties of the cancer cells (eg EMS1/cortactin)

Mapping Intermediality in Performance

NARCIS (Netherlands)

2010-01-01

Mapping Intermediality in Performance benadert het vraagstuk van intermedialiteit met betrekking tot performance (vooral theater) vanuit vijf verschillende invalshoeken: performativiteit en lichaam; tijd en ruimte; digitale cultuur en posthumanisme; netwerken; pedagogiek en praxis. In deze boeiende

Microevolution of human archaic groups of Arica, northern Chile, and its genetic contribution to populations from the Formative Period Microevolución de grupos humanos arcaicos de Arica, norte de Chile, y su contribución genética a las poblaciones del Período Formativo

Directory of Open Access Journals (Sweden)

HÉCTOR HUGO VARELA

2006-06-01

Full Text Available The microevolution of the archaic populations from Chile's northern coast and its morphological contribution to Formative period groups was studied. The sample comprised 181 individuals belonging to two Archaic (Morro-Uhle and Morro 1-1/6 and one Formative (Playa Miller-7 [Plm-7] series of the coast and one sample from the Formative (Alto Ramírez exhumed at the Azapa Valley. A total of 29 metric variables of the cranium were analyzed. Biological variability was assessed using discriminant analysis and Mahalanobis' D² distance stadistic (MDS. Population structure was inferred using a method based on quantitative genetic theory that predicts a lineal relationship between average within-group phenotypic variance and group distance to the population centroid. The four samples studied proved to be different from a morphologic point of view. The greatest distance was observed between Plm-7 (coast Formative and Alto Ramirez (valley Formative, the least between Morro-Uhle and Morro 1-1/6, the remaining distances presenting intermediate values. Regarding the total population, the most divergent group was Alto Ramírez and the least divergent was Morro1-1/6. A gradual biologic change was observed between Archaic (Morro Uhle and Morro 1-1/6 and coastal Formative populations (Plm-7 pointing to a morphological (genetic contribution of Archaic fishermen to Formative population of Chile's northern coast, without excluding gene flow from other groups of the South Central Andean AreaEstudiamos la microevolución de las poblaciones arcaicas de la costa norte y sus contribuciones morfológicas al Período Formativo. La muestra comprendió 181 individuos pertenecientes a dos colecciones arcaicas de la costa (Morro-Uhle y Morro 1-1/6 y una al formativo (Alto Ramírez exhumada en el Valle de Azapa. Un total de 29 variables métricas del cráneo fueron analizadas. La variabilidad biológica fue determinada utilizando análisis discriminante y distancias de

Dolichol related intermediates involved in N-linked gloycoprotein synthesis in Drosophila Kc cells

International Nuclear Information System (INIS)

Sagami, H.; Chap, R.; Rivero, M.; Lennarz, W.J.

1986-01-01

The purpose of this investigation is to study the regulation of the biosynthesis of dolichyl phosphate (Dol-P) in embryonic cells. Using embryonic Drosophila Kc cells which are known to lack the squalene-cholesterol branch of polyisoprenoid biosynthetic pathway, the authors labeled the cells in suspension culture for 4 hrs with [5- 3 H]mevalonic acid. After harvesting the cells, the incorporated radioactive lipids were extracted with CHCl 3 /CH 3 OH (2/1). Analysis of the extract by a combination of several methods consisting of ion exchange chromatography on DEAE-cellulose, gel filtration on Fractogel TSK-HW 40, and silica gel thin layer chromatography revealed that the extract contained coenzyme Q, farnesol, dolichol (Dol), Dol-P, and dolichol-linked sugar (Dol-P-Sugar). In a pulse-chase experiment the metabolism of these intermediates was measured for various times up to 30 hrs. The amount of radioactivity in Dol slightly increased with the chase time, while that in Dol-P decreased. The amount of radioactive Dol-P-Sugar remained unchanged. These results suggest that the de novo end product in dolichol biosynthesis is Dol-P and that the level of Dol-P can be controlled by varying the rate of de novo biosynthesis and by dephosphorylation. The authors are now investigating the effect of ecdysone, the molting hormone, on the level of these intermediates and on incorporation of sugars into glycoproteins

Degradation of ibuprofen by hydrodynamic cavitation: Reaction pathways and effect of operational parameters.

Science.gov (United States)

Musmarra, Dino; Prisciandaro, Marina; Capocelli, Mauro; Karatza, Despina; Iovino, Pasquale; Canzano, Silvana; Lancia, Amedeo

2016-03-01

Ibuprofen (IBP) is an anti-inflammatory drug whose residues can be found worldwide in natural water bodies resulting in harmful effects to aquatic species even at low concentrations. This paper deals with the degradation of IBP in water by hydrodynamic cavitation in a convergent-divergent nozzle. Over 60% of ibuprofen was degraded in 60 min with an electrical energy per order (EEO) of 10.77 kWh m(-3) at an initial concentration of 200 μg L(-1) and a relative inlet pressure pin=0.35 MPa. Five intermediates generated from different hydroxylation reactions were identified; the potential mechanisms of degradation were sketched and discussed. The reaction pathways recognized are in line with the relevant literature, both experimental and theoretical. By varying the pressure upstream the constriction, different degradation rates were observed. This effect was discussed according to a numerical simulation of the hydroxyl radical production identifying a clear correspondence between the maximum kinetic constant kOH and the maximum calculated OH production. Furthermore, in the investigated experimental conditions, the pH parameter was found not to affect the extent of degradation; this peculiar feature agrees with a recently published kinetic insight and has been explained in the light of the intermediates of the different reaction pathways. Copyright © 2015 Elsevier B.V. All rights reserved.

Product Lifecycle Management and the Quest for Sustainable Space Explorations

Science.gov (United States)

Caruso, Pamela W.; Dumbacher, Daniel L.

2010-01-01

Product Lifecycle Management (PLM) is an outcome of lean thinking to eliminate waste and increase productivity. PLM is inextricably tied to the systems engineering business philosophy, coupled with a methodology by which personnel, processes and practices, and information technology combine to form an architecture platform for product design, development, manufacturing, operations, and decommissioning. In this model, which is being implemented by the Engineering Directorate at the National Aeronautics and Space Administration's (NASA's) Marshall Space Flight Center, total lifecycle costs are important variables for critical decision-making. With the ultimate goal to deliver quality products that meet or exceed requirements on time and within budget, PLM is a powerful concept to shape everything from engineering trade studies and testing goals, to integrated vehicle operations and retirement scenarios. This paper will demonstrate how the Engineering Directorate is implementing PLM as part of an overall strategy to deliver safe, reliable, and affordable space exploration solutions. It has been 30 years since the United States fielded the Space Shuttle. The next generation space transportation system requires a paradigm shift such that digital tools and knowledge management, which are central elements of PLM, are used consistently to maximum effect. The outcome is a better use of scarce resources, along with more focus on stakeholder and customer requirements, as a new portfolio of enabling tools becomes second nature to the workforce. This paper will use the design and manufacturing processes, which have transitioned to digital-based activities, to show how PLM supports the comprehensive systems engineering and integration function. It also will go through a launch countdown scenario where an anomaly is detected to show how the virtual vehicle created from paperless processes will help solve technical challenges and improve the likelihood of launching on schedule

Public-private partnerships improve health outcomes in individuals with early stage Alzheimer's disease.

Science.gov (United States)

Galvin, James E; Tolea, Magdalena I; George, Nika; Wingbermuehle, Cheryl

2014-01-01

In a collaborative effort between the Missouri Department of Health, Area Agencies on Aging (AAA), Alzheimer Association, and academic researchers, we tested whether early dementia detection and comprehensive care consultations would improve health outcomes in care receivers (CRs) and their family caregivers (FCGs), therefore addressing an important public health concern. A total of 244 community-dwelling older adults screened for early-stage dementia by the AAA field staff were referred to the Alzheimer Association and participated in Project Learn MORE (Missouri Outreach and Referral Expanded) (PLM) - a 2-year, nonrandomized multisite intervention consisting of comprehensive care consultations to improve coping skills. PLM participants were compared against 96 controls receiving the Alzheimer Association's "usual services" between January 2011 and December 2012. We examined CR and FCG outcomes, including burden, care confidence, and mood, as effects of PLM, on delaying transitions in level of care. CRs showed improved knowledge (P=0.002) and reduced depression (P=0.007), while FCGs demonstrated improved knowledge (P=0.003) and ability to identify sources of support for the CR (P=0.032) and for themselves (P=0.043). However, FCGs were more burdened after PLM (P=0.02), due to increased awareness of Alzheimer's disease. PLM delayed transitions in care (odds ratio [OR] 3.32, 95% confidence level [CI]: 1.25-8.83) with the number needed to treat =6.82. PLM was successful in improving detection of incident cases of dementia in the community and in connecting patients and their families with needed services. Our findings support the use of state agencies and community service partners to detect dementia. Early implementation of psychosocial interventions could have significant impact in improving patient- and family-centered outcomes, potentially providing a cost-efficient alternative to pharmacotherapy.

The Glycerate and Phosphorylated Pathways of Serine Synthesis in Plants: The Branches of Plant Glycolysis Linking Carbon and Nitrogen Metabolism.

Science.gov (United States)

Igamberdiev, Abir U; Kleczkowski, Leszek A

2018-01-01

Serine metabolism in plants has been studied mostly in relation to photorespiration where serine is formed from two molecules of glycine. However, two other pathways of serine formation operate in plants and represent the branches of glycolysis diverging at the level of 3-phosphoglyceric acid. One branch (the glycerate - serine pathway) is initiated in the cytosol and involves glycerate formation from 3-phosphoglycerate, while the other (the phosphorylated serine pathway) operates in plastids and forms phosphohydroxypyruvate as an intermediate. Serine formed in these pathways becomes a precursor of glycine, formate and glycolate accumulating in stress conditions. The pathways can be linked to GABA shunt via transamination reactions and via participation of the same reductase for both glyoxylate and succinic semialdehyde. In this review paper we present a hypothesis of the regulation of redox balance in stressed plant cells via participation of the reactions associated with glycerate and phosphorylated serine pathways. We consider these pathways as important processes linking carbon and nitrogen metabolism and maintaining cellular redox and energy levels in stress conditions.

The Intermediate Neutrino Program

CERN Document Server

Adams, C.; Ankowski, A.M.; Asaadi, J.A.; Ashenfelter, J.; Axani, S.N.; Babu, K.; Backhouse, C.; Band, H.R.; Barbeau, P.S.; Barros, N.; Bernstein, A.; Betancourt, M.; Bishai, M.; Blucher, E.; Bouffard, J.; Bowden, N.; Brice, S.; Bryan, C.; Camilleri, L.; Cao, J.; Carlson, J.; Carr, R.E.; Chatterjee, A.; Chen, M.; Chen, S.; Chiu, M.; Church, E.D.; Collar, J.I.; Collin, G.; Conrad, J.M.; Convery, M.R.; Cooper, R.L.; Cowen, D.; Davoudiasl, H.; de Gouvea, A.; Dean, D.J.; Deichert, G.; Descamps, F.; DeYoung, T.; Diwan, M.V.; Djurcic, Z.; Dolinski, M.J.; Dolph, J.; Donnelly, B.; Dwyer, D.A.; Dytman, S.; Efremenko, Y.; Everett, L.L.; Fava, A.; Figueroa-Feliciano, E.; Fleming, B.; Friedland, A.; Fujikawa, B.K.; Gaisser, T.K.; Galeazzi, M.; Galehouse, D.C.; Galindo-Uribarri, A.; Garvey, G.T.; Gautam, S.; Gilje, K.E.; Gonzalez-Garcia, M.; Goodman, M.C.; Gordon, H.; Gramellini, E.; Green, M.P.; Guglielmi, A.; Hackenburg, R.W.; Hackenburg, A.; Halzen, F.; Han, K.; Hans, S.; Harris, D.; Heeger, K.M.; Herman, M.; Hill, R.; Holin, A.; Huber, P.; Jaffe, D.E.; Johnson, R.A.; Joshi, J.; Karagiorgi, G.; Kaufman, L.J.; Kayser, B.; Kettell, S.H.; Kirby, B.J.; Klein, J.R.; Kolomensky, Yu. G.; Kriske, R.M.; Lane, C.E.; Langford, T.J.; Lankford, A.; Lau, K.; Learned, J.G.; Ling, J.; Link, J.M.; Lissauer, D.; Littenberg, L.; Littlejohn, B.R.; Lockwitz, S.; Lokajicek, M.; Louis, W.C.; Luk, K.; Lykken, J.; Marciano, W.J.; Maricic, J.; Markoff, D.M.; Martinez Caicedo, D.A.; Mauger, C.; Mavrokoridis, K.; McCluskey, E.; McKeen, D.; McKeown, R.; Mills, G.; Mocioiu, I.; Monreal, B.; Mooney, M.R.; Morfin, J.G.; Mumm, P.; Napolitano, J.; Neilson, R.; Nelson, J.K.; Nessi, M.; Norcini, D.; Nova, F.; Nygren, D.R.; Orebi Gann, G.D.; Palamara, O.; Parsa, Z.; Patterson, R.; Paul, P.; Pocar, A.; Qian, X.; Raaf, J.L.; Rameika, R.; Ranucci, G.; Ray, H.; Reyna, D.; Rich, G.C.; Rodrigues, P.; Romero, E.Romero; Rosero, R.; Rountree, S.D.; Rybolt, B.; Sanchez, M.C.; Santucci, G.; Schmitz, D.; Scholberg, K.; Seckel, D.; Shaevitz, M.; Shrock, R.; Smy, M.B.; Soderberg, M.; Sonzogni, A.; Sousa, A.B.; Spitz, J.; St. John, J.M.; Stewart, J.; Strait, J.B.; Sullivan, G.; Svoboda, R.; Szelc, A.M.; Tayloe, R.; Thomson, M.A.; Toups, M.; Vacheret, A.; Vagins, M.; Van de Water, R.G.; Vogelaar, R.B.; Weber, M.; Weng, W.; Wetstein, M.; White, C.; White, B.R.; Whitehead, L.; Whittington, D.W.; Wilking, M.J.; Wilson, R.J.; Wilson, P.; Winklehner, D.; Winn, D.R.; Worcester, E.; Yang, L.; Yeh, M.; Yokley, Z.W.; Yoo, J.; Yu, B.; Yu, J.; Zhang, C.

2015-01-01

The US neutrino community gathered at the Workshop on the Intermediate Neutrino Program (WINP) at Brookhaven National Laboratory February 4-6, 2015 to explore opportunities in neutrino physics over the next five to ten years. Scientists from particle, astroparticle and nuclear physics participated in the workshop. The workshop examined promising opportunities for neutrino physics in the intermediate term, including possible new small to mid-scale experiments, US contributions to large experiments, upgrades to existing experiments, R&D plans and theory. The workshop was organized into two sets of parallel working group sessions, divided by physics topics and technology. Physics working groups covered topics on Sterile Neutrinos, Neutrino Mixing, Neutrino Interactions, Neutrino Properties and Astrophysical Neutrinos. Technology sessions were organized into Theory, Short-Baseline Accelerator Neutrinos, Reactor Neutrinos, Detector R&D and Source, Cyclotron and Meson Decay at Rest sessions.This report summ...

Diclofenac degradation in water by FeCeOx catalyzed H2O2: Influencing factors, mechanism and pathways.

Science.gov (United States)

Chong, Shan; Zhang, Guangming; Zhang, Nan; Liu, Yucan; Huang, Ting; Chang, Huazhen

2017-07-15

The degradation of diclofenac in a like Fenton system, FeCeO x -H 2 O 2 , was studied in details. The influencing factors, reaction kinetics, reaction mechanism and degradation pathways of diclofenac were investigated. The optimum conditions were at a solution pH of 5.0, H 2 O 2 concentration of 3.0mmol/L, diclofenac initial concentration of 0.07mmol/L, FeCeO x dosage of 0.5g/L, and 84% degradation of diclofenac was achieved within 40min. The kinetics of FeCeO x catalyzed H 2 O 2 process involved adsorption-dominating and degradation-dominating stages and fitted pseudo-second order model and pseudo-first order model, respectively. Singlet oxygen 1 O 2 was the primary intermediate oxidative species in the degradation process; superoxide radical anion O 2 - also participated in the reaction. The surface cerium and iron sites and the oxygen vacancies in the FeCeO x catalyst were proposed to play an important role in H 2 O 2 decomposition and active species generation. The detected intermediates were identified as hydroxylated derivatives (m/z of 310, 326 and 298), quinone imine compounds (m/z of 308, 278 and 264) and hydroxyl phenylamine (m/z of 178). The majority intermediates were hydroxylated derivatives and the minority was hydroxyl phenylamine. The degradation pathways were proposed to involve hydroxylation, decarboxylation, dehydrogenation and CN bond cleavage. Copyright © 2017 Elsevier B.V. All rights reserved.

The homogentisate pathway: a central catabolic pathway involved in the degradation of L-phenylalanine, L-tyrosine, and 3-hydroxyphenylacetate in Pseudomonas putida.

Science.gov (United States)

Arias-Barrau, Elsa; Olivera, Elías R; Luengo, José M; Fernández, Cristina; Galán, Beatriz; García, José L; Díaz, Eduardo; Miñambres, Baltasar

2004-08-01

Pseudomonas putida metabolizes Phe and Tyr through a peripheral pathway involving hydroxylation of Phe to Tyr (PhhAB), conversion of Tyr into 4-hydroxyphenylpyruvate (TyrB), and formation of homogentisate (Hpd) as the central intermediate. Homogentisate is then catabolized by a central catabolic pathway that involves three enzymes, homogentisate dioxygenase (HmgA), fumarylacetoacetate hydrolase (HmgB), and maleylacetoacetate isomerase (HmgC), finally yielding fumarate and acetoacetate. Whereas the phh, tyr, and hpd genes are not linked in the P. putida genome, the hmgABC genes appear to form a single transcriptional unit. Gel retardation assays and lacZ translational fusion experiments have shown that hmgR encodes a specific repressor that controls the inducible expression of the divergently transcribed hmgABC catabolic genes, and homogentisate is the inducer molecule. Footprinting analysis revealed that HmgR protects a region in the Phmg promoter that spans a 17-bp palindromic motif and an external direct repetition from position -16 to position 29 with respect to the transcription start site. The HmgR protein is thus the first IclR-type regulator that acts as a repressor of an aromatic catabolic pathway. We engineered a broad-host-range mobilizable catabolic cassette harboring the hmgABC, hpd, and tyrB genes that allows heterologous bacteria to use Tyr as a unique carbon and energy source. Remarkably, we show here that the catabolism of 3-hydroxyphenylacetate in P. putida U funnels also into the homogentisate central pathway, revealing that the hmg cluster is a key catabolic trait for biodegradation of a small number of aromatic compounds.

Intermediate Inflation or Late Time Acceleration?

International Nuclear Information System (INIS)

Sanyal, A.K.

2008-01-01

The expansion rate of intermediate inflation lies between the exponential and power law expansion but corresponding accelerated expansion does not start at the onset of cosmological evolution. Present study of intermediate inflation reveals that it admits scaling solution and has got a natural exit form it at a later epoch of cosmic evolution, leading to late time acceleration. The corresponding scalar field responsible for such feature is also found to behave as a tracker field for gravity with canonical kinetic term.

On financial equilibrium with intermediation costs

DEFF Research Database (Denmark)

Markeprand, Tobias Ejnar

2008-01-01

This paper studies the set of competitive equilibria in financial economies with intermediation costs. We consider an arbitrary dividend structure, which includes options and equity with limited liabilities.We show a general existence result and upper-hemi continuity of the equilibrium correspond......This paper studies the set of competitive equilibria in financial economies with intermediation costs. We consider an arbitrary dividend structure, which includes options and equity with limited liabilities.We show a general existence result and upper-hemi continuity of the equilibrium...

Intermediate product selection and blending in the food processing industry

DEFF Research Database (Denmark)

Kilic, Onur A.; Akkerman, Renzo; van Donk, Dirk Pieter

2013-01-01

This study addresses a capacitated intermediate product selection and blending problem typical for two-stage production systems in the food processing industry. The problem involves the selection of a set of intermediates and end-product recipes characterising how those selected intermediates...

A multi-platform metabolomics approach demonstrates changes in energy metabolism and the transsulfuration pathway in Chironomus tepperi following exposure to zinc

International Nuclear Information System (INIS)

Long, Sara M.; Tull, Dedreia L.; Jeppe, Katherine J.; De Souza, David P.; Dayalan, Saravanan; Pettigrove, Vincent J.; McConville, Malcolm J.; Hoffmann, Ary A.

2015-01-01

Highlights: • An integrated metabolomics approach was applied to examine zinc exposure in midges. • Changes in carbohydrate and energy metabolism were observed using GC–MS. • Transsulfuration pathway is affected by zinc exposure. • Heavy metals other than zinc affect the transsulfuration pathways differently. - Abstract: Measuring biological responses in resident biota is a commonly used approach to monitoring polluted habitats. The challenge is to choose sensitive and, ideally, stressor-specific endpoints that reflect the responses of the ecosystem. Metabolomics is a potentially useful approach for identifying sensitive and consistent responses since it provides a holistic view to understanding the effects of exposure to chemicals upon the physiological functioning of organisms. In this study, we exposed the aquatic non-biting midge, Chironomus tepperi, to two concentrations of zinc chloride and measured global changes in polar metabolite levels using an untargeted gas chromatography–mass spectrometry (GC–MS) analysis and a targeted liquid chromatography–mass spectrometry (LC–MS) analysis of amine-containing metabolites. These data were correlated with changes in the expression of a number of target genes. Zinc exposure resulted in a reduction in levels of intermediates in carbohydrate metabolism (i.e., glucose 6-phosphate, fructose 6-phosphate and disaccharides) and an increase in a number of TCA cycle intermediates. Zinc exposure also resulted in decreases in concentrations of the amine containing metabolites, lanthionine, methionine and cystathionine, and an increase in metallothionein gene expression. Methionine and cystathionine are intermediates in the transsulfuration pathway which is involved in the conversion of methionine to cysteine. These responses provide an understanding of the pathways affected by zinc toxicity, and how these effects are different to other heavy metals such as cadmium and copper. The use of complementary

A multi-platform metabolomics approach demonstrates changes in energy metabolism and the transsulfuration pathway in Chironomus tepperi following exposure to zinc

Energy Technology Data Exchange (ETDEWEB)

Long, Sara M., E-mail: hoskins@unimelb.edu.au [Centre for Aquatic Pollution, Identification and Management (CAPIM), School of BioSciences, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, 30 Flemington Road, Parkville, 3052 (Australia); Tull, Dedreia L., E-mail: dedreia@unimelb.edu.au [Metabolomics Australia, Bio21 Molecular Science and Biotechnology Institute, 30 Flemington Road, Parkville, 3052 (Australia); Jeppe, Katherine J., E-mail: k.jeppe@unimelb.edu.au [Centre for Aquatic Pollution, Identification and Management (CAPIM), School of BioSciences, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, 30 Flemington Road, Parkville, 3052 (Australia); Centre for Aquatic Pollution, Identification and Management (CAPIM), School of BioSciences, The University of Melbourne, 3010 (Australia); De Souza, David P., E-mail: desouzad@unimelb.edu.au [Metabolomics Australia, Bio21 Molecular Science and Biotechnology Institute, 30 Flemington Road, Parkville, 3052 (Australia); Dayalan, Saravanan, E-mail: sdayalan@unimelb.edu.au [Metabolomics Australia, Bio21 Molecular Science and Biotechnology Institute, 30 Flemington Road, Parkville, 3052 (Australia); Pettigrove, Vincent J., E-mail: vpet@unimelb.edu.au [Centre for Aquatic Pollution, Identification and Management (CAPIM), School of BioSciences, The University of Melbourne, 3010 (Australia); McConville, Malcolm J., E-mail: malcolmm@unimelb.edu.au [Metabolomics Australia, Bio21 Molecular Science and Biotechnology Institute, 30 Flemington Road, Parkville, 3052 (Australia); Hoffmann, Ary A., E-mail: ary@unimelb.edu.au [Centre for Aquatic Pollution, Identification and Management (CAPIM), School of BioSciences, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, 30 Flemington Road, Parkville, 3052 (Australia); School of BioSciences, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, 30 Flemington Road, Parkville, 3052 (Australia)

2015-05-15

Highlights: • An integrated metabolomics approach was applied to examine zinc exposure in midges. • Changes in carbohydrate and energy metabolism were observed using GC–MS. • Transsulfuration pathway is affected by zinc exposure. • Heavy metals other than zinc affect the transsulfuration pathways differently. - Abstract: Measuring biological responses in resident biota is a commonly used approach to monitoring polluted habitats. The challenge is to choose sensitive and, ideally, stressor-specific endpoints that reflect the responses of the ecosystem. Metabolomics is a potentially useful approach for identifying sensitive and consistent responses since it provides a holistic view to understanding the effects of exposure to chemicals upon the physiological functioning of organisms. In this study, we exposed the aquatic non-biting midge, Chironomus tepperi, to two concentrations of zinc chloride and measured global changes in polar metabolite levels using an untargeted gas chromatography–mass spectrometry (GC–MS) analysis and a targeted liquid chromatography–mass spectrometry (LC–MS) analysis of amine-containing metabolites. These data were correlated with changes in the expression of a number of target genes. Zinc exposure resulted in a reduction in levels of intermediates in carbohydrate metabolism (i.e., glucose 6-phosphate, fructose 6-phosphate and disaccharides) and an increase in a number of TCA cycle intermediates. Zinc exposure also resulted in decreases in concentrations of the amine containing metabolites, lanthionine, methionine and cystathionine, and an increase in metallothionein gene expression. Methionine and cystathionine are intermediates in the transsulfuration pathway which is involved in the conversion of methionine to cysteine. These responses provide an understanding of the pathways affected by zinc toxicity, and how these effects are different to other heavy metals such as cadmium and copper. The use of complementary

Intermediate product selection and blending in the food processing industry

NARCIS (Netherlands)

Kilic, Onur A.; Akkerman, Renzo; van Donk, Dirk Pieter; Grunow, Martin

2013-01-01

This study addresses a capacitated intermediate product selection and blending problem typical for two-stage production systems in the food processing industry. The problem involves the selection of a set of intermediates and end-product recipes characterising how those selected intermediates are

Pathway of Fermentative Hydrogen Production by Sulfate-reducing Bacteria

Energy Technology Data Exchange (ETDEWEB)

Wall, Judy D. [Univ. of Missouri, Columbia, MO (United States)

2015-02-16

Biofuels are a promising source of sustainable energy. Such biofuels are intermediate products of microbial metabolism of renewable substrates, in particular, plant biomass. Not only are alcohols and solvents produced in this degradative process but energy-rich hydrogen as well. Non photosynthetic microbial hydrogen generation from compounds other than sugars has not been fully explored. We propose to examine the capacity of the abundant soil anaerobes, sulfate-reducing bacteria, for hydrogen generation from organic acids. These apparently simple pathways have yet to be clearly established. Information obtained may facilitate the exploitation of other microbes not yet readily examined by molecular tools. Identification of the flexibility of the metabolic processes to channel reductant to hydrogen will be useful in consideration of practical applications. Because the tools for genetic and molecular manipulation of sulfate-reducing bacteria of the genus Desulfovibrio are developed, our efforts will focus on two strains, D. vulgaris Hildenborough and Desulfovibrio G20.Therefore total metabolism, flux through the pathways, and regulation are likely to be limiting factors which we can elucidate in the following experiments.

Future possibilities with intermediate-energy neutron beams

International Nuclear Information System (INIS)

Brady, F.P.

1987-01-01

Future possibilities for using neutrons of intermediate energies (50 - 200 MeV) as a probe of the nucleus are discussed. Some of the recent thinking concerning a systematic approach for studying elastic and inelastic scattering of electrons and hadrons and the important role of medium- and intermediate-energy neutrons in such a programme is reviewed. The advantages of neutrons in this energy range over neutrons with lower energies and over intermediate-energy pions for determining nuclear-transition and ground state densities, and for distinguishing proton from neutron density (isovector sensitivity), are noted. The important role of (n,p) charge exchange reactions in nuclear excitation studies is also reviewed. Experimental methods for utilizing neutrons as probes in elastic, inelastic, and charge exchange studies at these energies are discussed

Reactive ground-state pathways are not ubiquitous in red/green cyanobacteriochromes.

Science.gov (United States)

Chang, Che-Wei; Gottlieb, Sean M; Kim, Peter W; Rockwell, Nathan C; Lagarias, J Clark; Larsen, Delmar S

2013-09-26

Recent characterization of the red/green cyanobacteriochrome (CBCR) NpR6012g4 revealed a high quantum yield for its forward photoreaction [J. Am. Chem. Soc. 2012, 134, 130-133] that was ascribed to the activity of hidden, productive ground-state intermediates. The dynamics of the pathways involving these ground-state intermediates was resolved with femtosecond dispersed pump-dump-probe spectroscopy, the first such study reported for any CBCR. To address the ubiquity of such second-chance initiation dynamics (SCID) in CBCRs, we examined the closely related red/green CBCR NpF2164g6 from Nostoc punctiforme. Both NpF2164g6 and NpR6012g4 use phycocyanobilin as the chromophore precursor and exhibit similar excited-state dynamics. However, NpF2164g6 exhibits a lower quantum yield of 32% for the generation of the isomerized Lumi-R primary photoproduct, compared to 40% for NpR6012g4. This difference arises from significantly different ground-state dynamics between the two proteins, with the SCID mechanism deactivated in NpF2164g6. We present an integrated inhomogeneous target model that self-consistently fits the pump-probe and pump-dump-probe signals for both forward and reverse photoreactions in both proteins. This work demonstrates that reactive ground-state intermediates are not ubiquitous phenomena in CBCRs.

Product Lifecycle Management and the Quest for Sustainable Space Exploration Solutions

Science.gov (United States)

Caruso, Pamela W.; Dumbacher, Daniel L.

2010-01-01

Product Lifecycle Management (PLM) is an outcome of lean thinking to eliminate waste and increase productivity. PLM is inextricably tied to the systems engineering business philosophy, coupled with a methodology by which personnel, processes and practices, and information technology combine to form an architecture platform for product design, development, manufacturing, operations, and decommissioning. In this model, which is being implemented by the Engineering Directorate at the National Aeronautics and Space Administration's (NASA's) Marshall Space Flight Center, total lifecycle costs are important variables for critical decisionmaking. With the ultimate goal to deliver quality products that meet or exceed requirements on time and within budget, PLM is a powerful tool to shape everything from engineering trade studies and testing goals, to integrated vehicle operations and retirement scenarios. This paper will demonstrate how the Engineering Directorate is implementing PLM as part of an overall strategy to deliver safe, reliable, and affordable space exploration solutions. It has been 30 years since the United States fielded the Space Shuttle. The next generation space transportation system requires a paradigm shift such that digital tools and knowledge management, which are central elements of PLM, are used consistently to maximum effect. The outcome is a better use of scarce resources, along with more focus on stakeholder and customer requirements, as a new portfolio of enabling tools becomes second nature to the workforce. This paper will use the design and manufacturing processes, which have transitioned to digital-based activities, to show how PLM supports the comprehensive systems engineering and integration function. It also will go through a launch countdown scenario where an anomaly is detected to show how the virtual vehicle created from paperless processes will help solve technical challenges and improve the likelihood of launching on schedule, with

The Intermediate Neutrino Program

Energy Technology Data Exchange (ETDEWEB)

Adams, C.; et al.

2015-03-23

The US neutrino community gathered at the Workshop on the Intermediate Neutrino Program (WINP) at Brookhaven National Laboratory February 4-6, 2015 to explore opportunities in neutrino physics over the next five to ten years. Scientists from particle, astroparticle and nuclear physics participated in the workshop. The workshop examined promising opportunities for neutrino physics in the intermediate term, including possible new small to mid-scale experiments, US contributions to large experiments, upgrades to existing experiments, R&D plans and theory. The workshop was organized into two sets of parallel working group sessions, divided by physics topics and technology. Physics working groups covered topics on Sterile Neutrinos, Neutrino Mixing, Neutrino Interactions, Neutrino Properties and Astrophysical Neutrinos. Technology sessions were organized into Theory, Short-Baseline Accelerator Neutrinos, Reactor Neutrinos, Detector R&D and Source, Cyclotron and Meson Decay at Rest sessions.This report summarizes discussion and conclusions from the workshop.

The Intermediate Neutrino Program

Energy Technology Data Exchange (ETDEWEB)

Adams, C. [Yale Univ., New Haven, CT (United States); Alonso, J. R. [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Ankowski, A. M. [Virginia Polytechnic Inst. and State Univ. (Virginia Tech), Blacksburg, VA (United States); Asaadi, J. A. [Syracuse Univ., NY (United States); Ashenfelter, J. [Yale Univ., New Haven, CT (United States); Axani, S. N. [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Babu, K [Oklahoma State Univ., Stillwater, OK (United States); Backhouse, C. [California Inst. of Technology (CalTech), Pasadena, CA (United States); Band, H. R. [Yale Univ., New Haven, CT (United States); Barbeau, P. S. [Duke Univ., Durham, NC (United States); Barros, N. [Univ. of Pennsylvania, Philadelphia, PA (United States); Bernstein, A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Betancourt, M. [Illinois Inst. of Technology, Chicago, IL (United States); Bishai, M. [Brookhaven National Lab. (BNL), Upton, NY (United States); Blucher, E. [Univ. of Chicago, IL (United States); Bouffard, J. [State Univ. of New York (SUNY), Albany, NY (United States); Bowden, N. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Brice, S. [Illinois Inst. of Technology, Chicago, IL (United States); Bryan, C. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Camilleri, L. [Columbia Univ., New York, NY (United States); Cao, J. [Inst. of High Energy Physics, Beijing (China); Carlson, J. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Carr, R. E. [Columbia Univ., New York, NY (United States); Chatterjee, A. [Univ. of Texas, Arlington, TX (United States); Chen, M. [Univ. of California, Irvine, CA (United States); Chen, S. [Tsinghua Univ., Beijing (China); Chiu, M. [Brookhaven National Lab. (BNL), Upton, NY (United States); Church, E. D. [Illinois Inst. of Technology, Chicago, IL (United States); Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Collar, J. I. [Univ. of Chicago, IL (United States); Collin, G. [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Conrad, J. M. [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Convery, M. R. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Cooper, R. L. [Indiana Univ., Bloomington, IN (United States); Cowen, D. [Pennsylvania State Univ., University Park, PA (United States); Davoudiasl, H. [Brookhaven National Lab. (BNL), Upton, NY (United States); Gouvea, A. D. [Northwestern Univ., Evanston, IL (United States); Dean, D. J. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Deichert, G. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Descamps, F. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); DeYoung, T. [Michigan State Univ., East Lansing, MI (United States); Diwan, M. V. [Brookhaven National Lab. (BNL), Upton, NY (United States); Djurcic, Z. [Argonne National Lab. (ANL), Argonne, IL (United States); Dolinski, M. J. [Drexel Univ., Philadelphia, PA (United States); Dolph, J. [Brookhaven National Lab. (BNL), Upton, NY (United States); Donnelly, B. [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Dwyer, D. A. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Dytman, S. [Univ. of Pittsburgh, PA (United States); Efremenko, Y. [Univ. of Tennessee, Knoxville, TN (United States); Everett, L. L. [Univ. of Wisconsin, Madison, WI (United States); Fava, A. [University of Padua, Padova (Italy); Figueroa-Feliciano, E. [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Fleming, B. [Yale Univ., New Haven, CT (United States); Friedland, A. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Fujikawa, B. K. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Gaisser, T. K. [Univ. of Delaware, Newark, DE (United States); Galeazzi, M. [Univ. of Miami, FL (United States); Galehouse, DC [Univ. of Akron, OH (United States); Galindo-Uribarri, A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Garvey, G. T. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Gautam, S. [Tribhuvan Univ., Kirtipur (Nepal); Gilje, K. E. [Illinois Inst. of Technology, Chicago, IL (United States); Gonzalez-Garcia, M. [Stony Brook Univ., NY (United States); Goodman, M. C. [Argonne National Lab. (ANL), Argonne, IL (United States); Gordon, H. [Brookhaven National Lab. (BNL), Upton, NY (United States); Gramellini, E. [Yale Univ., New Haven, CT (United States); Green, M. P. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Guglielmi, A. [University of Padua, Padova (Italy); Hackenburg, R. W. [Brookhaven National Lab. (BNL), Upton, NY (United States); Hackenburg, A. [Yale Univ., New Haven, CT (United States); Halzen, F. [Univ. of Wisconsin, Madison, WI (United States); Han, K. [Yale Univ., New Haven, CT (United States); Hans, S. [Brookhaven National Lab. (BNL), Upton, NY (United States); Harris, D. [Illinois Inst. of Technology, Chicago, IL (United States); Heeger, K. M. [Yale Univ., New Haven, CT (United States); Herman, M. [Brookhaven National Lab. (BNL), Upton, NY (United States); Hill, R. [Univ. of Chicago, IL (United States); Holin, A. [Univ. College London, Bloomsbury (United Kingdom); Huber, P. [Virginia Polytechnic Inst. and State Univ. (Virginia Tech), Blacksburg, VA (United States); Jaffe, D. E. [Brookhaven National Lab. (BNL), Upton, NY (United States); Johnson, R. A. [Univ. of Cincinnati, OH (United States); Joshi, J. [Brookhaven National Lab. (BNL), Upton, NY (United States); Karagiorgi, G. [Univ. of Manchester (United Kingdom); Kaufman, L. J. [Indiana Univ., Bloomington, IN (United States); Kayser, B. [Illinois Inst. of Technology, Chicago, IL (United States); Kettell, S. H. [Brookhaven National Lab. (BNL), Upton, NY (United States); Kirby, B. J. [Brookhaven National Lab. (BNL), Upton, NY (United States); Klein, J. R. [Univ. of Texas, Arlington, TX (United States); Kolomensky, Y. G. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Univ. of California, Berkeley, CA (United States); Kriske, R. M. [Univ. of Minnesota, Minneapolis, MN (United States); Lane, C. E. [Drexel Univ., Philadelphia, PA (United States); Langford, T. J. [Yale Univ., New Haven, CT (United States); Lankford, A. [Univ. of California, Irvine, CA (United States); Lau, K. [Univ. of Houston, TX (United States); Learned, J. G. [Univ. of Hawaii, Honolulu, HI (United States); Ling, J. [Univ. of Illinois, Urbana-Champaign, IL (United States); Link, J. M. [Virginia Polytechnic Inst. and State Univ. (Virginia Tech), Blacksburg, VA (United States); Lissauer, D. [Brookhaven National Lab. (BNL), Upton, NY (United States); Littenberg, L. [Brookhaven National Lab. (BNL), Upton, NY (United States); Littlejohn, B. R. [Illinois Inst. of Technology, Chicago, IL (United States); Lockwitz, S. [Illinois Inst. of Technology, Chicago, IL (United States); Lokajicek, M. [Inst. of Physics of the Academy of Sciences of Czech Republic, Prague (Czech Republic); Louis, W. C. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Luk, K. [Univ. of California, Berkeley, CA (United States); Lykken, J. [Illinois Inst. of Technology, Chicago, IL (United States); Marciano, W. J. [Brookhaven National Lab. (BNL), Upton, NY (United States); Maricic, J. [Univ. of Hawaii, Honolulu, HI (United States); Markoff, D. M. [North Carolina Central Univ., Durham, NC (United States); Caicedo, D. A. M. [Illinois Inst. of Technology, Chicago, IL (United States); Mauger, C. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Mavrokoridis, K. [Univ. of Liverpool (United Kingdom); McCluskey, E. [Illinois Inst. of Technology, Chicago, IL (United States); McKeen, D. [Univ. of Washington, Seattle, WA (United States); McKeown, R. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Mills, G. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Mocioiu, I. [Pennsylvania State Univ., University Park, PA (United States); Monreal, B. [Univ. of California, Santa Barbara, CA (United States); Mooney, M. R. [Brookhaven National Lab. (BNL), Upton, NY (United States); Morfin, J. G. [Illinois Inst. of Technology, Chicago, IL (United States); Mumm, P. [National Inst. of Standards and Technology (NIST), Boulder, CO (United States); Napolitano, J. [Temple Univ., Philadelphia, PA (United States); Neilson, R. [Drexel Univ., Philadelphia, PA (United States); Nelson, J. K. [College of William and Mary, Williamsburg, VA (United States); Nessi, M. [European Organization for Nuclear Research (CERN), Geneva (Switzerland); Norcini, D. [Yale Univ., New Haven, CT (United States); Nova, F. [Univ. of Texas, Austin, TX (United States); Nygren, D. R. [Univ. of Texas, Arlington, TX (United States); Gann, GDO [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Univ. of California, Berkeley, CA (United States); Palamara, O. [Illinois Inst. of Technology, Chicago, IL (United States); Parsa, Z. [Brookhaven National Lab. (BNL), Upton, NY (United States); Patterson, R. [California Inst. of Technology (CalTech), Pasadena, CA (United States); Paul, P. [Stony Brook Univ., NY (United States); Pocar, A. [Univ. of Massachusetts, Amherst, MA (United States); Qian, X. [Brookhaven National Lab. (BNL), Upton, NY (United States); Raaf, J. L. [Illinois Inst. of Technology, Chicago, IL (United States); Rameika, R. [Illinois Inst. of Technology, Chicago, IL (United States); Ranucci, G. [National Inst. of Nuclear Physics, Milano (Italy); Ray, H. [Univ. of Florida, Gainesville, FL (United States); Reyna, D. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Rich, G. C. [Triangle Universities Nuclear Lab., Durham, NC (United States); Rodrigues, P. [Univ. of Rochester, NY (United States); Romero, E. R. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Univ. of Tennessee, Knoxville, TN (United States); Rosero, R. [Brookhaven National Lab. (BNL), Upton, NY (United States); Rountree, S. D. [Virginia Polytechnic Inst. and State Univ. (Virginia Tech), Blacksburg, VA (United States); Rybolt, B. [Univ. of Tennessee, Knoxville, TN (United States); Sanchez, M. C. [Iowa State Univ., Ames, IA (United States); Santucci, G. [Stony Brook Univ., NY (United States); Schmitz, D. [Univ. of Chicago, IL (United States); Scholberg, K. [Duke Univ., Durham, NC (United States); Seckel, D. [Univ. of Delaware, Newark, DE (United States); Shaevitz, M. [Columbia Univ., New York, NY (United States); Shrock, R. [Stony Brook Univ., NY (United States); Smy, M. B. [Univ. of California, Irvine, CA (United States); Soderberg, M. [Syracuse Univ., NY (United States); Sonzogni, A. [Brookhaven National Lab. (BNL), Upton, NY (United States); Sousa, A. B. [Univ. of Cincinnati, OH (United States); Spitz, J. [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); John, J. M. S. [Univ. of Cincinnati, OH (United States); Stewart, J. [Brookhaven National Lab. (BNL), Upton, NY (United States); Strait, J. B. [Illinois Inst. of Technology, Chicago, IL (United States); Sullivan, G. [Univ. of Maryland, College Park, MD (United States); Svoboda, R. [Univ. of California, Davis, CA (United States); Szelc, A. M. [Yale Univ., New Haven, CT (United States); Tayloe, R. [Indiana Univ., Bloomington, IN (United States); Thomson, M. A. [Univ. of Cambridge (United Kingdom); Toups, M. [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Vacheret, A. [Univ. of Oxford (United Kingdom); Vagins, M. [Univ. of California, Irvine, CA (United States); Water, R. G. V. D. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Vogelaar, R. B. [Virginia Polytechnic Inst. and State Univ. (Virginia Tech), Blacksburg, VA (United States); Weber, M. [Bern (Switzerland); Weng, W. [Brookhaven National Lab. (BNL), Upton, NY (United States); Wetstein, M. [Univ. of Chicago, IL (United States); White, C. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); White, B. R. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Whitehead, L. [Univ. of Houston, TX (United States); Whittington, D. W. [Indiana Univ., Bloomington, IN (United States); Wilking, M. J. [Stony Brook Univ., NY (United States); Wilson, R. J. [Colorado State Univ., Fort Collins, CO (United States); Wilson, P. [Illinois Inst. of Technology, Chicago, IL (United States); Winklehner, D. [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Winn, D. R. [Fairfield Univ., CT (United States); Worcester, E. [Brookhaven National Lab. (BNL), Upton, NY (United States); Yang, L. [Univ. of Illinois, Urbana-Champaign, IL (United States); Yeh, M [Brookhaven National Lab. (BNL), Upton, NY (United States); Yokley, Z. W. [Virginia Polytechnic Inst. and State Univ. (Virginia Tech), Blacksburg, VA (United States); Yoo, J. [Illinois Inst. of Technology, Chicago, IL (United States); Yu, B. [Brookhaven National Lab. (BNL), Upton, NY (United States); Yu, J. [Univ. of Texas, Arlington, TX (United States); Zhang, C. [Brookhaven National Lab. (BNL), Upton, NY (United States)

2017-04-03

The US neutrino community gathered at the Workshop on the Intermediate Neutrino Program (WINP) at Brookhaven National Laboratory February 4-6, 2015 to explore opportunities in neutrino physics over the next five to ten years. Scientists from particle, astroparticle and nuclear physics participated in the workshop. The workshop examined promising opportunities for neutrino physics in the intermediate term, including possible new small to mid-scale experiments, US contributions to large experiments, upgrades to existing experiments, R&D plans and theory. The workshop was organized into two sets of parallel working group sessions, divided by physics topics and technology. Physics working groups covered topics on Sterile Neutrinos, Neutrino Mixing, Neutrino Interactions, Neutrino Properties and Astrophysical Neutrinos. Technology sessions were organized into Theory, Short-Baseline Accelerator Neutrinos, Reactor Neutrinos, Detector R&D and Source, Cyclotron and Meson Decay at Rest sessions.This report summarizes discussion and conclusions from the workshop.

Pathway and Molecular Mechanisms for Malachite Green Biodegradation in Exiguobacterium sp. MG2

Science.gov (United States)

Wang, Ji’ai; Gao, Feng; Liu, Zhongzhong; Qiao, Min; Niu, Xuemei; Zhang, Ke-Qin; Huang, Xiaowei

2012-01-01

Malachite green (MG), N-methylated diaminotriphenylmethane, is one of the most common dyes in textile industry and has also been used as an effective antifungal agent. However, due to its negative impact on the environment and carcinogenic effects to mammalian cells, there is a significant interest in developing microbial agents to degrade this type of recalcitrant molecules. Here, an Exiguobacterium sp. MG2 was isolated from a river in Yunnan Province of China as one of the best malachite green degraders. This strain had a high decolorization capability even at the concentration of 2500 mg/l and maintained its stable activity within the pH range from 5.0 to 9.0. High-pressure liquid chromatography, liquid chromatography-mass spectrometry and gas chromatography–mass spectrometry were employed to detect the catabolic pathway of MG. Six intermediate products were identified and a potential biodegradation pathway was proposed. This pathway involves a series of reactions of N-demethylation, reduction, benzene ring-removal, and oxidation, which eventually converted N-methylated diaminotriphenylmethane into N, N-dimethylaniline that is the key precursor to MG. Furthermore, our molecular biology experiments suggested that both triphenylmethane reductase gene tmr and cytochrome P450 participated in MG degradation, consistent with their roles in the proposed pathway. Collectively, our investigation is the first report on a biodegradation pathway of triphenylmethane dye MG in bacteria. PMID:23251629

Chemical pathways for the formation of ammonia in Hanford wastes

Energy Technology Data Exchange (ETDEWEB)

Stock, L.M.; Pederson, L.R.

1997-09-01

This report reviews chemical reactions leading to the formation of ammonia in Hanford wastes. The general features of the chemistry of the organic compounds in the Hanford wastes are briefly outlined. The radiolytic and thermal free radical reactions that are responsible for the initiation and propagation of the oxidative degradation reactions of the nitrogen-containing complexants, trisodium HEDTA and tetrasodium EDTA, are outlined. In addition, the roles played by three different ionic reaction pathways for the oxidation of the same compounds and their degradation products are described as a prelude to the discussion of the formation of ammonia. The reaction pathways postulated for its formation are based on tank observations, laboratory studies with simulated and actual wastes, and the review of the scientific literature. Ammonia derives from the reduction of nitrite ion (most important), from the conversion of organic nitrogen in the complexants and their degradation products, and from radiolytic reactions of nitrous oxide and nitrogen (least important). Reduction of nitrite ions is believed to be the most important source of ammonia. Whether by radiolytic or thermal routes, nitrite reduction reactions proceed through nitrogen dioxide, nitric oxide, the nitrosyl anion, and the hyponitrite anion. Nitrite ion is also converted into hydroxylamine, another important intermediate on the pathway to form ammonia. These reaction pathways additionally result in the formation of nitrous oxide and molecular nitrogen, whereas hydrogen formation is produced in a separate reaction sequence.

Chemical pathways for the formation of ammonia in Hanford wastes

International Nuclear Information System (INIS)

Stock, L.M.; Pederson, L.R.

1997-09-01

This report reviews chemical reactions leading to the formation of ammonia in Hanford wastes. The general features of the chemistry of the organic compounds in the Hanford wastes are briefly outlined. The radiolytic and thermal free radical reactions that are responsible for the initiation and propagation of the oxidative degradation reactions of the nitrogen-containing complexants, trisodium HEDTA and tetrasodium EDTA, are outlined. In addition, the roles played by three different ionic reaction pathways for the oxidation of the same compounds and their degradation products are described as a prelude to the discussion of the formation of ammonia. The reaction pathways postulated for its formation are based on tank observations, laboratory studies with simulated and actual wastes, and the review of the scientific literature. Ammonia derives from the reduction of nitrite ion (most important), from the conversion of organic nitrogen in the complexants and their degradation products, and from radiolytic reactions of nitrous oxide and nitrogen (least important). Reduction of nitrite ions is believed to be the most important source of ammonia. Whether by radiolytic or thermal routes, nitrite reduction reactions proceed through nitrogen dioxide, nitric oxide, the nitrosyl anion, and the hyponitrite anion. Nitrite ion is also converted into hydroxylamine, another important intermediate on the pathway to form ammonia. These reaction pathways additionally result in the formation of nitrous oxide and molecular nitrogen, whereas hydrogen formation is produced in a separate reaction sequence

Comments on intermediate-scale models

International Nuclear Information System (INIS)

Ellis, J.; Enqvist, K.; Nanopoulos, D.V.; Olive, K.

1987-01-01

Some superstring-inspired models employ intermediate scales m I of gauge symmetry breaking. Such scales should exceed 10 16 GeV in order to avoid prima facie problems with baryon decay through heavy particles and non-perturbative behaviour of the gauge couplings above m I . However, the intermediate-scale phase transition does not occur until the temperature of the Universe falls below O(m W ), after which an enormous excess of entropy is generated. Moreover, gauge symmetry breaking by renormalization group-improved radiative corrections is inapplicable because the symmetry-breaking field has not renormalizable interactions at scales below m I . We also comment on the danger of baryon and lepton number violation in the effective low-energy theory. (orig.)

Multinucleation during C. trachomatis infections is caused by the contribution of two effector pathways.

Directory of Open Access Journals (Sweden)

Heather M Brown

Full Text Available Chlamydia trachomatis is an obligate intracellular bacterial pathogen and the second leading cause of sexually transmitted infections in the US. Infections cause significant morbidity and can lead to serious reproductive sequelae, including an epidemiological link to increased rates of reproductive cancers. One of the overt changes that infected cells exhibit is the development of genomic instability leading to multinucleation. Here we demonstrate that the induction of multinucleation is not conserved equally across chlamydial species; C. trachomatis L2 caused high levels of multinucleation, C. muridarum intermediate levels, and C. caviae had very modest effects on multinucleation. Our data show that at least two effector pathways together cause genomic instability during infection leading to multinucleation. We find that the highly conserved chlamydial protease CPAF is a key effector for one of these pathways. CPAF secretion is required for the loss of centrosome duplication regulation as well as inducing early mitotic exit. The second effector pathway involves the induction of centrosome position errors. This function is not conserved in three chlamydial species tested. Together these two pathways contribute to the induction of high levels of genomic instability and multinucleation seen in C. trachomatis infections.

Surface Intermediate Zone of Submerged Turbulent Buoyant Jet in Current

DEFF Research Database (Denmark)

Chen, H. B.; Larsen, Torben

1995-01-01

This paper deals with the intermediate zone between the jet and plume stages of a submerged buoyant discharge from sea outfall in current. The stability criteria, plume width and height after the intermediate zone and the dilution within the intermediate region have been studied theoretically and...

Computational uncertainties in silicon dioxide/plutonium intermediate neutron spectrum systems

International Nuclear Information System (INIS)

Jaegers, P.J.

1997-01-01

In the past several years, several proposals have been made for the long-term stabilization and storage of surplus fissile materials. Many of these proposed scenarios involve systems that have an intermediate neutron energy spectrum. Such intermediate-energy systems are dominated by scattering and fission events induced by neutrons ranging in energy from 1 eV to 100keV. To ensure adequate safety margins and cost effectiveness, it is necessary to have benchmark data for these intermediate-energy spectrum systems; however, a review of the nuclear criticality benchmarks indicates that no formal benchmarks are available. Nuclear data uncertainties have been reported for some types of intermediate-energy spectrum systems. Using a variety of Monte Carlo computer codes and cross-section sets, reported significant variations in the calculated k ∞ of intermediate-energy spectrum metal/ 235 U systems. We discuss the characteristics of intermediate neutron spectrum systems and some of the computational differences that can occur in calculating the k eff of these systems

On the stability of rotational discontinuities and intermediate shocks

International Nuclear Information System (INIS)

Lee, L.C.; Huang, L.; Chao, J.K.

1989-01-01

The stability of rotational discontinuities and intermediate shocks is studied based on a hybrid simulation code. The simulation results show that rotational discontinuities are stable and intermediate shocks are not stationary. Intermediate shocks tend to evolve to rotational discontinuities and waves. The authors employ several different initial profiles for the magnetic field in the transition region and find that the final structure of the discontinuities or shocks is not sensitive to the initial magnetic field profile. The present results are different from those obtained from the resistive MHD simulations. Furthermore, their study indicates that the kinetic effect of particles plays an important role in the structure and stability of rotational discontinuities and intermediate shocks

Development of a computer code for low-and intermediate-level radioactive waste disposal safety assessment

International Nuclear Information System (INIS)

Park, J. W.; Kim, C. L.; Lee, E. Y.; Lee, Y. M.; Kang, C. H.; Zhou, W.; Kozak, M. W.

2002-01-01

A safety assessment code, called SAGE (Safety Assessment Groundwater Evaluation), has been developed to describe post-closure radionuclide releases and potential radiological doses for low- and intermediate-level radioactive waste (LILW) disposal in an engineered vault facility in Korea. The conceptual model implemented in the code is focused on the release of radionuclide from a gradually degrading engineered barrier system to an underlying unsaturated zone, thence to a saturated groundwater zone. The radionuclide transport equations are solved by spatially discretizing the disposal system into a series of compartments. Mass transfer between compartments is by diffusion/dispersion and advection. In all compartments, radionuclides are decayed either as a single-member chain or as multi-member chains. The biosphere is represented as a set of steady-state, radionuclide-specific pathway dose conversion factors that are multiplied by the appropriate release rate from the far field for each pathway. The code has the capability to treat input parameters either deterministically or probabilistically. Parameter input is achieved through a user-friendly Graphical User Interface. An application is presented, which is compared against safety assessment results from the other computer codes, to benchmark the reliability of system-level conceptual modeling of the code

MNE Entrepreneurial Capabilities at Intermediate Levels

DEFF Research Database (Denmark)

Hoenen, Anne K.; Nell, Phillip Christopher; Ambos, Björn

2014-01-01

at intermediate geographical levels differ from local subsidiaries and global corporate headquarters, and why those differences are important. We illustrate our arguments using data on European regional headquarters (RHQs). We find that RHQs' entrepreneurial capabilities depend on their external embeddedness...... and on the heterogeneous information that is generated through dissimilar markets within the region. Our study opens up for an interesting discussion of the independence of these mechanisms. In sum, we contribute to the understanding of the entrepreneurial role of intermediate units in general and RHQs in particular....

Financial Intermediation and Economic Growth of Jordan 1964-1988

OpenAIRE

Magableh, Ali H.

1995-01-01

Until recently, the economics and financial literature placed little attention on the role that financial intermediation can play in accelerating the rate of economic development in less Developed Countries (LDCs). This has been changed now, however, where some instrumental role has been emphasised for financial intermediation in the process of economic development and growth. It is argued that an expansion of the financial system, size and intermediation in LDCs tends to increase the level o...

Perspective: Spectroscopy and kinetics of small gaseous Criegee intermediates

International Nuclear Information System (INIS)

Lee, Yuan-Pern

2015-01-01

The Criegee intermediates, carbonyl oxides proposed by Criegee in 1949 as key intermediates in the ozonolysis of alkenes, play important roles in many aspects of atmospheric chemistry. Because direct detection of these gaseous intermediates was unavailable until recently, previous understanding of their reactions, derived from indirect experimental evidence, had great uncertainties. Recent laboratory detection of the simplest Criegee intermediate CH 2 OO and some larger members, produced from ultraviolet irradiation of corresponding diiodoalkanes in O 2 , with various methods such as photoionization, ultraviolet absorption, infrared absorption, and microwave spectroscopy opens a new door to improved understanding of the roles of these Criegee intermediates. Their structures and spectral parameters have been characterized; their significant zwitterionic nature is hence confirmed. CH 2 OO, along with other products, has also been detected directly with microwave spectroscopy in gaseous ozonolysis reactions of ethene. The detailed kinetics of the source reaction, CH 2 I + O 2 , which is critical to laboratory studies of CH 2 OO, are now understood satisfactorily. The kinetic investigations using direct detection identified some important atmospheric reactions, including reactions with NO 2 , SO 2 , water dimer, carboxylic acids, and carbonyl compounds. Efforts toward the characterization of larger Criegee intermediates and the investigation of related reactions are in progress. Some reactions of CH 3 CHOO are found to depend on conformation. This perspective examines progress toward the direct spectral characterization of Criegee intermediates and investigations of the associated reaction kinetics, and indicates some unresolved problems and prospective challenges for this exciting field of research

Surface intermediates on metal electrodes at high temperatures

DEFF Research Database (Denmark)

Zachau-Christiansen, Birgit; Jacobsen, Torben; Bay, Lasse

1998-01-01

The mechanisms widely conceived for the O(2)-reduction or H(2)-oxidation reactions in SOFC's involve intermediate O/H species adsorbed on the electrode surface. The presence of these intermediates is investigated by linear sweep voltammetry. In air at moderate temperatures (500 degrees C) Pt...

Intermediate-Mass Black Holes

Science.gov (United States)

Miller, M. Coleman; Colbert, E. J. M.

2004-01-01

The mathematical simplicity of black holes, combined with their links to some of the most energetic events in the universe, means that black holes are key objects for fundamental physics and astrophysics. Until recently, it was generally believed that black holes in nature appear in two broad mass ranges: stellar-mass (M~3 20 M⊙), which are produced by the core collapse of massive stars, and supermassive (M~106 1010 M⊙), which are found in the centers of galaxies and are produced by a still uncertain combination of processes. In the last few years, however, evidence has accumulated for an intermediate-mass class of black holes, with M~102 104 M⊙. If such objects exist they have important implications for the dynamics of stellar clusters, the formation of supermassive black holes, and the production and detection of gravitational waves. We review the evidence for intermediate-mass black holes and discuss future observational and theoretical work that will help clarify numerous outstanding questions about these objects.

Intermediate Levels of Visual Processing

National Research Council Canada - National Science Library

Nakayama, Ken

1998-01-01

...) surface representation, here we have shown that there is an intermediate level of visual processing, between the analysis of the image and higher order representations related to specific objects; (2...

Intermediate energy proton and light-ion scattering

International Nuclear Information System (INIS)

Moss, J.M.

1981-01-01

A review is presented of recent (1979-81) developments in the field of intermediate-energy proton and light-ion scattering from nuclei. New theoretical and calculational techniques of particular interest to experimentalists are discussed. Emphasis is placed on topics in nuclear structure physics - giant resonances, pion-condensation precursor phenomena, and polarization transfer (spin-flip) experiments - where intermediate energy proton and light-ion scattering has made new and unique contributions

Parallel pathways of ethoxylated alcohol biodegradation under aerobic conditions

Energy Technology Data Exchange (ETDEWEB)

Zembrzuska, Joanna, E-mail: Joanna.Zembrzuska@put.poznan.pl; Budnik, Irena, E-mail: Irena.Budnik@gmail.com; Lukaszewski, Zenon, E-mail: zenon.lukaszewski@put.poznan.pl

2016-07-01

Non-ionic surfactants (NS) are a major component of the surfactant flux discharged into surface water, and alcohol ethoxylates (AE) are the major component of this flux. Therefore, biodegradation pathways of AE deserve more thorough investigation. The aim of this work was to investigate the stages of biodegradation of homogeneous oxyethylated dodecanol C{sub 12}E{sub 9} having 9 oxyethylene subunits, under aerobic conditions. Enterobacter strain Z3 bacteria were chosen as biodegrading organisms under conditions with C{sub 12}E{sub 9} as the sole source of organic carbon. Bacterial consortia of river water were used in a parallel test as an inoculum for comparison. The LC-MS technique was used to identify the products of biodegradation. Liquid-liquid extraction with ethyl acetate was selected for the isolation of C{sub 12}E{sub 9} and metabolites from the biodegradation broth. The LC-MS/MS technique operating in the multiple reaction monitoring (MRM) mode was used for quantitative determination of C{sub 12}E{sub 9}, C{sub 12}E{sub 8}, C{sub 12}E{sub 7} and C{sub 12}E{sub 6}. Apart from the substrate, the homologues C{sub 12}E{sub 8}, C{sub 12}E{sub 7} and C{sub 12}E{sub 6}, being metabolites of C{sub 12}E{sub 9} biodegradation by shortening of the oxyethylene chain, as well as intermediate metabolites having a carboxyl end group in the oxyethylene chain (C{sub 12}E{sub 8}COOH, C{sub 12}E{sub 7}COOH, C{sub 12}E{sub 6}COOH and C{sub 12}E{sub 5}COOH), were identified. Poly(ethylene glycols) (E) having 9, 8 and 7 oxyethylene subunits were also identified, indicating parallel central fission of C{sub 12}E{sub 9} and its metabolites. Similar results were obtained with river water as inoculum. It is concluded that AE, under aerobic conditions, are biodegraded via two parallel pathways: by central fission with the formation of PEG, and by Ω-oxidation of the oxyethylene chain with the formation of carboxylated AE and subsequent shortening of the oxyethylene chain by a

Microchemical Plant in a Liquid Droplet: Plasmonic Liquid Marble for Sequential Reactions and Attomole Detection of Toxin at Microliter Scale.

Science.gov (United States)

Han, Xuemei; Koh, Charlynn Sher Lin; Lee, Hiang Kwee; Chew, Wee Shern; Ling, Xing Yi

2017-11-15

Miniaturizing the continuous multistep operations of a factory into a microchemical plant offers a safe and cost-effective approach to promote high-throughput screening in drug development and enforcement of industrial/environmental safety. While particle-assembled microdroplets in the form of liquid marble are ideal as microchemical plant, these platforms are mainly restricted to single-step reactions and limited to ex situ reaction monitoring. Herein, we utilize plasmonic liquid marble (PLM), formed by encapsulating liquid droplet with Ag nanocubes, to address these issues and demonstrate it as an ideal microchemical plant to conduct reaction-and-detection sequences on-demand in a nondisruptive manner. Utilizing a two-step azo-dye formation as our model reaction, our microchemical plant allows rapid and efficient diazotization of nitroaniline to form diazonium nitrobenzene, followed by the azo coupling of this intermediate with target aromatic compound to yield azo-dye. These molecular events are tracked in situ via SERS measurement through the plasmonic shell and further verified with in silico investigation. Furthermore, we apply our microchemical plant for ultrasensitive SERS detection and quantification of bisphenol A (BPA) with detection limit down to 10 amol, which is 50 000-fold lower than the BPA safety limit. Together with the protections offered by plasmonic shell against external environments, these collective advantages empower PLM as a multifunctional microchemical plant to facilitate small-volume testing and optimization of processes relevant in industrial and research contexts.

Comments on intermediate-scale models

Energy Technology Data Exchange (ETDEWEB)

Ellis, J.; Enqvist, K.; Nanopoulos, D.V.; Olive, K.

1987-04-23

Some superstring-inspired models employ intermediate scales m/sub I/ of gauge symmetry breaking. Such scales should exceed 10/sup 16/ GeV in order to avoid prima facie problems with baryon decay through heavy particles and non-perturbative behaviour of the gauge couplings above m/sub I/. However, the intermediate-scale phase transition does not occur until the temperature of the Universe falls below O(m/sub W/), after which an enormous excess of entropy is generated. Moreover, gauge symmetry breaking by renormalization group-improved radiative corrections is inapplicable because the symmetry-breaking field has not renormalizable interactions at scales below m/sub I/. We also comment on the danger of baryon and lepton number violation in the effective low-energy theory.

Proceedings of the Workshop on Program Options in Intermediate-Energy Physics. Keynote address: New directions in intermediate-energy nuclear physics

International Nuclear Information System (INIS)

Brown, G.E.

1980-05-01

This report presents the keynote address given by G.E. Brown at a LASL colloquium on August 21, 1979, for the Workshop on Program Options in Intermediate-Energy Physics. Professor Brown reviewed major topics of interest in intermediate-energy nuclear physics and suggested experimental approaches that might be most productive in the near future. 22 figures

Manganese-Oxygen Intermediates in O-O Bond Activation and Hydrogen-Atom Transfer Reactions.

Science.gov (United States)

Rice, Derek B; Massie, Allyssa A; Jackson, Timothy A

2017-11-21

Biological systems capitalize on the redox versatility of manganese to perform reactions involving dioxygen and its derivatives superoxide, hydrogen peroxide, and water. The reactions of manganese enzymes influence both human health and the global energy cycle. Important examples include the detoxification of reactive oxygen species by manganese superoxide dismutase, biosynthesis by manganese ribonucleotide reductase and manganese lipoxygenase, and water splitting by the oxygen-evolving complex of photosystem II. Although these enzymes perform very different reactions and employ structurally distinct active sites, manganese intermediates with peroxo, hydroxo, and oxo ligation are commonly proposed in catalytic mechanisms. These intermediates are also postulated in mechanisms of synthetic manganese oxidation catalysts, which are of interest due to the earth abundance of manganese. In this Account, we describe our recent efforts toward understanding O-O bond activation pathways of Mn III -peroxo adducts and hydrogen-atom transfer reactivity of Mn IV -oxo and Mn III -hydroxo complexes. In biological and synthetic catalysts, peroxomanganese intermediates are commonly proposed to decay by either Mn-O or O-O cleavage pathways, although it is often unclear how the local coordination environment influences the decay mechanism. To address this matter, we generated a variety of Mn III -peroxo adducts with varied ligand environments. Using parallel-mode EPR and Mn K-edge X-ray absorption techniques, the decay pathway of one Mn III -peroxo complex bearing a bulky macrocylic ligand was investigated. Unlike many Mn III -peroxo model complexes that decay to oxo-bridged-Mn III Mn IV dimers, decay of this Mn III -peroxo adduct yielded mononuclear Mn III -hydroxo and Mn IV -oxo products, potentially resulting from O-O bond activation of the Mn III -peroxo unit. These results highlight the role of ligand sterics in promoting the formation of mononuclear products and mark an important

Reaction pathway and oxidation mechanisms of dibutyl phthalate by persulfate activated with zero-valent iron

Energy Technology Data Exchange (ETDEWEB)

Li, Huanxuan [School of Environment and Energy, South China University of Technology, Guangzhou 510006 (China); The Key Lab of Pollution Control and Ecosystem Restoration in Industry Clusters, Ministry of Education, China, Guangzhou 510640 (China); Wan, Jinquan, E-mail: ppjqwan@scut.edu.cn [School of Environment and Energy, South China University of Technology, Guangzhou 510006 (China); The Key Lab of Pollution Control and Ecosystem Restoration in Industry Clusters, Ministry of Education, China, Guangzhou 510640 (China); State Key Lab Pulp and Paper Engineering, South China University of Technology, Guangzhou 510640 (China); Ma, Yongwen [School of Environment and Energy, South China University of Technology, Guangzhou 510006 (China); The Key Lab of Pollution Control and Ecosystem Restoration in Industry Clusters, Ministry of Education, China, Guangzhou 510640 (China); State Key Lab Pulp and Paper Engineering, South China University of Technology, Guangzhou 510640 (China); Wang, Yan [School of Environment and Energy, South China University of Technology, Guangzhou 510006 (China); The Key Lab of Pollution Control and Ecosystem Restoration in Industry Clusters, Ministry of Education, China, Guangzhou 510640 (China)

2016-08-15

This study investigated reaction pathway and oxidation mechanisms of dibutyl phthalate (DBP) by persulfate (PS) activated with zero-valent iron (ZVI). The DBP degradation was studied at three pH values (acidic, neutral and basic) in the presence of different organic scavengers. Using a chemical probe method, both sulfate radical (SO{sub 4}·{sup −}) and hydroxyl radical (·OH) were found to be primary oxidants at pH 3.0 and pH 7.0, respectively while ·OH was the major specie to oxidize DBP at pH 11.0. A similar result was found in an experiment of Electron Spin Resonance spin-trapping where in addition to ·OH, superoxide radical (O{sub 2}·{sup −}) was detected at pH 11.0. The transformation of degradation products including dimethyl phthalate (DMP), diethyl phthalate (DEP), phthalic anhydride, and acetophenone exhibited diverse variation during the reaction processes. The phthalic anhydride concentration appeared to be maximum at all pHs. Another eleven intermediate products were also found at pH 3.0 by GC–MS and HPLC analysis, and their degradation mechanisms and pathways were proposed. It was suggested that dealkylation, hydroxylation, decarboxylation and hydrogen extraction were the dominant degradation mechanisms of DBP at pH 3.0. - Highlights: • Both SO{sub 4}{sup −}· and ·OH were found to be the major active species at pH 3.0 and pH 7.0. • ·OH and ·O2– were the primary oxidants pH 11.0. • The intermediate products were investigated as well as the degradation pathway. • Dealkylation, hydroxylation, decarboxylation, H-extraction were the major mechanisms.

Projecting non-diffracting waves with intermediate-plane holography.

Science.gov (United States)

Mondal, Argha; Yevick, Aaron; Blackburn, Lauren C; Kanellakopoulos, Nikitas; Grier, David G

2018-02-19

We introduce intermediate-plane holography, which substantially improves the ability of holographic trapping systems to project propagation-invariant modes of light using phase-only diffractive optical elements. Translating the mode-forming hologram to an intermediate plane in the optical train can reduce the need to encode amplitude variations in the field, and therefore complements well-established techniques for encoding complex-valued transfer functions into phase-only holograms. Compared to standard holographic trapping implementations, intermediate-plane holograms greatly improve diffraction efficiency and mode purity of propagation-invariant modes, and so increase their useful non-diffracting range. We demonstrate this technique through experimental realizations of accelerating modes and long-range tractor beams.

Surface Intermediates on Metal Electrodes at High Temperature

DEFF Research Database (Denmark)

Zachau-Christiansen, Birgit; Jacobsen, Torben; Bay, Lasse

1997-01-01

The mechanisms widely suggested for the O2-reduc-tion or H2-oxidation SOFC reactions involve inter-mediate O/H species adsorbed on the electrode surface. The presence of these intermediates is investigated by linear sweep voltammetry. In airat moderate temperatures (500øC) Pt in contact with YSZ...

Filling gaps in bacterial amino acid biosynthesis pathways with high-throughput genetics.

Directory of Open Access Journals (Sweden)

Morgan N Price

2018-01-01

Full Text Available For many bacteria with sequenced genomes, we do not understand how they synthesize some amino acids. This makes it challenging to reconstruct their metabolism, and has led to speculation that bacteria might be cross-feeding amino acids. We studied heterotrophic bacteria from 10 different genera that grow without added amino acids even though an automated tool predicts that the bacteria have gaps in their amino acid synthesis pathways. Across these bacteria, there were 11 gaps in their amino acid biosynthesis pathways that we could not fill using current knowledge. Using genome-wide mutant fitness data, we identified novel enzymes that fill 9 of the 11 gaps and hence explain the biosynthesis of methionine, threonine, serine, or histidine by bacteria from six genera. We also found that the sulfate-reducing bacterium Desulfovibrio vulgaris synthesizes homocysteine (which is a precursor to methionine by using DUF39, NIL/ferredoxin, and COG2122 proteins, and that homoserine is not an intermediate in this pathway. Our results suggest that most free-living bacteria can likely make all 20 amino acids and illustrate how high-throughput genetics can uncover previously-unknown amino acid biosynthesis genes.

Processing and validation of intermediate energy evaluated data files

International Nuclear Information System (INIS)

2000-01-01

Current accelerator-driven and other intermediate energy technologies require accurate nuclear data to model the performance of the target/blanket assembly, neutron production, activation, heating and damage. In a previous WPEC subgroup, SG13 on intermediate energy nuclear data, various aspects of intermediate energy data, such as nuclear data needs, experiments, model calculations and file formatting issues were investigated and categorized to come to a joint evaluation effort. The successor of SG13, SG14 on the processing and validation of intermediate energy evaluated data files, goes one step further. The nuclear data files that have been created with the aforementioned information need to be processed and validated in order to be applicable in realistic intermediate energy simulations. We emphasize that the work of SG14 excludes the 0-20 MeV data part of the neutron evaluations, which is supposed to be covered elsewhere. This final report contains the following sections: section 2: a survey of the data files above 20 MeV that have been considered for validation in SG14; section 3: a summary of the review of the 150 MeV intermediate energy data files for ENDF/B-VI and, more briefly, the other libraries; section 4: validation of the data library against an integral experiment with MCNPX; section 5: conclusions. (author)

Examining Escherichia coli glycolytic pathways, catabolite repression, and metabolite channeling using Δpfk mutants

DEFF Research Database (Denmark)

Hollinshead, Whitney D.; Rodriguez, Sarah; Martin, Hector Garcia

2016-01-01

Background: Glycolysis breakdowns glucose into essential building blocks and ATP/NAD(P)H for the cell, occupying a central role in its growth and bio-production. Among glycolytic pathways, the Entner Doudoroff pathway (EDP) is a more thermodynamically favorable pathway with fewer enzymatic steps...... directed through the EDP (~20 % of glycolysis flux). Disrupting the EMPP by phosphofructokinase I (pfkA) knockout increased flux through OPPP (~60 % of glycolysis flux) and the native EDP (~14 % of glycolysis flux), while overexpressing edd and eda in this ΔpfkA mutant directed ~70 % of glycolytic flux...... in glycolysis intermediates, possibly suggesting metabolite channeling (metabolites in glycolysis are pass from enzyme to enzyme without fully equilibrating within the cytosol medium). Conclusions: We engineered E. coli to redistribute its native glycolytic flux. The replacement of EMPP by EDP did not improve E...

An improved intermediate resonance method for heterogeneous media

International Nuclear Information System (INIS)

Chiovato, O.; Corno, S.; Pasquantonio, F.Di.

1977-01-01

A new formulation is described of the Intermediate Resonance method which incorporates the previous developments suitably modified and improved, together with some new contributions. The 'intermediate' character is directly introduced in the integral operator K, allowing a more rigorous deduction of the equations for evaluating the intermediate parameters related to the nuclides involved in the system. There is no limit to the number of internal (admixed in the fuel) and external moderators. The capability to take into account the interference scattering has been extended to heterogeneous systems. The Doppler broadening is described by means of new accurate rational approximations to the broadened line shape psi. Finally the use of energy mean values suitably defined refines the values of the resonance integrals and resonance absorption cross sections. The Intermediate Resonance method so extended and improved, has been coded in a group of FORTRAN routines, which have been inserted as a calculation option in the fast section of the GGC code for the evaluation of multigroup cross sections. A series of calculations has been carried out, using these routines, and comparisons have been made with Monte Carlo and Nordheim's methods. The results obtained show that the Intermediate Resonance method developed in the present work offers considerable advantages over Nordheim's method: better accuracy in evaluating resonance absorption cross sections, and much smaller computing times. (author)

PathwayAccess: CellDesigner plugins for pathway databases.

Science.gov (United States)

Van Hemert, John L; Dickerson, Julie A

2010-09-15

CellDesigner provides a user-friendly interface for graphical biochemical pathway description. Many pathway databases are not directly exportable to CellDesigner models. PathwayAccess is an extensible suite of CellDesigner plugins, which connect CellDesigner directly to pathway databases using respective Java application programming interfaces. The process is streamlined for creating new PathwayAccess plugins for specific pathway databases. Three PathwayAccess plugins, MetNetAccess, BioCycAccess and ReactomeAccess, directly connect CellDesigner to the pathway databases MetNetDB, BioCyc and Reactome. PathwayAccess plugins enable CellDesigner users to expose pathway data to analytical CellDesigner functions, curate their pathway databases and visually integrate pathway data from different databases using standard Systems Biology Markup Language and Systems Biology Graphical Notation. Implemented in Java, PathwayAccess plugins run with CellDesigner version 4.0.1 and were tested on Ubuntu Linux, Windows XP and 7, and MacOSX. Source code, binaries, documentation and video walkthroughs are freely available at http://vrac.iastate.edu/~jlv.

An ll-Diaminopimelate Aminotransferase Defines a Novel Variant of the Lysine Biosynthesis Pathway in Plants1[W

Science.gov (United States)

Hudson, André O.; Singh, Bijay K.; Leustek, Thomas; Gilvarg, Charles

2006-01-01

Although lysine (Lys) biosynthesis in plants is known to occur by way of a pathway that utilizes diaminopimelic acid (DAP) as a central intermediate, the available evidence suggests that none of the known DAP-pathway variants found in nature occur in plants. A new Lys biosynthesis pathway has been identified in Arabidopsis (Arabidopsis thaliana) that utilizes a novel transaminase that specifically catalyzes the interconversion of tetrahydrodipicolinate and ll-diaminopimelate, a reaction requiring three enzymes in the DAP-pathway variant found in Escherichia coli. The ll-DAP aminotransferase encoded by locus At4g33680 was able to complement the dapD and dapE mutants of E. coli. This result, in conjunction with the kinetic properties and substrate specificity of the enzyme, indicated that ll-DAP aminotransferase functions in the Lys biosynthetic direction under in vivo conditions. Orthologs of At4g33680 were identified in all the cyanobacterial species whose genomes have been sequenced. The Synechocystis sp. ortholog encoded by locus sll0480 showed the same functional properties as At4g33680. These results demonstrate that the Lys biosynthesis pathway in plants and cyanobacteria is distinct from the pathways that have so far been defined in microorganisms. PMID:16361515

Complete subunit structure of the Clostridium botulinum type D toxin complex via intermediate assembly with nontoxic components.

Science.gov (United States)

Mutoh, Shingo; Kouguchi, Hirokazu; Sagane, Yoshimasa; Suzuki, Tomonori; Hasegawa, Kimiko; Watanabe, Toshihiro; Ohyama, Tohru

2003-09-23

Clostridium botulinum serotype D strains usually produce two types of stable toxin complex (TC), namely, the 300 kDa M (M-TC) and the 660 kDa L (L-TC) toxin complexes. We previously proposed assembly pathways for both TCs [Kouguchi, H., et al. (2002) J. Biol. Chem. 277, 2650-2656]: M-TC is composed by association of neurotoxin (NT) and nontoxic nonhemagglutinin (NTNHA); conjugation of M-TC with three auxiliary types of hemagglutinin subcomponents (HA-33, HA-17, and HA-70) leads to the formation of L-TC. In this study, we found three TC species, 410, 540, and 610 kDa TC species, in the culture supernatant of type D strain 4947. The 540 and 610 kDa TC species displayed banding patterns on SDS-PAGE similar to that of L-TC but with less staining intensity of the HA-33 and HA-17 bands than those of L-TC, indicating that these are intermediate species in the pathway to L-TC assembly. In contrast, the 410 kDa TC species consisted of M-TC and two molecules of HA-70. All of the TC species, except L-TC, demonstrated no hemagglutination activity. When the intermediate TC species were mixed with an isolated HA-33/17 complex, every TC species converted to 650 kDa L-TC with full hemagglutination activity and had the same molecular composition of L-TC. On the basis of titration analysis with the HA-33/17 complex, the stoichiometry of the HA-33/17 complex molecules in the L-TC, 610 kDa, and 540 kDa TC species was estimated as 4, 3, and 2, respectively. In conclusion, the complete subunit composition of mature L-TC is deduced to be a dodecamer assembled by a single NT, a single NTNHA, two HA-70, four HA-33, and four HA-17 molecules.

Decisive Intermediates Responsible for the Carbonaceous Products of CO₂ Electro-reduction on Nitrogen-Doped sp² Nanocarbon Catalysts in NaHCO₃ Aqueous Electrolyte

DEFF Research Database (Denmark)

Xu, Junyuan; Zhang, Bingsen; Wang, Bolun

2017-01-01

CO2 and a secondary pathway leading to HCO2− from HCO3−. Neither hydrocarbon (CxHy) nor alcohol or aldehyde (CxHyOz) were detected in the reduction of CO2. However, CO, which is generally regarded as an intermediate to be transformed into these products on metal catalysts, can undoubtedly be produced...

Kinetic evidence for the formation of discrete 1,4-dehydrobenzene intermediates. Trapping by inter- and intramolecular hydrogen atom transfer and observation of high-temperature CIDNP

Energy Technology Data Exchange (ETDEWEB)

Lockhart, Thomas P. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Univ. of California, Berkeley, CA (United States); California Inst. of Technology (CalTech), Pasadena, CA (United States); Comita, Paul B. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Univ. of California, Berkeley, CA (United States); California Inst. of Technology (CalTech), Pasadena, CA (United States); Bergman, Robert G. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Univ. of California, Berkeley, CA (United States); California Inst. of Technology (CalTech), Pasadena, CA (United States)

1981-07-01

Upon heating, alkyl-substituted cis-1,2-diethynyl olefins undergo cyclization to yield reactive 1,4-dehydrobenzenes; the products isolated may be derived from either unimolecular or bimolecular reactions of the intermediate. (Z)-4,5-Diethynyl-4-octene (4) undergoes rearrangement to yield 2,3-di-n-propyl-1,4-dehydrobenzene (17). Solution pyrolysis of 4 in inert aromatic solvents produces three unimolecular products, (Z)-dodeca-4,8-diyn-6-ene (7), benzocyclooctene (9), and o-allyl-n-propylbenzene (10), in high yield. When 1,4-cyclohexadiene is added to the pyrolysis solution as a trapping agent, high yields of the reduced product o-di-n-propylbenzene (12) are obtained. The kinetics of solution pyrolysis of 4 in the presence and absence of trapping agent establish that 2,3-di-n-propyl-1,4-dehydrobenzene is a discrete intermediate on the pathway leading to products. When the reaction was run in the heated probe of an NMR spectrometer, CIDNP was observed in 10. This observation, along with kinetic and chemical trapping evidence, indicates the presence of two additional intermediates, formed from 17 by sequential intramolecular [1,5] hydrogen transfer, on the pathway to products. The observation of CIDNP, coupled with the reactivity exhibited by 17 and the other two intermediates, implicate a biradical description of these molecules. Biradical 17 has been estimated to have a lifetime of about 10^-9 s at 200°C and to lie in a well of about 5 kcal/mol with respect to the lowest energy unimolecular pathway ([1,5] hydrogen transfer). Ring opening (expected to be the lowest energy process for 1,4-dehydrobenzenes in which intramolecular hydrogen transfer is unlikely) to the isomeric diethynyl olefin 7 appears to have an activation enthalpy of about 10 kcal/moL Upon thermal reaction in the gas phase (400°C) or in solution in inert solvents (Z)-hexa-2,3-diethyl-1,5-diyn-3-ene (5) rearranges in good yield to the isomeric diethynyl olefin (Z)-deca-3,7-diyn-5-ene (8

The management of intermediate level wastes in Sweden

International Nuclear Information System (INIS)

Hultgren, Aa.; Thegerstroem, C.

1980-01-01

A brief overview of current practices and research in Sweden on the management of intermediate level wastes is given. Intermediate level wastes include spent resins, filters and core components from the six power reactors in operation; radioactive wastes from nuclear fuel development at Studsvik and from non-nuclear applications are a minor contribution. (Auth.)

Dynamic Modelling Reveals 'Hotspots' on the Pathway to Enzyme-Substrate Complex Formation.

Directory of Open Access Journals (Sweden)

Shane E Gordon

2016-03-01

Full Text Available Dihydrodipicolinate synthase (DHDPS catalyzes the first committed step in the diaminopimelate pathway of bacteria, yielding amino acids required for cell wall and protein biosyntheses. The essentiality of the enzyme to bacteria, coupled with its absence in humans, validates DHDPS as an antibacterial drug target. Conventional drug design efforts have thus far been unsuccessful in identifying potent DHDPS inhibitors. Here, we make use of contemporary molecular dynamics simulation and Markov state models to explore the interactions between DHDPS from the human pathogen Staphylococcus aureus and its cognate substrate, pyruvate. Our simulations recover the crystallographic DHDPS-pyruvate complex without a priori knowledge of the final bound structure. The highly conserved residue Arg140 was found to have a pivotal role in coordinating the entry of pyruvate into the active site from bulk solvent, consistent with previous kinetic reports, indicating an indirect role for the residue in DHDPS catalysis. A metastable binding intermediate characterized by multiple points of intermolecular interaction between pyruvate and key DHDPS residue Arg140 was found to be a highly conserved feature of the binding trajectory when comparing alternative binding pathways. By means of umbrella sampling we show that these binding intermediates are thermodynamically metastable, consistent with both the available experimental data and the substrate binding model presented in this study. Our results provide insight into an important enzyme-substrate interaction in atomistic detail that offers the potential to be exploited for the discovery of more effective DHDPS inhibitors and, in a broader sense, dynamic protein-drug interactions.

Approach on Lifecycles on Research Environment and Analysis Based on Systems Engineering (SE)

OpenAIRE

Lintala , Marja; Ovtcharova , Jivka; Bonnal , Pierre

2012-01-01

Part 8: Formalization for PLM; International audience; In recent years, researchers and industrial communities have been increasingly interested in Product Lifecycle Management (PLM); hence the product lifecycles have received considerable attention. The general features of the lifecycles are well known, however the special character of the equipment in research environment: the particularly long life, experimental character, complexity and interdisciplinary, are still not completely understo...

Role of the reaction intermediates in determining PHIP (parahydrogen induced polarization) effect in the hydrogenation of acetylene dicarboxylic acid with the complex [Rh (dppb)]+ (dppb: 1,4-bis(diphenylphosphino)butane)

International Nuclear Information System (INIS)

Reineri, F.; Aime, S.; Gobetto, R.; Nervi, C.

2014-01-01

This study deals with the parahydrogenation of the symmetric substrate acetylene dicarboxylic acid catalyzed by a Rh(I) complex bearing the chelating diphosphine dppb (1,4-bis(diphenylphosphino)butane). The two magnetically equivalent protons of the product yield a hyperpolarized emission signal in the 1 H-NMR spectrum. Their polarization intensity varies upon changing the reaction solvent from methanol to acetone. A detailed analysis of the hydrogenation pathway is carried out by means of density functional theory calculations to assess the structure of hydrogenation intermediates and their stability in the two solvents. The observed polarization effects have been accounted on the basis of the obtained structures. Insights into the lifetime of a short-lived reaction intermediate are also obtained

Functional analysis of aromatic biosynthetic pathways in Pseudomonas putida KT2440

Science.gov (United States)

Molina‐Henares, M. Antonia; García‐Salamanca, Adela; Molina‐Henares, A. Jesús; De La Torre, Jesús; Herrera, M. Carmen; Ramos, Juan L.; Duque, Estrella

2009-01-01

Summary Pseudomonas putida KT2440 is a non‐pathogenic prototrophic bacterium with high potential for biotechnological applications. Despite all that is known about this strain, the biosynthesis of essential chemicals has not been fully analysed and auxotroph mutants are scarce. We carried out massive mini‐Tn5 random mutagenesis and screened for auxotrophs that require aromatic amino acids. The biosynthesis of aromatic amino acids was analysed in detail including physical and transcriptional organization of genes, complementation assays and feeding experiments to establish pathway intermediates. There is a single pathway from chorismate leading to the biosynthesis of tryptophan, whereas the biosynthesis of phenylalanine and tyrosine is achieved through multiple convergent pathways. Genes for tryptophan biosynthesis are grouped in unlinked regions with the trpBA and trpGDE genes organized as operons and the trpI, trpE and trpF genes organized as single transcriptional units. The pheA and tyrA gene‐encoding multifunctional enzymes for phenylalanine and tyrosine biosynthesis are linked in the chromosome and form an operon with the serC gene involved in serine biosynthesis. The last step in the biosynthesis of these two amino acids requires an amino transferase activity for which multiple tyrB‐like genes are present in the host chromosome. PMID:21261884

Catalytic effect of KF-846 on the reforming of the primary intermediates from the co-pyrolysis of pubescens and LDPE

International Nuclear Information System (INIS)

Liu, Wen-wu; Hu, Chang-wei; Tong, Dong-mei; Yang, Yu; Li, Gui-ying; Zhu, Liang-fang; Tang, Jin-Qiang

2014-01-01

Highlights: • Reforming reactions were inhibited by H 2 , decrease of acidity and low temperature. • There was a synergistic effect on producing hydrogen between Ni and Mo. • The lattice oxygen over catalyst employed might transfer into the intermediates. • Co-pyrolysis, low temperature and N 2 could restrain oxygen transfer to some extent. - Abstract: Co-pyrolysis is regarded as an effective approach to upgrade the quality of pyrolysis products. In this work the activity of KF-846 was evaluated by co-pyrolysis of pubescens and low density polyethylene under different experimental conditions including catalytic mode, pyrolytic atmosphere and temperature, etc. The results showed that the fresh KF-846 exerted strong effects of cyclization, aromatization, hydrogen transfer and vapor-catalytic reforming reactions on the primary intermediates from the co-pyrolysis. The hydrogen-rich gases indicated a synergistic effect between Ni and Mo over KF-846 on producing hydrogen. More importantly, the reforming reactions might be inhibited to some extent by H 2 atmosphere, the low temperature and the decrease of acidity over catalyst. Furthermore, it was deduced that the oxygen over the lattice of catalyst or some intermediates might transfer into other intermediates, possibly resulting in more products with high oxygen content, but it was presumed that the low temperature, co-pyrolysis process and N 2 atmosphere could repress the trend to a certain degree. The mass and energy balance of co-pyrolysis were analyzed, and the main reaction pathways were also proposed. The interference in pyrolysis by regulating the catalytic mode, pyrolytic atmosphere and temperature, acidity over catalyst might posses a certain guiding significance for the pyrolytic technology and the design/selection of catalysts employed

Spectroscopic and Kinetic Characterization of Peroxidase-Like π-Cation Radical Pinch-Porphyrin-Iron(III Reaction Intermediate Models of Peroxidase Enzymes

Directory of Open Access Journals (Sweden)

Samuel Hernández Anzaldo

2016-06-01

Full Text Available The spectroscopic and kinetic characterization of two intermediates from the H2O2 oxidation of three dimethyl ester [(proto, (meso, (deuteroporphyrinato (picdien]Fe(III complexes ([FePPPic], [FeMPPic] and [FeDPPic], respectively pinch-porphyrin peroxidase enzyme models, with s = 5/2 and 3/2 Fe(III quantum mixed spin (qms ground states is described herein. The kinetic study by UV/Vis at λmax = 465 nm showed two different types of kinetics during the oxidation process in the guaiacol test for peroxidases (1–3 + guaiacol + H2O2 → oxidation guaiacol products. The first intermediate was observed during the first 24 s of the reaction. When the reaction conditions were changed to higher concentration of pinch-porphyrins and hydrogen peroxide only one type of kinetics was observed. Next, the reaction was performed only between pinch-porphyrins-Fe(III and H2O2, resulting in only two types of kinetics that were developed during the first 0–4 s. After this time a self-oxidation process was observed. Our hypotheses state that the formation of the π-cation radicals, reaction intermediates of the pinch-porphyrin-Fe(III family with the ligand picdien [N,N’-bis-pyridin-2-ylmethyl-propane-1,3-diamine], occurred with unique kinetics that are different from the overall process and was involved in the oxidation pathway. UV-Vis, 1H-NMR and ESR spectra confirmed the formation of such intermediates. The results in this paper highlight the link between different spectroscopic techniques that positively depict the kinetic traits of artificial compounds with enzyme-like activity.

Detection and Identification of the Keto-Hydroperoxide (HOOCH 2 OCHO) and Other Intermediates during Low-Temperature Oxidation of Dimethyl Ether

KAUST Repository

Moshammer, Kai

2015-07-16

In this paper we report the detection and identification of the keto-hydroperoxide (hydroperoxymethyl formate, HPMF, HOOCH2OCHO) and other partially oxidized intermediate species arising from the low-temperature (540 K) oxidation of dimethyl ether (DME). These observations were made possible by coupling a jet-stirred reactor with molecular-beam sampling capabilities, operated near atmospheric pressure, to a reflectron time-of-flight mass spectrometer that employs single-photon ionization via tunable synchrotron-generated vacuum-ultraviolet radiation. On the basis of experimentally observed ionization thresholds and fragmentation appearance energies, interpreted with the aid of ab initio calculations, we have identified HPMF and its conceivable decomposition products HC(O)O(O)CH (formic acid anhydride), HC(O)OOH (performic acid), and HOC(O)OH (carbonic acid). Other intermediates that were detected and identified include HC(O)OCH3 (methyl formate), cycl-CH2-O-CH2-O- (1,3-dioxetane), CH3OOH (methyl hydroperoxide), HC(O)OH (formic acid), and H2O2 (hydrogen peroxide). We show that the theoretical characterization of multiple conformeric structures of some intermediates is required when interpreting the experimentally observed ionization thresholds, and a simple method is presented for estimating the importance of multiple conformers at the estimated temperature (∼100 K) of the present molecular beam. We also discuss possible formation pathways of the detected species: for example, supported by potential energy surface calculations, we show that performic acid may be a minor channel of the O2 + CH2OCH2OOH reaction, resulting from the decomposition of the HOOCH2OCHOOH intermediate, which predominantly leads to the HPMF. © 2015 American Chemical Society.

Multicomponent kinetic analysis and theoretical studies on the phenolic intermediates in the oxidation of eugenol and isoeugenol catalyzed by laccase.

Science.gov (United States)

Qi, Yan-Bing; Wang, Xiao-Lei; Shi, Ting; Liu, Shuchang; Xu, Zhen-Hao; Li, Xiqing; Shi, Xuling; Xu, Ping; Zhao, Yi-Lei

2015-11-28

Laccase catalyzes the oxidation of natural phenols and thereby is believed to initialize reactions in lignification and delignification. Numerous phenolic mediators have also been applied in laccase-mediator systems. However, reaction details after the primary O-H rupture of phenols remain obscure. In this work two types of isomeric phenols, EUG (eugenol) and ISO (trans-/cis-isoeugenol), were used as chemical probes to explore the enzymatic reaction pathways, with the combined methods of time-resolved UV-Vis absorption spectra, MCR-ALS, HPLC-MS, and quantum mechanical (QM) calculations. It has been found that the EUG-consuming rate is linear to its concentration, while the ISO not. Besides, an o-methoxy quinone methide intermediate, (E/Z)-4-allylidene-2-methoxycyclohexa-2,5-dienone, was evidenced in the case of EUG with the UV-Vis measurement, mass spectra and TD-DFT calculations; in contrast, an ISO-generating phenoxyl radical, a (E/Z)-2-methoxy-4-(prop-1-en-1-yl) phenoxyl radical, was identified in the case of ISO. Furthermore, QM calculations indicated that the EUG-generating phenoxyl radical (an O-centered radical) can easily transform into an allylic radical (a C-centered radical) by hydrogen atom transfer (HAT) with a calculated activation enthalpy of 5.3 kcal mol(-1) and then be fast oxidized to the observed eugenol quinone methide, rather than an O-radical alkene addition with barriers above 12.8 kcal mol(-1). In contrast, the ISO-generating phenoxyl radical directly undergoes a radical coupling (RC) process, with a barrier of 4.8 kcal mol(-1), while the HAT isomerization between O- and C-centered radicals has a higher reaction barrier of 8.0 kcal mol(-1). The electronic conjugation of the benzyl-type radical and the aromatic allylic radical leads to differentiation of the two pathways. These results imply that competitive reaction pathways exist for the nascent reactive intermediates generated in the laccase-catalyzed oxidation of natural phenols, which is

Multistage reaction pathways in detonating high explosives

International Nuclear Information System (INIS)

Li, Ying; Kalia, Rajiv K.; Nakano, Aiichiro; Nomura, Ken-ichi; Vashishta, Priya

2014-01-01

Atomistic mechanisms underlying the reaction time and intermediate reaction products of detonating high explosives far from equilibrium have been elusive. This is because detonation is one of the hardest multiscale physics problems, in which diverse length and time scales play important roles. Here, large spatiotemporal-scale reactive molecular dynamics simulations validated by quantum molecular dynamics simulations reveal a two-stage reaction mechanism during the detonation of cyclotrimethylenetrinitramine crystal. Rapid production of N 2 and H 2 O within ∼10 ps is followed by delayed production of CO molecules beyond ns. We found that further decomposition towards the final products is inhibited by the formation of large metastable carbon- and oxygen-rich clusters with fractal geometry. In addition, we found distinct unimolecular and intermolecular reaction pathways, respectively, for the rapid N 2 and H 2 O productions

Multistage reaction pathways in detonating high explosives

Energy Technology Data Exchange (ETDEWEB)

Li, Ying [Collaboratory for Advanced Computing and Simulations, Department of Physics and Astronomy, Department of Computer Science, and Department of Chemical Engineering and Materials Science, University of Southern California, Los Angeles, California 90089-0242 (United States); Argonne Leadership Computing Facility, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Kalia, Rajiv K.; Nakano, Aiichiro; Nomura, Ken-ichi; Vashishta, Priya [Collaboratory for Advanced Computing and Simulations, Department of Physics and Astronomy, Department of Computer Science, and Department of Chemical Engineering and Materials Science, University of Southern California, Los Angeles, California 90089-0242 (United States)

2014-11-17

Atomistic mechanisms underlying the reaction time and intermediate reaction products of detonating high explosives far from equilibrium have been elusive. This is because detonation is one of the hardest multiscale physics problems, in which diverse length and time scales play important roles. Here, large spatiotemporal-scale reactive molecular dynamics simulations validated by quantum molecular dynamics simulations reveal a two-stage reaction mechanism during the detonation of cyclotrimethylenetrinitramine crystal. Rapid production of N{sub 2} and H{sub 2}O within ∼10 ps is followed by delayed production of CO molecules beyond ns. We found that further decomposition towards the final products is inhibited by the formation of large metastable carbon- and oxygen-rich clusters with fractal geometry. In addition, we found distinct unimolecular and intermolecular reaction pathways, respectively, for the rapid N{sub 2} and H{sub 2}O productions.

Preliminary thermal sizing of intermediate heat exchanger for NHDD system

International Nuclear Information System (INIS)

Kim, Chan Soo; Hong, Sung Deok; Kim, Yong Wan; Chang, Jongh Wa

2009-01-01

Nuclear Hydrogen Development and Demonstration (NHDD) system is a Very High Temperature gascooled Reactor (VHTR) coupled with hydrogen production systems. Intermediate heat exchanger transfers heat from the nuclear reactor to the hydrogen production system. This study presented the sensitivity analysis on a preliminary thermal sizing of the intermediate heat exchanger. Printed Circuit Heat Exchanger (PCHE) was selected for the thermal sizing because the printed circuit heat exchanger has the largest compactness among the heat exchanger types. The analysis was performed to estimate the effect of key parameters including the operating condition of the intermediate system, the geometrical factors of the PCHE, and the working fluid of the intermediate system.

Intermediate mass distribution of the dual resonance pomeron

International Nuclear Information System (INIS)

Chiu, C.B.; Matsuda, S.

1978-01-01

The intermediate mass distribution of the dual resonance pomeron is determined at the one-loop level and it is shown that the mass distribution obtained is remarkably similar to a suitably defined mass distribution in the dual multiperipheral model. Thus it is suggestive to identify the intermediate states of the dual resonance pomeron with multiperipheral processes. (Auth.)

CONDITIONING OF INTERMEDIATE-LEVEL WASTE AT FORSCHUNGSZENTRUM JUELICH GMBH

International Nuclear Information System (INIS)

Krumbach, H.

2003-01-01

This contribution to the group of low-level, intermediate, mixed and hazardous waste describes the conditioning of intermediate-level mixed waste (dose rate above 10 mSv/h at the surface) from Research Centre Juelich (FZJ). Conditioning of the waste by supercompaction is performed at Research Centre Karlsruhe (FZK). The waste described is radioactive waste arising from research at Juelich. This waste includes specimens and objects from irradiation experiments in the research reactors Merlin (FRJ-1) and Dido (FRJ-2) at FZJ. In principle, radioactive waste at Forschungszentrum Juelich GmbH is differentiated by the surface dose rate at the waste package. Up to a surface dose rate of 10 mSv/h, the waste is regarded as low-level. The radioactive waste described here has a surface dose rate above 10 mSv/h. Waste up to 10 mSv/h is conditioned at the Juelich site according to different conditioning methods. The intermediate-level waste can only be conditioned by supercompaction in the processing facility for intermediate-level waste from plant operation at Research Centre Karlsruhe. Research Centre Juelich also uses this waste cell to condition its intermediate-level waste from plant operation

Supersymmetry and intermediate symmetry breaking in SO(10) superunification

International Nuclear Information System (INIS)

Asatryan, H.M.; Ioannisyan, A.N.

1985-01-01

A scheme of simultaneous breakdown of intermediate symmetry SO(10) → SU(3)sub(c) x U(1) x SU(2)sub(L) x SU(2)sub(R) and supersymmetry by means of a single scale parameter is suggested. This intermediate symmetry, which is preferable physically, owing to the broken supersymmetry has a minimum lying lower than SU(4) x SU(2)sub(L) x SU(2)sub(R). The intermediate symmetry is broken by the vacuum expectation value of the Higgs superfields. Owing to the quantum corrections the potential minimum turns out to correspond to breakdown of the intermediate symmetry up to the standard group SU(3)sub(c) x SU(2)sub(L) x U(1)sub(y). The value of the Weinberg angle is less than that in the supersymmetric SU(5) model and agrees with the experiment

Atomistic picture for the folding pathway of a hybrid-1 type human telomeric DNA G-quadruplex.

Directory of Open Access Journals (Sweden)

Yunqiang Bian

2014-04-01

Full Text Available In this work we studied the folding process of the hybrid-1 type human telomeric DNA G-quadruplex with solvent and K(+ ions explicitly modeled. Enabled by the powerful bias-exchange metadynamics and large-scale conventional molecular dynamic simulations, the free energy landscape of this G-DNA was obtained for the first time and four folding intermediates were identified, including a triplex and a basically formed quadruplex. The simulations also provided atomistic pictures for the structures and cation binding patterns of the intermediates. The results showed that the structure formation and cation binding are cooperative and mutually supporting each other. The syn/anti reorientation dynamics of the intermediates was also investigated. It was found that the nucleotides usually take correct syn/anti configurations when they form native and stable hydrogen bonds with the others, while fluctuating between two configurations when they do not. Misfolded intermediates with wrong syn/anti configurations were observed in the early intermediates but not in the later ones. Based on the simulations, we also discussed the roles of the non-native interactions. Besides, the formation process of the parallel conformation in the first two G-repeats and the associated reversal loop were studied. Based on the above results, we proposed a folding pathway for the hybrid-1 type G-quadruplex with atomistic details, which is new and more complete compared with previous ones. The knowledge gained for this type of G-DNA may provide a general insight for the folding of the other G-quadruplexes.

On the chemistry of ethanol on basic oxides: revising mechanisms and intermediates in the Lebedev and Guerbet reactions.

Science.gov (United States)

Chieregato, Alessandro; Velasquez Ochoa, Juliana; Bandinelli, Claudia; Fornasari, Giuseppe; Cavani, Fabrizio; Mella, Massimo

2015-01-01

A common way to convert ethanol into chemicals is by upgrading it over oxide catalysts with basic features; this method makes it possible to obtain important chemicals such as 1-butanol (Guerbet reaction) and 1,3-butadiene (Lebedev reaction). Despite their long history in chemistry, the details of the close inter-relationship of these reactions have yet to be discussed properly. Our present study focuses on reactivity tests, in situ diffuse reflectance infrared Fourier transform spectroscopy, MS analysis, and theoretical modeling. We used MgO as a reference catalyst with pure basic features to explore ethanol conversion from its very early stages. Based on the obtained results, we formulate a new mechanistic theory able to explain not only our results but also most of the scientific literature on Lebedev and Guerbet chemistry. This provides a rational description of the intermediates shared by the two reaction pathways as well as an innovative perspective on the catalyst requirements to direct the reaction pathway toward 1-butanol or butadiene. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Intermediate energy data

International Nuclear Information System (INIS)

Koning, A.J.; Fukahori, T.; Hasegawa, A.

1998-01-01

Subgroup 13 (SG13) on Intermediate Energy Nuclear data was formed by NEA Nuclear Science Committee to solve common problems of these types of data for nuclear applications. An overview is presented in this final report of the present activities of SG13, including data needs, high-priority nuclear data request list (nuclides), compilation of experimental data, specialists meetings and benchmarks, data formats and data libraries. Some important accomplishments are summarized, and recommendations are presented. (R.P.)

Has Banks’ Financial Intermediation Improved in Russia?

OpenAIRE

Fungachova, Z.; Solanko, L.

2010-01-01

The aim of this paper is to analyze the increasing importance of banks in the Russian economy over the period following the financial crisis of 1998. We use several measures to assess the role of banks in domestic financial intermediation in Russia. The traditional macro-level view is complemented by the analysis of sectoral financial flows as well as by insights from micro-level studies. All of these confirm that banks are becoming increasingly important in financial intermediation. We find ...

Selection of Models for Ingestion Pathway and Relocation

International Nuclear Information System (INIS)

Blanchard, A.; Thompson, J.M.

1998-01-01

The area in which intermediate phase protective actions (such as food interdiction and relocation) may be needed following postulated accidents at three Savannah River Site nonreactor nuclear facilities will be determined by modeling. The criteria used to select dispersion/deposition models are presented. Several models are considered, including ARAC, MACCS, HOTSPOT, WINDS (coupled with PUFF-PLUME), and UFOTRI. Although ARAC and WINDS are expected to provide more accurate modeling of atmospheric transport following an actual release, analyses consistent with regulatory guidance for planning purposes may be accomplished with comparatively simple dispersion models such as HOTSPOT and UFOTRI. A recommendation is made to use HOTSPOT for non-tritium facilities and UFOTRI for tritium facilities. The most recent Food and Drug Administration Derived Intervention Levels (August 1998) are adopted as evaluation guidelines for ingestion pathways

Selection of Models for Ingestion Pathway and Relocation

International Nuclear Information System (INIS)

Blanchard, A.; Thompson, J.M.

1999-01-01

The area in which intermediate phase protective actions (such as food interdiction and relocation) may be needed following postulated accidents at three Savannah River Site nonreactor nuclear facilities will be determined by modeling. The criteria used to select dispersion/deposition models are presented. Several models are considered, including ARAC, MACCS, HOTSPOT, WINDS (coupled with PUFF-PLUME), and UFOTRI. Although ARAC and WINDS are expected to provide more accurate modeling of atmospheric transport following an actual release, analyses consistent with regulatory guidance for planning purposes may be accomplished with comparatively simple dispersion models such as HOTSPOT and UFOTRI. A recommendation is made to use HOTSPOT for non-tritium facilities and UFOTRI for tritium facilities. The most recent Food and Drug Administration Derived Intervention Levels (August 1998) are adopted as evaluation guidelines for ingestion pathways

n-Heptane cool flame chemistry: Unraveling intermediate species measured in a stirred reactor and motored engine

KAUST Repository

Wang, Zhandong

2017-10-03

This work identifies classes of cool flame intermediates from n-heptane low-temperature oxidation in a jet-stirred reactor (JSR) and a motored cooperative fuel research (CFR) engine. The sampled species from the JSR oxidation of a mixture of n-heptane/O2/Ar (0.01/0.11/0.88) were analyzed using a synchrotron vacuum ultraviolet radiation photoionization (SVUV-PI) time-of-flight molecular-beam mass spectrometer (MBMS) and an atmospheric pressure chemical ionization (APCI) Orbitrap mass spectrometer (OTMS). The OTMS was also used to analyze the sampled species from a CFR engine exhaust. Approximately 70 intermediates were detected by the SVUV-PI-MBMS, and their assigned molecular formulae are in good agreement with those detected by the APCI-OTMS, which has ultra-high mass resolving power and provides an accurate elemental C/H/O composition of the intermediate species. Furthermore, the results show that the species formed during the partial oxidation of n-heptane in the CFR engine are very similar to those produced in an ideal reactor, i.e., a JSR.The products can be classified by species with molecular formulae of C7H14Ox (x = 0–5), C7H12Ox (x = 0–4), C7H10Ox (x = 0–4), CnH2n (n = 2–6), CnH2n−2 (n = 4–6), CnH2n+2O (n = 1–4), CnH2nO (n = 1–6), CnH2n−2O (n = 2–6), CnH2n−4O (n = 4–6), CnH2n+2O2 (n = 0–4, 7), CnH2nO2 (n = 1–6), CnH2n−2O2 (n = 2–6), CnH2n−4O2 (n = 4–6), and CnH2nO3 (n = 3–6). The identified intermediate species include alkenes, dienes, aldehyde/keto compounds, olefinic aldehyde/keto compounds, diones, cyclic ethers, peroxides, acids, and alcohols/ethers. Reaction pathways forming these intermediates are proposed and discussed herein. These experimental results are important in the development of more accurate kinetic models for n-heptane and longer-chain alkanes.

Discovery of competing anaerobic and aerobic pathways in umpolung amide synthesis allows for site-selective amide 18O-labeling

Science.gov (United States)

Shackleford, Jessica P.; Shen, Bo; Johnston, Jeffrey N.

2012-01-01

The mechanism of umpolung amide synthesis was probed by interrogating potential sources for the oxygen of the product amide carbonyl that emanates from the α-bromo nitroalkane substrate. Using a series of 18O-labeled substrates and reagents, evidence is gathered to advance two pathways from the putative tetrahedral intermediate. Under anaerobic conditions, a nitro-nitrite isomerization delivers the amide oxygen from nitro oxygen. The same homolytic nitro-carbon fragmentation can be diverted by capture of the carbon radical intermediate with oxygen gas (O2) to deliver the amide oxygen from O2. This understanding was used to develop a straightforward protocol for the preparation of 18O-labeled amides in peptides by simply performing the umpolung amide synthesis reaction under an atmosphere of . PMID:22184227

Degradation pathway of malachite green in a novel dual-tank photoelectrochemical catalytic reactor.

Science.gov (United States)

Diao, Zenghui; Li, Mingyu; Zeng, Fanyin; Song, Lin; Qiu, Rongliang

2013-09-15

A novel dual-tank photoelectrochemical catalytic reactor was designed to investigate the degradation pathway of malachite green. A thermally formed TiO₂/Ti thin film electrode was used as photoanode, graphite was used as cathode, and a saturated calomel electrode was employed as the reference electrode in the reactor. In the reactor, the anode and cathode tanks were connected by a cation exchange membrane. Results showed that the decolorization ratio of malachite green in the anode and cathode was 98.5 and 96.5% after 120 min, respectively. Malachite green in the two anode and cathode tanks was oxidized, achieving the bipolar double effect. Malachite green in both the anode and cathode tanks exhibited similar catalytic degradation pathways. The double bond of the malachite green molecule was attacked by strong oxidative hydroxyl radicals, after which the organic compound was degraded by the two pathways into 4,4-bis(dimethylamino) benzophenone, 4-(dimethylamino) benzophenone, 4-(dimethylamino) phenol, and other intermediate products. Eventually, malachite green was degraded into oxalic acid as a small molecular organic acid, which was degraded by processes such as demethylation, deamination, nitration, substitution, addition, and other reactions. Copyright © 2013 Elsevier B.V. All rights reserved.

Heterophobia: Subverting Heterosexual Hegemony through Intermedial Applied Performance for Young People

Science.gov (United States)

Phillips, Hannah

2016-01-01

This article responds to intermediality through a case study of an intermedial applied performance for young people. "Heterophobia," a hybrid fusion of live performance, digital technology, social media and urban street art, aimed to challenge homophobia in schools and online. Intermediality was used as a tool to enhance young people's…

Chemical conversion pathways and kinetic modeling for the OH-initiated reaction of triclosan in gas-phase.

Science.gov (United States)

Zhang, Xue; Zhang, Chenxi; Sun, Xiaomin; Kang, Lingyan; Zhao, Yan

2015-04-10

As a widely used antimicrobial additive in daily consumption, attention has been paid to the degradation and conversion of triclosan for a long time. The quantum chemistry calculation and the canonical variational transition state theory are employed to investigate the mechanism and kinetic property. Besides addition and abstraction, oxidation pathways and further conversion pathways are also considered. The OH radicals could degrade triclosan to phenols, aldehydes, and other easily degradable substances. The conversion mechanisms of triclosan to the polychlorinated dibenzopdioxin and furan (PCDD/Fs) and polychlorinated biphenyls (PCBs) are clearly illustrated and the toxicity would be strengthened in such pathways. Single radical and diradical pathways are compared to study the conversion mechanism of dichlorodibenzo dioxin (DCDD). Furthermore, thermochemistry is discussed in detail. Kinetic property is calculated and the consequent ratio of k add/k total and k abs/k total at 298.15 K are 0.955 and 0.045, respectively. Thus, the OH radical addition reactions are predominant, the substitute position of OH radical on triclosan is very important to generate PCDD and furan, and biradical is also a vital intermediate to produce dioxin.

Chemical Conversion Pathways and Kinetic Modeling for the OH-Initiated Reaction of Triclosan in Gas-Phase

Directory of Open Access Journals (Sweden)

Xue Zhang

2015-04-01

Full Text Available As a widely used antimicrobial additive in daily consumption, attention has been paid to the degradation and conversion of triclosan for a long time. The quantum chemistry calculation and the canonical variational transition state theory are employed to investigate the mechanism and kinetic property. Besides addition and abstraction, oxidation pathways and further conversion pathways are also considered. The OH radicals could degrade triclosan to phenols, aldehydes, and other easily degradable substances. The conversion mechanisms of triclosan to the polychlorinated dibenzopdioxin and furan (PCDD/Fs and polychlorinated biphenyls (PCBs are clearly illustrated and the toxicity would be strengthened in such pathways. Single radical and diradical pathways are compared to study the conversion mechanism of dichlorodibenzo dioxin (DCDD. Furthermore, thermochemistry is discussed in detail. Kinetic property is calculated and the consequent ratio of kadd/ktotal and kabs/ktotal at 298.15 K are 0.955 and 0.045, respectively. Thus, the OH radical addition reactions are predominant, the substitute position of OH radical on triclosan is very important to generate PCDD and furan, and biradical is also a vital intermediate to produce dioxin.

42 CFR 54a.12 - Treatment of intermediate organizations.

Science.gov (United States)

2010-10-01

... 42 Public Health 1 2010-10-01 2010-10-01 false Treatment of intermediate organizations. 54a.12... CHARITABLE CHOICE REGULATIONS APPLICABLE TO STATES, LOCAL GOVERNMENTS AND RELIGIOUS ORGANIZATIONS RECEIVING... ABUSE PREVENTION AND TREATMENT SERVICES § 54a.12 Treatment of intermediate organizations. If a...

Financial Intermediation and the Nigerian Economy: A Time Series ...

African Journals Online (AJOL)

... and cointegration analysis based on Engle Granger cointegration theory and error correction methodology, we tested both short and long run relationships between financial intermediation and economic growth in Nigeria. The result revealed that a long–run relationship exists between financial intermediation and growth ...

Borderline Personality Disorder in an Intermediate Psychological Therapies Service

Science.gov (United States)

Ryan, Seamus; Danquah, Adam N.; Berry, Katherine; Hopper, Mary

2017-01-01

The intermediate psychological therapies service is provided for individuals referred with common mental health problems within the primary care psychological therapies service, but whose difficulties are longstanding and/or complex. The prevalence of borderline personality disorder (BPD) in intermediate psychological therapy services has not been…

General educational disciplines practice-oriented training in intermediate vocational education

Directory of Open Access Journals (Sweden)

Liya G. Skorobogatova

2011-01-01

Full Text Available The article concerns crucial issues of practice-oriented training in Russia's intermediate vocational education, designates directions of general educational disciplines study in intermediate vocational education.

Intermediate inflation from a non-canonical scalar field

Energy Technology Data Exchange (ETDEWEB)

Rezazadeh, K.; Karami, K. [Department of Physics, University of Kurdistan, Pasdaran St., Sanandaj (Iran, Islamic Republic of); Karimi, P., E-mail: rezazadeh86@gmail.com, E-mail: KKarami@uok.ac.ir, E-mail: parvin.karimi67@yahoo.com [Center for Excellence in Astronomy and Astrophysics (CEAA-RIAAM), P.O. Box 55134-441, Maragha (Iran, Islamic Republic of)

2015-09-01

We study the intermediate inflation in a non-canonical scalar field framework with a power-like Lagrangian. We show that in contrast with the standard canonical intermediate inflation, our non-canonical model is compatible with the observational results of Planck 2015. Also, we estimate the equilateral non-Gaussianity parameter which is in well agreement with the prediction of Planck 2015. Then, we obtain an approximation for the energy scale at the initial time of inflation and show that it can be of order of the Planck energy scale, i.e. M{sub P} ∼ 10{sup 18}GeV. We will see that after a short period of time, inflation enters in the slow-roll regime that its energy scale is of order M{sub P}/100 ∼ 10{sup 16}GeV and the horizon exit takes place in this energy scale. We also examine an idea in our non-canonical model to overcome the central drawback of intermediate inflation which is the fact that inflation never ends. We solve this problem without disturbing significantly the nature of the intermediate inflation until the time of horizon exit.

Estimation of intermediate grade uranium resources. Final report

International Nuclear Information System (INIS)

Lambie, F.W.; Kendall, G.R.; Klahn, L.J.; Davis, J.C.; Harbaugh, J.W.

1980-12-01

The purpose of this project is to analyze the technique currently used by DOE to estimate intermediate grade uranium (0.01 to 0.05% U 3 O 8 ) and, if possible, suggest alternatives to improve the accuracy and precision of the estimate. There are three principal conclusions resulting from this study. They relate to the quantity, distribution and sampling of intermediate grade uranium. While the results of this study must be validated further, they indicate that DOE may be underestimating intermediate level reserves by 20 to 30%. Plots of grade of U 3 O 8 versus tonnage of ore and tonnage U 3 O 8 indicate grade-tonnage relationships that are essentially log-linear, at least down to 0.01% U 3 O 8 . Though this is not an unexpected finding, it may provide a technique for reducing the uncertainty of intermediate grade endowment. The results of this study indicate that a much lower drill hole density is necessary for DOE to estimate uranium resources than for a mining company to calculate ore resources. Though errors in local estimates will occur, they will tend to cancel over the entire deposit

Analysis of the role of the Aspergillus niger aminolevulinic acid synthase (hemA) gene illustrates the difference between regulation of yeast and fungal haem- and sirohaem-dependent pathways

NARCIS (Netherlands)

Franken, A.C.; Christien Lokman, B.; Ram, A.F.; Hondel, C.A. van den; Weert, S. de; Punt, P.J.

2012-01-01

To increase knowledge on haem biosynthesis in filamentous fungi like Aspergillus niger, pathway-specific gene expression in response to haem and haem intermediates was analysed. This analysis showed that iron, 5′-aminolevulinic acid (ALA) and possibly haem control haem biosynthesis mostly via

Analysis of the role of the A. niger aminolevulinic acid synthase (hemA) gene illustrates the difference between regulation of yeast and fungal heme and siroheme dependent pathways

NARCIS (Netherlands)

A.F. Ram; C.A. van den Hondel; Christien Lokman; P.J. Punt; S. de Weert; A. Franken

2012-01-01

To increase knowledge on haem biosynthesis in filamentous fungi like Aspergillus niger, pathway-specific gene expression in response to haem and haem intermediates was analysed. This analysis showed that iron, 5'-aminolevulinic acid (ALA) and possibly haem control haem biosynthesis mostly via

Structure of replicating intermediates of human herpesvirus type 6

International Nuclear Information System (INIS)

Severini, Alberto; Sevenhuysen, Claire; Garbutt, Michael; Tipples, Graham A.

2003-01-01

We have studied the structure of the replicative intermediates of human herpesvirus 6 (HHV-6) using pulsed-field gel electrophoresis, partial digestion, two-dimensional gel electrophoresis, and sedimentation centrifugation. The results show that DNA replication of HHV-6 produces head-to-tail concatemeric intermediates as well as approximately equal amounts of circular monomers or oligomers. Unlike the situation in herpes simplex virus, the intermediates of human herpesvirus 6 replication are not highly branched, suggesting a difference in the mechanism of replication or a lower frequency of homologous recombination in human herpesvirus 6 compared to herpes simplex virus

Proceedings of the 2012 Model-Based Systems Engineering Symposium, 27 - 28 November 2012, DSTO Edinburgh, South Australia

Science.gov (United States)

2013-02-01

particular interest in Model-Based Systems Engineering. He holds a bachelor degree and a doctorate, both in the field of mechatronics . He currently...exploration is examined, along with the key lessons learned from embedding MBSE into the system development process. Finally, with the increasing use...PLM 2.0 concepts have been embedded in engineering software applications such as CAD and PLM systems as well as in Microsoft Office documents. However

Mechanisms of deterioration of intermediate moisture food systems

Science.gov (United States)

Labuza, T. P.

1972-01-01

A study of shelf stability in intermediate moisture foods was made. Major efforts were made to control lipid oxidation and nonenzymatic browning. In order to determine means of preventing these reactions, model systems were developed having the same water activity content relationship of intermediate moisture foods. Models were based on a cellulose-lipid and protein-lipid system with glycerol added as the humectant. Experiments with both systems indicate that lipid oxidation is promoted significantly in the intermediate moisture range. The effect appeared to be related to increased mobility of either reactants or catalysts, since when the amount of water in the system reached a level where capillary condensation occurred and thus free water was present, the rates of oxidation increased. With added glycerol, which is water soluble and thus increases the amount of mobile phase, the increase in oxidation rate occurs at a lower relative humidity. The rates of oxidation were maximized at 61% RH and decreased again at 75% RH probably due to dilution. No significant non-enzymatic browning occurred in the protein-lipid systems. Prevention of oxidation by the use of metal chelating agents was enhanced in the cellulose system, whereas, with protein present, the lipid soluble chain terminating antioxidants (such as BHA) worked equally as well. Preliminary studies of foods adjusted to the intermediate moisture range bear out the results of oxidation in model systems. It can be concluded that for most fat containing intermediate moisture foods, rancidity will be the reaction most limiting stability.

Nonclassical nucleation pathways in protein crystallization.

Science.gov (United States)

Zhang, Fajun

2017-11-08

Classical nucleation theory (CNT), which was established about 90 years ago, has been very successful in many research fields, and continues to be the most commonly used theory in describing the nucleation process. For a fluid-to-solid phase transition, CNT states that the solute molecules in a supersaturated solution reversibly form small clusters. Once the cluster size reaches a critical value, it becomes thermodynamically stable and favored for further growth. One of the most important assumptions of CNT is that the nucleation process is described by one reaction coordinate and all order parameters proceed simultaneously. Recent studies in experiments, computer simulations and theory have revealed nonclassical features in the early stage of nucleation. In particular, the decoupling of order parameters involved during a fluid-to-solid transition leads to the so-called two-step nucleation mechanism, in which a metastable intermediate phase (MIP) exists between the initial supersaturated solution and the final crystals. Depending on the exact free energy landscapes, the MIPs can be a high density liquid phase, mesoscopic clusters, or a pre-ordered state. In this review, we focus on the studies of nonclassical pathways in protein crystallization and discuss the applications of the various scenarios of two-step nucleation theory. In particular, we focus on protein solutions in the presence of multivalent salts, which serve as a model protein system to study the nucleation pathways. We wish to point out the unique features of proteins as model systems for further studies.

Nonclassical nucleation pathways in protein crystallization

Science.gov (United States)

Zhang, Fajun

2017-11-01

Classical nucleation theory (CNT), which was established about 90 years ago, has been very successful in many research fields, and continues to be the most commonly used theory in describing the nucleation process. For a fluid-to-solid phase transition, CNT states that the solute molecules in a supersaturated solution reversibly form small clusters. Once the cluster size reaches a critical value, it becomes thermodynamically stable and favored for further growth. One of the most important assumptions of CNT is that the nucleation process is described by one reaction coordinate and all order parameters proceed simultaneously. Recent studies in experiments, computer simulations and theory have revealed nonclassical features in the early stage of nucleation. In particular, the decoupling of order parameters involved during a fluid-to-solid transition leads to the so-called two-step nucleation mechanism, in which a metastable intermediate phase (MIP) exists between the initial supersaturated solution and the final crystals. Depending on the exact free energy landscapes, the MIPs can be a high density liquid phase, mesoscopic clusters, or a pre-ordered state. In this review, we focus on the studies of nonclassical pathways in protein crystallization and discuss the applications of the various scenarios of two-step nucleation theory. In particular, we focus on protein solutions in the presence of multivalent salts, which serve as a model protein system to study the nucleation pathways. We wish to point out the unique features of proteins as model systems for further studies.

Explorations into Chemical Reactions and Biochemical Pathways.

Science.gov (United States)

Gasteiger, Johann

2016-12-01

A brief overview of the work in the research group of the present author on extracting knowledge from chemical reaction data is presented. Methods have been developed to calculate physicochemical effects at the reaction site. It is shown that these physicochemical effects can quite favourably be used to derive equations for the calculation of data on gas phase reactions and on reactions in solution such as aqueous acidity of alcohols or carboxylic acids or the hydrolysis of amides. Furthermore, it is shown that these physicochemical effects are quite effective for assigning reactions into reaction classes that correspond to chemical knowledge. Biochemical reactions constitute a particularly interesting and challenging task for increasing our understanding of living species. The BioPath.Database is a rich source of information on biochemical reactions and has been used for a variety of applications of chemical, biological, or medicinal interests. Thus, it was shown that biochemical reactions can be assigned by the physicochemical effects into classes that correspond to the classification of enzymes by the EC numbers. Furthermore, 3D models of reaction intermediates can be used for searching for novel enzyme inhibitors. It was shown in a combined application of chemoinformatics and bioinformatics that essential pathways of diseases can be uncovered. Furthermore, a study showed that bacterial flavor-forming pathways can be discovered. © 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Studies on the nature of intermediates in enzyme mechanisms

International Nuclear Information System (INIS)

Clark, J.D.

1988-01-01

The reaction pathway followed by malate synthase has been studied by the double isotope fractionation method to determine whether the reaction is stepwise or concerted. A primary deuterium kinetic isotope effect ( D V/K) of 1.3 ± 0.1 has been found using [ 2 H 3 ]acetyl-CoA as substrate. The 13 C isotope effect at the aldehydic carbon of glyoxylate has also been measured. For this determination, the malate product was quantitatively transformed into a new sample of malate having the carbon of interest at C-4. This material was decarboxylated to produce the appropriate CO 2 for isotope ratio mass spectrometric analysis. If the essential Zn(II) ion of yeast aldolase interacts with the carbonyl groups of bound substrates, we can expect that these will be more reactive toward reduction by borohydrides than those free in solution. Tritiated sodium borohydride was therefore used to reduce the substrates of yeast aldolase in the presence and absence of enzyme, and the enantiomeric and diastereomeric ratios of the products were analyzed. Experiments were conducted in an effort to distinguish between endocyclic and exocyclic cleavage in the hydrolysis catalyzed by lysozyme. Tritiated sodium borohydride was used in an attempt to trap the putative oxocarbonium intermediate

Intermediate Collaborative Adaptive Management Strategies Build Stakeholder Capacity

Directory of Open Access Journals (Sweden)

Martha C. Monroe

2013-06-01

Full Text Available Efforts to implement collaborative adaptive management (CAM often suffer from challenges, such as an unwillingness of managers to share power, unresolved conflicts between stakeholders, and lack of capacity among stakeholders. Some aspects considered essential to CAM, e.g., trust and stakeholder capacity, may be more usefully viewed as goals for intermediate strategies rather than a set of initial conditions. From this perspective, intermediate steps that focus on social learning and building experience could overcome commonly cited barriers to CAM. An exploration of Springs Basin Working Groups, organized around major clusters of freshwater springs in north Florida, provides a case study of how these intermediate steps enable participants to become more reasonable and engaged. This strategy may be easily implemented by agencies beginning a CAM process.

Formation of intermediate shocks in both two-fluid and hybrid models

International Nuclear Information System (INIS)

Wu, C.C.; Hada, T.

1991-01-01

Intermediate shocks are shocks with shock frame fluid velocities greater than the Alfven speed ahead and less than the Alfven speed behind, or equivalently, across intermediate shocks the sign of the transverse component of the magnetic field changes. These shocks had been considered extraneous, or nonevolutionary, or unstable, and they had been thought not to correspond to physical reality [Germain, 1960; Jeffrey and Taniuti, 1964; Kantrowitz and Petschek, 1966]. However, it has been shown that intermediate shocks can be formed from continuous waves according to dissipative magnetohydrodynamics (MHD) [Wu, 1987, 1988a, b, 1990]. Thus according to the formation argument which requires that physical shocks be formed by the wave steepening process, the intermediate shocks should be considered physical. Here, intermediate shocks are studied in a two-fluid model that includes finite ion inertia dispersion and in a hybrid model in which the full ion dynamics is retained while the electrons are treated as a massless fluid. The authors show that in both models intermediate shocks can be formed through wave steepening, meaning that they are stable and possess shock structures

Characterization of C₃--C₄ intermediate species in the genus Heliotropium L. (Boraginaceae): anatomy, ultrastructure and enzyme activity.

Science.gov (United States)

Muhaidat, Riyadh; Sage, Tammy L; Frohlich, Michael W; Dengler, Nancy G; Sage, Rowan F

2011-10-01

Photosynthetic pathway characteristics were studied in nine species of Heliotropium (sensu lato, including Euploca), using assessments of leaf anatomy and ultrastructure, activities of PEP carboxylase and C₄ acid decarboxylases, and immunolocalization of ribulose 1·5-bisphosphate carboxylase/oxygenase (Rubisco) and the P-subunit of glycine decarboxylase (GDC). Heliotropium europaeum, Heliotropium calcicola and Heliotropium tenellum are C₃ plants, while Heliotropium texanum and Heliotropium polyphyllum are C₄ species. Heliotropium procumbens and Heliotropium karwinskyi are functionally C₃, but exhibit 'proto-Kranz' anatomy where bundle sheath (BS) cells are enlarged and mitochondria primarily occur along the centripetal (inner) wall of the BS cells; GDC is present throughout the leaf. Heliotropium convolvulaceum and Heliotropium greggii are C₃--C₄ intermediates, with Kranz-like enlargement of the BS cells, localization of mitochondria along the inner BS wall and a loss of GDC in the mesophyll (M) tissue. These C₃--C₄ species of Heliotropium probably shuttle photorespiratory glycine from the M to the BS tissue for decarboxylation. Heliotropium represents an important new model for studying C₄ evolution. Where existing models such as Flaveria emphasize diversification of C₃--C₄ intermediates, Heliotropium has numerous C₃ species expressing proto-Kranz traits that could represent a critical initial phase in the evolutionary origin of C₄ photosynthesis. © 2011 Blackwell Publishing Ltd.

Early spatiotemporal-specific changes in intermediate signals are predictive of cytotoxic sensitivity to TNFα and co-treatments

Science.gov (United States)

Loo, Lit-Hsin; Bougen-Zhukov, Nicola Michelle; Tan, Wei-Ling Cecilia

2017-03-01

Signaling pathways can generate different cellular responses to the same cytotoxic agents. Current quantitative models for predicting these differential responses are usually based on large numbers of intracellular gene products or signals at different levels of signaling cascades. Here, we report a study to predict cellular sensitivity to tumor necrosis factor alpha (TNFα) using high-throughput cellular imaging and machine-learning methods. We measured and compared 1170 protein phosphorylation events in a panel of human lung cancer cell lines based on different signals, subcellular regions, and time points within one hour of TNFα treatment. We found that two spatiotemporal-specific changes in an intermediate signaling protein, p90 ribosomal S6 kinase (RSK), are sufficient to predict the TNFα sensitivity of these cell lines. Our models could also predict the combined effects of TNFα and other kinase inhibitors, many of which are not known to target RSK directly. Therefore, early spatiotemporal-specific changes in intermediate signals are sufficient to represent the complex cellular responses to these perturbations. Our study provides a general framework for the development of rapid, signaling-based cytotoxicity screens that may be used to predict cellular sensitivity to a cytotoxic agent, or identify co-treatments that may sensitize or desensitize cells to the agent.

PLM and the single reactor utility - or how a single reactor utility can face the PLM issues

International Nuclear Information System (INIS)

Ross, M.H.

1994-01-01

Although Gentilly-2 reactor was planned to last for 30 years, its life could be significantly shorter if nothing were done, whereas retubing and refurbishment after, say, 25 years should result in an extension of service life to 45-50 years. In the long run, dimensional changes rather than hydriding may prove to be the pressure tubes' life limiting factor. Hydro Quebec, New Brunswick Power and AECL have an agreement to cooperate in developing a life management program for CANDU-6 reactors. The author expresses the opinion that cost-benefit criteria should be introduced in regulatory decision making. 6 refs., 9 figs

A new intermediate for the production of flexible stable polymers

Science.gov (United States)

Webster, J. A.

1973-01-01

Method of incorporating ether linkages into perfluoroalkylene segment of a dianydride intermediate yields intermediate that may be used in synthesis of flexible, stable polyimides for use as high-temperature, solvent-resistant sealants.

Outcomes of Adolescent and Adult Patients with Lung Metastatic Osteosarcoma and Comparison of Synchronous and Metachronous Lung Metastatic Groups.

Directory of Open Access Journals (Sweden)

Ayse Gok Durnali

Full Text Available Osteosarcomas with lung metastases are rather heterogenous group. We aimed to evaluate the clinicopathological characteristics and outcomes of osteosarcoma patients with lung metastases and to compare the synchronous and metachronous lung metastatic groups. A total of 93 adolescent and adult patients with lung metastatic osteosarcoma, from March 1995 to July 2011, in a single center, were included. Sixty-five patients (69.9% were male. The median age was 19 years (range, 14-74. Thirty-nine patients (41.9% had synchronous lung metastases (Group A and 54 patients (58.1% had metachronous lung metastases (Group B. The 5-year and 10-year post-lung metastases overall survival (PLM-OS was 17% and 15%, respectively. In multivariate analysis for PLM-OS, time to lung metastases (p = 0.010, number of metastatic pulmonary nodules (p = 0.020, presence of pulmonary metastasectomy (p = 0.007 and presence of chemotherapy for lung metastases (p< 0.001 were found to be independent prognostic factors. The median PLM-OS of Group A and Group B was 16 months and 9 months, respectively. In Group B, the median PLM-OS of the patients who developed lung metastases within 12 months was 6 months, whereas that of the patients who developed lung metastases later was 16 months. Time to lung metastases, number and laterality of metastatic pulmonary nodules, chemotherapy for lung metastatic disease and pulmonary metastasectomy were independent prognostic factors for patients with lung metastatic osteosarcoma. The best PLM-OS was in the subgroup of patients treated both surgery and chemotherapy. The prognosis of the patients who developed lung metastases within 12 months after diagnosis was worst.

Combined application of Product Lifecycle and Software Configuration Management systems for ITER remote handling

International Nuclear Information System (INIS)

Muhammad, Ali; Esque, Salvador; Aha, Liisa; Mattila, Jouni; Siuko, Mikko; Vilenius, Matti; Jaervenpaeae, Jorma; Irving, Mike; Damiani, Carlo; Semeraro, Luigi

2009-01-01

The advantages of Product Lifecycle Management (PLM) systems are widely understood among the industry and hence a PLM system is already in use by International Thermonuclear Experimental Reactor (ITER) Organization (IO). However, with the increasing involvement of software in the development, the role of Software Configuration Management (SCM) systems have become equally important. The SCM systems can be useful to meet the higher demands on Safety Engineering (SE), Quality Assurance (QA), Validation and Verification (V and V) and Requirements Management (RM) of the developed software tools. In an experimental environment, such as ITER, the new remote handling requirements emerge frequently. This means the development of new tools or the modification of existing tools and the development of new remote handling procedures or the modification of existing remote handling procedures. PLM and SCM systems together can be of great advantage in the development and maintenance of such remote handling system. In this paper, we discuss how PLM and SCM systems can be integrated together and play their role during the development and maintenance of ITER remote handling system. We discuss the possibility to investigate such setup at DTP2 (Divertor Test Platform 2), which is the full scale mock-up facility to verify the ITER divertor remote handling and maintenance concepts.

High level active n+ doping of strained germanium through co-implantation and nanosecond pulsed laser melting

Science.gov (United States)

Pastor, David; Gandhi, Hemi H.; Monmeyran, Corentin P.; Akey, Austin J.; Milazzo, Ruggero; Cai, Yan; Napolitani, Enrico; Gwilliam, Russell M.; Crowe, Iain F.; Michel, Jurgen; Kimerling, L. C.; Agarwal, Anuradha; Mazur, Eric; Aziz, Michael J.

2018-04-01

Obtaining high level active n+ carrier concentrations in germanium (Ge) has been a significant challenge for further development of Ge devices. By ion implanting phosphorus (P) and fluorine (F) into Ge and restoring crystallinity using Nd:YAG nanosecond pulsed laser melting (PLM), we demonstrate 1020 cm-3 n+ carrier concentration in tensile-strained epitaxial germanium-on-silicon. Scanning electron microscopy shows that after laser treatment, samples implanted with P have an ablated surface, whereas P + F co-implanted samples have good crystallinity and a smooth surface topography. We characterize P and F concentration depth profiles using secondary ion mass spectrometry and spreading resistance profiling. The peak carrier concentration, 1020 cm-3 at 80 nm below the surface, coincides with the peak F concentration, illustrating the key role of F in increasing donor activation. Cross-sectional transmission electron microscopy of the co-implanted sample shows that the Ge epilayer region damaged during implantation is a single crystal after PLM. High-resolution X-ray diffraction and Raman spectroscopy measurements both indicate that the as-grown epitaxial layer strain is preserved after PLM. These results demonstrate that co-implantation and PLM can achieve the combination of n+ carrier concentration and strain in Ge epilayers necessary for next-generation, high-performance Ge-on-Si devices.

Structure of a Venezuelan equine encephalitis virus assembly intermediate isolated from infected cells

International Nuclear Information System (INIS)

Lamb, Kristen; Lokesh, G.L.; Sherman, Michael; Watowich, Stanley

2010-01-01

Venezuelan equine encephalitis virus (VEEV) is a prototypical enveloped ssRNA virus of the family Togaviridae. To better understand alphavirus assembly, we analyzed newly formed nucleocapsid particles (termed pre-viral nucleocapsids) isolated from infected cells. These particles were intermediates along the virus assembly pathway, and ultimately bind membrane-associated viral glycoproteins to bud as mature infectious virus. Purified pre-viral nucleocapsids were spherical with a unimodal diameter distribution. The structure of one class of pre-viral nucleocapsids was determined with single particle reconstruction of cryo-electron microscopy images. These studies showed that pre-viral nucleocapsids assembled into an icosahedral structure with a capsid stoichiometry similar to the mature nucleocapsid. However, the individual capsomers were organized significantly differently within the pre-viral and mature nucleocapsids. The pre-viral nucleocapsid structure implies that nucleocapsids are highly plastic and undergo glycoprotein and/or lipid-driven rearrangements during virus self-assembly. This mechanism of self-assembly may be general for other enveloped viruses.

Intermediate heat exchanger for HTR process heat application

International Nuclear Information System (INIS)

Crambes, M.

1980-01-01

In the French study on the nuclear gasification of coal, the following options were recommended: Coal hydrogenation, the hydrogen being derived from CH 4 reforming under the effects of HTR heat; the use of an intermediate helium circuit between the nuclear plant and the reforming plant. The purpose of the present paper is to describe the heat exchanger designed to transfer heat from the primary to the intermediate circuit

Shelf stable intermediate moisture fruit cubes using radiation technology

International Nuclear Information System (INIS)

Mishra, Bibhuti B.; Saxena, Sudhanshu; Gautam, Satyendra; Chander, Ramesh; Sharma, Arun

2009-01-01

A process has been developed to prepare shelf stable ready-to-eat (RTE) intermediate moisture pineapple slices and papaya cubes using radiation technology. The combination of hurdles including osmotic dehydration, blanching, infrared drying, and gamma radiation dose of 1 kGy successfully reduced the microbial load to below detectable limit. The shelf life of the intermediate moisture pineapple slices and papaya cubes was found to be 40 days at ambient temperature (28 ± 2 deg C). The control samples spoiled within 6 days. The RTE intermediate moisture fruit products were found to have good texture, colour and sensory acceptability during this 40 days storage. (author)

Observation of enhanced infrared absorption in silicon supersaturated with gold by pulsed laser melting of nanometer-thick gold films

Science.gov (United States)

Chow, Philippe K.; Yang, Wenjie; Hudspeth, Quentin; Lim, Shao Qi; Williams, Jim S.; Warrender, Jeffrey M.

2018-04-01

We demonstrate that pulsed laser melting (PLM) of thin 1, 5, and 10 nm-thick vapor-deposited gold layers on silicon enhances its room-temperature sub-band gap infrared absorption, as in the case of ion-implanted and PLM-treated silicon. The former approach offers reduced fabrication complexity and avoids implantation-induced lattice damage compared to ion implantation and pulsed laser melting, while exhibiting comparable optical absorptance. We additionally observed strong broadband absorptance enhancement in PLM samples made using 5- and 10-nm-thick gold layers. Raman spectroscopy and Rutherford backscattering analysis indicate that such an enhancement could be explained by absorption by a metastable, disordered and gold-rich surface layer. The sheet resistance and the diode electrical characteristics further elucidate the role of gold-supersaturation in silicon, revealing the promise for future silicon-based infrared device applications.

Material Voices: Intermediality and Autism

Science.gov (United States)

Trimingham, Melissa; Shaughnessy, Nicola

2016-01-01

Autism continues to be regarded enigmatically; a community that is difficult to access due to perceived disruptions of interpersonal connectedness. Through detailed observations of two children participating in the Arts and Humanities Research Council funded project "Imagining Autism: Drama, Performance and Intermediality as Interventions for…

Release of lungworm larvae from snails in the environment: potential for alternative transmission pathways.

Directory of Open Access Journals (Sweden)

Alessio Giannelli

2015-04-01

Full Text Available Gastropod-borne parasites may cause debilitating clinical conditions in animals and humans following the consumption of infected intermediate or paratenic hosts. However, the ingestion of fresh vegetables contaminated by snail mucus and/or water has also been proposed as a source of the infection for some zoonotic metastrongyloids (e.g., Angiostrongylus cantonensis. In the meantime, the feline lungworms Aelurostrongylus abstrusus and Troglostrongylus brevior are increasingly spreading among cat populations, along with their gastropod intermediate hosts. The aim of this study was to assess the potential of alternative transmission pathways for A. abstrusus and T. brevior L3 via the mucus of infected Helix aspersa snails and the water where gastropods died. In addition, the histological examination of snail specimens provided information on the larval localization and inflammatory reactions in the intermediate host.Twenty-four specimens of H. aspersa received ~500 L1 of A. abstrusus and T. brevior, and were assigned to six study groups. Snails were subjected to different mechanical and chemical stimuli throughout 20 days in order to elicit the production of mucus. At the end of the study, gastropods were submerged in tap water and the sediment was observed for lungworm larvae for three consecutive days. Finally, snails were artificially digested and recovered larvae were counted and morphologically and molecularly identified. The anatomical localization of A. abstrusus and T. brevior larvae within snail tissues was investigated by histology. L3 were detected in the snail mucus (i.e., 37 A. abstrusus and 19 T. brevior and in the sediment of submerged specimens (172 A. abstrusus and 39 T. brevior. Following the artificial digestion of H. aspersa snails, a mean number of 127.8 A. abstrusus and 60.3 T. brevior larvae were recovered. The number of snail sections positive for A. abstrusus was higher than those for T. brevior.Results of this study

Insignificant disease among men with intermediate-risk prostate cancer.

Science.gov (United States)

Hong, Sung Kyu; Vertosick, Emily; Sjoberg, Daniel D; Scardino, Peter T; Eastham, James A

2014-12-01

A paucity of data exists on the insignificant disease potentially suitable for active surveillance (AS) among men with intermediate-risk prostate cancer (PCa). We tried to identify pathologically insignificant disease and its preoperative predictors in men who underwent radical prostatectomy (RP) for intermediate-risk PCa. We analyzed data of 1,630 men who underwent RP for intermediate-risk disease. Total tumor volume (TTV) data were available in 332 men. We examined factors associated with classically defined pathologically insignificant cancer (organ-confined disease with TTV ≤0.5 ml with no Gleason pattern 4 or 5) and pathologically favorable cancer (organ-confined disease with no Gleason pattern 4 or 5) potentially suitable for AS. Decision curve analysis was used to assess clinical utility of a multivariable model including preoperative variables for predicting pathologically unfavorable cancer. In the entire cohort, 221 of 1,630 (13.6 %) total patients had pathologically favorable cancer. Among 332 patients with TTV data available, 26 (7.8 %) had classically defined pathologically insignificant cancer. Between threshold probabilities of 20 and 40 %, decision curve analysis demonstrated that using multivariable model to identify AS candidates would not provide any benefit over simply treating all men who have intermediate-risk disease with RP. Although a minority of patients with intermediate-risk disease may harbor pathologically favorable or insignificant cancer, currently available conventional tools are not sufficiently able to identify those patients.

Multifragmentation in intermediate energy heavy ion collisions

International Nuclear Information System (INIS)

Jacak, B.V.; Britt, H.C.; Claesson, G.

1986-01-01

There has been considerable recent interest in the production of intermediate mass fragments (A > 4) in intermediate and high energy nucleus-nucleus collisions. The mechanism for production of these fragments is not well understood and has been described by models employing a variety of assumptions. Some examples are: disassembly of a system in thermal equilibrium into nucleons and nuclear fragments, liquid-vapor phase transitions in nuclear matter, final state coalescence of nucleons and dynamical correlations between nucleons at breakup. Previous studies of fragment production, with one exception, have been single particle inclusive measurements; the observed fragment mass (or charge) distributions can be described by all of the models above. To gain insight into the fragment production mechanism, the authors used the GSI/LBL Plastic Ball detector system to get full azimuthal coverage for intermediate mass fragments in the forward hemisphere in the center of mass system while measuring all the light particles in each event. The authors studied the systems 200 MeV/nucleon Au + Au and Au + Fe

Intermediate-energy neutron beam for NCT at MURR

International Nuclear Information System (INIS)

Brugger, R.M.; Less, T.J.; Passmore, G.G.

1986-01-01

The University of Missouri Research Reactor (MURR) is one of the high-flux reactors in the USA and it can be used to produce an intense beam of intermediate-energy neutrons for neutron capture therapy. Two methods are being evaluated at MURR to produce such a beam. The first uses a moderator of Al 2 O 3 replacing part of the graphite and water on one side of the core of the reactor to produce a source of predominantly intermediate-energy neutrons. The second method is a filter of 238 U between the core and the patient position to pass only intermediate-energy neutrons. The results of these evaluations are presented in this paper along with an outline of the other resources at the University of Missouri-Columbia that are available to support an NCT program. 4 references, 7 figures, 1 table

Comparative study of electrochemical oxidation of herbicide 2,4,5-T: Kinetics, parametric optimization and mineralization pathway

Directory of Open Access Journals (Sweden)

Hicham Zazou

2017-01-01

Full Text Available Oxidative degradation of herbicide 2,4,5-T was studied by electrochemical advanced oxidation processes anodic oxidation and electro-Fenton (EF using Pt/carbon felt and BDD/carbon felt cells. The effect of main operating parameters on oxidation of 2,4,5-T and mineralization of its aqueous solution were investigated. The rate constant for oxidation of 2,4,5-T by ·≡OH was determined as (3.7 ± 0.2 × 109 M−1 s−1 using competition kinetics method. The EF process with BDD anode was shown to be very efficient reaching 94% mineralization in 3 h treatment. Based on identified aromatic intermediates, short-chain carboxylic acids, released inorganic ions and total organic carbon removal measurements, a plausible oxidation pathway for mineralization of 2,4,5-T by hydroxyl radical was proposed. In addition, the evolution of solution toxicity during treatment was monitored by Microtox method showing the formation of toxic aromatic/cyclic intermediates. The results showed also that EF process was able to remove efficiently toxic intermediates and consequently solution toxicity.

Thermogravimetric control of intermediate compounds in uranium metallurgy

International Nuclear Information System (INIS)

Gasco Sanchez, L.; Fernandez Cellini, R.

1959-01-01

The thermal decomposition of some intermediate compounds in the metallurgy of the uranium as uranium peroxide, ammonium uranate, uranium and ammonium penta-fluoride, uranium tetrafluoride and uranous oxide has been study by means of the Chevenard's thermo balance. Some data on pyrolysis of synthetic mixtures of intermediate compounds which may occasionally appear during the industrial process, are given. Thermogravimetric methods of control are suggested, usable in interesting products in the uranium metallurgy. (Author) 20 refs

Intermediate-energy neutron beams from reactors for NCT

International Nuclear Information System (INIS)

Brugger, R.M.; Less, T.J.; Passmore, G.G.

1986-01-01

This paper discusses ways that a beam of intermediate-energy neutrons might be extracted from a nuclear reactor. The challenge is to suppress the fast-neutron component and the gamma-ray component of the flux while leaving enough of the intermediate-energy neutrons in the beam to be able to perform neutron capture therapy in less than an hour exposure time. Moderators, filters, and reflectors are considered. 11 references, 7 figures, 3 tables

Corrective effects of hepatotoxicity by hepatic Dyrk1a gene delivery in mice with intermediate hyperhomocysteinemia

Directory of Open Access Journals (Sweden)

Alizée Latour

2015-03-01

Full Text Available Hyperhomocysteinemia results from hepatic metabolism dysfunction and is characterized by a high plasma homocysteine level, which is also an independent risk factor for cardiovascular disease. Elevated levels of homocysteine in plasma lead to hepatic lesions and abnormal lipid metabolism. Therefore, lowering homocysteine levels might offer therapeutic benefits. Recently, we were able to lower plasma homocysteine levels in mice with moderate hyperhomocysteinemia using an adenoviral construct designed to restrict the expression of DYRK1A, a serine/threonine kinase involved in methionine metabolism (and therefore homocysteine production, to hepatocytes. Here, we aimed to extend our previous findings by analyzing the effect of hepatocyte-specific Dyrk1a gene transfer on intermediate hyperhomocysteinemia and its associated hepatic toxicity and liver dysfunction. Commensurate with decreased plasma homocysteine and alanine aminotransferase levels, targeted hepatic expression of DYRK1A in mice with intermediate hyperhomocysteinemia resulted in elevated plasma paraoxonase-1 and lecithin:cholesterol acyltransferase activities and apolipoprotein A–I levels. It also rescued hepatic apolipoprotein E, J, and D levels. Further, Akt/GSK3/cyclin D1 signaling pathways in the liver of treated mice were altered, which may help prevent homocysteine-induced cell cycle dysfunction. DYRK1A gene therapy could be useful in the treatment of hyperhomocysteinemia in populations, such as end-stage renal disease patients, who are unresponsive to B-complex vitamin therapy.

Pathways of the Maillard reaction under physiological conditions.

Science.gov (United States)

Henning, Christian; Glomb, Marcus A

2016-08-01

Initially investigated as a color formation process in thermally treated foods, nowadays, the relevance of the Maillard reaction in vivo is generally accepted. Many chronic and age-related diseases such as diabetes, uremia, atherosclerosis, cataractogenesis and Alzheimer's disease are associated with Maillard derived advanced glycation endproducts (AGEs) and α-dicarbonyl compounds as their most important precursors in terms of reactivity and abundance. However, the situation in vivo is very challenging, because Maillard chemistry is paralleled by enzymatic reactions which can lead to both, increases and decreases in certain AGEs. In addition, mechanistic findings established under the harsh conditions of food processing might not be valid under physiological conditions. The present review critically discusses the relevant α-dicarbonyl compounds as central intermediates of AGE formation in vivo with a special focus on fragmentation pathways leading to formation of amide-AGEs.

Larval helminths in intermediate hosts

DEFF Research Database (Denmark)

Fredensborg, Brian Lund; Poulin, R

2005-01-01

Density-dependent effects on parasite fitness have been documented from adult helminths in their definitive hosts. There have, however, been no studies on the cost of sharing an intermediate host with other parasites in terms of reduced adult parasite fecundity. Even if larval parasites suffer a ...

Intermediate/Advanced Research Design and Statistics

Science.gov (United States)

Ploutz-Snyder, Robert

2009-01-01

The purpose of this module is To provide Institutional Researchers (IRs) with an understanding of the principles of advanced research design and the intermediate/advanced statistical procedures consistent with such designs

Pimelic acid, the first precursor of the Bacillus subtilis biotin synthesis pathway, exists as the free acid and is assembled by fatty acid synthesis.

Science.gov (United States)

Manandhar, Miglena; Cronan, John E

2017-05-01

Biotin synthetic pathways are readily separated into two stages, synthesis of the seven carbon α, ω-dicarboxylic acid pimelate moiety and assembly of the fused heterocyclic rings. The biotin pathway genes responsible for pimelate moiety synthesis vary widely among bacteria whereas the ring synthesis genes are highly conserved. Bacillus subtilis seems to have redundant genes, bioI and bioW, for generation of the pimelate intermediate. Largely consistent with previous genetic studies it was found that deletion of bioW caused a biotin auxotrophic phenotype whereas deletion of bioI did not. BioW is a pimeloyl-CoA synthetase that converts pimelic acid to pimeloyl-CoA. The essentiality of BioW for biotin synthesis indicates that the free form of pimelic acid is an intermediate in biotin synthesis although this is not the case in E. coli. Since the origin of pimelic acid in Bacillus subtilis is unknown, 13 C-NMR studies were carried out to decipher the pathway for its generation. The data provided evidence for the role of free pimelate in biotin synthesis and the involvement of fatty acid synthesis in pimelate production. Cerulenin, an inhibitor of the key fatty acid elongation enzyme, FabF, markedly decreased biotin production by B. subtilis resting cells whereas a strain having a cerulenin-resistant FabF mutant produced more biotin. In addition, supplementation with pimelic acid fully restored biotin production in cerulenin-treated cells. These results indicate that pimelic acid originating from fatty acid synthesis pathway is a bona fide precursor of biotin in B. subtilis. © 2017 John Wiley & Sons Ltd.

The endoplasmic reticulum is a hub to sort proteins toward unconventional traffic pathways and endosymbiotic organelles.

Science.gov (United States)

Bellucci, Michele; De Marchis, Francesca; Pompa, Andrea

2017-12-18

The discovery that much of the extracellular proteome in eukaryotic cells consists of proteins lacking a signal peptide, which cannot therefore enter the secretory pathway, has led to the identification of alternative protein secretion routes bypassing the Golgi apparatus. However, proteins harboring a signal peptide for translocation into the endoplasmic reticulum can also be transported along these alternative routes, which are still far from being well elucidated in terms of the molecular machineries and subcellular/intermediate compartments involved. In this review, we first try to provide a definition of all the unconventional protein secretion pathways in eukaryotic cells, as those pathways followed by proteins directed to an 'external space' bypassing the Golgi, where 'external space' refers to the extracellular space plus the lumen of the secretory route compartments and the inner space of mitochondria and plastids. Then, we discuss the role of the endoplasmic reticulum in sorting proteins toward unconventional traffic pathways in plants. In this regard, various unconventional pathways exporting proteins from the endoplasmic reticulum to the vacuole, plasma membrane, apoplast, mitochondria, and plastids are described, including the short routes followed by the proteins resident in the endoplasmic reticulum. © The Author(s) 2017. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Thin-film intermediate band chalcopyrite solar cells

International Nuclear Information System (INIS)

Fuertes Marron, D.; Marti, A.; Luque, A.

2009-01-01

Chalcopyrite-based solar cells currently lead the efficiency tables of thin-film photovoltaic technologies. Further improvements are foreseen upon implementation of an intermediate band in the absorber layers. We present a theoretical analysis of the efficiency limit for this type of device as a function of factors such as the gap of the host, the relative position of the intermediate band with respect to the band edge and the level of light concentration used as illumination. We have also considered the impact of non-idealities on the performance of the device, particularly the effect of electronic losses related to non-radiative recombination

Top predators induce the evolutionary diversification of intermediate predator species.

Science.gov (United States)

Zu, Jian; Yuan, Bo; Du, Jianqiang

2015-12-21

We analyze the evolutionary branching phenomenon of intermediate predator species in a tritrophic food chain model by using adaptive dynamics theory. Specifically, we consider the adaptive diversification of an intermediate predator species that feeds on a prey species and is fed upon by a top predator species. We assume that the intermediate predator׳s ability to forage on the prey can adaptively improve, but this comes at the cost of decreased defense ability against the top predator. First, we identify the general properties of trade-off relationships that lead to a continuously stable strategy or to evolutionary branching in the intermediate predator species. We find that if there is an accelerating cost near the singular strategy, then that strategy is continuously stable. In contrast, if there is a mildly decelerating cost near the singular strategy, then that strategy may be an evolutionary branching point. Second, we find that after branching has occurred, depending on the specific shape and strength of the trade-off relationship, the intermediate predator species may reach an evolutionarily stable dimorphism or one of the two resultant predator lineages goes extinct. Crown Copyright © 2015. Published by Elsevier Ltd. All rights reserved.

Conditioning of intermediate-level waste at Forschungszentrum Juelich GmbH

International Nuclear Information System (INIS)

Krumbach, H.

2003-01-01

This contribution to the group of low-level, intermediate, mixed and hazardous waste describes the conditioning of intermediate-level mixed waste (dose rate above 10 mSv/h at the surface) from Research Centre Juelich (FZJ). Conditioning of the waste by supercompaction is performed at Research Centre Karlsruhe (FZK). The waste described is radioactive waste arising from research at Juelich. This waste includes specimens and objects from irradiation experiments in the research reactors Merlin (FRJ-1) and Dido (FRJ-2) at FZJ. In principle, radioactive waste at Forschungszentrum Juelich GmbH is differentiated by the surface dose rate at the waste package. Up to a surface dose rate of 10 mSv/h, the waste is regarded as low-level. The radioactive waste described here has a surface dose rate above 10 mSv/h. Waste up to 10 mSv/h is conditioned at the Juelich site according to different conditioning methods. The intermediate-level waste can only be conditioned by supercompaction in the processing facility for intermediate-level waste from plant operation at Research Centre Karlsruhe. Research Centre Juelich also uses this waste cell to condition its intermediate-level waste from plant operation. (orig.)

Cryo-EM structures of two bovine adenovirus type 3 intermediates

International Nuclear Information System (INIS)

Cheng, Lingpeng; Huang, Xiaoxing; Li, Xiaomin; Xiong, Wei; Sun, Wei; Yang, Chongwen; Zhang, Kai; Wang, Ying; Liu, Hongrong; Huang, Xiaojun; Ji, Gang; Sun, Fei; Zheng, Congyi; Zhu, Ping

2014-01-01

Adenoviruses (Ads) infect hosts from all vertebrate species and have been investigated as vaccine vectors. We report here near-atomic structures of two bovine Ad type 3 (BAd3) intermediates obtained by cryo-electron microscopy. A comparison between the two intermediate structures reveals that the differences are localized in the fivefold vertex region, while their facet structures are identical. The overall facet structure of BAd3 exhibits a similar structure to human Ads; however, BAd3 protein IX has a unique conformation. Mass spectrometry and cryo-electron tomography analyses indicate that one intermediate structure represents the stage during DNA encapsidation, whilst the other intermediate structure represents a later stage. These results also suggest that cleavage of precursor protein VI occurs during, rather than after, the DNA encapsidation process. Overall, our results provide insights into the mechanism of Ad assembly, and allow the first structural comparison between human and nonhuman Ads at backbone level. - Highlights: • First structure of bovine adenovirus type 3. • Some channels are located at the vertex of intermediate during DNA encapsidation. • Protein IX exhibits a unique conformation of trimeric coiled–coiled structure. • Cleavage of precursor protein VI occurs during the DNA encapsidation process

Intermediate Filaments at the Junction of Mechanotransduction, Migration, and Development

Directory of Open Access Journals (Sweden)

Rucha Sanghvi-Shah

2017-09-01

Full Text Available Mechanically induced signal transduction has an essential role in development. Cells actively transduce and respond to mechanical signals and their internal architecture must manage the associated forces while also being dynamically responsive. With unique assembly-disassembly dynamics and physical properties, cytoplasmic intermediate filaments play an important role in regulating cell shape and mechanical integrity. While this function has been recognized and appreciated for more than 30 years, continually emerging data also demonstrate important roles of intermediate filaments in cell signal transduction. In this review, with a particular focus on keratins and vimentin, the relationship between the physical state of intermediate filaments and their role in mechanotransduction signaling is illustrated through a survey of current literature. Association with adhesion receptors such as cadherins and integrins provides a critical interface through which intermediate filaments are exposed to forces from a cell's environment. As a consequence, these cytoskeletal networks are posttranslationally modified, remodeled and reorganized with direct impacts on local signal transduction events and cell migratory behaviors important to development. We propose that intermediate filaments provide an opportune platform for cells to both cope with mechanical forces and modulate signal transduction.

Cryo-EM structures of two bovine adenovirus type 3 intermediates

Energy Technology Data Exchange (ETDEWEB)

Cheng, Lingpeng; Huang, Xiaoxing; Li, Xiaomin [National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101 (China); Xiong, Wei [State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Luo-jia-shan, Wuhan, Hubei 430072 (China); Sun, Wei; Yang, Chongwen; Zhang, Kai; Wang, Ying [National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101 (China); Liu, Hongrong [College of Physics and Information Science, Hunan Normal University, Changsha, Hunan 410081 (China); Huang, Xiaojun; Ji, Gang; Sun, Fei [National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101 (China); Zheng, Congyi, E-mail: cctcc202@whu.edu.cn [State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Luo-jia-shan, Wuhan, Hubei 430072 (China); Zhu, Ping, E-mail: zhup@ibp.ac.cn [National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101 (China)

2014-02-15

Adenoviruses (Ads) infect hosts from all vertebrate species and have been investigated as vaccine vectors. We report here near-atomic structures of two bovine Ad type 3 (BAd3) intermediates obtained by cryo-electron microscopy. A comparison between the two intermediate structures reveals that the differences are localized in the fivefold vertex region, while their facet structures are identical. The overall facet structure of BAd3 exhibits a similar structure to human Ads; however, BAd3 protein IX has a unique conformation. Mass spectrometry and cryo-electron tomography analyses indicate that one intermediate structure represents the stage during DNA encapsidation, whilst the other intermediate structure represents a later stage. These results also suggest that cleavage of precursor protein VI occurs during, rather than after, the DNA encapsidation process. Overall, our results provide insights into the mechanism of Ad assembly, and allow the first structural comparison between human and nonhuman Ads at backbone level. - Highlights: • First structure of bovine adenovirus type 3. • Some channels are located at the vertex of intermediate during DNA encapsidation. • Protein IX exhibits a unique conformation of trimeric coiled–coiled structure. • Cleavage of precursor protein VI occurs during the DNA encapsidation process.

Singlet channel coupling in deuteron elastic scattering at intermediate energies

International Nuclear Information System (INIS)

Al-Khalili, J.S.; Tostevin, J.A.; Johnson, R.C.

1990-01-01

Intermediate energy deuteron elastic scattering is investigated in a three-body model incorporating relativistic kinematics. The effects of deuteron breakup to singlet spin intermediate states, on the elastic scattering observables for the 58 Ni(d vector, d) 58 Ni reaction at 400 and 700 MeV, are studied quantitatively. The singlet-breakup contributions to the elastic amplitude are estimated within an approximate two-step calculation. The calculation makes an adiabatic approximation in the intermediate states propagator which allows the use of closure over the np intermediate states continuum. The singlet channel coupling is found to produce large effects on the calculated reaction tensor analysing power A yy , characteristic of a dynamically induced second-rank tensor interaction. By inspection of the calculated breakup amplitudes we show this induced interaction to be of the T L tensor type. (orig.)

Radiological assessment of the impact on human populations and the environment of the 1949 to 1982 dumping of low and intermediate level radioactive waste in the deep North-East Atlantic

International Nuclear Information System (INIS)

Chartier, M.; Menard, F.

1990-12-01

A thorough radiological assessment of the impact of the 1949 to 1982 dumping of low- and intermediate- level radioactive waste in the deep North-East Atlantic is performed with the numerical compartmental REJMAR model. The calculations include the assessment of the dose equivalent to the individuals of a theoretical critical group through a large set of pathways, and the collective dose to mankind through the ingestion pathways. The complete dumping performed in the deep North-East Atlantic is taken into account. The assumptions of biological short-circuit through marin food chains are tested. The order of magnitude of the dose delivered to marine organisms living near the dumping site is assessed [fr

"Affective Encounters": Live Intermedial Spaces in Sites of Trauma

Science.gov (United States)

Scott, Jo

2016-01-01

This article addresses live intermediality as a tool for creative learning in the context of workshops carried out with young people in the town of Terezin, in the Czech Republic, site of the Nazi concentration camp, Theresienstadt. Live intermediality, as a mode of live media practice, involves the real time mixing and merging of sound, image,…

Oxidative demethylation of lanosterol in cholesterol biosynthesis: accumulation of sterol intermediates

International Nuclear Information System (INIS)

Shafiee, A.; Trzaskos, J.M.; Paik, Y.K.; Gaylor, J.L.

1986-01-01

With [ 3 H-24,25]-dihydrolanosterol as substrate, large-scale metabolic formation of intermediates of lanosterol demethylation was carried out to identify all compounds in the metabolic process. Utilizing knowledge of electron transport of lanosterol demethylation, we interrupted the demethylation reaction allowing accumulation and confirmation of the structure of the oxygenated intermediates lanost-8-en-3 beta,32-diol and 3 beta-hydroxylanost-8-en-32-al, as well as the demethylation product 4,4-dimethyl-cholesta-8,14-dien-3 beta-ol. Further metabolism of the delta 8.14-diene intermediate to a single product 4,4-dimethyl-cholest-8-en-3 beta-ol occurs under interruption conditions in the presence of 0.5 mM CN-1. With authentic compounds, each intermediate has been rigorously characterized by high performance liquid chromatography and gas-liquid chromatography plus mass spectral analysis of isolated and derivatized sterols. Intermediates that accumulated in greater abundance were further characterized by ultraviolet, 1 H-NMR, and infrared spectroscopy of the isolated sterols

About the investigation of the ultrasonic absorption in intermediate states of superconductors

International Nuclear Information System (INIS)

Shepelev, A.G.

2003-01-01

Investigation of intermediate state in the bulk of superconductors are surveyed. Consideration is given to a previous attempt of eliminating edge effects in the ultrasonic investigation of intermediate states of pure gallium and molybdenum;it is demonstrated that those results are in strong contradiction with Landau's intermediate-state theory

Identification of combustion intermediates in low-pressure premixed pyridine/oxygen/argon flames.

Science.gov (United States)

Tian, Zhenyu; Li, Yuyang; Zhang, Taichang; Zhu, Aiguo; Qi, Fei

2008-12-25

Combustion intermediates of two low-pressure premixed pyridine/oxygen flames with respective equivalence ratios of 0.56 (C/O/N = 1:4.83:0.20) and 2.10 (C/O/N = 1:1.29:0.20) have been identified with tunable synchrotron vacuum ultraviolet (VUV) photoionization and molecular-beam mass spectrometry techniques. About 80 intermediates in the rich flame and 60 intermediates in the lean flame, including nitrogenous, oxygenated, and hydrocarbon intermediates, have been identified by measurements of photoionization mass spectra and photoionization efficiency spectra. Some radicals and new nitrogenous intermediates are identified in the present work. The experimental results are useful for studying the conversion of volatile nitrogen compounds and understanding the formation mechanism of NO(x) in flames of nitrogenous fuels.

Mixed fuel strategy for carbon deposition mitigation in solid oxide fuel cells at intermediate temperatures.

Science.gov (United States)

Su, Chao; Chen, Yubo; Wang, Wei; Ran, Ran; Shao, Zongping; Diniz da Costa, João C; Liu, Shaomin

2014-06-17

In this study, we propose and experimentally verified that methane and formic acid mixed fuel can be employed to sustain solid oxide fuel cells (SOFCs) to deliver high power outputs at intermediate temperatures and simultaneously reduce the coke formation over the anode catalyst. In this SOFC system, methane itself was one part of the fuel, but it also played as the carrier gas to deliver the formic acid to reach the anode chamber. On the other hand, the products from the thermal decomposition of formic acid helped to reduce the carbon deposition from methane cracking. In order to clarify the reaction pathways for carbon formation and elimination occurring in the anode chamber during the SOFC operation, O2-TPO and SEM analysis were carried out together with the theoretical calculation. Electrochemical tests demonstrated that stable and high power output at an intermediate temperature range was well-maintained with a peak power density of 1061 mW cm(-2) at 750 °C. With the synergic functions provided by the mixed fuel, the SOFC was running for 3 days without any sign of cell performance decay. In sharp contrast, fuelled by pure methane and tested at similar conditions, the SOFC immediately failed after running for only 30 min due to significant carbon deposition. This work opens a new way for SOFC to conquer the annoying problem of carbon deposition just by properly selecting the fuel components to realize their synergic effects.

Stable isotope fractionation during bacterial sulfate reduction is controlled by reoxidation of intermediates

Science.gov (United States)

Mangalo, Muna; Meckenstock, Rainer U.; Stichler, Willibald; Einsiedl, Florian

2007-09-01

Bacterial sulfate reduction is one of the most important respiration processes in anoxic habitats and is often assessed by analyzing the results of stable isotope fractionation. However, stable isotope fractionation is supposed to be influenced by the reduction rate and other parameters, such as temperature. We studied here the mechanistic basics of observed differences in stable isotope fractionation during bacterial sulfate reduction. Batch experiments with four sulfate-reducing strains ( Desulfovibrio desulfuricans, Desulfobacca acetoxidans, Desulfonatronovibrio hydrogenovorans, and strain TRM1) were performed. These microorganisms metabolize different carbon sources (lactate, acetate, formate, and toluene) and showed broad variations in their sulfur isotope enrichment factors. We performed a series of experiments on isotope exchange of 18O between residual sulfate and ambient water. Batch experiments were conducted with 18O-enriched (δ 18O water = +700‰) and depleted water (δ 18O water = -40‰), respectively, and the stable 18O isotope shift in the residual sulfate was followed. For Desulfovibrio desulfuricans and Desulfonatronovibrio hydrogenovorans, which are both characterized by low sulfur isotope fractionation ( ɛS > -13.2‰), δ 18O values in the remaining sulfate increased by only 50‰ during growth when 18O-enriched water was used for the growth medium. In contrast, with Desulfobacca acetoxidans and strain TRM1 ( ɛS factor ( ɛS exchange with water during sulfate reduction. However, this neither takes place in the sulfate itself nor during formation of APS (adenosine-5'-phosphosulfate), but rather in intermediates of the sulfate reduction pathway. These may in turn be partially reoxidized to form sulfate. This reoxidation leads to an incorporation of oxygen from water into the "recycled" sulfate changing the overall 18O isotopic composition of the remaining sulfate fraction. Our study shows that such incorporation of 18O is correlated with the

Benchmarking pathway interaction network for colorectal cancer to identify dysregulated pathways

Directory of Open Access Journals (Sweden)

Q. Wang

Full Text Available Different pathways act synergistically to participate in many biological processes. Thus, the purpose of our study was to extract dysregulated pathways to investigate the pathogenesis of colorectal cancer (CRC based on the functional dependency among pathways. Protein-protein interaction (PPI information and pathway data were retrieved from STRING and Reactome databases, respectively. After genes were aligned to the pathways, each pathway activity was calculated using the principal component analysis (PCA method, and the seed pathway was discovered. Subsequently, we constructed the pathway interaction network (PIN, where each node represented a biological pathway based on gene expression profile, PPI data, as well as pathways. Dysregulated pathways were then selected from the PIN according to classification performance and seed pathway. A PIN including 11,960 interactions was constructed to identify dysregulated pathways. Interestingly, the interaction of mRNA splicing and mRNA splicing-major pathway had the highest score of 719.8167. Maximum change of the activity score between CRC and normal samples appeared in the pathway of DNA replication, which was selected as the seed pathway. Starting with this seed pathway, a pathway set containing 30 dysregulated pathways was obtained with an area under the curve score of 0.8598. The pathway of mRNA splicing, mRNA splicing-major pathway, and RNA polymerase I had the maximum genes of 107. Moreover, we found that these 30 pathways had crosstalks with each other. The results suggest that these dysregulated pathways might be used as biomarkers to diagnose CRC.

Hγ Line Spectrum of Intermediate Polars

Directory of Open Access Journals (Sweden)

Yonggi Kim

1998-06-01

Full Text Available Kim & Beuermann (1995, 1996 have developed a model for the propagation of X-rays from the accreting white dwarf through the infalling material and the re-emission of the energy deposited by photo-absorption in the optical (and UV spectral range. By using this model, we calculate the profiles of the Hγ emission-line spectrum of intermediate polars. Photoabsorption of X-rays by the infalling material is the dominant process in forming the observed energy-dependent rotational modulation of the X-ray flux. X-ray and optical modulations are sensitive to model parameters in different ways. In principle, these dependencies allow us to obtain improved insight into the accretion geometry of the intermediate polars. We present results of our calculations and compare them with the Hβ line spectrum (Kim & Beuermann 1996.

A metabolic pathway for catabolizing levulinic acid in bacteria

International Nuclear Information System (INIS)

Rand, Jacqueline M.; Pisithkul, Tippapha; Clark, Ryan L.; Thiede, Joshua M.; Mehrer, Christopher R.

2017-01-01

Microorganisms can catabolize a wide range of organic compounds and therefore have the potential to perform many industrially relevant bioconversions. One barrier to realizing the potential of biorefining strategies lies in our incomplete knowledge of metabolic pathways, including those that can be used to assimilate naturally abundant or easily generated feedstocks. For instance, levulinic acid (LA) is a carbon source that is readily obtainable as a dehydration product of lignocellulosic biomass and can serve as the sole carbon source for some bacteria. Yet, the genetics and structure of LA catabolism have remained unknown. Here, we report the identification and characterization of a seven-gene operon that enables LA catabolism in Pseudomonas putida KT2440. When the pathway was reconstituted with purified proteins, we observed the formation of four acyl-CoA intermediates, including a unique 4-phosphovaleryl-CoA and the previously observed 3-hydroxyvaleryl-CoA product. Using adaptive evolution, we obtained a mutant of Escherichia coli LS5218 with functional deletions of fadE and atoC that was capable of robust growth on LA when it expressed the five enzymes from the P. putida operon. Here, this discovery will enable more efficient use of biomass hydrolysates and metabolic engineering to develop bioconversions using LA as a feedstock.

Nuclear spin-orbit splitting from an intermediate Δ excitation

International Nuclear Information System (INIS)

Ohta, K.; Terasawa, T.; Tohyama, M.

1980-01-01

The strength of the single particle spin-orbit potential is calculated from the two pion exchange box diagrams involving an intermediate Δ(1232) resonance excitation by taking account of the exclusion principle for the intermediate nucleon states. The effect of the rho meson is also considered. The predicted strength is found to account for a substantial part of the empirical spin-orbit splittings

Homologous recombination and non-homologous end-joining repair pathways in bovine embryos with different developmental competence

Energy Technology Data Exchange (ETDEWEB)

Henrique Barreta, Marcos [Universidade Federal de Santa Catarina, Campus Universitario de Curitibanos, Curitibanos, SC (Brazil); Laboratorio de Biotecnologia e Reproducao Animal-BioRep, Universidade Federal de Santa Maria, Santa Maria, RS (Brazil); Garziera Gasperin, Bernardo; Braga Rissi, Vitor; Cesaro, Matheus Pedrotti de [Laboratorio de Biotecnologia e Reproducao Animal-BioRep, Universidade Federal de Santa Maria, Santa Maria, RS (Brazil); Ferreira, Rogerio [Centro de Educacao Superior do Oeste-Universidade do Estado de Santa Catarina, Chapeco, SC (Brazil); Oliveira, Joao Francisco de; Goncalves, Paulo Bayard Dias [Laboratorio de Biotecnologia e Reproducao Animal-BioRep, Universidade Federal de Santa Maria, Santa Maria, RS (Brazil); Bordignon, Vilceu, E-mail: vilceu.bordignon@mcgill.ca [Department of Animal Science, McGill University, Ste-Anne-De-Bellevue, QC (Canada)

2012-10-01

This study investigated the expression of genes controlling homologous recombination (HR), and non-homologous end-joining (NHEJ) DNA-repair pathways in bovine embryos of different developmental potential. It also evaluated whether bovine embryos can respond to DNA double-strand breaks (DSBs) induced with ultraviolet irradiation by regulating expression of genes involved in HR and NHEJ repair pathways. Embryos with high, intermediate or low developmental competence were selected based on the cleavage time after in vitro insemination and were removed from in vitro culture before (36 h), during (72 h) and after (96 h) the expected period of embryonic genome activation. All studied genes were expressed before, during and after the genome activation period regardless the developmental competence of the embryos. Higher mRNA expression of 53BP1 and RAD52 was found before genome activation in embryos with low developmental competence. Expression of 53BP1, RAD51 and KU70 was downregulated at 72 h and upregulated at 168 h post-insemination in response to DSBs induced by ultraviolet irradiation. In conclusion, important genes controlling HR and NHEJ DNA-repair pathways are expressed in bovine embryos, however genes participating in these pathways are only regulated after the period of embryo genome activation in response to ultraviolet-induced DSBs.

Homologous recombination and non-homologous end-joining repair pathways in bovine embryos with different developmental competence

International Nuclear Information System (INIS)

Henrique Barreta, Marcos; Garziera Gasperin, Bernardo; Braga Rissi, Vitor; Cesaro, Matheus Pedrotti de; Ferreira, Rogério; Oliveira, João Francisco de; Gonçalves, Paulo Bayard Dias; Bordignon, Vilceu

2012-01-01

This study investigated the expression of genes controlling homologous recombination (HR), and non-homologous end-joining (NHEJ) DNA-repair pathways in bovine embryos of different developmental potential. It also evaluated whether bovine embryos can respond to DNA double-strand breaks (DSBs) induced with ultraviolet irradiation by regulating expression of genes involved in HR and NHEJ repair pathways. Embryos with high, intermediate or low developmental competence were selected based on the cleavage time after in vitro insemination and were removed from in vitro culture before (36 h), during (72 h) and after (96 h) the expected period of embryonic genome activation. All studied genes were expressed before, during and after the genome activation period regardless the developmental competence of the embryos. Higher mRNA expression of 53BP1 and RAD52 was found before genome activation in embryos with low developmental competence. Expression of 53BP1, RAD51 and KU70 was downregulated at 72 h and upregulated at 168 h post-insemination in response to DSBs induced by ultraviolet irradiation. In conclusion, important genes controlling HR and NHEJ DNA-repair pathways are expressed in bovine embryos, however genes participating in these pathways are only regulated after the period of embryo genome activation in response to ultraviolet-induced DSBs.

Degradation pathway of malachite green in a novel dual-tank photoelectrochemical catalytic reactor

International Nuclear Information System (INIS)

Diao, Zenghui; Li, Mingyu; Zeng, Fanyin; Song, Lin; Qiu, Rongliang

2013-01-01

Highlights: • A novel dual-tank photoelectrochemical catalytic reactor was designed. • Malachite green degraded in bipolar double-effect mode. • Salt bridge replaced by a cation exchange membrane in the reactor. • Degradation pathways of malachite green in the cathode and anode tanks were similar. -- Abstract: A novel dual-tank photoelectrochemical catalytic reactor was designed to investigate the degradation pathway of malachite green. A thermally formed TiO 2 /Ti thin film electrode was used as photoanode, graphite was used as cathode, and a saturated calomel electrode was employed as the reference electrode in the reactor. In the reactor, the anode and cathode tanks were connected by a cation exchange membrane. Results showed that the decolorization ratio of malachite green in the anode and cathode was 98.5 and 96.5% after 120 min, respectively. Malachite green in the two anode and cathode tanks was oxidized, achieving the bipolar double effect. Malachite green in both the anode and cathode tanks exhibited similar catalytic degradation pathways. The double bond of the malachite green molecule was attacked by strong oxidative hydroxyl radicals, after which the organic compound was degraded by the two pathways into 4,4-bis(dimethylamino) benzophenone, 4-(dimethylamino) benzophenone, 4-(dimethylamino) phenol, and other intermediate products. Eventually, malachite green was degraded into oxalic acid as a small molecular organic acid, which was degraded by processes such as demethylation, deamination, nitration, substitution, addition, and other reactions

Validation of RetroPath, a computer-aided design tool for metabolic pathway engineering.

Science.gov (United States)

Fehér, Tamás; Planson, Anne-Gaëlle; Carbonell, Pablo; Fernández-Castané, Alfred; Grigoras, Ioana; Dariy, Ekaterina; Perret, Alain; Faulon, Jean-Loup

2014-11-01

Metabolic engineering has succeeded in biosynthesis of numerous commodity or high value compounds. However, the choice of pathways and enzymes used for production was many times made ad hoc, or required expert knowledge of the specific biochemical reactions. In order to rationalize the process of engineering producer strains, we developed the computer-aided design (CAD) tool RetroPath that explores and enumerates metabolic pathways connecting the endogenous metabolites of a chassis cell to the target compound. To experimentally validate our tool, we constructed 12 top-ranked enzyme combinations producing the flavonoid pinocembrin, four of which displayed significant yields. Namely, our tool queried the enzymes found in metabolic databases based on their annotated and predicted activities. Next, it ranked pathways based on the predicted efficiency of the available enzymes, the toxicity of the intermediate metabolites and the calculated maximum product flux. To implement the top-ranking pathway, our procedure narrowed down a list of nine million possible enzyme combinations to 12, a number easily assembled and tested. One round of metabolic network optimization based on RetroPath output further increased pinocembrin titers 17-fold. In total, 12 out of the 13 enzymes tested in this work displayed a relative performance that was in accordance with its predicted score. These results validate the ranking function of our CAD tool, and open the way to its utilization in the biosynthesis of novel compounds. Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

42 CFR 422.750 - Types of intermediate sanctions and civil money penalties.

Science.gov (United States)

2010-10-01

... 42 Public Health 3 2010-10-01 2010-10-01 false Types of intermediate sanctions and civil money... § 422.750 Types of intermediate sanctions and civil money penalties. (a) The following intermediate... organization. (b) CMS may impose civil money penalties as specified in 422.760. [72 FR 68725, Dec. 5, 2007, as...

Microdosimetry of intermediate energy neutrons in fast neutron fields

International Nuclear Information System (INIS)

Saion, E.B.; Watt, D.E.

1988-01-01

A coaxial double cylindrical proportional counter has been constructed for microdosimetry of intermediate energy neutrons in mixed fields. Details are given of the measured gas gain and resolution characteristics of the counter for a wide range of anode voltages. Event spectra due to intermediate neutrons in any desired energy band is achieved by an appropriate choice of thickness of the common dividing wall in the counter and by appropriate use of the coincidence, anticoincidence pulse counting arrangements. Calculated estimates indicate that the dose contribution by fast neutrons to the energy deposition events in the intermediate neutron range may be as large as 25%. Empirical procedures being investigated aim to determine the necessary corrections to be applied to the microdose distributions, with a precision of 10%. (author)

About the structure of quantum intermediate state of superconductors

International Nuclear Information System (INIS)

Ledenev, O.P.

2008-01-01

The calculation of spatial structure of a quantum intermediate state in Type I superconductors is completed. Theoretical model of thermodynamics of considered state was proposed by Andreev. It is shown, that in a quantum case, the period of structure appears significantly smaller and has different dependence on both the magnetic field and temperature than in the classical intermediate Landau state. The decrease of thickness of normal layers results in increase of characteristic distance between the quantum Andreev levels of electronic excitations, and the transition to the quantum intermediate from classical state is realized at higher temperatures ∼1 K, than it was supposed in previous works. The comparison of calculation data with experimental results, for example using the sample of mono-crystal gallium, is conducted

Negotiating comfort in low energy housing: The politics of intermediation

International Nuclear Information System (INIS)

Grandclément, Catherine; Karvonen, Andrew; Guy, Simon

2015-01-01

Optimising the energy performance of buildings is technically and economically challenging but it also has significant social implications. Maintaining comfortable indoor conditions while reducing energy consumption involves careful design, construction, and management of the built environment and its inhabitants. In this paper, we present findings from the study of a new low energy building for older people in Grenoble, France where conflicts emerged over the simultaneous pursuit of energy efficiency and comfort. The findings contribute to the contemporary literature on the sociotechnical study of buildings and energy use by focusing on intermediation, those activities that associate a technology to end users. Intermediation activities take many forms, and in some cases, can result in the harmonisation or alignment of energy efficiency goals and comfort goals. In other cases, intermediation is unsuccessful, leading to the conventional dichotomy between optimising technical performance and meeting occupant preferences. By highlighting the multiple ways that comfort and energy efficiency is negotiated, we conclude that buildings are provisional achievements that are constantly being intermediated. This suggests that building energy efficiency policies and programmes need to provide opportunities for intermediaries to negotiate the desires and preferences of the multiple stakeholders that are implicated in low energy buildings. -- Highlights: •Energy efficiency and comfort are two possibly contradictory aims of buildings. •We study the pursuit of these aims at the occupation stage of a new building. •Aligning these aims involve negotiating them with occupants. •Intermediation processes are key to such negotiations. •Intermediation processes involve both actors and technical devices

Deep and intermediate mediterranean water in the western Alboran Sea

Science.gov (United States)

Parrilla, Gregorio; Kinder, Thomas H.; Preller, Ruth H.

1986-01-01

Hydrographic and current meter data, obtained during June to October 1982, and numerical model experiments are used to study the distribution and flow of Mediterranean waters in the western Alboran Sea. The Intermediate Water is more pronounced in the northern three-fourths of the sea, but its distribution is patchy as manifested by variability of the temperature and salinity maxima at scales ≤10 km. Current meters in the lower Intermediate Water showed mean flow toward the Strait at 2 cm s -1. A reversal of this flow lasted about 2 weeks. A rough estimate of the mean westward Intermediate Water transport was 0.4 × 10 6 m 3 s -1, about one-third of the total outflow, so that the best estimates of the contributions of traditionally defined Intermediate Water and Deep Water account for only about one-half of the total outflow. The Deep Water was uplifted against the southern continental slope from Alboran Island (3°W) to the Strait. There was also a similar but much weaker banking against the Spanish slope, but a deep current record showed that the eastward recirculation implied by this banking is probably intermittent. Two-layer numerical model experiments simulated the Intermediate Water flow with a flat bottom and the Deep Water with realistic bottom topography. Both experiments replicated the major circulation features, and the Intermediate Water flow was concentrated in the north because of rotation and the Deep Water flow in the south because of topographic control.

A hybrid intermediate language between SSA and CPS

DEFF Research Database (Denmark)

Torrens, Paulo; Vasconcellos, Cristiano; Gonçalves, Ju

2017-01-01

passing style (CPS) lambda calculus has been used as intermediate language for functional language compilers, they are (almost) equivalent and it is possible to draw syntactic translations between them. This short paper aims to present an untyped intermediate language which may be interpreted as both SSA...... and CPS, in order to provide a common language for both imperative and functional compilers, as well to take advantage of optimizations designed for either one of the approaches. Finally, potential variants and research opportunities are discussed....

Intermediate states in quantum cryptography and Bell inequalities

International Nuclear Information System (INIS)

Bechmann-Pasquinucci, H.; Gisin, N.

2003-01-01

Intermediate states are known from intercept/resend eavesdropping in the Bennett-Brassard 1984 (BB84) quantum cryptographic protocol. But they also play fundamental roles in the optimal eavesdropping strategy on the BB84 protocol and in the CHSH (Clauser-Horne-Shimony-Holt) inequality. We generalize the intermediate states to an arbitrary dimension and consider intercept/resend eavesdropping, optimal eavesdropping on the generalized BB84 protocol and present a generalized Clauser-Horne-Shimony-Holt inequality for two entangled qudits based on these states

Identification of the degradation pathways of alkanolamines with TiO2 photocatalysis

International Nuclear Information System (INIS)

Lu, Chung-Shin; Chen, Chiing-Chang; Mai, Fu-Der; Li, Hua-Kuang

2009-01-01

The present study deals with the photocatalytic degradation of the alkanolamine, 2-dimethylamino-2-methyl-1-propanol (DMAMP), in the presence of TiO 2 particles and UV-A (λ = 365 nm) radiation. The obtained results show complete oxidation of DMAMP after 20 h, and a little over 90% of DMAMP was mineralization after 64-h of treatment. The effects of the solution pH, catalyst loading, and anions on the photocatalytic degradation of DMAMP were investigated, as well as the reaction intermediates that were formed during treatment. To the best of our knowledge, this is the first time that reports the degradation pathways of DMAMP. A number of intermediates were identified by GC/MS techniques during the treatment of DMAMP, following three tentative degradation routes. The first one is based on the oxidation of the primary alcohol group leading to the formation of corresponding aldehyde and carboxylic acid. The second route is based on the rupture of the N-C bond to form 2-methylpropanal and acetone. The last degradation route is based on the cyclization of the β-amino alcohol group to form the oxazolidine derivatives.

Reactivity of Criegee Intermediates toward Carbon Dioxide.

Science.gov (United States)

Lin, Yen-Hsiu; Takahashi, Kaito; Lin, Jim Jr-Min

2018-01-04

Recent theoretical work by Kumar and Francisco suggested that the high reactivity of Criegee intermediates (CIs) could be utilized for designing efficient carbon capture technologies. Because the anti-CH 3 CHOO + CO 2 reaction has the lowest barrier in their study, we chose to investigate it experimentally. We probed anti-CH 3 CHOO with its strong UV absorption at 365 nm and measured the rate coefficient to be ≤2 × 10 -17 cm 3 molecule -1 s -1 at 298 K, which is consistent with our theoretical value of 2.1 × 10 -17 cm 3  molecule -1 s -1 at the QCISD(T)/CBS//B3LYP/6-311+G(2d,2p) level but inconsistent with their results obtained at the M06-2X/aug-cc-pVTZ level, which tends to underestimate the barrier heights. The experimental result indicates that the reaction of a Criegee intermediate with atmospheric CO 2 (400 ppmv) would be inefficient (k eff < 0.2 s -1 ) and cannot compete with other decay processes of Criegee intermediates like reactions with water vapor (∼10 3 s -1 ) or thermal decomposition (∼10 2 s -1 ).

Succinate modulates Ca(2+) transient and cardiomyocyte viability through PKA-dependent pathway.

Science.gov (United States)

Aguiar, Carla J; Andrade, Vanessa L; Gomes, Enéas R M; Alves, Márcia N M; Ladeira, Marina S; Pinheiro, Ana Cristina N; Gomes, Dawidson A; Almeida, Alvair P; Goes, Alfredo M; Resende, Rodrigo R; Guatimosim, Silvia; Leite, M Fatima

2010-01-01

GPR91 is an orphan G-protein-coupled receptor (GPCR) that has been characterized as a receptor for succinate, a citric acid cycle intermediate, in several tissues. In the heart, the role of succinate is unknown. We now report that rat ventricular cardiomyocytes express GPR91. We found that succinate, through GPR91, increases the amplitude and the rate of decline of global Ca(2+) transient, by increasing the phosphorylation levels of ryanodine receptor and phospholamban, two well known Ca(2+) handling proteins. The effects of succinate on Ca(2+) transient were abolished by pre-treatment with adenylyl cyclase and cAMP-dependent protein kinase (PKA) inhibitors. Direct PKA activation by succinate was further confirmed using a FRET-based A-kinase activity reporter. Additionally, succinate decreases cardiomyocyte viability through a caspase-3 activation pathway, effect also prevented by PKA inhibition. Taken together, these observations show that succinate acts as a signaling molecule in cardiomyocytes, modulating global Ca(2+) transient and cell viability through a PKA-dependent pathway. 2009 Elsevier Ltd. All rights reserved.

Does guessing matter? Differences between ability estimates from 2PL and 3PL IRT models in case of guessing

Directory of Open Access Journals (Sweden)

Tomasz Żółtak

2015-09-01

Full Text Available Modern approaches to measuring cognitive ability and testing knowledge frequently use multiple-choice items. These can be simply and rapidly scored without problems associated with rater subjectivity. Nevertheless, multiple-choice tests are often criticized owing to their vulnerability to guessing. In this paper the impact of guessing was examined using simulation. Ability estimates were obtained from the two IRT models commonly used for binary-scored items: the two-parameter logistic model and the three-parameter logistic model. The latter approach explicitly models guessing, whilst the former does not. Rather counter-intuitively, little difference was identified for point estimates of ability from the 2PLM and 3PLM. Nevertheless, it should be noted that difficulty and discrimination parameters are severely downwardly biased if a 2PLM is used to calibrate data generated by processes involving guessing. Estimated standard errors for ability estimates also differ considerably between these models.

Summary of plant life management evaluation for Onagawa Nuclear Power Station Unit-1

International Nuclear Information System (INIS)

Nodate, Kazumi

2014-01-01

The Onagawa Nuclear Power Station Unit-1 (Onagawa NPS-1) began commercial operation on June 1, 1984, and has reached 30-year from starting of operation on June of 2014. To that end, we implemented the Plant Life Management (PLM) evaluation for Onagawa NPS-1 as our first experience. We decided on a Long-term Maintenance Management Policy from result of the evaluation, and then applied the Safety-Regulations change approval application on November 6, 2013 and its correcting application on April 16, 2014. Our application was approved on May 21, 2014 through investigation by the Nuclear Regulatory Agency. Also at implementation of the PLM evaluation, we considered effects of the Great East Japan Earthquake that occurred on March 11, 2011 against ageing phenomena. In this paper, we introduce summary of PLM evaluation for Onagawa NPS-1 and the evaluation that considered effects of the Great East Japan Earthquake. (author)

Early metabolic adaptation in C57BL/6 mice resistant to high fat diet induced weight gain involves an activation of mitochondrial oxidative pathways.

Science.gov (United States)

Boulangé, Claire L; Claus, Sandrine P; Chou, Chieh J; Collino, Sebastiano; Montoliu, Ivan; Kochhar, Sunil; Holmes, Elaine; Rezzi, Serge; Nicholson, Jeremy K; Dumas, Marc E; Martin, François-Pierre J

2013-04-05

We investigated the short-term (7 days) and long-term (60 days) metabolic effect of high fat diet induced obesity (DIO) and weight gain in isogenic C57BL/6 mice and examined the specific metabolic differentiation between mice that were either strong-responders (SR), or non-responders (NR) to weight gain. Mice (n = 80) were fed a standard chow diet for 7 days prior to randomization into a high-fat (HF) (n = 56) or a low-fat (LF) (n = 24) diet group. The (1)H NMR urinary metabolic profiles of LF and HF mice were recorded 7 and 60 days after the diet switch. On the basis of the body weight gain (BWG) distribution of HF group, we identified NR mice (n = 10) and SR mice (n = 14) to DIO. Compared with LF, HF feeding increased urinary excretion of glycine conjugates of β-oxidation intermediate (hexanoylglycine), branched chain amino acid (BCAA) catabolism intermediates (isovalerylglycine, α-keto-β-methylvalerate and α-ketoisovalerate) and end-products of nicotinamide adenine dinucleotide (NAD) metabolism (N1-methyl-2-pyridone-5-carboxamide, N1-methyl-4-pyridone-3-carboxamide) suggesting up-regulation of mitochondrial oxidative pathways. In the HF group, NR mice excreted relatively more hexanoylglycine, isovalerylglycine, and fewer tricarboxylic acid (TCA) cycle intermediate (succinate) in comparison to SR mice. Thus, subtle regulation of ketogenic pathways in DIO may alleviate the saturation of the TCA cycle and mitochondrial oxidative metabolism.

Intermediate-range order in lead metasilicate glass

Energy Technology Data Exchange (ETDEWEB)

Suzuya, Kentaro [Japan Atomic Energy Research Inst., Ako, Hyogo (Japan)]|[Argonne National Lab., IL (United States). Materials Science Div.; Price, D.L.; Saboungi, M.L. [Argonne National Lab., IL (United States). Materials Science Div.; Ohno, Hideo [Japan Atomic Energy Research Inst., Ako, Hyogo (Japan)

1997-03-01

The complementarity of anomalous X-ray scattering (AXS) and neutron diffraction (ND) techniques is used here to investigate the nature and origin of intermediate-range order in lead metasilicate glass. Both X-ray and neutron source factors reveal small peaks at low wave vector which are shown to be associated with intermediate-range order of the Pb-O network. The combination of AXS and ND is shown to be a powerful tool to correlate contributions from the different atom pairs to such a peak. The information thus derived is compared with results from alkali germanate glasses and with structural data on corresponding crystalline compounds.

Substrate recognition and catalysis by GH47 α-mannosidases involved in Asn-linked glycan maturation in the mammalian secretory pathway

Energy Technology Data Exchange (ETDEWEB)

Xiang, Yong; Karaveg, Khanita; Moremen, Kelley W.

2016-11-17

Asn-linked glycosylation of newly synthesized polypeptides occurs in the endoplasmic reticulum of eukaryotic cells. Glycan structures are trimmed and remodeled as they transit the secretory pathway, and processing intermediates play various roles as ligands for folding chaperones and signals for quality control and intracellular transport. Key steps for the generation of these trimmed intermediates are catalyzed by glycoside hydrolase family 47 (GH47) α-mannosidases that selectively cleave α1,2-linked mannose residues. Despite the sequence and structural similarities among the GH47 enzymes, the molecular basis for residue-specific cleavage remains obscure. The present studies reveal enzyme–substrate complex structures for two related GH47 α-mannosidases and provide insights into how these enzymes recognize the same substrates differently and catalyze the complementary glycan trimming reactions necessary for glycan maturation.

Intermediate organizations in the innovation process in Mexico

Directory of Open Access Journals (Sweden)

Maria del Pilar Monserrat Pérez Hernández

2016-07-01

Full Text Available The innovation activity depends strongly on the interaction between generating actors and end-users of new knowledge and technologies. There are several intermediate organizations (IO that facilitate translating the needs of the users with the new technologies that are beingdeveloped, in order to satisfy more effectively their demands. This paper analyzes the mediation process involved in the IO in innovative activity in Mexico, to identify structural holes in the innovation process. The relevant results in the Mexican intermediation process points that threeimportant structural holes of the process are missing: one between the negotiation process and sponsorship, the second in marketing and commercial profit of the obtained results and the last one in the regulation and referring activities. It is very important that the detected missinglinks in the intermediation process are filled, because they can hinder considerably the overall profit and benefits that society could obtained of the innovation process.

Pathway cross-talk network analysis identifies critical pathways in neonatal sepsis.

Science.gov (United States)

Meng, Yu-Xiu; Liu, Quan-Hong; Chen, Deng-Hong; Meng, Ying

2017-06-01

Despite advances in neonatal care, sepsis remains a major cause of morbidity and mortality in neonates worldwide. Pathway cross-talk analysis might contribute to the inference of the driving forces in bacterial sepsis and facilitate a better understanding of underlying pathogenesis of neonatal sepsis. This study aimed to explore the critical pathways associated with the progression of neonatal sepsis by the pathway cross-talk analysis. By integrating neonatal transcriptome data with known pathway data and protein-protein interaction data, we systematically uncovered the disease pathway cross-talks and constructed a disease pathway cross-talk network for neonatal sepsis. Then, attract method was employed to explore the dysregulated pathways associated with neonatal sepsis. To determine the critical pathways in neonatal sepsis, rank product (RP) algorithm, centrality analysis and impact factor (IF) were introduced sequentially, which synthetically considered the differential expression of genes and pathways, pathways cross-talks and pathway parameters in the network. The dysregulated pathways with the highest IF values as well as RPpathways in neonatal sepsis. By integrating three kinds of data, only 6919 common genes were included to perform the pathway cross-talk analysis. By statistic analysis, a total of 1249 significant pathway cross-talks were selected to construct the pathway cross-talk network. Moreover, 47 dys-regulated pathways were identified via attract method, 20 pathways were identified under RPpathways with the highest IF were also screened from the pathway cross-talk network. Among them, we selected 8 common pathways, i.e. critical pathways. In this study, we systematically tracked 8 critical pathways involved in neonatal sepsis by integrating attract method and pathway cross-talk network. These pathways might be responsible for the host response in infection, and of great value for advancing diagnosis and therapy of neonatal sepsis. Copyright © 2017

Synthesis and reactions of deuterated 2-(alkylimino)-3-nitrosooxazolidines, 3-alkly-1-(2-hydroxyethyl)-1-nitrosoureas, and related compounds as possible intermediates in the aqueous decomposition of 3-alkyl-1-(2-chloroethyl)-1-nitrosoureas

International Nuclear Information System (INIS)

Lown, J.W.; Chauhan, S.M.S.

1981-01-01

Decomposition of 1-(2-chloroethyl)-3-cyclohexyl-1-nitrosourea-α-d 2 (CCNU-α-d 2 ) (7) in pH 7.2 phosphate buffer or of CINO-α-d 2 (9) or CHNU-α-d 2 (8) with the addition of chloride ion gives rise to the same spectrum of products, including deuterium-free acetaldehyde (29), a mixture of the two deuterio-2-chloroethanols, 2-hydroxy-2,2-dideuterioethyl cyclohexyl carbamates, and vinyl chloride containing one deuterium (i.e., opposite the results obtained in the corresponding reaction of BCNU-α-d 4 ). The products were identified and the number and position of the deuterium labels determined by GC/MS. The results are interpreted in terms of two decomposition pathways for CCNU. The first decomposition pathway operating for CCNU is via an intermediate-2-chloroethanediazohydroxide or the equivalent 2-chloroethyl cation in agreement with the results of other workers. The second pathway may involve reversible conversion of CCNU-α-d 2 (7) to CINO-α-d 2 (9) and then ring opening of the latter to CHNU-α-d 2 (8). Independent decomposition of 8 provides evidence for its conversion to a 1.1-dideuterio-2-hydroxyethanediazohydroxide (41) leading to the isolated carbamates 36 and 44. The intermediacy of species 41 may account for the formation of 2-hydroxyethylated nucleosides observed when (2-chloroethyl)nitrosoureas react with DNA. An alternative ring-opening reaction of 9 leads to a 2-hydroxydiazoethyl cyclohexylcarbamate species (37), elimination of which and attack by halide ion may account for the vinyl halide species formed. Further evidence in support of these competing pathways employing additional specifically deuterated intermediates is described and discussed

Germline Polymorphisms of the VEGF Pathway Predict Recurrence in Nonadvanced Differentiated Thyroid Cancer.

Science.gov (United States)

Marotta, Vincenzo; Sciammarella, Concetta; Capasso, Mario; Testori, Alessandro; Pivonello, Claudia; Chiofalo, Maria Grazia; Gambardella, Claudio; Grasso, Marica; Antonino, Antonio; Annunziata, Annamaria; Macchia, Paolo Emidio; Pivonello, Rosario; Santini, Luigi; Botti, Gerardo; Losito, Simona; Pezzullo, Luciano; Colao, Annamaria; Faggiano, Antongiulio

2017-02-01

Tumor angiogenesis is determined by host genetic background rather than environment. Germline single nucleotide polymorphisms (SNPs) of the vascular endothelial growth factor (VEGF) pathway have demonstrated prognostic value in different tumors. Our main objective was to test the prognostic value of germline SNPs of the VEGF pathway in nonadvanced differentiated thyroid cancer (DTC). Secondarily, we sought to correlate analyzed SNPs with microvessel density (MVD). Multicenter, retrospective, observational study. Four referral centers. Blood samples were obtained from consecutive DTC patients. Genotyping was performed according to the TaqMan protocol, including 4 VEGF-A (-2578C>A, -460T>C, +405G>C, and +936C>T) and 2 VEGFR-2 (+1192 C>T and +1719 T>A) SNPs. MVD was estimated by means of CD34 staining. Rate of recurrent structural disease/disease-free survival (DFS). Difference in MVD between tumors from patients with different genotype. Two hundred four patients with stage I-II DTC (mean follow-up, 73 ± 64 months) and 240 patients with low- to intermediate-risk DTC (mean follow-up, 70 ± 60 months) were enrolled. Two "risk" genotypes were identified by combining VEGF-A SNPs -2578 C>A, -460 T>C, and +405 G>C. The ACG homozygous genotype was protective in both stage I-II (odds ratio [OR], 0.08; 95% confidence interval [CI], 0.01 to 1.43; P = 0.018) and low- to intermediate-risk (OR, 0.14; 95% CI, 0.01 to 1.13; P = 0.035) patients. The CTG homozygous genotype was significantly associated with recurrence in stage I-II (OR, 5.47; 95% CI, 1.15 to 26.04; P = 0.018) and was slightly deleterious in low- to intermediate-risk (OR, 3.39; 95% CI, 0.8 to 14.33; P = 0.079) patients. MVD of primary tumors from patients harboring a protective genotype was significantly lower (median MVD, 76.5 ± 12.7 and 86.7 ± 27.9, respectively; P = 0.024). Analysis of germline VEGF-A SNPs could empower a prognostic approach to DTC. Copyright © 2017 by the Endocrine Society

The deterioration of intermediate moisture foods

Science.gov (United States)

Labruza, T. P.

1971-01-01

Deteriorative reactions are low and food quality high if intermediate moisture content of a food is held at a water activity of 0.6 to 0.75. Information is of interest to food processing and packaging industry.

Production of intermediate-mass dileptons in relativistic heavy ion collisions

International Nuclear Information System (INIS)

Kvasnikova, Ioulia; Gale, Charles; Kumar Srivastava, Dinesh

2002-01-01

The production of intermediate-mass dileptons in ultrarelativistic nuclear collisions at SPS energies is studied. The acceptance and detector resolution inherent to measurements by the NA50 experimental collaboration are accurately modeled. The measured centrality dependence of the intermediate mass lepton pair excess is also addressed

Intermediate uveitis

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Babu B

2010-01-01

Full Text Available Intermediate uveitis (IU is described as inflammation in the anterior vitreous, ciliary body and the peripheral retina. In the Standardization of Uveitis Nomenclature (SUN working group′s international workshop for reporting clinical data the consensus reached was that the term IU should be used for that subset of uveitis where the vitreous is the major site of the inflammation and if there is an associated infection (for example, Lyme disease or systemic disease (for example, sarcoidosis. The diagnostic term pars planitis should be used only for that subset of IU where there is snow bank or snowball formation occurring in the absence of an associated infection or systemic disease (that is, "idiopathic". This article discusses the clinical features, etiology, pathogenesis, investigations and treatment of IU.

File list: Unc.PSC.50.AllAg.iPSC_intermediates [Chip-atlas[Archive

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File list: Unc.PSC.05.AllAg.iPSC_intermediates [Chip-atlas[Archive

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Full Text Available Unc.PSC.05.AllAg.iPSC_intermediates mm9 Unclassified Pluripotent stem cell iPSC intermediates... http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/Unc.PSC.05.AllAg.iPSC_intermediates.bed ...

Visual dictionaries as intermediate features in the human brain

Directory of Open Access Journals (Sweden)

Kandan eRamakrishnan

2015-01-01

Full Text Available The human visual system is assumed to transform low level visual features to object and scene representations via features of intermediate complexity. How the brain computationally represents intermediate features is still unclear. To further elucidate this, we compared the biologically plausible HMAX model and Bag of Words (BoW model from computer vision. Both these computational models use visual dictionaries, candidate features of intermediate complexity, to represent visual scenes, and the models have been proven effective in automatic object and scene recognition. These models however differ in the computation of visual dictionaries and pooling techniques. We investigated where in the brain and to what extent human fMRI responses to short video can be accounted for by multiple hierarchical levels of the HMAX and BoW models. Brain activity of 20 subjects obtained while viewing a short video clip was analyzed voxel-wise using a distance-based variation partitioning method. Results revealed that both HMAX and BoW explain a significant amount of brain activity in early visual regions V1, V2 and V3. However BoW exhibits more consistency across subjects in accounting for brain activity compared to HMAX. Furthermore, visual dictionary representations by HMAX and BoW explain significantly some brain activity in higher areas which are believed to process intermediate features. Overall our results indicate that, although both HMAX and BoW account for activity in the human visual system, the BoW seems to more faithfully represent neural responses in low and intermediate level visual areas of the brain.

Reactor-moderated intermediate-energy neutron beams for neutron-capture therapy

International Nuclear Information System (INIS)

Less, T.J.

1987-01-01

One approach to producing an intermediate energy beam is moderating fission neutrons escaping from a reactor core. The objective of this research is to evaluate materials that might produce an intermediate beam for NCT via moderation of fission neutrons. A second objective is to use the more promising moderator material in a preliminary design of an NCT facility at a research reactor. The evaluations showed that several materials or combinations of materials could produce a moderator source for an intermediate beam for NCT. The best neutron spectrum for use in NCT is produced by Al 2 O 3 , but mixtures of Al metal and D 2 O are also attractive. Using the best moderator materials, results were applied to the design of an NCT moderator at the Georgia Institute of Technology Research Reactor's bio-medical facility. The amount of photon shielding and thermal neutron absorber were optimized with respect to the desired photon dose rate and intermediate neutron flux at the patient position

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Full Text Available DNS.PSC.10.AllAg.iPSC_intermediates mm9 DNase-seq Pluripotent stem cell iPSC intermediates... http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/DNS.PSC.10.AllAg.iPSC_intermediates.bed ...

File list: DNS.PSC.05.AllAg.iPSC_intermediates [Chip-atlas[Archive

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Full Text Available DNS.PSC.05.AllAg.iPSC_intermediates mm9 DNase-seq Pluripotent stem cell iPSC intermediates... http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/DNS.PSC.05.AllAg.iPSC_intermediates.bed ...

Intermediality and the Child Performer

Science.gov (United States)

Budd, Natasha

2016-01-01

This report details examples of praxis in the creation and presentation of "Joy Fear and Poetry": an intermedial theatre performance in which children aged 7-12 years generated aesthetic gestures using a range of new media forms. The impetus for the work's development was a desire to make an intervention into habituated patterns of…

ABA-alcohol is an intermediate in abscisic acid biosynthesis

International Nuclear Information System (INIS)

Rock, C.D.; Zeevaart, J.A.D.

1990-01-01

It has been established that ABA-aldehyde is a precursor to ABA. The ABA-deficient flacca and sitiens mutants of tomato are blocked in the conversion of ABA-aldehyde to ABA, and accumulate trans-ABA-alcohol. 18 O-Labeling studies of ABA in flacca and sitiens show that these mutants synthesize a large percentage of [ 18 O]ABA which contains two 18 O atoms in the carboxyl group. Furthermore, the mutants synthesize much greater amounts of trans-ABA-glucose ester (t-ABA-GE) compared with the wild type, and this [ 18 O]t-ABA-GE is also double labeled in the carboxyl group. Our interpretation of these data is that the 18 O in ABA-aldehyde is trapped in the side chain by reduction to [ 18 O]ABA-alcohol, followed by isomerization to [ 18 O]t-ABA-alcohol and oxidation with 18 O 2 to [ 18 O]t-ABA. The [ 18 O]t-ABA is then rapidly converted to [ 18 O]t-ABA-GE. Because [ 18 O]ABA doubly labeled in the carboxyl group has been observed in small amounts in labeling experiments with several species, and various species have been shown to convert ABA-aldehyde to ABA-alcohol and t-ABA-alcohol, we propose that ABA-alcohol is an ABA intermediate in a shunt pathway

Characterization of monomeric intermediates during VSV glycoprotein structural transition.

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Aurélie A Albertini

2012-02-01

Full Text Available Entry of enveloped viruses requires fusion of viral and cellular membranes, driven by conformational changes of viral glycoproteins. Crystal structures provide static pictures of pre- and post-fusion conformations of these proteins but the transition pathway remains elusive. Here, using several biophysical techniques, including analytical ultracentrifugation, circular dichroïsm, electron microscopy and small angle X-ray scattering, we have characterized the low-pH-induced fusogenic structural transition of a soluble form of vesicular stomatitis virus (VSV glycoprotein G ectodomain (G(th, aa residues 1-422, the fragment that was previously crystallized. While the post-fusion trimer is the major species detected at low pH, the pre-fusion trimer is not detected in solution. Rather, at high pH, G(th is a flexible monomer that explores a large conformational space. The monomeric population exhibits a marked pH-dependence and adopts more elongated conformations when pH decreases. Furthermore, large relative movements of domains are detected in absence of significant secondary structure modification. Solution studies are complemented by electron micrographs of negatively stained viral particles in which monomeric ectodomains of G are observed at the viral surface at both pH 7.5 and pH 6.7. We propose that the monomers are intermediates during the conformational change and thus that VSV G trimers dissociate at the viral surface during the structural transition.

Bioorthogonal Cycloadditions with Sub-Millisecond Intermediates.

Science.gov (United States)

Qing, Yujia; Pulcu, Gökçe Su; Bell, Nicholas A W; Bayley, Hagan

2018-01-26

Tetrazine- and sydnone-based click reactions have emerged as important bioconjugation strategies with fast kinetics and N 2 or CO 2 as the only byproduct. Mechanistic studies of these reactions have focused on the initial rate-determining cycloaddition steps. The subsequent N 2 or CO 2 release from the bicyclic intermediates has been approached mainly through computational studies, which have predicted lifetimes of femtoseconds. In the present study, bioorthogonal cycloadditions involving N 2 or CO 2 extrusion have been examined experimentally at the single-molecule level by using a protein nanoreactor. At the resolution of this approach, the reactions appeared to occur in a single step, which places an upper limit on the lifetimes of the intermediates of about 80 μs, which is consistent with the computational work. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Intermediate L-K molecular orbital radiation from heavy ion collisions

International Nuclear Information System (INIS)

Heinig, K.H.; Jaeger, H.U.; Richter, H.; Woittennek, H.

1975-09-01

The structure of x-ray continua observed recently in violent collisions between intermediate mass atoms can be explained by a superposition of K molecular orbital (KMO) radiation and of an intermediate L-K molecular orbital (ILKMO) radiation of high intensity which is due to 2psigma vacancies. (author)

Is Adjuvant Chemoradiotherapy Overtreatment in Cervical Cancer Patients With Intermediate Risk Factors?

International Nuclear Information System (INIS)

Ryu, Sang-Young; Park, Sang-Il; Nam, Byung-Ho; Cho, Chul-Koo; Kim, Kidong; Kim, Beob-Jong; Kim, Moon-Hong; Choi, Seok-Cheol; Lee, Eui-Don; Lee, Kyoung-Hee

2011-01-01

Purpose: To determine whether adjuvant chemoradiotherapy (CRT) improves the outcome of cervical cancer patients with intermediate risk factors. Methods and Materials: Between January 2000 and June 2006, the medical records of 735 patients who had undergone radical surgery for Stage IB-IIA cervical cancer were reviewed retrospectively. Of the 735 patients, 172 with two or more intermediate risk factors (i.e., lymphovascular space involvement, deep stromal invasion, and tumor size ≥2 cm) were grouped as follows according to the adjuvant treatment received: 34 patients, no further treatment; 49 patients, RT; and 89 patients, CRT. The significance of the clinical parameters and recurrence-free survival of each group were analyzed. Results: Of the 172 patients with any of the intermediate risk factors, 137 (79.6%) had two or more intermediate risk factors. Of the 172 patients, 12 developed recurrences (6.4%)->(7.0%), with 6 in the pelvis and 6 in distant sites. All 12 recurrences occurred in those who had two or more intermediate risk factors (sensitivity, 100%); however, only six recurrences were detected in patients who met the Gynecologic Oncology Group criteria for the intermediate-risk group (sensitivity, 50%; Z test, p .05). Conclusion: Postoperative adjuvant CRT can improve the outcome of cervical cancer patients with intermediate risk factors, with low increase in toxicity.

Prokaryotic Homologs of the Eukaryotic 3-Hydroxyanthranilate 3,4-Dioxygenase and 2-Amino-3-Carboxymuconate-6-Semialdehyde Decarboxylase in the 2-Nitrobenzoate Degradation Pathway of Pseudomonas fluorescens Strain KU-7†

OpenAIRE

Muraki, Takamichi; Taki, Masami; Hasegawa, Yoshie; Iwaki, Hiroaki; Lau, Peter C. K.

2003-01-01

The 2-nitrobenzoic acid degradation pathway of Pseudomonas fluorescens strain KU-7 proceeds via a novel 3-hydroxyanthranilate intermediate. In this study, we cloned and sequenced a 19-kb DNA locus of strain KU-7 that encompasses the 3-hydroxyanthranilate meta-cleavage pathway genes. The gene cluster, designated nbaEXHJIGFCDR, is organized tightly and in the same direction. The nbaC and nbaD gene products were found to be novel homologs of the eukaryotic 3-hydroxyanthranilate 3,4-dioxygenase a...

Optimal design of the cable metro with unified intermediate supports

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Lagerev A.V.

2017-12-01

Full Text Available In article was formulated and solved the problem of conditional nonlinear technical and economic optimization of the distance between intermediate supports, uniform in height, during the design of the cable metro lines in highly urban-ized city environment. The optimization problem involves a single-criterion objective function that expresses the cost of construction of the cable metro line (total cost of intermediate supports and their foundations, traction and carrying steel cables and technical equipment. The specified objective function subject to minimization by finding the optimal combination of the distance between intermediate supports and tension carrying ropes with accounting constructive, modal, structural and planning constraints in the form of nonlinear inequalities. The optimization algorithm was based on the direct method of optimization type, Hooke-Jeeves, which was modified taking into account the need of varying the height of intermediate supports with a constant step equal to the step of unification. When constructing the objective function were considered three possible forms sagging of carrying ropes, which can be implemented for various values of the efforts of their tension. Analysis was done of the influence of the step unification and minimum size of interme-diate supports on their optimum step, the cost of intermediate supports, the cost of 1 km cable metro line for different values of the angle of the longitudinal slope of the surface relief along the cable metro line. The graph of height of uni-fied supports from the angle of the longitudinal slope of the surface relief has discrete-step type. With the increase of the step unify the discreteness increases: the width of the range of angles of the longitudinal slope of the surface relief within which the height of the supports remains constant, increases. The graph of step installation of unified supports along the cable metro line from the angle of the longitudinal

Carbon emission, energy consumption and intermediate goods trade: A regional study of East Asia

International Nuclear Information System (INIS)

Zhang, Jingjing

2015-01-01

Using country level panel data from East Asia over the period 1998–2011, this paper examines the implications of international production fragmentation-induced intermediate goods trade on the link between energy consumption and carbon pollution. The paper focuses on the interaction effect between energy consumption and trade in intermediate goods on carbon emission. The empirical results presented suggest that international trade in intermediate goods decreases the positive impact on carbon emission of energy consumption. When compared with the trade in final goods, intermediate goods trade contributes to a greater decrease in carbon pollution resulting from energy consumption. These results confirm that the link between energy consumption and carbon pollution in East Asia is significantly affected by international production fragmentation-induced trade in intermediate goods. The results presented in this paper have some important policy implications. - Highlights: • This paper tests the role of intermediates trade in energy-development nexus. • Empirical study is based on data of East Asia. • International trade can reduce the carbon pollution caused by energy use. • Intermediates trade has higher moderating effect than non-intermediate trade.

Intermediate coupling collision strengths from LS coupled R-matrix elements

International Nuclear Information System (INIS)

Clark, R.E.H.

1978-01-01

Fine structure collision strength for transitions between two groups of states in intermediate coupling and with inclusion of configuration mixing are obtained from LS coupled reactance matrix elements (R-matrix elements) and a set of mixing coefficients. The LS coupled R-matrix elements are transformed to pair coupling using Wigner 6-j coefficients. From these pair coupled R-matrix elements together with a set of mixing coefficients, R-matrix elements are obtained which include the intermediate coupling and configuration mixing effects. Finally, from the latter R-matrix elements, collision strengths for fine structure transitions are computed (with inclusion of both intermediate coupling and configuration mixing). (Auth.)

Intermediate statistics in quantum maps

Energy Technology Data Exchange (ETDEWEB)

Giraud, Olivier [H H Wills Physics Laboratory, University of Bristol, Tyndall Avenue, Bristol BS8 1TL (United Kingdom); Marklof, Jens [School of Mathematics, University of Bristol, University Walk, Bristol BS8 1TW (United Kingdom); O' Keefe, Stephen [School of Mathematics, University of Bristol, University Walk, Bristol BS8 1TW (United Kingdom)

2004-07-16

We present a one-parameter family of quantum maps whose spectral statistics are of the same intermediate type as observed in polygonal quantum billiards. Our central result is the evaluation of the spectral two-point correlation form factor at small argument, which in turn yields the asymptotic level compressibility for macroscopic correlation lengths. (letter to the editor)

Influence of an Intermediate Option on the Description-Experience Gap and Information Search.

Science.gov (United States)

Sharma, Neha; Debnath, Shoubhik; Dutt, Varun

2018-01-01

Research shows that people tend to overweight small probabilities in description and underweight them in experience, thereby leading to a different pattern of choices between description and experience; a phenomenon known as the Description-Experience (DE) gap. However, little is known on how the addition of an intermediate option and contextual framing influences the DE gap and people's search strategies. This paper tests the effects of an intermediate option and contextual framing on the DE gap and people's search strategies, where problems require search for information before a consequential choice. In the first experiment, 120 participants made choice decisions across investment problems that differed in the absence or presence of an intermediate option. Results showed that adding an intermediate option did not reduce the DE gap on the maximizing option across a majority of problems. There were a large majority of choices for the intermediate option. Furthermore, there was an increase in switching between options due to the presence of the intermediate option. In the second experiment, 160 participants made choice decisions in problems like those presented in experiment 1; however, problems lacked the investment framing. Results replicated findings from the first experiment and showed a similar DE gap on the maximizing option in a majority of problems in both the absence and presence of the intermediate option. Again, there were a large majority of choices for the intermediate option. Also, there was an increase in switching between options due to the presence of the intermediate option. Meta-analyses revealed that the absence or presence of the intermediate option created certain differences in the strength of frequency and recency processes. Also, a single natural-mean heuristic model was able to account for the experimental results across both experiments. We discuss implications of our findings to consequential decisions made after information search.

Influence of an Intermediate Option on the Description-Experience Gap and Information Search

Directory of Open Access Journals (Sweden)

Neha Sharma

2018-03-01

Full Text Available Research shows that people tend to overweight small probabilities in description and underweight them in experience, thereby leading to a different pattern of choices between description and experience; a phenomenon known as the Description-Experience (DE gap. However, little is known on how the addition of an intermediate option and contextual framing influences the DE gap and people’s search strategies. This paper tests the effects of an intermediate option and contextual framing on the DE gap and people’s search strategies, where problems require search for information before a consequential choice. In the first experiment, 120 participants made choice decisions across investment problems that differed in the absence or presence of an intermediate option. Results showed that adding an intermediate option did not reduce the DE gap on the maximizing option across a majority of problems. There were a large majority of choices for the intermediate option. Furthermore, there was an increase in switching between options due to the presence of the intermediate option. In the second experiment, 160 participants made choice decisions in problems like those presented in experiment 1; however, problems lacked the investment framing. Results replicated findings from the first experiment and showed a similar DE gap on the maximizing option in a majority of problems in both the absence and presence of the intermediate option. Again, there were a large majority of choices for the intermediate option. Also, there was an increase in switching between options due to the presence of the intermediate option. Meta-analyses revealed that the absence or presence of the intermediate option created certain differences in the strength of frequency and recency processes. Also, a single natural-mean heuristic model was able to account for the experimental results across both experiments. We discuss implications of our findings to consequential decisions made after

Determination Bounds for Intermediate Products in a Two-Stage Network DEA

Directory of Open Access Journals (Sweden)

Hadi Bagherzadeh Valami

2016-03-01

Full Text Available The internal structure of decision making unit (DMU is the key element at extension of network DEA. In general considering internal performance evaluation of system is a better criterion than the conventional DEA-models, essentially based on the initial inputs and final outputs of the system. The internal performance of a system is dependent on the relation between sub-DMUs and intermediate products. Since the intermediate measures are consumed by some sub-DMUs produced by the others, it is possible to produce systems; the role of intermediate production is twice output and input. That's why they can be analyzed based on conventional mathematical modeling. In this paper we introduce a new method for determining bounds for intermediate product in a two stage network DEA structure.

Unification of favourable intermediate-, unfavourable intermediate-, and very high-risk stratification criteria for prostate cancer.

Science.gov (United States)

Zumsteg, Zachary S; Zelefsky, Michael J; Woo, Kaitlin M; Spratt, Daniel E; Kollmeier, Marisa A; McBride, Sean; Pei, Xin; Sandler, Howard M; Zhang, Zhigang

2017-11-01

To improve on the existing risk-stratification systems for prostate cancer. This was a retrospective investigation including 2 248 patients undergoing dose-escalated external beam radiotherapy (EBRT) at a single institution. We separated National Comprehensive Cancer Network (NCCN) intermediate-risk prostate cancer into 'favourable' and 'unfavourable' groups based on primary Gleason pattern, percentage of positive biopsy cores (PPBC), and number of NCCN intermediate-risk factors. Similarly, NCCN high-risk prostate cancer was stratified into 'standard' and 'very high-risk' groups based on primary Gleason pattern, PPBC, number of NCCN high-risk factors, and stage T3b-T4 disease. Patients with unfavourable-intermediate-risk (UIR) prostate cancer had significantly inferior prostate-specific antigen relapse-free survival (PSA-RFS, P prostate cancer-specific mortality (PCSM, P prostate cancer. Similarly, patients with very high-risk (VHR) prostate cancer had significantly worse PSA-RFS (P prostate cancer. Moreover, patients with FIR and low-risk prostate cancer had similar outcomes, as did patients with UIR and SHR prostate cancer. Consequently, we propose the following risk-stratification system: Group 1, low risk and FIR; Group 2, UIR and SHR; and Group 3, VHR. These groups have markedly different outcomes, with 8-year distant metastasis rates of 3%, 9%, and 29% (P < 0.001) for Groups 1, 2, and 3, respectively, and 8-year PCSM of 1%, 4%, and 13% (P < 0.001) after EBRT. This modified stratification system was significantly more accurate than the three-tiered NCCN system currently in clinical use for all outcomes. Modifying the NCCN risk-stratification system to group FIR with low-risk patients and UIR with SHR patients, results in modestly improved prediction of outcomes, potentially allowing better personalisation of therapeutic recommendations. © 2017 The Authors BJU International © 2017 BJU International Published by John Wiley & Sons Ltd.

Isomerization Intermediates In Solution Phase Photochemistry Of Stilbenes

Science.gov (United States)

Doany, F. E.; Hochstrasser, R. M.; Greene, B. I.

1985-04-01

Picosecond and subpicosecond spectroscopic studies have revealed evidence for an isomerization intermediate between cis and trans in the photoinduced isomerism of both stilbene and biindanyledene ("stiff" stilbene). In stiff stilbene, a transient absorption at 351 nm displays time evolution and viscosity dependence consistent with absorption by a twisted intermediate ("phantom" state) with a lOps lifetime. An analagous bottleneck state with a life-time of 4ps is also consistent with the ground state recovery dynamics of t-stilbene following excitation of c-stilbene when monitored with 0.1ps resolution.

Big Data Based Analysis Framework for Product Manufacturing and Maintenance Process

OpenAIRE

Zhang , Yingfeng; Ren , Shan

2015-01-01

Part 8: Cloud-Based Manufacturing; International audience; With the widely use of smart sensor devices in the product lifecycle management (PLM), it creates amount of real-time and muti-source lifecycle big data. These data allow decision makers to make better-informed PLM decisions. In this article, an overview framework of big data based analysis for product lifecycle (BDA-PL) was presented to provide a new paradigm by extending the techniques of Internet of Things (IoT) and big data analys...

Construction and Optimization of a Heterologous Pathway for Protocatechuate Catabolism in Escherichia coli Enables Bioconversion of Model Aromatic Compounds.

Science.gov (United States)

Clarkson, Sonya M; Giannone, Richard J; Kridelbaugh, Donna M; Elkins, James G; Guss, Adam M; Michener, Joshua K

2017-09-15

The production of biofuels from lignocellulose yields a substantial lignin by-product stream that currently has few applications. Biological conversion of lignin-derived compounds into chemicals and fuels has the potential to improve the economics of lignocellulose-derived biofuels, but few microbes are able both to catabolize lignin-derived aromatic compounds and to generate valuable products. While Escherichia coli has been engineered to produce a variety of fuels and chemicals, it is incapable of catabolizing most aromatic compounds. Therefore, we engineered E. coli to catabolize protocatechuate, a common intermediate in lignin degradation, as the sole source of carbon and energy via heterologous expression of a nine-gene pathway from Pseudomonas putida KT2440. We next used experimental evolution to select for mutations that increased growth with protocatechuate more than 2-fold. Increasing the strength of a single ribosome binding site in the heterologous pathway was sufficient to recapitulate the increased growth. After optimization of the core pathway, we extended the pathway to enable catabolism of a second model compound, 4-hydroxybenzoate. These engineered strains will be useful platforms to discover, characterize, and optimize pathways for conversions of lignin-derived aromatics. IMPORTANCE Lignin is a challenging substrate for microbial catabolism due to its polymeric and heterogeneous chemical structure. Therefore, engineering microbes for improved catabolism of lignin-derived aromatic compounds will require the assembly of an entire network of catabolic reactions, including pathways from genetically intractable strains. Constructing defined pathways for aromatic compound degradation in a model host would allow rapid identification, characterization, and optimization of novel pathways. We constructed and optimized one such pathway in E. coli to enable catabolism of a model aromatic compound, protocatechuate, and then extended the pathway to a related

Investigating multiple dysregulated pathways in rheumatoid arthritis based on pathway interaction network.

Science.gov (United States)

Song, Xian-Dong; Song, Xian-Xu; Liu, Gui-Bo; Ren, Chun-Hui; Sun, Yuan-Bo; Liu, Ke-Xin; Liu, Bo; Liang, Shuang; Zhu, Zhu

2018-03-01

The traditional methods of identifying biomarkers in rheumatoid arthritis (RA) have focussed on the differentially expressed pathways or individual pathways, which however, neglect the interactions between pathways. To better understand the pathogenesis of RA, we aimed to identify dysregulated pathway sets using a pathway interaction network (PIN), which considered interactions among pathways. Firstly, RA-related gene expression profile data, protein-protein interactions (PPI) data and pathway data were taken up from the corresponding databases. Secondly, principal component analysis method was used to calculate the pathway activity of each of the pathway, and then a seed pathway was identified using data gleaned from the pathway activity. A PIN was then constructed based on the gene expression profile, pathway data, and PPI information. Finally, the dysregulated pathways were extracted from the PIN based on the seed pathway using the method of support vector machines and an area under the curve (AUC) index. The PIN comprised of a total of 854 pathways and 1064 pathway interactions. The greatest change in the activity score between RA and control samples was observed in the pathway of epigenetic regulation of gene expression, which was extracted and regarded as the seed pathway. Starting with this seed pathway, one maximum pathway set containing 10 dysregulated pathways was extracted from the PIN, having an AUC of 0.8249, and the result indicated that this pathway set could distinguish RA from the controls. These 10 dysregulated pathways might be potential biomarkers for RA diagnosis and treatment in the future.

Post-crisis financial intermediation

Directory of Open Access Journals (Sweden)

Ilie MIHAI

2015-09-01

Full Text Available The recent financial crisis that begun in 2007 in the US, which then swept around the world, has left deep scars on the already wrinkled face of the global economy. Some national and regional economies, which had money for expensive makeup, or created money[1], managed to blur or hide the scars left by the crisis, others are still facing difficulties in overcoming the effects of this. The rapacity of banks, their greed and risk ignorance, were the origin of the outbreak of the last major economic and financial crisis but unfortunately those who were responsible or, rather, irresponsible, paid little or nothing at all for the burden of their bad loan portfolio. This cost has been supported by the population, either directly by paying high interest and fees [Mihai I., 2007], or indirectly, through the use of public budgets to cover the losses of banks, most of which had private capital. In this context, we intend to examine the state of financial intermediation in Romania in the post-crisis period, and to primarily follow: (i The structure and evolution of the banking system; (ii Non-government credit situation; (iii The level of savings; (iiii Loan-deposit ratio; (v The degree of financial intermediation and disintegration phenomenon etc., and to articulate some conclusions and suggestions on the matters that have been explored.

Determination of the vildagliptin intermediate enantiomer by chiralce-columns

Directory of Open Access Journals (Sweden)

Weina LI

2017-06-01

Full Text Available In order to establish a NP-HPLC method for the determination of enantiomer in vildagliptin intermediate, the determination is carried out on the column of ChiralpakAD-H(250 mm×4.6 mm, 5 μm, with the mobile phase of n-hexane, ethanol and methanol（volume ratio of 65∶25∶10）at flow rate of 0.8 mL/min. The sample volume is 10 μL, the wavelength is 210 nm and the column temperature is 35 ℃. The result shows that the vildagliptin intermediate and its enantiomer could be well separated and detected effectively; blank solvent doesn't interfere with the enantiomer assaying; the detection limit is 27 ng/mL and the quantification limit is 81 ng/mL; in repetitive test, the RSD of enantiomer assaying of samples are no more than 2.0%; in stability test, the RSD are no more than 2.0% in 12 h; the vildagliptin intermediate and its enantiomer could be well separated in the test of durability with all RSDs below 2.0%. The method is simple, reliable, accurate and durable, and can be used for determination of enantiomer in vildagliptin intermediate.

Continuous Flow-Resonance Raman Spectroscopy of an Intermediate Redox State of Cytochrome-C

DEFF Research Database (Denmark)

Forster, M.; Hester, R. E.; Cartling, B.

1982-01-01

An intermediate redox state of cytochrome c at alkaline pH, generated upon rapid reduction by sodium dithionite, has been observed by resonance Raman (RR) spectroscopy in combination with the continuous flow technique. The RR spectrum of the intermediate state is reported for excitation both...... in the (alpha, beta) and the Soret optical absorption band. The spectra of the intermediate state are more like those of the stable reduced form than those of the stable oxidized form. For excitation of 514.5 nm, the most prominent indication of an intermediate state is the wave-number shift of one RR band from...... 1,562 cm-1 in the stable oxidized state through 1,535 cm-1 in the intermediate state to 1,544 cm-1 in the stable reduced state. For excitation at 413.1 nm, a band, present at 1,542 cm-1 in the stable reduced state but not present in the stable oxidized state, is absent in the intermediate state. We...