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Sample records for metal-catalyzed reactions progress

  1. Recent progress in transition-metal-catalyzed reduction of molecular dinitrogen under ambient reaction conditions.

    Science.gov (United States)

    Nishibayashi, Yoshiaki

    2015-10-05

    This paper describes our recent progress in catalytic nitrogen fixation by using transition-metal-dinitrogen complexes as catalysts. Two reaction systems for the catalytic transformation of molecular dinitrogen into ammonia and its equivalent such as silylamine under ambient reaction conditions have been achieved by the molybdenum-, iron-, and cobalt-dinitrogen complexes as catalysts. Many new findings presented here may provide new access to the development of economical nitrogen fixation in place of the Haber-Bosch process.

  2. Metal-catalyzed asymmetric aldol reactions

    Energy Technology Data Exchange (ETDEWEB)

    Dias, Luiz C.; Lucca Junior, Emilio C. de; Ferreira, Marco A. B.; Polo, Ellen C., E-mail: ldias@iqm.unicamp.br [Universidade de Campinas (UNICAMP), SP (Brazil). Inst. de Quimica

    2012-12-15

    The aldol reaction is one of the most powerful and versatile methods for the construction of C-C bonds. Traditionally, this reaction was developed in a stoichiometric version; however, great efforts in the development of chiral catalysts for aldol reactions were performed in recent years. Thus, in this review article, the development of metal-mediated chiral catalysts in Mukaiyama-type aldol reaction, reductive aldol reaction and direct aldol reaction are discussed. Moreover, the application of these catalysts in the total synthesis of complex molecules is discussed. (author)

  3. Synthesis of heterocycles through transition-metal-catalyzed isomerization reactions

    DEFF Research Database (Denmark)

    Ishøy, Mette; Nielsen, Thomas Eiland

    2014-01-01

    of structurally complex and diverse heterocycles. In this Concept article, we attempt to cover this area of research through a selection of recent versatile examples. A sea of opportunities! Transition-metal-catalyzed isomerization of N- and O-allylic compounds provides a mild, selective and synthetically...... versatile method to form iminium and oxocarbenium ions. Given the number of reactions involving these highly electrophilic intermediates, this concept provides a sea of opportunities for heterocycle synthesis, (see scheme; Nu=nucleophile). © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim....

  4. Recent advances in transition metal-catalyzed N -atom transfer reactions of azides

    Science.gov (United States)

    Driver, Tom G.

    2011-01-01

    Transition metal-catalyzed N-atom transfer reactions of azides provide efficient ways to construct new carbon–nitrogen and sulfur–nitrogen bonds. These reactions are inherently green: no additive besides catalyst is needed to form the nitrenoid reactive intermediate, and the by-product of the reaction is environmentally benign N2 gas. As such, azides can be useful precursors for transition metal-catalyzed N-atom transfer to sulfides, olefins and C–H bonds. These methods offer competitive selectivities and comparable substrate scope as alternative processes to generate metal nitrenoids. PMID:20617243

  5. Investigation of transition metal-catalyzed nitrene transfer reactions in water.

    Science.gov (United States)

    Alderson, Juliet M; Corbin, Joshua R; Schomaker, Jennifer M

    2018-04-11

    Transition metal-catalyzed nitrene transfer is a powerful method for incorporating new CN bonds into relatively unfunctionalized scaffolds. In this communication, we report the first examples of site- and chemoselective CH bond amination reactions in aqueous media. The unexpected ability to employ water as the solvent in these reactions is advantageous in that it eliminates toxic solvent use and enables reactions to be run at increased concentrations with lower oxidant loadings. Using water as the reaction medium has potential to expand the scope of nitrene transfer to encompass a variety of biomolecules and highly polar substrates, as well as enable pH control over the site-selectivity of CH bond amination. Copyright © 2018 Elsevier Ltd. All rights reserved.

  6. Transition-metal-catalyzed enantioselective heteroatom-hydrogen bond insertion reactions.

    Science.gov (United States)

    Zhu, Shou-Fei; Zhou, Qi-Lin

    2012-08-21

    Carbon-heteroatom bonds (C-X) are ubiquitous and are among the most reactive components of organic compounds. Therefore investigations of the construction of C-X bonds are fundamental and vibrant fields in organic chemistry. Transition-metal-catalyzed heteroatom-hydrogen bond (X-H) insertions via a metal carbene or carbenoid intermediate represent one of the most efficient approaches to form C-X bonds. Because of the availability of substrates, neutral and mild reaction conditions, and high reactivity of these transformations, researchers have widely applied transition-metal-catalyzed X-H insertions in organic synthesis. Researchers have developed a variety of rhodium-catalyzed asymmetric C-H insertion reactions with high to excellent enantioselectivities for a wide range of substrates. However, at the time that we launched our research, very few highly enantioselective X-H insertions had been documented primarily because of a lack of efficient chiral catalysts and indistinct insertion mechanisms. In this Account, we describe our recent studies of copper- and iron-catalyzed asymmetric X-H insertion reactions by using chiral spiro-bisoxazoline and diimine ligands. The copper complexes of chiral spiro-bisoxazoline ligands proved to be highly enantioselective catalysts for N-H insertions of α-diazoesters into anilines, O-H insertions of α-diazoesters into phenols and water, O-H insertions of α-diazophosphonates into alcohols, and S-H insertions of α-diazoesters into mercaptans. The iron complexes of chiral spiro-bisoxazoline ligands afforded the O-H insertion of α-diazoesters into alcohols and water with unprecedented enantioselectivities. The copper complexes of chiral spiro-diimine ligands exhibited excellent reactivity and enantioselectivity in the Si-H insertion of α-diazoacetates into a wide range of silanes. These transition-metal-catalyzed X-H insertions have many potential applications in organic synthesis because the insertion products, including chiral

  7. Carbocyclization versus oxycyclization on the metal-catalyzed reactions of oxyallenyl C3-linked indoles.

    Science.gov (United States)

    Alcaide, Benito; Almendros, Pedro; Alonso, José M; Fernández, Israel

    2013-07-05

    The preparation of previously unknown (indol-3-yl)-α-allenols and -allenones was accomplished from indole-3-carbaldehydes, through indium-mediated Barbier allenylation reaction taking advantage of the N-(2-pyridyl)sulfonyl group. Metal-catalyzed cyclizations of oxyallenyl C3-linked indoles proceeded in two ways depending on the presence or absence of the N-(2-pyridyl)sulfonyl group. For allenols, gold-catalyzed oxycyclization occurred in the presence of the protecting group; in the absence of the protecting group, palladium- and gold-catalyzed benzannulations operated. On the contrary, under gold catalysis furyl-indoles were obtained as exclusive products from NH-allenones, while 5-endo carbocyclization adducts were the major components starting from N-SO2py-protected allenones. These cyclization reactions have been developed experimentally, and their mechanisms have additionally been investigated by a computational study.

  8. Transition Metal Catalyzed Reactions of Carbohydrates: a Nonoxidative Approach to Oxygenated Organics

    Energy Technology Data Exchange (ETDEWEB)

    Andrews, Mark

    1997-01-08

    There is a critical need for new environmentally friendly processes in the United States chemical industry as legislative and economic pressures push the industry to zero-waste and cradle-to-grave responsibility for the products they produce. Carbohydrates represent a plentiful, renewable resource, which for some processes might economically replace fossil feedstocks. While the conversion of biomass to fuels, is still not generally economical, the selective synthesis of a commodity or fine chemical, however, could compete effectively if appropriate catalytic conversion systems can be found. Oxygenated organics, found in a variety of products such as nylon and polyester, are particularly attractive targets. We believe that with concerted research efforts, homogeneous transition metal catalyzed reactions could play a significant role in bringing about this future green chemistry technology.

  9. Tunable Metal-Catalyzed Heterocyclization Reactions of Allenic Amino Alcohols: An Experimental and Theoretical Study.

    Science.gov (United States)

    Alcaide, Benito; Almendros, Pedro; Aragoncillo, Cristina; Gómez-Campillos, Gonzalo; Quirós, M Teresa; Soriano, Elena

    2016-08-10

    Controlled preparation of 2,5-dihydro-1H-pyrroles, 3,6-dihydro-2H-pyrans, and pyrroles has been achieved through switchable chemo- and regioselectivity in the metal-catalyzed heterocyclization reactions of allenic amino alcohols. The gold-catalyzed cycloisomerization reaction of α-amino-β-hydroxyallenes was effective as 5-endo cyclization by addition of amino functionality to the distal allene carbon to yield enantiopure 2,5-dihydro-1H-pyrroles, whereas their palladium-catalyzed cyclizative coupling reactions furnished 3,6-dihydro-2H-pyrans through a chemo- and regioselective 6-endo cycloetherification. Conversely, the gold-catalyzed heterocyclization reaction of β-amino-γ-hydroxyallenes generated exclusively pyrrole derivatives. These results could be explained through a chemo- and regioselective 5-exo aminocyclization to the central allene carbon followed by aromatization. Chemo- and regioselectivity depend on both linker elongation as well as the type of catalyst. This behavior can be justified by means of density functional theory calculations.

  10. Tunable differentiation of tertiary C-H bonds in intramolecular transition metal-catalyzed nitrene transfer reactions.

    Science.gov (United States)

    Corbin, Joshua R; Schomaker, Jennifer M

    2017-04-13

    Metal-catalyzed nitrene transfer reactions are an appealing and efficient strategy for accessing tetrasubstituted amines through the direct amination of tertiary C-H bonds. Traditional catalysts for these reactions rely on substrate control to achieve site-selectivity in the C-H amination event; thus, tunability is challenging when competing C-H bonds have similar steric or electronic features. One consequence of this fact is that the impact of catalyst identity on the selectivity in the competitive amination of tertiary C-H bonds has not been well-explored, despite the potential for progress towards predictable and catalyst-controlled C-N bond formation. In this communication, we report investigations into tunable and site-selective nitrene transfers between tertiary C(sp 3 )-H bonds using a combination of transition metal catalysts, including complexes based on Ag, Mn, Rh and Ru. Particularly striking was the ability to reverse the selectivity of nitrene transfer by a simple change in the identity of the N-donor ligand supporting the Ag(i) complex. The combination of our Ag(i) catalysts with known Rh 2 (ii) complexes expands the scope of successful catalyst-controlled intramolecular nitrene transfer and represents a promising springboard for the future development of intermolecular C-H N-group transfer methods.

  11. Elucidation of Mechanisms and Selectivities of Metal-Catalyzed Reactions using Quantum Chemical Methodology.

    Science.gov (United States)

    Santoro, Stefano; Kalek, Marcin; Huang, Genping; Himo, Fahmi

    2016-05-17

    Quantum chemical techniques today are indispensable for the detailed mechanistic understanding of catalytic reactions. The development of modern density functional theory approaches combined with the enormous growth in computer power have made it possible to treat quite large systems at a reasonable level of accuracy. Accordingly, quantum chemistry has been applied extensively to a wide variety of catalytic systems. A huge number of problems have been solved successfully, and vast amounts of chemical insights have been gained. In this Account, we summarize some of our recent work in this field. A number of examples concerned with transition metal-catalyzed reactions are selected, with emphasis on reactions with various kinds of selectivities. The discussed cases are (1) copper-catalyzed C-H bond amidation of indoles, (2) iridium-catalyzed C(sp(3))-H borylation of chlorosilanes, (3) vanadium-catalyzed Meyer-Schuster rearrangement and its combination with aldol- and Mannich-type additions, (4) palladium-catalyzed propargylic substitution with phosphorus nucleophiles, (5) rhodium-catalyzed 1:2 coupling of aldehydes and allenes, and finally (6) copper-catalyzed coupling of nitrones and alkynes to produce β-lactams (Kinugasa reaction). First, the methodology adopted in these studies is presented briefly. The electronic structure method in the great majority of these kinds of mechanistic investigations has for the last two decades been based on density functional theory. In the cases discussed here, mainly the B3LYP functional has been employed in conjunction with Grimme's empirical dispersion correction, which has been shown to improve the calculated energies significantly. The effect of the surrounding solvent is described by implicit solvation techniques, and the thermochemical corrections are included using the rigid-rotor harmonic oscillator approximation. The reviewed examples are chosen to illustrate the usefulness and versatility of the adopted methodology in

  12. Metal-Catalyzed Cyclization Reactions of 2,3,4-Trien-1-ols: A Joint Experimental-Computational Study.

    Science.gov (United States)

    Alcaide, Benito; Almendros, Pedro; Cembellín, Sara; Fernández, Israel; Martínez Del Campo, Teresa

    2016-08-08

    Controlled preparation of tri- and tetrasubstituted furans, as well as carbazoles has been achieved through chemo- and regioselective metal-catalyzed cyclization reactions of cumulenic alcohols. The gold- and palladium-catalyzed cycloisomerization reactions of cumulenols, including indole-tethered 2,3,4-trien-1-ols, to trisubstituted furans was effective, due to a 5-endo-dig oxycyclization by attack of the hydroxy group onto the central cumulene double bond. In contrast, palladium-catalyzed heterocyclization/coupling reactions with 3-bromoprop-1-enes furnished tetrasubstituted furans. Also studied was the palladium-catalyzed cyclization/coupling sequence involving protected indole-tethered 2,3,4-trien-1-ols and 3-bromoprop-1-enes that exclusively generated trisubstituted carbazole derivatives. These results could be explained through a selective 6-endo-dig cumulenic hydroarylation, followed by aromatization. DFT calculations were carried out to understand this difference in reactivity. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Transition metal catalyzed carbonylation reactions carbonylative activation of C-X bonds

    CERN Document Server

    Beller, Matthias

    2014-01-01

    This book provides students and researchers in organic synthesis with a detailed discussion of carbonylation from the basics through to applications. It discusses the past, present and future of carbonylation reactions.

  14. Metal-catalyzed double migratory cascade reactions of propargylic esters and phosphates.

    Science.gov (United States)

    Kazem Shiroodi, Roohollah; Gevorgyan, Vladimir

    2013-06-21

    Propargylic esters and phosphates are easily accessible substrates, which exhibit rich and tunable reactivities in the presence of transition metal catalysts. π-Acidic metals, mostly gold and platinum salts, activate these substrates for an initial 1,2- or 1,3-acyloxy and phosphatyloxy migration process to form reactive intermediates. These intermediates are able to undergo further cascade reactions leading to a variety of diverse structures. This tutorial review systematically introduces the double migratory reactions of propargylic esters and phosphates as a novel synthetic method, in which further cascade reaction of the reactive intermediate is accompanied by a second migration of a different group, thus offering a rapid route to a wide range of functionalized products. The serendipitous observations, as well as designed approaches involving the double migratory cascade reactions, will be discussed with emphasis placed on the mechanistic aspects and the synthetic utilities of the obtained products.

  15. Metal-catalyzed Asymmetric Hetero-Diels-Alder Reactions of Unactivated Dienes with Glyoxylates

    DEFF Research Database (Denmark)

    Johannsen, Mogens; Yao, Sulan; Graven, Anette

    1998-01-01

    The development of a catalytic asymmetric hetero-Diels-Alder methodology for the reaction of unactivated dienes with glyoxylates is presented. Several different asymmetric catalysts can be used, but copper-bisoxazolines and aluminium-BINOL give the highest yield, and the best chemo- and enantiose...

  16. Transition-metal-catalyzed C-N bond forming reactions using organic azides as the nitrogen source: a journey for the mild and versatile C-H amination.

    Science.gov (United States)

    Shin, Kwangmin; Kim, Hyunwoo; Chang, Sukbok

    2015-04-21

    Owing to the prevalence of nitrogen-containing compounds in functional materials, natural products and important pharmaceutical agents, chemists have actively searched for the development of efficient and selective methodologies allowing for the facile construction of carbon-nitrogen bonds. While metal-catalyzed C-N cross-coupling reactions have been established as one of the most general protocols for C-N bond formation, these methods require starting materials equipped with functional groups such as (hetero)aryl halides or their equivalents, thus generating stoichiometric amounts of halide salts as byproducts. To address this aspect, a transition-metal-catalyzed direct C-H amination approach has emerged as a step- and atom-economical alternative to the conventional C-N cross-coupling reactions. However, despite the significant recent advances in metal-mediated direct C-H amination reactions, most available procedures need harsh conditions requiring stoichiometric external oxidants. In this context, we were curious to see whether a transition-metal-catalyzed mild C-H amination protocol could be achieved using organic azides as the amino source. We envisaged that a dual role of organic azides as an environmentally benign amino source and also as an internal oxidant via N-N2 bond cleavage would be key to develop efficient C-H amination reactions employing azides. An additional advantage of this approach was anticipated: that a sole byproduct is molecular nitrogen (N2) under the perspective catalytic conditions. This Account mainly describes our research efforts on the development of rhodium- and iridium-catalyzed direct C-H amination reactions with organic azides. Under our initially optimized Rh(III)-catalyzed amination conditions, not only sulfonyl azides but also aryl- and alkyl azides could be utilized as facile amino sources in reaction with various types of C(sp(2))-H bonds bearing such directing groups as pyridine, amide, or ketoxime. More recently, a new

  17. Direct Carboxylation of C(sp3-H and C(sp2-H Bonds with CO2 by Transition-Metal-Catalyzed and Base-Mediated Reactions

    Directory of Open Access Journals (Sweden)

    Immacolata Tommasi

    2017-12-01

    Full Text Available This review focuses on recent advances in the field of direct carboxylation reactions of C(sp3-H and C(sp2-H bonds using CO2 encompassing both transition-metal-catalysis and base-mediated approach. The review is not intended to be comprehensive, but aims to analyze representative examples from the literature, including transition-metal catalyzed carboxylation of benzylic and allylic C(sp3-H functionalities using CO2 which is at a “nascent stage”. Examples of light-driven carboxylation reactions of unactivated C(sp3-H bonds are also considered. Concerning C(sp3-H and C(sp2-H deprotonation reactions mediated by bases with subsequent carboxylation of the carbon nucleophile, few examples of catalytic processes are reported in the literature. In spite of this, several examples of base-promoted reactions integrating “base recycling” or “base regeneration (through electrosynthesis” steps have been reported. Representative examples of synthetically efficient, base-promoted processes are included in the review.

  18. Development of a methodology based on metal-catalyzed oxidation reactions and mass spectrometry to determine the metal binding sites in copper metalloproteins.

    Science.gov (United States)

    Lim, Jihyeon; Vachet, Richard W

    2003-03-01

    Efforts have been made to develop a method that uses metal-catalyzed oxidation (MCO) reactions and mass spectrometry (MS) to identify the binding site of copper in metalloproteins. This method uses MCO reactions to oxidize the amino acids in the metal-binding site and MS to identify the amino acids that have been oxidized. Several reaction conditions, including Cu(II)/ascorbate/O2, Cu(II)/O2/H2O2, and Cu(II)/ascorbate/O2/H2O2, have been tested at varying concentrations to find the optimum conditions for specific oxidation of only the amino acids bound to copper. For small peptides, such as angiotensin I (Agt I) and [Gln11]-amyloid-beta-protein fragment 1-16 (A beta(1-16)), the optimum conditions for specific modification involve the use of Cu(II)/ascorbate/O2. For a larger protein, azurin, the speed and specificity of the MCO reactions are enhanced by the presence of a relatively high concentration of ascorbate (100 mM) and a small concentration of H2O2 (1 mM). Optimized reaction conditions combined with MS/MS and MSn analysis on a quadrupole ion trap mass spectrometer allow the copper-binding sites to be specifically identified. For Agt I and A beta(1-16), the amino acids bound to copper can be identified without any false positives. For azurin, four of the five amino acids bound to copper are identified with one false positive. This false positive, however, corresponds to the oxidation of Met44, which is probably due to its susceptibility to oxidation and its proximity to the only residue not identified (i.e., Gly45). The results altogether suggest that MCO reactions and MS provide a very promising approach for identifying the amino acid residues bound to copper in metalloproteins.

  19. Metal-Catalyzed Asymmetric Michael Addition in Natural Product Synthesis.

    Science.gov (United States)

    Hui, Chunngai; Pu, Fan; Xu, Jing

    2017-03-23

    Asymmetric catalysis for chiral compound synthesis is a rapidly growing field in modern organic chemistry. Asymmetric catalytic processes have been indispensable for the synthesis of enantioselective materials to meet demands from various fields. Michael addition has been used extensively for the construction of C-C bonds under mild conditions. With the discovery and development of organo- and metal-catalyzed asymmetric Michael additions, the synthesis of enantioselective and/or diastereoselective Michael adducts has become possible and increasingly prevalent in the literature. In particular, metal-catalyzed asymmetric Michael addition has been employed as a key reaction in natural product synthesis for the construction of contiguous quaternary stereogenic center(s), which is still a difficult task in organic synthesis. Previously reported applications of metal-catalyzed asymmetric Michael additions in natural product synthesis are presented here and discussed in depth. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Transition-Metal-Catalyzed Cyanation by Using an Electrophilic Cyanating Agent, N-Cyano-N-phenyl-p-toluenesulfonamide (NCTS).

    Science.gov (United States)

    Cui, Jie; Song, Jian; Liu, Qing; Liu, Hui; Dong, Yunhui

    2018-03-02

    The ability to introduce a nitrile group into a biologically active compound is very useful in organic synthesis, owing to the importance of nitrile groups in transformations and tuning molecular properties. To date, nucleophilic cyanation has been the most used strategy for this purpose, whilst electrophilic cyanation reactions are less developed. Recently, the electrophilic cyanation reagent N-cyano-N-phenyl-p-toluenesulfonamide (NCTS) has received increasing attention, owing to its superior properties in terms of safety and practicality. This Focus Review summarizes recent progress in transition-metal-catalyzed cyanation reactions that use NCTS. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Computational studies on the regioselectivity of metal-catalyzed synthesis of 1,2,3 triazoles via click reaction: a review.

    Science.gov (United States)

    Hosseinnejad, Tayebeh; Fattahi, Bahareh; Heravi, Majid M

    2015-10-01

    Recently, the experimental and computational chemists have been attracted widely to the click synthesis of 1,2,3 triazoles and their derivatives, mainly due to the fact that they are interesting from structural and mechanistic points of view. Moreover, catalyzed click have been well established as a successful strategy showing high regioselectivity and high yield for the synthesis of 1,2,3-triazoles. In this review, we try to highlight the recently reported computational assessments on the origins and predection of regioselectivity in the catalyzed click synthesis of triazoles from the mechanistic and thermodynamical points of view. In this light, density functional theory (DFT) calculations on the free energy profiles of azide-alkyne cycloaddition reactions have been underscored. The stereoelectronic features for the role of copper, ruthenium, and iridium as catalyst on regioselectivity of click reactions have also be discussed. Graphical Abstract Computational origins for the regioselective behavior of 1,2,3 triazoles click synthesis.

  2. Enantioselective, transition metal catalyzed cycloisomerizations.

    Science.gov (United States)

    Marinetti, Angela; Jullien, Hélène; Voituriez, Arnaud

    2012-07-21

    This review illustrates enantioselective transition-metal promoted skeletal rearrangements of polyunsaturated substrates possessing olefin, alkyne or allene functions. These processes are classified according to the number of carbon atoms involved in the cyclization, from (1C+1C) to (2C+2C+2C) or (2C+5C) cyclizations. Thus, for instance, (1C+1C) processes are typified notably by Alder-ene type reactions taking place mainly under palladium and rhodium catalysis, in the presence of chiral phosphorus ligands. Also, rhodium, platinum, and gold promoted insertions of unsaturated carbon-carbon bonds into C-H bonds belong to this class. For each class of reactions or substrate type the best ligand-metal pairs are highlighted. Unfortunately, unlike other transition metal promoted reactions, the mechanisms of chiral induction and stereochemical pathways have not been established so far in any of these reactions. In only a few instances, qualitative heuristic models have been tentatively proposed. Although the available stereochemical information is systematically given here, the paper focuses mainly on synthetic aspects of enantioselective cycloisomerizations.

  3. Synthesis of 2-substituted tetraphenylenes via transition-metal-catalyzed derivatization of tetraphenylene

    Directory of Open Access Journals (Sweden)

    Shulei Pan

    2016-06-01

    Full Text Available A new strategy for the synthesis of 2-substituted tetraphenylenes through a transition-metal-catalyzed derivatization has been developed. Three types of functionalities, including OAc, X (Cl, Br, I and carbonyl, were introduced onto tetraphenylene, which allows the easy access to a variety of monosubstituted tetraphenylenes. These reactions could accelerate research on the properties and application of tetraphenylene derivatives.

  4. Effective alkaline metal-catalyzed oxidative delignification of hybrid poplar.

    Science.gov (United States)

    Bhalla, Aditya; Bansal, Namita; Stoklosa, Ryan J; Fountain, Mackenzie; Ralph, John; Hodge, David B; Hegg, Eric L

    2016-01-01

    Strategies to improve copper-catalyzed alkaline hydrogen peroxide (Cu-AHP) pretreatment of hybrid poplar were investigated. These improvements included a combination of increasing hydrolysis yields, while simultaneously decreasing process inputs through (i) more efficient utilization of H2O2 and (ii) the addition of an alkaline extraction step prior to the metal-catalyzed AHP pretreatment. We hypothesized that utilizing this improved process could substantially lower the chemical inputs needed during pretreatment. Hybrid poplar was pretreated utilizing a modified process in which an alkaline extraction step was incorporated prior to the Cu-AHP treatment step and H2O2 was added batch-wise over the course of 10 h. Our results revealed that the alkaline pre-extraction step improved both lignin and xylan solubilization, which ultimately led to improved glucose (86 %) and xylose (95 %) yields following enzymatic hydrolysis. An increase in the lignin solubilization was also observed with fed-batch H2O2 addition relative to batch-only addition, which again resulted in increased glucose and xylose yields (77 and 93 % versus 63 and 74 %, respectively). Importantly, combining these strategies led to significantly improved sugar yields (96 % glucose and 94 % xylose) following enzymatic hydrolysis. In addition, we found that we could substantially lower the chemical inputs (enzyme, H2O2, and catalyst), while still maintaining high product yields utilizing the improved Cu-AHP process. This pretreatment also provided a relatively pure lignin stream consisting of ≥90 % Klason lignin and only 3 % xylan and 2 % ash following precipitation. Two-dimensional heteronuclear single-quantum coherence (2D HSQC) NMR and size-exclusion chromatography demonstrated that the solubilized lignin was high molecular weight (Mw ≈ 22,000 Da) and only slightly oxidized relative to lignin from untreated poplar. This study demonstrated that the fed-batch, two-stage Cu-AHP pretreatment

  5. Benchtop monitoring of reaction progress via visual recognition with a handheld UV lamp: in situ monitoring of boronic acids in the Suzuki-Miyaura reaction.

    Science.gov (United States)

    Barder, Timothy E; Buchwald, Stephen L

    2007-01-04

    [reaction: see text] Although boronic acids are widely used in metal-catalyzed reactions, it is difficult to assay their consumption. As such, we developed a reversible fluorescent sensor that is activated upon binding a boronic acid. The sensor can be used to monitor consumption of a boronic acid in Suzuki-Miyaura reactions. Importantly, only a standard handheld long-wave UV lamp (365 nm) is required and fluorescence is easily detectable with the naked eye without disturbing the reaction mixture.

  6. Heterocycles by Transition Metals Catalyzed Intramolecular Cyclization of Acetylene Compounds

    International Nuclear Information System (INIS)

    Vizer, S.A.; Yerzhanov, K.B.; Dedeshko, E.C.

    2003-01-01

    Review shows the new strategies in the synthesis of heterocycles, having nitrogen, oxygen and sulfur atoms, via transition metals catalyzed intramolecular cyclization of acetylenic compounds on the data published at the last 30 years, Unsaturated heterocyclic compounds (pyrroles and pyrroline, furans, dihydro furans and benzofurans, indoles and iso-indoles, isoquinolines and isoquinolinones, aurones, iso coumarins and oxazolinone, lactams and lactones with various substitutes in heterocycles) are formed by transition metals, those salts [PdCl 2 , Pd(OAc) 2 , HgCl 2 , Hg(OAc) 2 , Hg(OCOCF 3 ) 2 , AuCl 3 ·2H 2 O, NaAuCl 4 ·2H 2 O, CuI, CuCl], oxides (HgO) and complexes [Pd(OAc) 2 (PPh 3 )2, Pd(PPh 3 ) 4 , PdCl 2 (MeCN) 2 , Pd(OAc ) 2 /TPPTS] catalyzed intramolecular cyclization of acetylenic amines, amides, ethers, alcohols, acids, ketones and βdiketones. More complex hetero polycyclic systems typical for natural alkaloids can to obtain similar. Proposed mechanisms of pyrroles, isoquinolines, iso indoles and indoles, benzofurans and iso coumarins, thiazolopyrimidinones formation are considered. (author)

  7. Transition Metal Catalyzed Synthesis of Carboxylic Acids, Imines, and Biaryls

    DEFF Research Database (Denmark)

    Santilli, Carola; Madsen, Robert

    Dehydrogenative synthesis of carboxylic acids catalyzed by a ruthenium N- heterocycliccarbene complex. A new methodology for the synthesis of carboxylic acids from primary alcohols and hydroxide has been developed. The reaction is catalyzed by the ruthenium N-heterocycliccarbene complex [RuCl2(Ii...... to the carboxylic acids can be explained by the involvement of a competing Cannizzaro reaction. The scope of the dehydrogenation was further extended to linear and branched saturated aliphatic alcohols, although longer reaction times are necessary to ensure complete substrate conversions. The kinetic isotope effect...... the carboxylate.  Manganese catalyzed radical Kumada-type reaction between aryl halidesand aryl Grignard reagents. The reaction between aryl halides and aryl Grignard reagents catalyzed by MnCl2 has been extended to several methyl-substituted aryl iodide reagents byperforming the reaction at 120 ˚C in a microwave...

  8. TRANSITION METAL CATALYZED ATOM TRANSFER RADICAL POLYMERIZATION. (R826735)

    Science.gov (United States)

    The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

  9. Chemical Reactions at Surfaces. Final Progress Report

    Energy Technology Data Exchange (ETDEWEB)

    Freud, Hans-Joachim [Max-Planck-Gesellschaft, Berlin (Germany). Fritz-Haber-Inst.

    2003-02-21

    The Gordon Research Conference (GRC) on Chemical Reactions at Surfaces was held at Holiday Inn, Ventura, California, 2/16-21/03. Emphasis was placed on current unpublished research and discussion of the future target areas in this field.

  10. Metal-catalyzed hydrosilylation of alkenes and alkynes using dimethyl(pyridyl)silane.

    Science.gov (United States)

    Itami, Kenichiro; Mitsudo, Koichi; Nishino, Akira; Yoshida, Jun-ichi

    2002-04-19

    Metal-catalyzed hydrosilylation of alkenes and alkynes using dimethyl(pyridyl)silane is described. The hydrosilylation of alkenes using dimethyl(2-pyridyl)silane (2-PyMe(2)SiH) proceeded well in the presence of a catalytic amount of RhCl(PPh(3))(3) with virtually complete regioselectivity. By taking advantage of the phase tag property of the 2-PyMe(2)Si group, hydrosilylation products were isolated in greater than 95% purity by simple acid-base extraction. Strategic catalyst recovery was also demonstrated. The hydrosilylation of alkynes using 2-PyMe(2)SiH proceeded with a Pt(CH(2)=CHSiMe(2))(2)O/P(t-Bu)(3) catalyst to give alkenyldimethyl(2-pyridyl)silanes in good yield with high regioselectivity. A reactivity comparison of 2-PyMe(2)SiH with other related hydrosilanes (3-PyMe(2)SiH, 4-PyMe(2)SiH, and PhMe(2)SiH) was also performed. In the rhodium-catalyzed reaction, the reactivity order of hydrosilane was 2-PyMe(2)SiH > 3-PyMe(2)SiH, 4-PyMe(2)SiH, PhMe(2)SiH, indicating a huge rate acceleration with 2-PyMe(2)SiH. In the platinum-catalyzed reaction, the reactivity order of hydrosilane was PhMe(2)SiH, 3-PyMe(2)SiH > 4-PyMe(2)SiH > 2-PyMe(2)SiH, indicating a rate deceleration with 2-PyMe(2)SiH and 4-PyMe(2)SiH. It seems that these reactivity differences stem primarily from the governance of two different mechanisms (Chalk-Harrod and modified Chalk-Harrod mechanisms). From the observed reactivity order, coordination and electronic effects of dimethyl(pyridyl)silanes have been implicated.

  11. Complementary Strategies for Directed C(sp3)-H Functionalization: A Comparison of Transition-Metal-Catalyzed Activation, Hydrogen Atom Transfer, and Carbene/Nitrene Transfer.

    Science.gov (United States)

    Chu, John C K; Rovis, Tomislav

    2018-01-02

    The functionalization of C(sp 3 )-H bonds streamlines chemical synthesis by allowing the use of simple molecules and providing novel synthetic disconnections. Intensive recent efforts in the development of new reactions based on C-H functionalization have led to its wider adoption across a range of research areas. This Review discusses the strengths and weaknesses of three main approaches: transition-metal-catalyzed C-H activation, 1,n-hydrogen atom transfer, and transition-metal-catalyzed carbene/nitrene transfer, for the directed functionalization of unactivated C(sp 3 )-H bonds. For each strategy, the scope, the reactivity of different C-H bonds, the position of the reacting C-H bonds relative to the directing group, and stereochemical outcomes are illustrated with examples in the literature. The aim of this Review is to provide guidance for the use of C-H functionalization reactions and inspire future research in this area. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Ammonia and hydrazine. Transition-metal-catalyzed hydroamination and metal-free catalyzed functionalization

    Energy Technology Data Exchange (ETDEWEB)

    Bertrand, Guy [Univ. of California, San Diego, CA (United States)

    2012-06-29

    high temperatures and long reaction times. To address this issue, we have developed several new families of carbon- and boron-based ligands, which are even better donors. The corresponding metal complexes (particularly gold, rhodium, iridium, and ruthenium) of all these species will be tested in the Markovnikov and anti-Markovnikov hydroamination of alkynes, allenes, and also alkenes with ammonia and hydrazine. We will also develop metal-free catalytic processes for the functionalization of ammonia and hydrazine. By possessing both a lone pair of electrons and an accessible vacant orbital, singlet carbenes resemble and can mimic the chemical behavior of transition metals. Our preliminary results demonstrate that specially designed carbenes can split the N–H bond of ammonia by an initial nucleophilic activation that prevents the formation of Lewis acid-base adducts, which is the major hurdle for the transition metal catalyzed functionalization of NH3. The use of purely organic compounds as catalysts will eliminate the major drawbacks of transition-metal-catalysis technology, which are the excessive cost of metal complexes (metal + ligands) and in many cases the toxicity of the metal.

  13. Transition-Metal-Catalyzed Asymmetric Hydrogenation and Transfer Hydrogenation: Sustainable Chemistry to Access Bioactive Molecules.

    Science.gov (United States)

    Ayad, Tahar; Phansavath, Phannarath; Ratovelomanana-Vidal, Virginie

    2016-12-01

    Over the last few decades, the development of new and highly efficient synthetic methods to obtain chiral compounds has become an increasingly important and challenging research area in modern synthetic organic chemistry. In this account, we review recent work from our laboratory toward the synthesis of valuable chiral building blocks through transition-metal-catalyzed asymmetric hydrogenation and transfer hydrogenation of C=O, C=N and C=C bonds. Application to the synthesis of biologically relevant products is also described. © 2016 The Chemical Society of Japan & Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Transition-metal-catalyzed hydrogen-transfer annulations: access to heterocyclic scaffolds.

    Science.gov (United States)

    Nandakumar, Avanashiappan; Midya, Siba Prasad; Landge, Vinod Gokulkrishna; Balaraman, Ekambaram

    2015-09-14

    The ability of hydrogen-transfer transition-metal catalysts, which enable increasingly rapid access to important structural scaffolds from simple starting materials, has led to a plethora of research efforts on the construction of heterocyclic scaffolds. Transition-metal-catalyzed hydrogen-transfer annulations are environmentally benign and highly atom-economical as they release of water and hydrogen as by-product and utilize renewable feedstock alcohols as starting materials. Recent advances in this field with respect to the annulations of alcohols with various nucleophilic partners, thus leading to the formation of heterocyclic scaffolds, are highlighted herein. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Progress in all-order breakup reaction theories

    Indian Academy of Sciences (India)

    Progress in breakup reaction theories, like the distorted wave Born approximation, the continuum discretized coupled channels method and the dynamical eikonal approximation, is brought into focus. The need to calculate ... R Chatterjee1. Department of Physics, Indian Institute of Technology, Roorkee 247 667, India ...

  16. [Measurements of observables of pion-nucleon reactions]. Progress report

    International Nuclear Information System (INIS)

    Sadler, M.E.

    1985-01-01

    This document reports the progress of the research of pion reactions. These include (1) a study to measure observables in the pion-nucleon system in the momentum interval 400 to 700 MeV/c, (2) differential cross section measurements at low energy for pion-nucleon charge exchange, and (3) elastic and inelastic scattering of π +- on 3 H and 3 He. Individual experiments will be indexed separately

  17. Transition Metal Catalyzed Reactions for Forming Carbon–Oxygen and Carbon–Carbon Bonds

    DEFF Research Database (Denmark)

    Sølvhøj, Amanda Birgitte

    of ether and hydrocarbon radicals with -bromostyrenes was serendipitously discovered and subsequently optimized. By screening of various radical initiators and transition metal salts the best conditions were found to involve addition of three to four equivalents of Me2Zn to a solution of -bromostyrene...

  18. Protein carbonylation and metal-catalyzed protein oxidation in a cellular perspective

    DEFF Research Database (Denmark)

    Møller, Ian Max; Rogowska-Wrzesinska, Adelina; Rao, Shyama Prasad

    2011-01-01

    Proteins can become oxidatively modified in many different ways, either by direct oxidation of amino acid side chains and protein backbone or indirectly by conjugation with oxidation products of polyunsaturated fatty acids and carbohydrates. While reversible oxidative modifications are thought...... to be relevant in physiological processes, irreversible oxidative modifications are known to contribute to cellular damage and disease. The most well-studied irreversible protein oxidation is carbonylation. In this work we first examine how protein carbonylation occurs via metal-catalyzed oxidation (MCO) in vivo...... and in vitro with an emphasis on cellular metal ion homeostasis and metal binding. We then review proteomic methods currently used for identifying carbonylated proteins and their sites of modification. Finally, we discuss the identified carbonylated proteins and the pattern of carbonylation sites in relation...

  19. Vesicular Contact Reaction May Progress into Erythema Multiforme.

    Science.gov (United States)

    Czarnecka-Operacz, Magdalena; Jenerowicz, Dorota; Szulczyńska-Gabor, Joanna; Teresiak-Mikołajczak, Ewa; Szyfter-Harris, Joanna; Bowszyc-Dmochowska, Monika

    2016-12-01

    Dear Editor, Erythema multiforme is considered an acute skin condition, characterized by a self-limiting and sometimes recurrent course. It is regarded as a type IV hypersensitivity reaction associated with certain infections, medications, and other various triggers. Allergic contact dermatitis is in turn a delayed type of induced allergy as a result of cutaneous contact with a specific allergen to which the patient develops specific sensitivity. This type of cutaneous reaction is associated with inflammation manifesting with erythema, edema, and vesicles. A 27-year old female patient presented with a 3-day history of erythematous and vesicular lesions which developed 24 hours after cesarean section. Initially the lesions were localized in the area of surgery (mainly the abdomen and upper thighs) and on the next day progressed to the buttocks and lumbar area. The patient was referred to the Outpatient Clinic and was treated with antihistamines, but her dermatological state deteriorated rapidly. At the day of admission to the Department of Dermatology, numerous erythematous and vesicular lesions were present on the skin of the abdomen, thighs, and back (Figure 1, a), but the skin of the neck, chest, and extremities was also covered with erythematous and edematous patches. On the second day of hospitalization, we observed the evolution of lesions localized within the chest and extremities into an erythema multiforme-like targetoid eruption (Figure 1, b). Initially the patient was treated with intravenous injections of dexamethasone and ceftriaxone and orally with second-generation antihistamines (in four-fold doses), followed by intravenous metyloprednisolone pulse-therapy (total dose of 3 g). As the new vesicobullous lesions started to appear on the face and arms, we introduced cyclosporine A orally 400 mg daily. We could then observe gradual remission, but on the seventh day of hospitalization the patient developed a massive labial herpes simplex infection and had

  20. Reaction studies of hot silicon and germanium radicals. Progress report, September 1, 1979-August 31, 1980

    International Nuclear Information System (INIS)

    Gaspar, P.P.

    1980-01-01

    The experimental approach to attaining the goals of this research program is briefly outlined and the progress made in the last year is reviewed in sections entitled: (a) primary steps in the reaction of recoiling silicon and germanium atoms and the identification of reactive intermediates in the recoil reactions; (b) thermally induced silylene and germylene reactions; (c) ion-molecule reaction studies

  1. Ultrafast synthesis of ultrahigh molar mass polymers by metal-catalyzed living radical polymerization of acrylates, methacrylates, and vinyl chloride mediated by SET at 25 degrees C.

    Science.gov (United States)

    Percec, Virgil; Guliashvili, Tamaz; Ladislaw, Janine S; Wistrand, Anna; Stjerndahl, Anna; Sienkowska, Monika J; Monteiro, Michael J; Sahoo, Sangrama

    2006-11-01

    Conventional metal-catalyzed organic radical reactions and living radical polymerizations (LRP) performed in nonpolar solvents, including atom-transfer radical polymerization (ATRP), proceed by an inner-sphere electron-transfer mechanism. One catalytic system frequently used in these polymerizations is based on Cu(I)X species and N-containing ligands. Here, it is reported that polar solvents such as H(2)O, alcohols, dipolar aprotic solvents, ethylene and propylene carbonate, and ionic liquids instantaneously disproportionate Cu(I)X into Cu(0) and Cu(II)X(2) species in the presence of a diversity of N-containing ligands. This disproportionation facilitates an ultrafast LRP in which the free radicals are generated by the nascent and extremely reactive Cu(0) atomic species, while their deactivation is mediated by the nascent Cu(II)X(2) species. Both steps proceed by a low activation energy outer-sphere single-electron-transfer (SET) mechanism. The resulting SET-LRP process is activated by a catalytic amount of the electron-donor Cu(0), Cu(2)Se, Cu(2)Te, Cu(2)S, or Cu(2)O species, not by Cu(I)X. This process provides, at room temperature and below, an ultrafast synthesis of ultrahigh molecular weight polymers from functional monomers containing electron-withdrawing groups such as acrylates, methacrylates, and vinyl chloride, initiated with alkyl halides, sulfonyl halides, and N-halides.

  2. Japan Nuclear Reaction Data Centre (JCPRG), Progress Report

    International Nuclear Information System (INIS)

    Aikawa, M.

    2012-01-01

    In this report, we review the activities of Japan Nuclear Reaction Data Centre (JCPRG) since the last NRDC meeting in 2011. Our main objectives are as follows: a) Compilation of nuclear reaction data for two databases, NRDF and EXFOR b) Evaluation of astrophysical nuclear reaction data c) Development of software and systems d) Development of collaboration among Asian countries. (author)

  3. Japan Nuclear Reaction Data Centre (JCPRG) Progress Report

    International Nuclear Information System (INIS)

    2011-01-01

    In this report, we give a brief review of the activities carried out by the ''Japan Nuclear Reaction Data Centre (JCPRG)'' since the last NRDC meeting in 2009. The main subjects of our activities are; (1) reaction data compilation, (2) evaluation of the astrophysical nuclear reaction data for light nuclei, and (3) cooperation of nuclear data activities in Asia. Our activities in detail are as follows. a) New reaction data compilation (NRDF and EXFOR) b) Conversion of old NRDF to EXFOR c) Bibliography compilation (CINDA) d) Evaluation of astrophysical nuclear reaction data based on theoretical calculations for light nuclei e) Collaboration among nuclear data physicists in Asia for the EXFOR compilation to form a stable base f) Database maintenance and services (NRDF, EXFOR/ENDF and CINDA) g) Development of software systems (GSYS) h) Customer services

  4. Fundamental studies of metal fluorination reactions. Third annual progress report

    Energy Technology Data Exchange (ETDEWEB)

    Rapp, R.A.; Reddy, S.N.S.; Chou, S.F.; Lee, B.S.

    1978-01-01

    Results are presented of investigations of the solubility and diffusivity of fluorine in copper. Other research is reported on the electronic conductivity of CaF/sub 2/ electrolyte and mixed electrode reactions in solid electrolyte cells. (JRD)

  5. Progress Report: Nuclear Reaction Data Group at ATOMKI

    International Nuclear Information System (INIS)

    Takacs, S.; Tarkanyi, F.; Kiraly, B.; Ditroi, F.; Szelecsenyi, F.; Kovacs, Z.; Szucs, Z.; Csikai, J.

    2011-01-01

    The ATOMKI is stands for Institute of Nuclear Research of the Hungarian Academy of Sciences. The general profile of the Atomki Nuclear Reaction Data Group consists of measurement, compilation, evaluation and application of low and medium energy charged particle induced nuclear reaction data. The work is done in international collaborations. The experiments, data compilation and data evaluation are mainly connected to running international projects. Every day applications at home and collaborating institutes also initiate the required data measurements.

  6. Reactions and Coulex at TRIUMF, progress and prospects of SHARC

    Science.gov (United States)

    Diget, Christian Aa.; Sarazin, Fred

    2008-10-01

    The Silicon Highly-segmented Array for Reactions and Coulex (SHARC) is a multi-purpose array for charged-particle detection. The array is designed to have high spatial resolution, a large solid angle coverage, and particle identification of the measured reaction products. This combination offers unique capabilities when integrated with the TIGRESS gamma-ray detectors and the post-accelerated beams at the ISAC-II facility at TRIUMF, Canada. Two major research programs will gain significantly from the utilization of SHARC: Reaction studies with particular emphasis on transfer reactions used to indirectly probe nuclear reaction rates important for explosive stellar scenarios as well as nuclear structure studies in which Coulomb excitation will play an important role. The project is funded by the UK-STFC and is lead from the University of York with collaborators from the UK Universities of Birmingham, Liverpool, Manchester, and Surrey, and Daresbury Laboratory; Colorado School of Mines and Louisiana State University of the USA; and from Canada: TRIUMF as well as McMaster, Saint Mary's, and Simon Fraser Universities.

  7. Charged particle-induced nuclear fission reactionsProgress and ...

    Indian Academy of Sciences (India)

    progress made in recent years and the prospects in the area of nuclear fission research will be the focus of this review. Keywords. Nuclear fission; charged particle-induced fission; heavy ions; fission angular distribu- tions; mass distributions; fission barrier; moment of inertia; shell effect in fission. PACS Nos 25.70.Jj; 25.85.

  8. [Studies of heavy-ion induced reactions]: Annual progress report

    International Nuclear Information System (INIS)

    Mignerey, A.C.

    1986-10-01

    An experiment was performed at the Lawrence Berkeley Laboratory Bevalac, extending previous studies using inverse reactions to 50 MeV/u 139 La incident on targets of C and Al. Studies of excitation energy division in lower energy division in lower energy heavy-ion reactions were furthered using kinematic coincidences to measure the excitation energies of primary products in the Fe + Ho reaction at 12 MeV/u. These results will provide important systematics for comparisons with previous measurements at 9 MeV/u on the same system and at 15 MeV/u on the Fe + Fe and Fe + U systems. Also studied were different aspects of 15 MeV/u Fe-induced reactions, with experiments performed at the Oak Ridge HHIRF. The first three contributions of this report constitute a major portion of the results from this research. Finally, at the Lawrence Berkeley Laboratory Bevalac a large detector array for coincident detection of fragmentation products in heavy-ion collisions below 100 MeV/u is being built. A list of publications, personnel, and activities is provided

  9. Progress in all-order breakup reaction theories

    Indian Academy of Sciences (India)

    reaction observables calculated – like the momentum distributions, relative energy spectra, angular distributions – are of ... is thus a strong case to calculate more exclusive observables, like double- and triple- differential cross-sections, where ..... ically solvable bremsstrahlung integral [34]. This theory could then be applied ...

  10. Metal-catalyzed oxidation of Aβ and the resulting reorganization of Cu binding sites promote ROS production†

    Science.gov (United States)

    Cheignon, Clémence; Faller, Peter; Testemale, Denis; Hureau, Christelle; Collin, Fabrice

    2017-01-01

    In the context of Alzheimer’s disease (AD), the production of HO• by copper–amyloid beta (Aβ) in the presence of ascorbate is known to be deleterious for the Aβ peptide itself and also for the surrounding molecules, thus establishing a direct link between AD and oxidative stress. The metal-catalyzed oxidation (MCO) of Aβ primarily targets the residues involved in copper coordination during HO• production. In the present work, we demonstrate that the oxidative damage undergone by Aβ during MCO lead to a change in copper coordination, with enhanced catalytic properties that increases the rates of ascorbate consumption and HO• production, and the amount of HO• released by the system. This phenomenon is observed after the peptide has been sufficiently oxidized. PMID:27730227

  11. Research progress on trifluoromethyl-based radical reaction process

    Science.gov (United States)

    Song, Hao

    2017-12-01

    Due to the unique properties imparted by the trifluoromethyl group, such as high electron density and strong lipotropy, which effectively improve acidity, lipophilicity and metabolic stability of the molecule itself, trifluoromethyl-substituted organic compounds are becoming increasingly important as structural motifs in pharmaceuticals, agrochemicals and organic materials. In this review, we present several methods developed for the direct introduction of a trifluoromethyl group, beginning with its rich and storied history. Then the present article addresses mechanism and process in carbon-carbon bond forming reaction based on radical process which is divided into three parts according to the way of CF3 radical generation. Finally, challenges and opportunities of researches on trifluoromethylation reactions facing are prospected.

  12. Progress of sperm Izumo1 relocation during spontaneous acrosome reaction

    Czech Academy of Sciences Publication Activity Database

    Šebková, N.; Děd, Lukáš; Veselá, K.; Dvořáková-Hortová, K.

    2014-01-01

    Roč. 147, č. 2 (2014), s. 231-240 ISSN 1470-1626 R&D Projects: GA ČR(CZ) GAP503/12/1834; GA MŠk ED1.1.00/02.0109 Grant - others:GA ČR(CZ) GAP506/12/1046 Institutional research plan: CEZ:AV0Z50520701 Keywords : Acrosome reaction * Capacitation * Izumo 1 Subject RIV: EC - Immunology Impact factor: 3.174, year: 2014

  13. A metal-catalyzed enyne-cyclization step for the synthesis of bi- and tricyclic scaffolds amenable to molecular library production

    DEFF Research Database (Denmark)

    Wu, Peng; Cohrt, Anders Emil O'Hanlon; Petersen, Rico

    2016-01-01

    A facile metal-catalyzed diversification step for the synthesis of novel bi- and tricyclic scaffolds from enyne substrates is reported in this study. From a single starting material, topologically diverse scaffolds for library synthesis can be generated and decorated in a few steps. The methodology...... was used to produce a library of 490 compounds within the European Lead Factory (ELF) Consortium....

  14. Transition Metal Catalyzed Hydroarylation of Multiple Bonds: Exploration of Second Generation Ruthenium Catalysts and Extension to Copper Systems

    Energy Technology Data Exchange (ETDEWEB)

    T. Brent Gunnoe

    2011-02-17

    Catalysts provide foundational technology for the development of new materials and can enhance the efficiency of routes to known materials. New catalyst technologies offer the possibility of reducing energy and raw material consumption as well as enabling chemical processes with a lower environmental impact. The rising demand and expense of fossil resources has strained national and global economies and has increased the importance of accessing more efficient catalytic processes for the conversion of hydrocarbons to useful products. The goals of the research are to develop and understand single-site homogeneous catalysts for the conversion of readily available hydrocarbons into useful materials. A detailed understanding of these catalytic reactions could lead to the development of catalysts with improved activity, longevity and selectivity. Such transformations could reduce the environmental impact of hydrocarbon functionalization, conserve energy and valuable fossil resources and provide new technologies for the production of liquid fuels. This project is a collaborative effort that incorporates both experimental and computational studies to understand the details of transition metal catalyzed C-H activation and C-C bond forming reactions with olefins. Accomplishments of the current funding period include: (1) We have completed and published studies of C-H activation and catalytic olefin hydroarylation by TpRu{l_brace}P(pyr){sub 3}{r_brace}(NCMe)R (pyr = N-pyrrolyl) complexes. While these systems efficiently initiate stoichiometric benzene C-H activation, catalytic olefin hydroarylation is hindered by inhibition of olefin coordination, which is a result of the steric bulk of the P(pyr){sub 3} ligand. (2) We have extended our studies of catalytic olefin hydroarylation by TpRu(L)(NCMe)Ph systems to L = P(OCH{sub 2}){sub 3}CEt. Thus, we have now completed detailed mechanistic studies of four systems with L = CO, PMe{sub 3}, P(pyr){sub 3} and P(OCH{sub 2}){sub 3}CEt

  15. Progression of radical reactions on microscopic scale in food emulsions

    DEFF Research Database (Denmark)

    Raudsepp, Piret

    Understanding the progression of lipid oxidation in oil-in-water emulsions from the aspect of the food quality and safety, consumer satisfaction and cleaner food label is of importance, because most of the food emulsions are oil-in-water emulsions. There is an increasing tendency in the food...... industry to incorporate unsaturated oils into food products, but that results in shortened shelf-life. Therefore, studying the factors and consequences of the oxidative instability provides beneficial insight into prolonging the antioxidative stage and inhibiting undergoing oxidation processes to improve...

  16. Merging Visible Light Photoredox Catalysis with Metal Catalyzed C–H Activations: On the Role of Oxygen and Superoxide Ions as Oxidants

    Science.gov (United States)

    2016-01-01

    catalyst via a coupled electron transfer (ET) process. Here we describe our first successful endeavors to address the above challenges by combining visible light photoredox catalysis with different ruthenium, rhodium, or palladium catalyzed C–H activations. Since only small amounts of the oxidant are generated and are immediately consumed in these transformations, side reactions of substrates or products can be avoided. Thus, usually oxidant-sensible substrates can be used, which makes these methods highly suitable for complex molecular structure syntheses. Moreover, mechanistic studies shed light on new reaction pathways, intermediates, and in situ generated species. The successful development of our dual catalysis concept, consisting of combined visible light photoredox catalysis and metal catalyzed C–H functionalization, provides many new opportunities for further explorations in the field of C–H functionalization. PMID:27556812

  17. N-Alkylation by Hydrogen Autotransfer Reactions.

    Science.gov (United States)

    Ma, Xiantao; Su, Chenliang; Xu, Qing

    2016-06-01

    Owing to the importance of amine/amide derivatives in all fields of chemistry, and also the green and environmentally benign features of using alcohols as alkylating reagents, the relatively high atom economic dehydrative N-alkylation reactions of amines/amides with alcohols through hydrogen autotransfer processes have received much attention and have developed rapidly in recent decades. Various efficient homogeneous and heterogeneous transition metal catalysts, nano materials, electrochemical methods, biomimetic methods, asymmetric N-alkylation reactions, aerobic oxidative methods, and even certain transition metal-free, catalyst-free, or autocatalyzed methods, have also been developed in recent years. With a brief introduction to the background and developments in this area of research, this chapter focuses mainly on recent progress and technical and conceptual advances contributing to the development of this research in the last decade. In addition to mainstream research on homogeneous and heterogeneous transition metal-catalyzed reactions, possible mechanistic routes for hydrogen transfer and alcohol activation, which are key processes in N-alkylation reactions but seldom discussed in the past, the recent reports on computational mechanistic studies of the N-alkylation reactions, and the newly emerged N-alkylation methods based on novel alcohol activation protocols such as air-promoted reactions and transition metal-free methods, are also reviewed in this chapter. Problems and bottlenecks that remained to be solved in the field, and promising new research that deserves greater future attention and effort, are also reviewed and discussed.

  18. High-Performance Black Multicrystalline Silicon Solar Cells by a Highly Simplified Metal-Catalyzed Chemical Etching Method

    KAUST Repository

    Ying, Zhiqin

    2016-05-20

    A wet-chemical surface texturing technique, including a two-step metal-catalyzed chemical etching (MCCE) and an extra alkaline treatment, has been proven as an efficient way to fabricate high-efficiency black multicrystalline (mc) silicon solar cells, whereas it is limited by the production capacity and the cost cutting due to the complicated process. Here, we demonstrated that with careful control of the composition in etching solution, low-aspect-ratio bowl-like nanostructures with atomically smooth surfaces could be directly achieved by improved one-step MCCE and with no posttreatment, like alkali solution. The doublet surface texture of implementing this nanobowl structure upon the industrialized acidic-textured surface showed concurrent improvement in optical and electrical properties for realizing 18.23% efficiency mc-Si solar cells (156 mm × 156 mm), which is sufficiently higher than 17.7% of the solely acidic-textured cells in the same batch. The one-step MCCE method demonstrated in this study may provide a cost-effective way to manufacture high-performance mc-Si solar cells for the present photovoltaic industry. © 2016 IEEE.

  19. Noble metal catalyzed hydrogen generation from formic acid in nitrite-containing simulated nuclear waste media

    International Nuclear Information System (INIS)

    King, R.B.; Bhattacharyya, N.K.; Wiemers, K.D.

    1994-08-01

    Simulants for the Hanford Waste Vitrification Plant (HWVP) feed containing the major non-radioactive components Al, Cd, Fe, Mn, Nd, Ni, Si, Zr, Na, CO 3 2- , NO 3 -, and NO 2 - were used as media to evaluate the stability of formic acid towards hydrogen evolution by the reaction HCO 2 H → H 2 + CO 2 catalyzed by the noble metals Ru, Rh, and/or Pd found in significant quantities in uranium fission products. Small scale experiments using 40-50 mL of feed simulant in closed glass reactors (250-550 mL total volume) at 80-100 degree C were used to study the effect of nitrite and nitrate ion on the catalytic activities of the noble metals for formic acid decomposition. Reactions were monitored using gas chromatography to analyze the CO 2 , H 2 , NO, and N 2 O in the gas phase as a function of time. Rhodium, which was introduced as soluble RhCl 3 ·3H 2 O, was found to be the most active catalyst for hydrogen generation from formic acid above ∼80 degree C in the presence of nitrite ion in accord with earlier observations. The inherent homogeneous nature of the nitrite-promoted Rh-catalyzed formic acid decomposition is suggested by the approximate pseudo first-order dependence of the hydrogen production rate on Rh concentration. Titration of the typical feed simulants containing carbonate and nitrite with formic acid in the presence of rhodium at the reaction temperature (∼90 degree C) indicates that the nitrite-promoted Rh-catalyzed decomposition of formic acid occurs only after formic acid has reacted with all of the carbonate and nitrite present to form CO 2 and NO/N 2 O, respectively. The catalytic activities of Ru and Pd towards hydrogen generation from formic acid are quite different than those of Rh in that they are inhibited rather than promoted by the presence of nitrite ion

  20. Single-site catalyst promoters accelerate metal-catalyzed nitroarene hydrogenation

    KAUST Repository

    Wang, Liang

    2018-04-04

    Atomically dispersed supported metal catalysts are drawing wide attention because of the opportunities they offer for new catalytic properties combined with efficient use of the metals. We extend this class of materials to catalysts that incorporate atomically dispersed metal atoms as promoters. The catalysts are used for the challenging nitroarene hydrogenation and found to have both high activity and selectivity. The promoters are single-site Sn on TiO2 supports that incorporate metal nanoparticle catalysts. Represented as M/Sn-TiO2 (M = Au, Ru, Pt, Ni), these catalysts decidedly outperform the unpromoted supported metals, even for hydrogenation of nitroarenes substituted with various reducible groups. The high activity and selectivity of these catalysts result from the creation of oxygen vacancies on the TiO2 surface by single-site Sn, which leads to efficient, selective activation of the nitro group coupled with a reaction involving hydrogen atoms activated on metal nanoparticles.

  1. Nested arithmetic progressions of oscillatory phases in Olsen's enzyme reaction model

    Science.gov (United States)

    Gallas, Marcia R.; Gallas, Jason A. C.

    2015-06-01

    We report some regular organizations of stability phases discovered among self-sustained oscillations of a biochemical oscillator. The signature of such organizations is a nested arithmetic progression in the number of spikes of consecutive windows of periodic oscillations. In one of them, there is a main progression of windows whose consecutive number of spikes differs by one unit. Such windows are separated by a secondary progression of smaller windows whose number of spikes differs by two units. Another more complex progression involves a fan-like nested alternation of stability phases whose number of spikes seems to grow indefinitely and to accumulate methodically in cycles. Arithmetic progressions exist abundantly in several control parameter planes and can be observed by tuning just one among several possible rate constants governing the enzyme reaction.

  2. The Associations of Anticipated Parental Reactions with Smoking Initiation and Progression in Adolescents

    NARCIS (Netherlands)

    Leeuw, R.N.H. de; Scholte, R.H.J.; Vermulst, A.A.; Engels, R.C.M.E.

    2013-01-01

    Background and Objectives The aim of this study was to examine whether anticipated parental reactions to smoking were related to smoking onset and progression during adolescence. Methods Data were used from the six-wave, 5-year longitudinal “Family and Health” project, in which N = 428 adolescents

  3. Reaction studies of hot silicon and germanium radicals. Progress report, February 1, 1982-July 31, 1984

    International Nuclear Information System (INIS)

    Gaspar, P.P.

    1984-01-01

    The experimental approach toward attaining the goals of this research program is briefly outlined, and the progress made in the 1982 to 1984 period is reviewed in sections entitled: (1) Recoil atom experiments, (2) Studies of thermally and photochemically generated silicon and germanium radicals, and (3) Ion-molecule reaction studies

  4. HPLC method for rapidly following biodiesel fuel transesterification reaction progress using a core-shell column.

    Science.gov (United States)

    Allen, Samuel J; Ott, Lisa S

    2012-07-01

    There are a wide and growing variety of feedstocks for biodiesel fuel. Most commonly, these feedstocks contain triglycerides which are transesterified into the fatty acid alkyl esters (FAAEs) which comprise biodiesel fuel. While the tranesterification reaction itself is simple, monitoring the reaction progress and reaction products is not. Gas chromatography-mass spectrometry is useful for assessing the FAAE products, but does not directly address either the tri-, di-, or monoglycerides present from incomplete transesterification or the free fatty acids which may also be present. Analysis of the biodiesel reaction mixture is complicated by the solubility and physical property differences among the components of the tranesterification reaction mixture. In this contribution, we present a simple, rapid HPLC method which allows for monitoring all of the main components in a biodiesel fuel transesterification reaction, with specific emphasis on the ability to monitor the reaction as a function of time. The utilization of a relatively new, core-shell stationary phase for the HPLC column allows for efficient separation of peaks with short elution times, saving both time and solvent.

  5. Theory of photon and electron induced reactions: Progress report, July 1, 1986-June 30, 1987

    International Nuclear Information System (INIS)

    Onley, D.S.; Wright, L.E.

    1988-07-01

    During the third year of our three-year contract from the Department of Energy, we have made considerable progress or have completed our studies on the following aspects of the general investigation of electron and photon induced reactions; photo- and electro-production of mesons; the radiation tail accompanying elastic electron scattering and pair production; studies involving relativistic shell model; and electrofission coincidence angular distributions. We will report on each of these developments in this paper

  6. Nuclear excitations and reaction mechanisms. Progress report, 1 August-31 July 1984

    International Nuclear Information System (INIS)

    Fallieros, S.; Levin, F.S.

    1984-01-01

    This progress report describes activities of the Nuclear Theory group at Brown University during the period 1 August 1983 to 31 July 1984. Completed and ongoing research include various theoretical and numerical studies of few-particle systems, nuclear reaction models, nuclear electroexcitation and photon scattering from nuclei. In addition, research on atomic and molecular structure has essentially been concluded and no further DOE-supported research in this area is anticipated

  7. Light particle and gamma ray emission measurements in heavy ion reactions. Progress report

    International Nuclear Information System (INIS)

    Petitt, G.A.

    1983-01-01

    Studies of neutron and charged particle emission in heavy ion reactions using the facilities at the HHIRF and the new computer facilities at Georgia State are briefly described. A progress report for 1982 to 1983 is combined with a proposal for work to be performed during 1983 to 1984. Present activities and immediate plans for a run already approved by the Program Advisory Committee of the HHIRF are discussed

  8. TORUS: Theory of Reactions for Unstable iSotopes - Year 1 Continuation and Progress Report

    Energy Technology Data Exchange (ETDEWEB)

    Arbanas, G; Elster, C; Escher, J; Mukhamedzhanov, A; Nunes, F; Thompson, I J

    2011-02-24

    The TORUS collaboration derives its name from the research it focuses on, namely the Theory of Reactions for Unstable iSotopes. It is a Topical Collaboration in Nuclear Theory, and funded by the Nuclear Theory Division of the Office of Nuclear Physics in the Office of Science of the Department of Energy. The funding started on June 1, 2010, it will have been running for nine months by the date of submission of this Annual Continuation and Progress Report on March 1, 2011. The extent of funding was reduced from the original application, and now supports one postdoctoral researcher for the years 1 through 3. The collaboration brings together as Principal Investigators a large fraction of the nuclear reaction theorists currently active within the USA. The mission of the TORUS Topical Collaboration is to develop new methods that will advance nuclear reaction theory for unstable isotopes by using three-body techniques to improve direct-reaction calculations, and, by using a new partial-fusion theory, to integrate descriptions of direct and compound-nucleus reactions. This multi-institution collaborative effort is directly relevant to three areas of interest: the properties of nuclei far from stability; microscopic studies of nuclear input parameters for astrophysics, and microscopic nuclear reaction theory.

  9. Reaction studies of hot silicon, germanium and carbon atoms: Progress report, February 1, 1985-July 31, 1987

    International Nuclear Information System (INIS)

    Gaspar, P.P.

    1987-01-01

    The experimental approach toward attaining the goals of this research program is briefly outlined, and the progress made in the 1985 to 1987 period is reviewed in sections entitled: (1) reactions of recoiling silicon atoms; (2) reactions of recoiling carbon atoms; and (3) reactions of thermally evaporated germanium atoms

  10. Recent Progress on Fe/N/C Electrocatalysts for the Oxygen Reduction Reaction in Fuel Cells

    Directory of Open Access Journals (Sweden)

    Jing Liu

    2015-07-01

    Full Text Available In order to reduce the overall system cost, the development of inexpensive, high-performance and durable oxygen reduction reaction (ORRN, Fe-codoped carbon-based (Fe/N/C electrocatalysts to replace currently used Pt-based catalysts has become one of the major topics in research on fuel cells. This review paper lays the emphasis on introducing the progress made over the recent five years with a detailed discussion of recent work in the area of Fe/N/C electrocatalysts for ORR and the possible Fe-based active sites. Fe-based materials prepared by simple pyrolysis of transition metal salt, carbon support, and nitrogen-rich small molecule or polymeric compound are mainly reviewed due to their low cost, high performance, long stability and because they are the most promising for replacing currently used Pt-based catalysts in the progress of fuel cell commercialization. Additionally, Fe-base catalysts with small amount of Fe or new structure of Fe/Fe3C encased in carbon layers are presented to analyze the effect of loading and existence form of Fe on the ORR catalytic activity in Fe-base catalyst. The proposed catalytically Fe-centered active sites and reaction mechanisms from various authors are also discussed in detail, which may be useful for the rational design of high-performance, inexpensive, and practical Fe-base ORR catalysts in future development of fuel cells.

  11. Hot atom reactions involving multivalent and univalent species. Progress report, February 1979-January 1980

    International Nuclear Information System (INIS)

    Tang, Y.N.

    1980-01-01

    The major progress during this period was in the study of recoil 31 Si and recoil 11 C reactions and in the initiation of the studies on the interaction of molecular tritium on solid surfaces. For the recoil 31 Si systems, heterogeneous hydrogenation experiments have been designed to positively confirm that a major unknown product, derived from the interaction of 31 Si atoms with 1,3-butadiene, is 1-silacyclopenta-2,4-diene. This compound has been shown to be very sensitive to γ-ray irradiation and to be thermally unstable at a temperature higher than 100 0 C. Another recoil 31 Si experiment was designed to review the mechanism of the 31 Si abstraction reactions. From the fact that high yields of [ 31 Si]-1-fluorosilacyclopent-3-ene were obtained as a product from a mixture of PH 3 and PF 3 together with 1,3-butadiene, the stepwise abstraction mechanism is definitely much more predominant than the possible simultaneous abstraction. Other recoil 31 Si works involved a detailed systematic composition study of 31 SiF 2 reactions with 1,3-butadiene, some neon moderator studies, and the continuation of the studies on the reactions of 31 SiF 2 and 31 SiH 2 with conjugated hexadienes. By using 2- 14 C-propanone and 1,3- 14 C-propanone, the mechanism of solvent-free oxidative cleavage of propanone by KMnO 4 was elucidated. Information thus derived was used to degradate the 11 C-labelled propadiene derived from the reactions of recoil 11 C atoms with ethylene. Results indicate that 73% of the 11 C-labelled propadiene was center-labelled. This value was observed to change with additives. Various mechanistic studies on the heterogeneous interactions of molecular T 2 on solid surfaces such as Pd supported on active carbon have been initiated

  12. Progress in biocatalysis with immobilized viable whole cells: systems development, reaction engineering and applications.

    Science.gov (United States)

    Polakovič, Milan; Švitel, Juraj; Bučko, Marek; Filip, Jaroslav; Neděla, Vilém; Ansorge-Schumacher, Marion B; Gemeiner, Peter

    2017-05-01

    Viable microbial cells are important biocatalysts in the production of fine chemicals and biofuels, in environmental applications and also in emerging applications such as biosensors or medicine. Their increasing significance is driven mainly by the intensive development of high performance recombinant strains supplying multienzyme cascade reaction pathways, and by advances in preservation of the native state and stability of whole-cell biocatalysts throughout their application. In many cases, the stability and performance of whole-cell biocatalysts can be highly improved by controlled immobilization techniques. This review summarizes the current progress in the development of immobilized whole-cell biocatalysts, the immobilization methods as well as in the bioreaction engineering aspects and economical aspects of their biocatalytic applications.

  13. Hot atom reactions involving multivalent and univalent species. Progress report, February 1979-January 1980

    Energy Technology Data Exchange (ETDEWEB)

    Tang, Y.N.

    1980-01-01

    The major progress during this period was in the study of recoil /sup 31/Si and recoil /sup 11/C reactions and in the initiation of the studies on the interaction of molecular tritium on solid surfaces. For the recoil /sup 31/Si systems, heterogeneous hydrogenation experiments have been designed to positively confirm that a major unknown product, derived from the interaction of /sup 31/Si atoms with 1,3-butadiene, is 1-silacyclopenta-2,4-diene. This compound has been shown to be very sensitive to ..gamma..-ray irradiation and to be thermally unstable at a temperature higher than 100/sup 0/C. Another recoil /sup 31/Si experiment was designed to review the mechanism of the /sup 31/Si abstraction reactions. From the fact that high yields of (/sup 31/Si)-1-fluorosilacyclopent-3-ene were obtained as a product from a mixture of PH/sub 3/ and PF/sub 3/ together with 1,3-butadiene, the stepwise abstraction mechanism is definitely much more predominant than the possible simultaneous abstraction. Other recoil /sup 31/Si works involved a detailed systematic composition study of /sup 31/SiF/sub 2/ reactions with 1,3-butadiene, some neon moderator studies, and the continuation of the studies on the reactions of /sup 31/SiF/sub 2/ and /sup 31/SiH/sub 2/ with conjugated hexadienes. By using 2-/sup 14/C-propanone and 1,3-/sup 14/C-propanone, the mechanism of solvent-free oxidative cleavage of propanone by KMnO/sub 4/ was elucidated. Information thus derived was used to degradate the /sup 11/C-labelled propadiene derived from the reactions of recoil /sup 11/C atoms with ethylene. Results indicate that 73% of the /sup 11/C-labelled propadiene was center-labelled. This value was observed to change with additives. Various mechanistic studies on the heterogeneous interactions of molecular T/sub 2/ on solid surfaces such as Pd supported on active carbon have been initiated.

  14. Noble metal catalyzed aqueous phase hydrogenation and hydrodeoxygenation of lignin-derived pyrolysis oil and related model compounds.

    Science.gov (United States)

    Mu, Wei; Ben, Haoxi; Du, Xiaotang; Zhang, Xiaodan; Hu, Fan; Liu, Wei; Ragauskas, Arthur J; Deng, Yulin

    2014-12-01

    Aqueous phase hydrodeoxygenation of lignin pyrolysis oil and related model compounds were investigated using four noble metals supported on activated carbon. The hydrodeoxygenation of guaiacol has three major reaction pathways and the demethylation reaction, mainly catalyzed by Pd, Pt and Rh, produces catechol as the products. The presence of catechol and guaiacol in the reaction is responsible for the coke formation and the catalysts deactivation. As expected, there was a significant decrease in the specific surface area of Pd, Pt and Rh catalysts during the catalytic reaction because of the coke deposition. In contrast, no catechol was produced from guaiacol when Ru was used so a completely hydrogenation was accomplished. The lignin pyrolysis oil upgrading with Pt and Ru catalysts further validated the reaction mechanism deduced from model compounds. Fully hydrogenated bio-oil was produced with Ru catalyst. Copyright © 2014 Elsevier Ltd. All rights reserved.

  15. Concentrated Aqueous Sodium Tosylate as Green Medium for Alkene Oxidation and Nucleophilic Substitution Reactions.

    Science.gov (United States)

    Sela, Tal; Lin, Xiaoxi; Vigalok, Arkadi

    2017-11-03

    A hydrotropic solution of highly concentrated sodium tosylate (NaOTs) can be used as a recyclable medium for the environmentally benign oxidation of conjugated alkenes with H 2 O 2 . Both uncatalyzed and metal-catalyzed reactions provided the corresponding oxidation products in higher yields than in pure water or many common organic solvents.

  16. Development of deuterium labeling method based on the heterogeneous platinum group metal-catalyzed C-H activation.

    Science.gov (United States)

    Sajiki, Hironao

    2013-01-01

    Deuterium (D) labeled compounds are utilized in various scientific fields such as mechanistic elucidation of reactions, preparation of new functional materials, tracers for microanalysis, deuterium labeled heavy drugs and so on. Although the H-D exchange reaction is a straightforward method to produce deuterated organic compounds, many precedent methods require expensive deuterium gas and/or harsh reaction conditions. A part of our leading research agendas is intended to the development of novel and functional heterogeneous platinum-group catalysts and the reclamation of unknown functionalities of existing heterogeneous platinum-group catalysts. During the course of the study, benzylic positions of substrates were site-selectively deuterated under mild and palladium-on-carbon (Pd/C)-catalyzed hydrogenation conditions in heavy water (D2O). Heat conditions promoted the H-D exchange reactivity and facilitated the H-D exchange reaction at not only the benzylic sites but also inactive C-H bonds and heterocyclic nuclei. It is noteworthy that platinum-on-carbon (Pt/C) indicated a quite high affinity toward aromatic nuclei, and the H-D exchange reaction was strongly enhanced by the use of Pt/C as a catalyst under milder conditions. The mixed use of Pd/C and Pt/C was found to be more efficient in the H-D exchange reaction compared to the independent use of Pd/C or Pt/C. Furthermore, simple alkanes could also be efficiently deuterated under rhodium-on-carbon (Rh/C)-catalyzed conditions. The use of ruthenium-on-carbon (Ru/C) enabled the regiospecific and efficient deuterium incorporation at α-positions of alcohols and results were applied as a regio- and stereoselective multi-deuteration method of sugar derivatives.

  17. Manipulating Micellar Environments for Enhancing Transition Metal-Catalyzed Cross-Couplings in Water at Room Temperature

    Science.gov (United States)

    Ghorai, Subir; Leong, Wendy Wen Yi; Taft, Benjamin R.; Krogstad, Daniel V.

    2012-01-01

    The remarkable effects of added salts on the properties of aqueous micelles derived from the amphiphile PTS are described. Most notably Heck reactions run in the presence of NaCl lead to couplings on aryl bromides in water at room temperature. Olefin cross- and ring-closing metathesis reactions run in the presence of small amounts of pH-lowering KHSO4 are also accelerated, another phenomenon that does not apply to typical processes in organic media. These salt effects allow, in general, for synthetically valuable C-C bond-forming processes to be conducted under environmentally benign conditions. Recycling of the surfactant is also demonstrated. PMID:21539384

  18. Emerging approaches for the synthesis of triazoles: beyond metal-catalyzed and strain-promoted azide-alkyne cycloaddition.

    Science.gov (United States)

    Lima, Carolina G S; Ali, Akbar; van Berkel, Sander S; Westermann, Bernhard; Paixão, Márcio W

    2015-07-11

    Metal-free 1,3-dipolar cycloaddition reactions have proven to be a powerful tool for the assembly of key heterocycles, in particular diversely functionalized 1,2,3-triazoles. A number of metal-free (3+2)-cycloaddition approaches have been developed up to date with the aim to circumvent the use of metal catalysts allowing these reactions to take place in biological systems without perturbation of the naturally occurring processes. This feature article specifically provides an overview of emerging metal-free synthetic routes, and their mechanistic features, in the formation of functionalized 1,2,3-triazoles.

  19. Nuclear excitations and reaction mechanisms. Report of progress, February 1, 1975--October 31, 1975

    International Nuclear Information System (INIS)

    1975-01-01

    Progress in the following areas of research is reported: Energies of giant isoscalar monopole and quadrupole excitations, energy-weighted sum rules, the random-phase approximation, Hartree-Fock calculations, spreading widths, physical consequences of the locality of current-density commutators and current-current sum rules. Electron-hydrogen scattering using the inhomogenous equation method; variational calculation of e - + H scattering using the symmetrized channel coupling array equation; K operators and unitary approximations for the 3-body problem; approximate calculation of model (d-p) and (dd) amplitudes and cross sections; multi-step processes in direct reactions; bound state calculations using the channel coupling array theory. Methods for determining nuclear charge distributions, relativistic effects in nuclei, dispersion corrections and recoil corrections to elastic electron scattering; unitarity of elastic scattering amplitudes; low energy theorems for two-photon processes; pion-exchange contributions to the charge density; recoil effects and energy-dependent Hamiltonians; pion-exchange contributions to two-photon processes; hypervirial theorems for the Dirac equation; Coulomb energies of nuclei. Pion-nucleus scattering, diagonalization of the Δ-(nucleon-hole) configurations, doorway states and doorway dominance, calculations for 4 He, discussion of experimental results

  20. Generation of Stoichiometric Ethylene and Isotopic Derivatives and Application in Transition Metal-Catalyzed Vinylation and Enyne Metathesis

    DEFF Research Database (Denmark)

    Min, Geanna; Bjerglund, Klaus Meier; Kramer, Søren

    2013-01-01

    labeled ethylene, from simple alkene precursors by using Ru catalysis. Applying a two-chamber reactor allows both the synthesis of ethylene and its immediate consumption in a chemical transformation permitting reactions to be performed with only stoichiometric amounts of this two carbon olefin...

  1. Investigations of nuclear structure and nuclear reactions induced by complex projectiles. Technical progress report, November 1, 1978-October 31, 1979. [Summaries of research activities at Washington Univ

    Energy Technology Data Exchange (ETDEWEB)

    Sarantites, D.G.

    1979-01-01

    Experimental research on nuclear structure and reactions both published and in progress is summarized. Included are fusion reactions, strongly damped heavy ion collisions, and nuclear structure at high angular momentum. A list of publications is included. (JFP)

  2. New Gateways to the Platinum Group Metal-Catalyzed Direct Deuterium-Labeling Method Utilizing Hydrogen as a Catalyst Activator.

    Science.gov (United States)

    Sawama, Yoshinari; Park, Kwihwan; Yamada, Tsuyoshi; Sajiki, Hironao

    2018-01-01

    Deuterium-labeled compounds are widely utilized in various scientific fields. We summarize the recent advances in the direct deuteration of sugar, saturated fatty acid, and arene derivatives using heterogeneous platinum group metal on carbon catalysts by our research group. Hydrogen gas is a key catalyst-activator to facilitate the present H-D exchange reactions. In this review, the direct activation method of catalysts using in situ-generated hydrogen based on the dehydrogenation of alcohols is introduced. The obtained multiple deuterium-labeled products, including bioactive compounds, are expected to contribute to the development of many scientific investigations.

  3. Orientation in metal-catalyzed hydrogen exchange between alkanes, naphthalene, or biphenyl and deuterium or deuterium oxide

    International Nuclear Information System (INIS)

    Long, M.A.; Moyes, R.B.; Wells, P.B.; Garnett, J.L.

    1978-01-01

    Hydrogen isotope exchange between deuterium gas and protium in hexane, pentane, 2-methyl-butane, 2-methylpentane, 3-methylpentane, 2,3-dimethylbutane, and 2,4-dimethylpentane has been catalyzed by clean platinum films (70--100 0 C). A selection of these reactions has been catalyzed by films of rhodium and iridium (typically -13 to -35 0 C). In all cases, multiple exchange occurred. Product analysis by mass and proton NMR spectroscopy showed that exchange in methylene and methine groups was more rapid than that in methyl groups. A similar orientation effect was observed in reactions over platinum powder but not over platinum-alumina. For exchange between deuterium oxide and hexane catalyzed by platinum films at 200 0 C, the rate of exchange in methyl groups exceeded that in methylene groups. It is proposed that preferential exchange in methylene and methine groups is normal behavior during alkane exchange with molecular deuterium over these platinum metals when their surfaces (i) are initially clean or (ii) contain several adjacent sites which are unperturbed by the presence of any electronegative adsorbed species. Preferential exchange in the methyl groups of hexane results from contamination of the surface by adsorbed D 2 O, OD, or O; this may be a geometric effect or an electronic effect, depending on the magnitude of the surface coverage of water, which is unknown. Orientation in the exchange between deuterium gas and naphthalene or biphenyl catalyzed by films of platinum and iridium does not differ from that observed in exchanges where the isotope source is deuterium oxide or deuterated solvent, but the M value calculated for exchange in naphthalene is higher than that previously reported

  4. Metal-Catalyzed Oxidation of Protein Methionine Residues in Human Parathyroid Hormone (1-34): Formation of Homocysteine and a Novel Methionine-Dependent Hydrolysis Reaction

    Science.gov (United States)

    Mozziconacci, Olivier; Ji, Junyan A.; Wang, Y. John; Schöneich, Christian

    2013-01-01

    The oxidation of PTH(1-34) catalyzed by ferrous ethylenediaminetetraacetic acid (EDTA) is site-specific. The oxidation of PTH(1-34) is localized primarily to the residues Met[8] and His[9]. Beyond the transformation of Met[8] and His[9] into methionine sulfoxide and 2-oxo-histidine, respectively, we observed a hydrolytic cleavage between Met[8] and His[9]. This hydrolysis requires the presence of FeII and oxygen and can be prevented by diethylenetriaminepentaacetic acid (DTPA) and phosphate buffer. Conditions leading to this site-specific hydrolysis also promote the transformation of Met[8] into homocysteine, indicating that the hydrolysis and transformation of homocysteine may proceed through a common intermediate. PMID:23289936

  5. Highly Functionalized and Potent Antiviral Cyclopentane Derivatives Formed by a Tandem Process Consisting of Organometallic, Transition-Metal-Catalyzed, and Radical Reaction Steps

    Czech Academy of Sciences Publication Activity Database

    Jagtap, Pratap; Ford, Leigh Robert; Deister, E.; Pohl, Radek; Císařová, I.; Hodek, Jan; Weber, Jan; Mackman, R.; Bahador, G.; Jahn, Ullrich

    2014-01-01

    Roč. 20, č. 33 (2014), s. 10298-10304 ISSN 0947-6539 R&D Projects: GA ČR GA203/09/1936 Institutional support: RVO:61388963 Keywords : antiviral activity * cyclopentanes * isomerization * organic synthesis * radicals Subject RIV: CC - Organic Chemistry Impact factor: 5.731, year: 2014

  6. Transition-Metal-Catalyzed Chain-Growth Polymerization of 1,4-Diethynylbenzene into Microporous Crosslinked Poly(phenylacetylene)s: the Effect of Reaction Conditions

    Czech Academy of Sciences Publication Activity Database

    Slováková, E.; Zukal, Arnošt; Brus, Jiří; Balcar, Hynek; Brabec, Libor; Bondarev, D.; Sedláček, J.

    2014-01-01

    Roč. 215, č. 19 (2014), s. 1855-1869 ISSN 1022-1352 R&D Projects: GA ČR(CZ) GAP108/11/1661 Institutional support: RVO:61388955 ; RVO:61389013 Keywords : Conjugated microporous polymers * Conjugated polymers * Microporous organic polymers Subject RIV: CF - Physical ; Theoretical Chemistry; CD - Macromolecular Chemistry (UMCH-V) Impact factor: 2.616, year: 2014

  7. Highly functionalized and potent antiviral cyclopentane derivatives formed by a tandem process consisting of organometallic, transition-metal-catalyzed, and radical reaction steps.

    Science.gov (United States)

    Jagtap, Pratap R; Ford, Leigh; Deister, Elmar; Pohl, Radek; Císařová, Ivana; Hodek, Jan; Weber, Jan; Mackman, Richard; Bahador, Gina; Jahn, Ullrich

    2014-08-11

    A simple modular tandem approach to multiply substituted cyclopentane derivatives is reported, which succeeds by joining organometallic addition, conjugate addition, radical cyclization, and oxygenation steps. The key steps enabling this tandem process are the thus far rarely used isomerization of allylic alkoxides to enolates and single-electron transfer to merge the organometallic step with the radical and oxygenation chemistry. This controlled lineup of multiple electronically contrasting reactive intermediates provides versatile access to highly functionalized cyclopentane derivatives from very simple and readily available commodity precursors. The antiviral activity of the synthesized compounds was screened and a number of compounds showed potent activity against hepatitis C and dengue viruses. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Theory of nuclear structure and reactions. Annual technical progress report, April 1, 1984-March 31, 1985

    International Nuclear Information System (INIS)

    Macfarlane, M.H.; Serot, B.D.

    1985-01-01

    In the period covered by this report, work focused on five main areas: (1) relativistic effects in intermediate-energy nuclear reactions; (2) the role of quarks and gluons in nuclear physics; (3) quantum hadrodynamics and relativistic nuclear mean-field theory; (4) structure and reaction effects in intermediate-energy nuclear reactions; and (5) weak and electromagnetic interactions in nuclei. Results and publications in these areas are summarized. Publications are listed

  9. Vitamin D receptor expression levels determine the severity and complexity of disease progression among leprosy reaction patients

    Directory of Open Access Journals (Sweden)

    D. Mandal

    2015-07-01

    Full Text Available We studied the roles of vitamin D and its receptor, VDR, in the progression of leprosy. The majority of individuals with leprosy from Kolkata, India, with a type 1 or type 2 reaction have low levels of vitamin D3 in serum samples. Interestingly, individuals with a type 2 reaction associated with neuritis/erythema nodosum leprosum had very low VDR mRNA expression levels, ranging from 5% to 10%, compared to that of healthy control subjects; these patients also had a high bacilli index, ranging from 3+ to 5+. This is the first report to indicate that VDR expression levels may determine the complexity and severity of the progression of leprosy.

  10. Light particle emission measurements in heavy ion reactions: Progress report, June 1, 1987-May 31, 1988

    International Nuclear Information System (INIS)

    Petitt, G.A.

    1988-01-01

    This paper discusses work on heavy ion reactions done at Georgia State University. Topics and experiments discussed are: energy division in damped reactions between 58 Ni projectiles and 165 Ho and 58 Ni targets using time-of-flight methods; particle-particle correlations; and development works on the Hili detector system. 10 refs., 9 figs

  11. Nuclear excitations and reaction mechanisms. Progress report, 1 November 1979-30 September 1980

    International Nuclear Information System (INIS)

    1980-01-01

    Among the topics investigated were the following: photon scattering and consistency condition between seagull quadrupole terms and the absorption sum rule; Raman scattering to negative-parity states; nonlocal terms due to exchange and retardation effects in charge-transfer reactions; consistency and meaning of various approximate channel coupling array equations; derivation of equations used in empirical nuclear reaction analyses; multicluster, n-particle scattering theory; converged molecular bound state calculations; consistency of approximate channel coupling array equations; derivations of equations used in empirical nuclear reaction analyses; and WKB-type approximation in angular momenta for central potentials. References to publications are given

  12. Kinetics of elementary atom and radical reactions. Progress report, December 1, 1981-November 30, 1982

    International Nuclear Information System (INIS)

    Gordon, R.J.

    1982-01-01

    Research projects discussed include: the branching ratio for abstraction vs. exchange in the reaction D + HCl; kinetics of O + H 2 ; energy storage in polyatomic molecules; and optoacoustic measurements of ir absorption and relaxation in large molecules

  13. Pulse radiolysis studies of fast reactions in molecular systems. Progress report, November 1976--October 1977

    International Nuclear Information System (INIS)

    Dorfman, L.M.

    1977-01-01

    Results from research in the following two areas are given: formation, properties, and reactivity of molecular ionic species in irradiated liquid systems; and pulse radiolysis of elementary reactions in protein function

  14. Progress in biocatalysis with immobilized viable whole cells: systems development, reaction engineering and applications

    Czech Academy of Sciences Publication Activity Database

    Polakovič, M.; Švitel, J.; Bučko, M.; Filip, J.; Neděla, Vilém; Ansorge-Schumacher, M.B.; Gemeiner, P.

    2017-01-01

    Roč. 39, č. 5 (2017), s. 667-683 ISSN 0141-5492 Institutional support: RVO:68081731 Keywords : biocatalysis * immobilization methods * immobilized whole-cell biocatalyst * multienzyme cascade reactions * process economics * reaction engineering Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering OBOR OECD: Bioprocessing technologies (industrial processes relying on biological agents to drive the process) biocatalysis, fermentation Impact factor: 1.730, year: 2016

  15. Studies of heavy ion reactions and transuranic nuclei. Progress report, August 1, 1979-July 31, 1980

    International Nuclear Information System (INIS)

    Huizenga, J.R.

    1980-07-01

    The study of heavy-ion reaction mechanisms at the SuperHILAC and LAMPF is reported. Preprints of five articles and manuscripts of four recent conference papers are given, along with complete citations of publications and a list of personnel. Significant work was performed in the following areas: the bombarding energy dependence of the 209 Bi + 136 Xe reaction; the fragment yields for specific Z and A for projectile-like fragments produced in the reaction of 8.3-MeV/u 56 Fe ions with targets of 56 Fe, 165 Ho, 209 Bi, and 238 U; and time distributions of fragments from delayed fission after muon capture for muonic 235 U, 238 U, 237 Np, 239 Pu, and 242 Pu

  16. Reactions between rocks and the hydroxides of calcium, sodium and potassium: progress report no. 1

    International Nuclear Information System (INIS)

    Van Aardt, J.H.P.; Visser, S.

    1982-01-01

    The reaction between the hydroxides of calcium, sodium and potassium, and clay minerals, feldspars, and some rocks (aggregates for use in concrete) was investigated. The reaction products were examined by means of x-ray diffraction and chemical analysis. The solid reaction products identified were hydrated calcium silicates,hydrated calcium aluminates, and hydrated calcium alumina silicates. It was found that, in the presence of water, calcium hydroxide liberated alkali into solution if the rocks and minerals contained alkali metals in their structure. Two crystalline hydrated sodium calcium silicates (12A and 16A) were prepared in the system Na 2 O-CaO-SiO 2 -H 2 O at 80 degrees Celsius. The one compound (12A) was also observed when sodium hydroxide plus calcium hydroxide and water reacted with silica- or silicate-containing rocks

  17. Pulse radiolysis studies of fast reactions in molecular systems. Progress report, November 1979-September 1980

    International Nuclear Information System (INIS)

    Dorfman, L.M.

    1980-01-01

    The rates of elementary chemical reactions in irradiated solutions are being studied by observation of reactive intermediates using the pulse radiolysis technique. Optical absorption spectra of these transient species, which determine the course of the chemistry, are being obtained. The types of reactive species currently of interest are organic molecule ions (both cations and anions) and radical ions, and transition metal carbonyl radicals in solution. Since reaction is initiated by a pulse of high energy electrons, our investigations inherently relate to radiation chemical systems. The information obtained is, however, also of interest in various areas of organic reaction kinetics in which ionic species are known to play a central role. The reactivity of the transition metal carbonyl radicals is of interest in the area of homogeneous catalysis. Current activities involve: spectra and reactivities of transition metal carbonyl radicals of the type M(CO) 5 ; reactivity of organic ionic species (including carbocations and carbanions) in irradiated solutions

  18. Studies of nuclear reactions at very low energies: Annual progress report

    International Nuclear Information System (INIS)

    Cecil, F.E.

    1988-01-01

    The main thrust of the research program was directed at the acquisition, installation and initial operation of the General Ionex Model 1545 charged particle accelerator which will be used in the subsequent reaction cross section measurements. The initial operation of the accelerator has been quite successful, with all of the crucial characteristics meeting or exceeding design specifications. We have made preliminary measurements of the reactions 12C(rho,γ)13N 11 B(rho,γ) 12 C, and D(rho,γ) 3 He as tests of total system integrity and have carried out studies of the interaction of proton and alpha particle beams with deuterated-polyethylene targets. 11 refs

  19. A study of catalysts and mechanisms in synthesis reactions. Progress report, January 1994--December 1994

    Energy Technology Data Exchange (ETDEWEB)

    Lunsford, J.H.

    1994-08-01

    Surface-generated gas-phase radicals, which are the subject of this study, may function as important intermediates in several important partial and complete oxidation reactions. Two examples are the role of CH{sub 3} radicals in the oxidative coupling of CH{sub 4} and the role of OH radicals in the catalytic combustion of CH{sub 4}. Although the gas phase chemistry of simple hydrocarbon radicals is reasonably well understood, very little is known about the reactions that occur between these radicals and metal oxide surfaces. Moreover, the formation of hydroxyl radicals over oxides is a largely unexplored area of catalysis. Recent work in the laboratory has been devoted to the reactions of methyl radicals with reactive metal oxides, and the production of hydroxyl radicals under rate limiting conditions. This paper describes reactions of CH{sub 3} radicals with metal oxides; catalytic conversion of CH{sub 3} radicals to CH{sub 3}OH and HCHO; identification of surface-generated benzyl radicals; and formation of OH radicals under rate limiting conditions.

  20. Theoretical studies in nuclear reaction and nuclear structure. Progress report, August 1, 1977--July 31, 1978

    International Nuclear Information System (INIS)

    MacDonald, W.M.; Redish, E.F.

    1978-01-01

    The research program covers four major areas of nuclear theory: reaction theory including both few-body and many-body systems, intermediate energy reactions including nucleon-nucleon processes, pion physics, and nuclear dynamics. In many-body reaction theory the major achievement has been the development of a unitary and connected Hamiltonian formulation adapted to approximate calculations which include 3-body channels. A new analysis of isobaric analog states attracts high resolution data parameters which characterize these states and provide information about the nucleon-nucleon interaction. The multiple-scattering analysis of approximately GeV proton-nucleus scattering has been validated by agreement in absolute magnitude with new experimental data, and contributions of a nucleon isobar were identified. The Banerjee-Cammarata dynamical theory of the pion-nucleon interaction has been found to satisfy several independent tests of dispersion relations as well as predicting experimental phase shifts. In nuclear dynamics a new S-matrix theory of time-dependent Hartree-Fock promises to provide a new approach to heavy-ion reactions. A list of publications is included

  1. Kinetics and reversibility of radionuclide sorption reactions with rocks. Progress report for fiscal year 1978

    International Nuclear Information System (INIS)

    Barney, G.S.; Anderson, P.D.

    1978-01-01

    Sorption reactions of environmentally significant radionuclides with rocks from proposed waste repository sites were examined. The kinetics and reversibility of sorption were studied by measuring the distribution of radioactive tracers between synthetic groundwaters and crushed basalt, granite, and argillite in batch experiments. The initial rapid sorption reaction is followed by a slow reaction which results from changes in the composition of the rock surface and bulk solution. Equilibrium concentrations of radionuclides were not reached even after 91 days. Dissolution of some rock components is also incomplete after this time. A relatively large amount of silica is dissolved in groundwaters contacted with basalt due to dissolution of the glassy phase of the basalt sample. This silica appears to increase the solubility of plutonium and americium. Artificially weathering basalt greatly increases the sorption capacity for each of the radionuclides studied. Weathering of granite had no observable effect on sorption. However, weathered argillite sorbs cesium, plutonium, and americium more strongly than unweathered argillite. Several irreversible sorption reactions were identified. Cesium is irreversibly sorbed on granite and ruthenium is irreversibly sorbed on basalt, granite, and argillite. Strontium and neptunium sorption are reversible for each rock type

  2. Research concerning ionic and free radical reactions in radiation chemistry. Progress report, September 15, 1976--September 15, 1977

    International Nuclear Information System (INIS)

    Williams, T.F.

    1977-01-01

    Progress is reported on ESR studies of fluorocarbon radicals and intermediate radicals. A detailed study was made of the dimethyl, diethyl, and di-n-propyl carbonates. Studies were continued on hydrogen-atom abstraction reactions at low temperatures with view to evaluating the contribution from quantum-mechanical tunneling. Detection of the transient dimer radical anion of acetonitrile in the upper crystalline phase at -50 0 C is reported. Abstracts of current reports are included on electron attachment to fluorocarbons hydrogen atom abstraction by methyl radicals. EPR spectra of the tetrafluoroethylene radical anion, and addition of tetrafluoroethylene to the tetrafluoroethylene radical anion

  3. Light particle emission measurements in heavy ion reactions: Progress report, June 1, 1986-May 31, 1987

    International Nuclear Information System (INIS)

    Petitt, G.A.

    1987-01-01

    During the past year we have completed our work on neutron emission in coincidence with fission fragments from the 158 Er system. In addition to this we have completed preliminary analysis of our results on neutron emission from products of damped reactions between 58 Ni and 165 Ho at 930 MeV. Two experiments were planned for the present contract period as discussed in our proposal for 1986-87. One of these, to measure the mass and charge distributions from projectile-like fragments (PLF) in the reactions 58 Ni + 165 Ho and 58 Ni + 58 Ni using the time-of-flight facility at the HHIRF has been successfully completed. The other, to measure momentum correlations between neutrons and charged particles produced in central collisions between 32 S + 197 Au is scheduled to be run in mid-February. 14 refs., 4 figs

  4. Progress toward chemcial accuracy in the computer simulation of condensed phase reactions

    Energy Technology Data Exchange (ETDEWEB)

    Bash, P.A.; Levine, D.; Hallstrom, P. [Argonne National Lab., IL (United States); Ho, L.L. [Yale Univ., New Haven, CT (United States). Dept. of Physics; Mackerell, A.D. Jr. [Univ. of Maryland, Baltimore, MD (United States). Dept. of Pharmaceutical Sciences

    1996-03-01

    A procedure is described for the generation of chemically accurate computer-simulation models to study chemical reactions in the condensed phase. The process involves (1) the use of a coupled semiempirical quantum and classical molecular mechanics method to represent solutes and solvent, respectively; (2) the optimization of semiempirical quantum mechanics (QM) parameters to produce a computationally efficient and chemically accurate QM model; (3) the calibration of a quantum/classical microsolvation model using ab initio quantum theory; and (4) the use of statistical mechanical principles and methods to simulate, on massively parallel computers, the thermodynamic properties of chemical reactions in aqueous solution. The utility of this process is demonstrated by the calculation of the enthalpy of reaction in vacuum and free energy change in aqueous solution for a proton transfer involving methanol, methoxide, imidazole, and imidazolium, which are functional groups involved with proton transfers in many biochemical systems. An optimized semiempirical QM model is produced, which results in the calculation of heats of formation of the above chemical species to within 1.0 kcal/mol of experimental values. The use of the calibrated QM and microsolvation QM/MM models for the simulation of a proton transfer in aqueous solution gives a calculated free energy that is within 1.0 kcal/mol (12.2 calculated vs. 12.8 experimental) of a value estimated from experimental pKa`s of the reacting species.

  5. Progress Report, Nuclear Reaction Data Group at ATOMKI (NRDC Meeting, 16-19 April 2012)

    International Nuclear Information System (INIS)

    Tarkanyi, F.; Takacs, S.; Ditroi, F.; Szelecsenyi, F.; Kovacs, Z.; Szucs, Z.; Kiraly, B.; Csikai, J.

    2012-01-01

    The research program of the Atomki Nuclear Reaction Data Group consists of measurement, compilation, evaluation and application of low and medium energy charged particle induced nuclear reaction data. The work is done in international collaborations. The experiments, data compilation and data evaluation are mainly connected to running international projects. Every day applications at ATOMKI and collaborating institutes also initiate data measurements. One initiative is the systematic experimental study of activation cross sections of proton and deuteron induced reactions for comparison with the results of modern theoretical codes to establish a more reliable experimental database and to prepare of a general use activation file up to 100 MeV protons and 50 MeV deuterons. Second program is the systematic investigation of nuclear data for production of radioisotopes candidate for use in radiotherapy. The staff members are active referrers of different journals and conference proceedings reporting nuclear data related works (Applied Radiation and Isotopes, Journal of Radioanalytical and nuclear Chemistry, Nuclear Instruments and Methods, Annals of Nuclear Energy, etc)

  6. Japan Nuclear Reaction Data Center (JCPRG), Faculty of Science, Hokkaido University, Steering Committee. Progress report

    International Nuclear Information System (INIS)

    2009-01-01

    The Japan Nuclear Reaction Data center (JCPRG) started at Apri1, 2007. The center has three main tasks: 1) database activities, 2) data evaluations and 3) Asian network activities. We are continuing data compilation for charged-particle nuclear reaction data obtained in Japan. We are scanning 17 journals for Japanese charged-particle and photo-nuclear nuclear reaction data compilation: PR/C, PRL, PL/B, EPJ/A, NST, NIM/A, NIM/B, JPJ, ARI, RCA, JRN, KPS, NSTS, CPL, ZP/A, PAN and JNRS. After Memo CP-E No.136, we newly found up 6 mistakes (Memo CP-E No.137) of the CINDA master file in bibliographic information. These 2 memos were reviewed at NEA Data Bank (A45, NRDC 2008). Cooperating with them, we verified error propagation from EXFOR to CINDA. Actually that had happened in the 34 lines (Memo CP-D No.561). Current EXFOR or NRDF Format is specific to itself. We suppose that a nuclear data exchange format of the next generation should be defined based on XML. If the exchange format was redefined based on XML, the data available from libraries (EXFOR, NRDF, etc.) would enable us to have wider common bases for our various software applications. We highly appreciate the presentation of Viktor Zerkin and discussions held in Sapporo, on March, 2009. To achieve an exchange format agreed, we will continue to gain various experiences with using XML and to apply the IntelligentPad technology for EXFOR systems

  7. Recent progress in the development of a polarized proton target for reactions with radioactive ion beams

    International Nuclear Information System (INIS)

    Urrego-Blanco, J.P.; Bingham, C.R.; Brandt, B. van den; Galindo-Uribarri, A.; Gomez del Campo, J.; Hautle, P.; Konter, J.A.; Padilla-Rodal, E.; Schmelzbach, P.A.

    2007-01-01

    Polarization observables in nuclear reactions with stable beams have provided important information concerning structural properties of nuclei and reaction mechanisms and hold great promise in the context of exotic nuclei. We report on the development of a polarized target based on plastic foils of 20-200 μm thickness to be used with radioactive ion beams. The operation of such a target requires a moderately high magnetic field and very low temperatures. The plastic foil is placed inside a chamber attached to the mixing chamber of a 3 He- 4 He dilution refrigerator. Cooling of the foil is achieved via a superfluid film of 4 He that can be supplied through two capillaries. The chamber has two thin, highly uniform silicon nitride windows. An NMR coil is attached to the target to monitor the polarization. Results of a first test to characterize the target system, using the elastic scattering of 38 MeV 12 C by protons in inverse kinematics are presented

  8. Measurement of alkali-silica reaction progression by ultrasonic waves attenuation

    International Nuclear Information System (INIS)

    Saint-Pierre, Francois; Rivard, Patrice; Ballivy, Gerard

    2007-01-01

    Development of non-destructive methods, developed specifically for assessing the damage induced by alkali-silica reaction (ASR) in concrete structures, is needed in order to carry out a systematic evaluation of the concrete condition. The aim of this study is to monitor the evolution of the ASR-damage in laboratory with concrete samples with ultrasonic pulse velocity and attenuation of ultrasonic waves methods. For this study, results of both methods were compared with expansion and mass variation. One reactive concrete mixture was made with reactive aggregate, and one other mixture, incorporating non-reactive aggregate, was made as a control. Specimens were kept at 38 deg. C in a 1 mol l -1 NaOH solution to accelerate the reaction. Attenuation of transmitted ultrasonic waves appeared to be more appropriate for the evaluation of ASR-damage compared with pulse velocity. The attenuation of accelerated reactive concrete cylinders increased by 90% after 1 year while it increased by 40% for the non-reactive concrete used as a control. Major part of the attenuation increase in the non-reactive concrete is due to liquid absorption. This work suggests that in-situ non-destructive techniques based on ultrasonic wave attenuation, like ultrasonic attenuation tomography, should be developed in order to evaluate the development of ASR in concrete structures. Petrographic examination confirmed that damage to concrete is associated with ASR

  9. Investigation of the structure of photosynthetic reaction centers. Progress report, June 1, 1981-April 1, 1982

    International Nuclear Information System (INIS)

    van Willigen, H.

    1982-04-01

    The investigation is concerned with the application of Electron Nuclear Double Resonance (ENDOR) and Electron Nuclear Triple Resonance (TRIPLE) in the study of the photo excited triplet state of photosynthetic resonance methods hyperfine interactions between unpaired electrons and nuclear spins can be measured, giving an insight in the electronic and geometric structure of paramagnetic systems. During this initial phase of the project, research has focused on the following areas. (1) Instrumental aspects associated with the application of ENDOR and TRIPLE on the photo excited triplets randomly oriented in solid solution. (2) Exploration of the conditions required for these studies employing ground state triplet systems. (3) Study of photo excited triplet states of model systems such as naphthylene, zinc and magnesium tetraphenyl-porphyrin in polymethylmethacrylate or polycrystalline benzophenone. Progress made in these areas is discussed

  10. Electron transfer reactions in microporous solids. Progress report, September 1990--January 1993

    Energy Technology Data Exchange (ETDEWEB)

    Mallouk, T.E.

    1993-01-01

    Basic thrust the research program involves use of microporous solids (zeolites, clays, layered and tunnel structure oxide semiconductors) as organizing media for artificial photosynthetic systems. Purpose of the microporous solid is twofold. First, it induces spatial organization of photoactive and electroactive components (sensitizers, semiconductor particles, electron relays, and catalysts) at the solid-solution interface, enhancing the quantum efficiency of charge separation and separating physically the ultimate electron donor and acceptor in the electron transport chain. Second, since the microcrystalline solid admits only molecules of a certain charge and size, it is possible to achieve permanent charge separation by sieving chemical photoproducts (e.g., H{sub 2} and I{sub 3}{sup {minus}}, or H{sub 2} and O{sub 2)} from each other. Spectroscopic and electrochemical methods are used to study the kinetics of electron transfer reactions in these hybrid molecular/solid state assemblies.

  11. Development of an apparatus to study chemical reactions at high temperature - a progress report

    Energy Technology Data Exchange (ETDEWEB)

    Sturzenegger, M.; Schelling, Th.; Steiner, E.; Wuillemin, D. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1999-08-01

    TREMPER is an apparatus that was devised to study kinetic and thermodynamic aspects of high-temperature reactions under concentrated solar irradiation. The design allows investigations on solid or liquid samples under inert or reactive atmospheres. The working temperature is adjustable; the upper limit that has yet been reached is about 1900 K. TREMPER will facilitate chemical reactivity studies on a temperature level that is difficult to access by other means. First experiments were conducted to study the decomposition of manganese oxide MnO{sub 2}. Chemical analysis of exposed samples confirmed that the parent MnO{sub 2} was decomposed to mixtures of Mn O and Mn{sub 3}O{sub 4}. The amount of Mn O ranged from 60 mol-% in air to 86 mol-% under inert atmosphere. (author) 1 fig., 1 tab., 2 refs.

  12. Real-time monitoring of the progress of polymerization reactions directly on surfaces at open atmosphere by ambient mass spectrometry.

    Science.gov (United States)

    Nørgaard, Asger W; Vaz, Boniek G; Lauritsen, Frants R; Eberlin, Marcos N

    2010-12-15

    The progress of an on-surface polymerization process involving alkyl and perfluoroalkyl silanes and siloxanes was monitored in real-time via easy ambient sonic spray ionization mass spectrometry (EASI-MS). When sprayed on surfaces, the organosilicon compounds present in commercially available nanofilm products (NFPs) react by condensation to form a polymeric coating. A NFP for coating of floor materials (NFP-1) and a second NFP for coating tiles and ceramics (NFP-2) were applied to glass, filter paper or cotton surfaces and the progress of the polymerization was monitored by slowly scanning the surface. Via EASI(+)-MS monitoring, significant changes in the composition of hydrolysates and condensates of 1H,1H,2H,2H-perfluorooctyl triisopropoxysilane (NFP-1) and hexadecyl triethoxysilane (NFP-2) were observed over time. The abundances of the hydrolyzed species decreased compared with those of the non-hydrolysed species for both NFP-1 and NFP-2 and the heavier oligomers became relatively more abundant over a period of 15-20 min. A similar tendency favouring the heavier oligomers was observed via EASI(-)-MS. This work illustrates the potential of ambient mass spectrometry for the direct monitoring of polymerization reactions on surfaces. Copyright © 2010 John Wiley & Sons, Ltd.

  13. Sequential decarboxylative azide–alkyne cycloaddition and dehydrogenative coupling reactions: one-pot synthesis of polycyclic fused triazoles

    Directory of Open Access Journals (Sweden)

    Kuppusamy Bharathimohan

    2014-12-01

    Full Text Available Herein, we describe a one-pot protocol for the synthesis of a novel series of polycyclic triazole derivatives. Transition metal-catalyzed decarboxylative CuAAC and dehydrogenative cross coupling reactions are combined in a single flask and achieved good yields of the respective triazoles (up to 97% yield. This methodology is more convenient to produce the complex polycyclic molecules in a simple way.

  14. Pathology and polymerase chain reaction detection of ovine progressive pneumonia (maedi) cases in slaughtered sheep in India.

    Science.gov (United States)

    Singh, Rahul; Kumar, Pawan; Singh, Rajendra; Dhama, Kuldeep; Kumari, Swati; Yadav, Jay Prakash; Kashyap, Gayatri; Singh, Karam Pal; Singh, Vidya; Sahoo, Monalisa

    2017-11-01

    The small ruminant lentiviruses are known to cause maedi-visna (MV) and caprine arthritis - encephalitis in sheep and goats, typically affecting joints, udder, lungs, and the central nervous system. The diagnosis usually involves serology, clinical signs, immunohistochemistry, and polymerase chain reaction (PCR). In the present study, the histopathologically positive pneumonia cases of MV were confirmed by PCR in lung tissue probably for the first time in India. A total of 888 lungs of adult sheep, aged between 2 and 5 years, were screened during slaughter, of which 121 were found to have pneumonic lesions. The tissues from each pneumonic lung including associated lymph nodes were collected in 10% neutral buffered formalin for histopathology. The frozen tissues of the same were also collected and stored at -20°C for PCR confirmation. Three of 121 cases of pneumonic lungs of sheep revealed gross and histopathological lesions suggestive of maedi or ovine progressive pneumonia infection. These 3 cases were further confirmed by PCR technique that amplified 291-base pair DNA in the long terminal repeat sequence of MV provirus. This study suggests the low occurrence of MV virus (MVV) infection in India in naturally affected sheep based on pathomorphological lesions and using the molecular tool of PCR detection of the virus in tissues. Further, a combination of pathomorphology or/and PCR testing might be optimal for detecting the animals infected with MVV.

  15. Pathology and polymerase chain reaction detection of ovine progressive pneumonia (maedi cases in slaughtered sheep in India

    Directory of Open Access Journals (Sweden)

    Rahul Singh

    2017-11-01

    Full Text Available Aim: The small ruminant lentiviruses are known to cause maedi-visna (MV and caprine arthritis - encephalitis in sheep and goats, typically affecting joints, udder, lungs, and the central nervous system. The diagnosis usually involves serology, clinical signs, immunohistochemistry, and polymerase chain reaction (PCR. In the present study, the histopathologically positive pneumonia cases of MV were confirmed by PCR in lung tissue probably for the first time in India. Materials and Methods: A total of 888 lungs of adult sheep, aged between 2 and 5 years, were screened during slaughter, of which 121 were found to have pneumonic lesions. The tissues from each pneumonic lung including associated lymph nodes were collected in 10% neutral buffered formalin for histopathology. The frozen tissues of the same were also collected and stored at -20°C for PCR confirmation. Results: Three of 121 cases of pneumonic lungs of sheep revealed gross and histopathological lesions suggestive of maedi or ovine progressive pneumonia infection. These 3 cases were further confirmed by PCR technique that amplified 291-base pair DNA in the long terminal repeat sequence of MV provirus. Conclusion: This study suggests the low occurrence of MV virus (MVV infection in India in naturally affected sheep based on pathomorphological lesions and using the molecular tool of PCR detection of the virus in tissues. Further, a combination of pathomorphology or/and PCR testing might be optimal for detecting the animals infected with MVV.

  16. Reactions of charged and neutral recoil particles following nuclear transformations. Progress report No. 11, September 1976--August 1977

    International Nuclear Information System (INIS)

    Ache, H.J.

    1977-09-01

    The status of the following programs is reported: study of the stereochemistry of halogen atom reactions produced via (n,γ) nuclear reactions with diastereomeric molecules in the condensed phase; decay-induced labelling of compounds of biochemical interest; reactions of energetic tritium species in graphite; and positron lifetime measurements in γ-irradiated organic solids

  17. NMR for direct determination of K(m) and V(max) of enzyme reactions based on the Lambert W function-analysis of progress curves.

    Science.gov (United States)

    Exnowitz, Franziska; Meyer, Bernd; Hackl, Thomas

    2012-03-01

    (1)H NMR spectroscopy was used to follow the cleavage of sucrose by invertase. The parameters of the enzyme's kinetics, K(m) and V(max), were directly determined from progress curves at only one concentration of the substrate. For comparison with the classical Michaelis-Menten analysis, the reaction progress was also monitored at various initial concentrations of 3.5 to 41.8mM. Using the Lambert W function the parameters K(m) and V(max) were fitted to obtain the experimental progress curve and resulted in K(m)=28mM and V(max)=13μM/s. The result is almost identical to an initial rate analysis that, however, costs much more time and experimental effort. The effect of product inhibition was also investigated. Furthermore, we analyzed a much more complex reaction, the conversion of farnesyl diphosphate into (+)-germacrene D by the enzyme germacrene D synthase, yielding K(m)=379μM and k(cat)=0.04s(-1). The reaction involves an amphiphilic substrate forming micelles and a water insoluble product; using proper controls, the conversion can well be analyzed by the progress curve approach using the Lambert W function. Copyright © 2011. Published by Elsevier B.V.

  18. Single particle tracking-based reaction progress kinetic analysis reveals a series of molecular mechanisms of cetuximab-induced EGFR processes in a single living cell.

    Science.gov (United States)

    Kim, Do-Hyeon; Kim, Dong-Kyun; Zhou, Kai; Park, Soyeon; Kwon, Yonghoon; Jeong, Min Gyu; Lee, Nam Ki; Ryu, Sung Ho

    2017-07-01

    Cellular processes occur through the orchestration of multi-step molecular reactions. Reaction progress kinetic analysis (RPKA) can provide the mechanistic details to elucidate the multi-step molecular reactions. However, current tools have limited ability to simultaneously monitor dynamic variations in multiple complex states at the single molecule level to apply RPKA in living cells. In this research, a single particle tracking-based reaction progress kinetic analysis (sptRPKA) was developed to simultaneously determine the kinetics of multiple states of protein complexes in the membrane of a single living cell. The subpopulation ratios of different states were quantitatively (and statistically) reliably extracted from the diffusion coefficient distribution rapidly acquired by single particle tracking at constant and high density over a long period of time using super-resolution microscopy. Using sptRPKA, a series of molecular mechanisms of epidermal growth factor receptor (EGFR) cellular processing induced by cetuximab were investigated. By comprehensively measuring the rate constants and cooperativity of the molecular reactions involving four EGFR complex states, a previously unknown intermediate state was identified that represents the rate limiting step responsible for the selectivity of cetuximab-induced EGFR endocytosis to cancer cells.

  19. Studies of complex fragment emission in heavy ion reactions. Progress report, January 1, 1993 - September 1, 1995

    International Nuclear Information System (INIS)

    Charity, R.J.; Sobotka, L.G.

    1995-01-01

    This work involves the study of low and intermediate energy heavy-ion nuclear reactions. This work has two foci. First, the authors desired to learn about the properties of both nuclei and nuclear matter under abnormal conditions. Their efforts towards this end run abreast of those for their second focus which is the study of the relevant reaction mechanisms. The two objectives are inexorably linked because their experimental laboratory for studying nuclear properties is a dynamic one. Their task is to answer the questions of how nuclear and nuclear matter properties are reflected in the dynamics of the reactions. The second objective also has great intrinsic value in that they can anticipate improving upon their understanding of the reaction mechanism themselves and therefore to the response characteristics of finite, perhaps non-equilibrium, strongly interacting systems. The program has been: to study the dynamics of fusion reactions, specifically the dynamics of energy, mass, and angular momentum deposition. This work includes reactions near the Coulomb barrier, where fusion dominates the reaction cross section as well as higher energies where incomplete fusion reactions are the primary reactions. This includes the dynamics of fission, still the premier example of collective nuclear motion, as a function of excitation, spin, mass, and mass asymmetry. The authors push these kinds of studies into the intermediate energy domain, and where novel reaction scenarios are predicted. They have studied very central and peripheral collisions between very massive nuclei, and simplified projectile fragmentation reactions utilizing medium to light mass projectiles. The study of central collisions has shown us the importance of collective expansion. The study of peripheral collisions between very heavy nuclei has demonstrated the importance of dynamical production of fragments from the neck region

  20. Rapid disease progression in human immunodeficiency virus type 1-infected individuals with adverse reactions to trimethoprim-sulfamethoxazole prophylaxis

    NARCIS (Netherlands)

    Veenstra, J.; Veugelers, P. J.; Keet, I. P.; van der Ven, A. J. A. M.; Miedema, F.; Lange, J. M.; Coutinho, R. A.

    1997-01-01

    We studied the relation between the occurrence of adverse reactions to trimethoprim-sulfamethoxazole (TMP-SMZ) prophylaxis and the subsequent course of human immunodeficiency virus (HIV) infection in a cohort of homosexual men. Adverse reactions to TMP-SMZ were associated with a more rapid

  1. Synthesis and spectral characterization of 2,2-diphenylethyl glucosinolate and HPLC-based reaction progress curve data for the enzymatic hydrolysis of glucosinolates by Sinapis alba myrosinase

    Directory of Open Access Journals (Sweden)

    Chase A. Klingaman

    2017-02-01

    Full Text Available The data presented in this article are related to the research article, “HPLC-based enzyme kinetics assay for glucosinolate hydrolysis facilitate analysis of systems with both multiple reaction products and thermal enzyme denaturation” (C.K. Klingaman, M.J. Wagner, J.R. Brown, J.B. Klecker, E.H. Pauley, C.J. Noldner, J.R. Mays, [1]. This data article describes (1 the synthesis and spectral characterization data of a non-natural glucosinolate analogue, 2,2-diphenylethyl glucosinolate, (2 HPLC standardization data for glucosinolate, isothiocyanate, nitrile, and amine analytes, (3 reaction progress curve data for enzymatic hydrolysis reactions with variable substrate concentration, enzyme concentration, buffer pH, and temperature, and (4 normalized initial velocities of hydrolysis/formation for analytes. These data provide a comprehensive description of the enzyme-catalyzed hydrolysis of 2,2-diphenylethyl glucosinolate (5 and glucotropaeolin (6 under widely varied conditions.

  2. Synthesis of the Azepinobisindole Alkaloid Iheyamine A Enabled by a Cross-Mannich Reaction.

    Science.gov (United States)

    Lindsay, Ashley C; Leung, Ivanhoe K H; Sperry, Jonathan

    2016-10-05

    The total synthesis of the azepinobisindole alkaloid iheyamine A is described. The successful strategy hinged on an intermolecular cross-Mannich reaction between 5-methoxy-3-acetoxyindole and a protected tryptamine to access an unsymmetrical 2,2'-bisindole, which was subsequently converted into iheyamine A via a deep-blue 3-indolone intermediate. VT 1 H NMR infers that iheyamine A exists as a mixture of tautomers that undergo intermediate chemical exchange on the NMR time scale. The intermolecular cross-Mannich reaction described herein is a viable alternative to metal-catalyzed cross-coupling strategies commonly employed to access 2,2'-bisindoles.

  3. Photogenerated carrier-induced reactions on uhv semiconductor surfaces. Technical progress report, December 15, 1989--December 14, 1992

    Energy Technology Data Exchange (ETDEWEB)

    Osgood, R.M. Jr.

    1992-05-28

    The objective for this experimental work was to examine the reaction mechanisms, half-collision dynamics, and other optically induced chemical effects, that are operable on a well characterized single-crystal semiconductor surface. Of particular interest were reactions induced by charge transfer from the semiconductor surface including hot carrier and thermalized carrier processes. The primary technique to measure the desorbed fragment translational energies was time-of-flight mass-spectroscopy, used in conjunction with a pulsed tunable laser source. The work was carried out in ultrahigh vacuum, thus other surface spectroscopies such as temperature-programmed desorption, (TPD), (LEED), etc. were used as needed. In the project, the photoreactions of several halogen-containing molecules on GaAs(110) surfaces have been investigated. The studies have made the first observations of several new photochemical processes on uhv prepared surfaces including intermolecular charge transfer; desorption by thermal-carrier-induced reactions (including the measurement of coverage-dependent changes in the translational energies of the desorbed products); interferometric oscillation of photoinduced reactions; and self-quenching of thermal carrier reactions on surfaces.

  4. Studies of heavy-ion reactions and transuranic nuclei: Progress report, September 1, 1987--August 31, 1988

    International Nuclear Information System (INIS)

    Schroeder, W.U.; Huizenga, J.R.

    1988-08-01

    The effect of successively increasing gradients of the potential energy surface on mass and charge transport was studied experimentally and theoretically with a series of damped reactions induced by 48 Ca, 64 Ni, 58 Ni, and 40 Ca projectiles on 238 U targets. Combined transport-evaporation calculations that were performed for the interpretation of data demonstrate a systematic deficiency of quantitative reaction theory. A new type of experimental method has been employed to study several moments of the energy partition in damped reactions, measuring multiplicity correlations of neutrons emitted from the asymptotic fragments with a specially designed, directionally sensitive multiplicity counter. First results indicate significant departures of damped reaction systems from thermal equilibrium. Employing realistic Monte Carlo simulation of published experiments, it was demonstrated that the directions of net mass transfer and energy deposit are uncorrelated in damped reactions. Evaporative and preequilibrium neutron emission has been studied for the asymmetric heavy-ion system 139 La + 40 Ar. The disequilibrium energy transport phenomena observed in the experiment are quantitatively reproduced by model calculations. A strong impact-parameter dependence of preequilibrium emission is demonstrated. The emission patterns of α particles evaporated from high spin compound nuclei, previously attributed to exotic nuclear shapes, have been explained in realistic statistical model calculations for nuclei with conventional shapes. A new octal digital delay module has been designed and tested

  5. Studies of complex fragment emission in heavy ion reactions. Progress report, January 1, 1993--September 15, 1993

    Energy Technology Data Exchange (ETDEWEB)

    Charity, R.J.; Sobotka, L.G.

    1993-09-12

    The study of intermediate-energy heavy-ion nuclear reactions is reported. This work has two foci: the properties of nuclear matter under abnormal conditions, in this energy domain, predominately low densities and the study of the relevant reaction mechanisms. Nuclear matter properties, such as phase transitions, are reflected in the dynamics of the reactions. The process leads to an understanding of the reaction mechanism themselves and therefore to the response characteristics of finite, perhaps non-equilibrium, strongly interacting systems. The program has the following objectives: to study energy, mass, and angular momentum deposition by studying incomplete fusion reactions; to gain confidence in the understanding of how highly excited systems decompose by studying all emissions from the highly excited systems; to push these kinds of studies into the intermediate energy domain (where intermediate mass fragment emission is not improbable) with excitation function studies; and to learn about the dynamics of the decays using particle-particle correlations. The last effort focuses on simple systems, where definitive statements are possible. These avenues of research share a common theme, large complex fragment production. It is this feature, more than any other, which distinguishes the intermediate energy domain.

  6. Studies of heavy-ion reactions and transuranic nuclei. Progress report, September 1, 1992--August 31, 1993

    Energy Technology Data Exchange (ETDEWEB)

    Schroeder, W.U.

    1993-08-01

    This report contain papers on the following topics: The Cold-Fusion Saga; Decay Patterns of Dysprosium Nuclei Produced in {sup 32}S + {sup 118,124}Sn Fusion Reactions; Unexpected Features of Reactions Between Very Heavy Ions at Intermediate Bombarding Energies; Correlations Between Neutrons and Charged Products from the Dissipative Reaction {sup 197}Au+{sup 208}Pb at E/A = 29 MeV; Dissipative Dynamics of Projectile-Like Fragment Production in the Reaction {sup 209}Bi+{sup 136}Xe at E/A = 28.2 MeV; Dynamical Production of Intermediate-Mass Fragments in Peripheral {sup 209}Bi+{sup 136}Xe Collisions at E{sub lab}/A = 28.2 MeV; The Rochester 960-Liter Neutron Multiplicity Meter; A Simple Pulse Processing Concept for a Low-Cost Pulse-Shape-Based Particle Identification; A One-Transistor Preamplifier for PMT Anode Signals; A Five-Channel Multistop TDC/Event Handler for the SuperBall Neutron Multiplicity Meter; Construction of the SuperBall -- a 16,000-Liter Neutron Detector for Calorimetric Studies of Intermediate-Energy Heavy-Ion Reactions; A Computer Code for Light Detection Efficiency Calculations for Photo-multipliers of a Neutron Detector; Evaluation of Gd-Loaded Liquid Scintillators for the SuperBall Neutron Calorimeter; and Measurement of the Interaction of Cosmic-Ray {mu}{sup {minus}} with a Muon Telescope.

  7. Pulse radiolysis studies of fast reactions in molecular systems. Progress report, February 1, 1981-September 30, 1982

    International Nuclear Information System (INIS)

    Dorfman, L.M.

    1982-01-01

    The rates of elementary chemical reactions in irradiated solutions are being studied by observation of the formation and decay of reactive intermediates using the pulse radiolysis technique. These short-lived species are monitored by fast optical absorption measurement; optical absorption spectra of the transients are also obtained. Reactive species currently of interest include organic molecule ions (both cations and anions) and radical anions. Transition metal carbonyl radicals in solution, another category of intermediates, are also under investigation. Since the reactions are initiated by a pulse of high energy electrons, this work inherently relates to radiation chemical systems. The information obtained is also of interest in various areas of organic reaction kinetics in which ions play a central role. In the area of homogeneous catalysis, the reactivity of transition metal carbonyl radicals is of interest. Current activities are directed at reactivity of organic ionic species (carbocations and carbanions) in irradiated solutions; and optical spectra and reactivities of transition metal carbonyl radicals

  8. High energy halogen atom reactions activated by nuclear transformations. Progress report, February 15, 1978--February 14, 1979

    International Nuclear Information System (INIS)

    Rack, E.P.

    1979-02-01

    High energy reactions of halogen atoms or ions, activated by nuclear transformations, were studied in gaseous, high pressure and condensed phase saturated and unsaturated hydrocarbons, halomethanes and other organic systems in order to better understand the mechanisms and dynamics of high energy monovalent species. The experimental and theoretical program consists of six interrelated areas: (1) the reactions of iodine with alkenes and alkynes activated by radiative neutron capture and isomeric transition in low pressure gaseous systems employing additives and rare gas moderators, high pressure and liquid systems; (2) the gas to condensed state transition in halogen high chemistry, involving bromine activated by the (n,γ) and (I.T.) processes in ethane was investigated in more detail; (3) systematics of halogen hot atom reactions. The reactions of 80 Br/sup m/, 80 Br, 82 Br/sup m/ + 82 Br, 82 Br, 128 I, 130 I, and 130 I/sup m/ + 130 I activated by radiative neutron capture or isomeric transition in hydrocarbons and halo-substituted alkanes in low pressure and high pressure gaseous systems employing additives and rare gas moderators; (4) kinetic theory applications of high energy reactions and mathematical development of caging mechanisms were developed; (5) the sterochemistry of 38 Cl substitution reactions involving diastereomeric 1,2-dichloro-1,2-difluorethane in liquid mixtures was completed, suggesting that the stereochemical course of the substitution process is controlled by the properties of the solvent molecules; and (6) the applications of high energy chemistry techniques and theory to neutron activation analysis of biological systems was continued, especially involving aluminum and vanadium trace determinations

  9. Studies of complex fragment emission in heavy ion reactions: Progress report, September 1, 1987--August 31, 1988

    International Nuclear Information System (INIS)

    Sobotka, L.G.

    1988-01-01

    The production of large fragments, fragments with mass between light particles and fission fragments, in intermediate and high energy nuclear reactions has fostered the proposal of a number of novel reaction mechanisms. These include liquid-vapor equilibrium and nuclear shattering. Temporarily left in the wake of these exciting proposed mechanisms was the old standard, statistical decay of compound nuclei. To be sure, the standard treatment of compound nucleus decay did not deal with large fragment production. However, this emission was not due to any fundamental deficiency of statistical models, but rather an uncertainty concerning exactly how to splice large fragment emission into statistical models. A large portion of our program deals with this problem. Specifically, by studying the yields of large fragments produced in sufficiently low energy reactions we are attempting to deduce the asymmetry and l-wave dependence of large fragment emission from compound nuclear intermediates. This, however, is only half of the problem. Since the novel mechanisms proposed for large fragment emission were spawned by intermediate and high energy reaction data, we must also realize the relevance of the compound nucleus mechanisms at high energies. It is not unreasonable to suspect that compound nucleus-like objects are formed with less than complete momentum transfer and perhaps less than complete mass transfer. Therefore the study of large fragment production in low energy reactions should go hand in hand with the study of energy, mass, and angular momentum transfer in incomplete fusion and non-compound reactions. This thread joins the apparently divergent subjects covered in this report

  10. High energy halogen atom reactions activated by nuclear transformations. Progress report, February 15, 1980-February 14, 1981

    Energy Technology Data Exchange (ETDEWEB)

    1981-02-01

    The stereochemistry of high energy /sup 18/F, /sup 34m/Cl, and /sup 76/Br substitution reactions involving enantiomeric molecules in the gas and condensed phase is studied. The gas to condensed state transition in halogen high energy chemistry, involving chlorine, bromine, and iodine activated by the (n,..gamma..) and (I.T.) processes in halomethanes, saturated and unsaturated hydrocarbons is being investigated in more detail. Special attention is given to defining the nature of the enhancement yields in the condensed phase. High energy halogen reactions in liquid and frozen aqueous solutions of organic and biomolecular solutes are studied in an attempt to learn more about these reactions. The applications of high energy chemistry techniques and theory to neutron activation analysis of biological systems are being continued. Special attention is given to developing procedures for trace molecular determinations in biological systems. The applications of hot halogen atoms as indicators of solute-solute interactions in liquid and frozen aqueous solutions of halogenated bases and nucleosides are being developed. Experiments are designed to explain the mechanisms of the radioprotection offered biomolecular solutes trapped within the frozen ice lattice. Reactions of bromine and iodine activated by isomeric transition with halogenated biomolecular solutes in liquid and frozen aqueous solutions are studied. The high energy reactions of iodine with the isomers of pentene have been studied in low pressure gaseous systems employing additives and rare gas moderators and liquid systems. Reactivity of excited complex formation and structural effects of electrophilic iodine attack on the pi-bond systems are studied.

  11. High energy halogen atom reactions activated by nuclear transformations. Progress report, February 15, 1980-February 14, 1981

    International Nuclear Information System (INIS)

    1981-02-01

    The stereochemistry of high energy 18 F, /sup 34m/Cl, and 76 Br substitution reactions involving enantiomeric molecules in the gas and condensed phase is studied. The gas to condensed state transition in halogen high energy chemistry, involving chlorine, bromine, and iodine activated by the (n,γ) and (I.T.) processes in halomethanes, saturated and unsaturated hydrocarbons is being investigated in more detail. Special attention is given to defining the nature of the enhancement yields in the condensed phase. High energy halogen reactions in liquid and frozen aqueous solutions of organic and biomolecular solutes are studied in an attempt to learn more about these reactions. The applications of high energy chemistry techniques and theory to neutron activation analysis of biological systems are being continued. Special attention is given to developing procedures for trace molecular determinations in biological systems. The applications of hot halogen atoms as indicators of solute-solute interactions in liquid and frozen aqueous solutions of halogenated bases and nucleosides are being developed. Experiments are designed to explain the mechanisms of the radioprotection offered biomolecular solutes trapped within the frozen ice lattice. Reactions of bromine and iodine activated by isomeric transition with halogenated biomolecular solutes in liquid and frozen aqueous solutions are studied. The high energy reactions of iodine with the isomers of pentene have been studied in low pressure gaseous systems employing additives and rare gas moderators and liquid systems. Reactivity of excited complex formation and structural effects of electrophilic iodine attack on the pi-bond systems are studied

  12. Recent progress in ab-initio studies of nuclear reactions of astrophysical interest with A ≤ 3

    Science.gov (United States)

    Marcucci, Laura E.

    2018-03-01

    We review the most recent theoretical studies of nuclear reactions of astrophysical interest involving few-nucleon systems. In particular, we focus on the consequences for the solar neutrino fluxes of the recent determination for the astrophysical S-factor of the proton weak capture by proton, and on the radiative capture of protons by deuterons in the energy range of interest for Big Bang Nucleosynthesis.

  13. Recent Progresses in Ab-Initio Studies of Low-Energy Few-Nucleon Reactions of Astrophysical Interest

    Science.gov (United States)

    Marcucci, Laura E.

    2017-03-01

    We review the most recent theoretical studies of nuclear reactions of astrophysical interest involving few-nucleon systems. In particular, we focus on the radiative capture of protons by deuterons in the energy range of interest for Big Bang Nucleosynthesis. Related to this, we will discuss also the most recent calculation of tritium β -decay. Two frameworks will be considered, the conventional and the chiral effective field theory approach.

  14. Removal of As, Mn, Mo, Se, U, V and Zn from groundwater by zero-valent iron in a passive treatment cell: reaction progress modeling

    Science.gov (United States)

    Morrison, Stan J.; Metzler, Donald R.; Dwyer, Brian P.

    2002-05-01

    Three treatment cells were operated at a site near Durango, CO. One treatment cell operated for more than 3 years. The treatment cells were used for passive removal of contamination from groundwater at a uranium mill tailings repository site. Zero-valent iron [Fe(0)] that had been powdered, bound with aluminosilicate and molded into plates was used as a reactive material in one treatment cell. The others used granular Fe(0) and steel wool. The treatment cells significantly reduced concentrations of As, Mn, Mo, Se, U, V and Zn in groundwater that flowed through it. Zero-valent iron [Fe(0)], magnetite (Fe 3O 4), calcite (CaCO 3), goethite (FeOOH) and mixtures of contaminant-bearing phases were identified in the solid fraction of one treatment cell. A reaction progress approach was used to model chemical evolution of water chemistry as it reacted with the Fe(0). Precipitation of calcite, ferrous hydroxide [Fe(OH) 2] and ferrous sulfide (FeS) were used to simulate observed changes in major-ion aqueous chemistry. The amount of reaction progress differed for each treatment cell. Changes in contaminant concentrations were consistent with precipitation of reduced oxides (UO 2, V 2O 3), sulfides (As 2S 3, ZnS), iron minerals (FeSe 2, FeMoO 4) and carbonate (MnCO 3). Formation of a free gas phase and precipitation of minerals contributed to loss of hydraulic conductivity in one treatment cell.

  15. The effects of stress concentrations on reaction progress: an example from experimental growth of magnesio-aluminate spinel at corundum - periclase interfaces under uniaxial load

    Science.gov (United States)

    Jerabek, Petr; Abart, Rainer; Rybacki, Erik; Habler, Gerlinde

    2014-05-01

    The study aims to understand the reaction progress and chemical, microstructural and textural evolution of magnesio-aluminate spinel reaction rims formed at varying experimental settings (load, temperature and experiment duration). The spinel rims were grown at the contacts between periclase and corundum at temperatures of 1250°C to 1350°C and dry atmosphere, maintained by a constant argon gas flow, under uniaxial load of 0.026 and 0.26 kN per 9 mm2 of initial contact area. Single crystals of periclase with [100] and of corundum with [0001] perpendicular to the polished reaction interface as well as polycrystalline corundum were used as starting materials. Two loading procedures, immediate application of the load before heating and loading after the desired temperature had been reached, were used. An important byproduct of our experiments stemmed from the immediate application of the load, which led to deformation twinning and fracturing of corundum. This internal deformation of corundum disturbed the reaction interface and introduced loci of concentrated stress due to opening of void spaces in between the reactant crystals. Whenever cracks formed in the initial stages of an experiment, the void space opened immediately and no spinel formed along these interface segments. In the case of deformation twinning, the decreased rim thickness indicates later opening of void spaces. This is because next to twins, the reaction interface is characterized by tight physical contact on the one side and less tight contact on the other side of the twin individual. The tight contacts are characterized by enhanced reaction progress which together with the overall positive volume change of the reaction and limits on plasticity of the studied phases led to the opening of void spaces at places characterized by less tight contacts. The thickness variations are less pronounced in our high load (0.26 kN) experiments where periclase behaves plastically and to some extent reduces the

  16. Laser-enhanced chemical-reaction studies. Technical progress report, April 1, 1980 to January 1, 1982

    International Nuclear Information System (INIS)

    Flynn, G.

    1982-01-01

    Progress on four interrelated projects in the area of laser photochemistry and photophysics is described. A method for producing polyatomic molecular beams with high vibrational energy content has been developed and applied to SF 6 . This technique employs laser excitation of molecules in the collisional region of a supersonic nozzle expansion. The photochemistry and relaxation dynamics of electronically excited Br 2 trapped in low temperature rare gas matrices have also been investigated. The relaxation forces operative in this system appear to be delicately balanced and lead to population of and subsequent emission from the B, A, and A' electronic states. The A' Br 2 level has been tentatively identified for the first time. Vibrational energy transfer in the ground electronic states of (COF) 2 has been studied and found to be extremely fast. The presence of a low lying torsional mode in this molecule, which provides a one dimensional quasi-continuum at low energies, is believed to enhanced intermode energy transfer processes for (COF) 2 . Energy disposal in HBr/CO 2 mixtures, where the HBr has been photodissociated by an excimer laser pulse, has been studied. Strong emission from bend-antisymmetric stretch combination bands of CO 2 , excited by fast H atoms producing during photolysis, has been observed

  17. Processing of high level waste: Spectroscopic characterization of redox reactions in supercritical water. 1998 annual progress report

    International Nuclear Information System (INIS)

    Arrington, C.A. Jr.

    1998-01-01

    'The author is engaged in a collaborative research effort with Los Alamos staff scientists Steven Buelow, Jeanne Robinson, and Bernie Foy all staff members in group CST-6. The work proposed by these LANL staff scientists is directed towards the destruction of complexants and oxidation of chromium and technetium by hydrothermal processing in near critical or supercritical aqueous solutions. The work addresses two areas of investigation related to ongoing efforts at LANL: (1) kinetic studies of oxidation-reduction reactions in supercritical water; (2) measurement of physical properties of ionic solutes in supercritical water. All of the work during this first year was carried out at Los Alamos National Lab. During the Summer program at LANL all equipment and supplies were provided through Dr. Buelow''s program at LANL. The author has now set up a Raman spectroscopy lab at Furman. Using departmental funds he purchased an optical bench, a laser, and a CCD detector, and a grant from the Dreyfus Foundation assisted in the purchase of a Raman spectrometer. He is now able to carry out experiments using the Raman system at Furman. The plan is to continue the Summer collaboration at LANL and carry out experiments at Furman during the academic year.'

  18. Characterization of porosity via secondary reactions. Quarterly technical progress report, 15 December 1991--15 March 1992

    Energy Technology Data Exchange (ETDEWEB)

    Calo, J.M.

    1992-09-01

    The new TPD-MS/TGA system has been constructed and successfully tested. This system is constructed around a new Cahn D-200 digital recording microbalance, which was purchased for this purpose. The TPD reactor is the ``hangdown`` tube for the microbalance. The system can operate at pressures from vacuum to atmospheric. Control and data logging of this new experimental system are performed using a Macintosh II microcomputer with a GW Instruments 625 Jr. interface. All the control software has been written and tested. A new furnace with low ``thermal capacitance`` was constructed for this system which allows linear heating rates to 1100{degree}C at rates as high as 20OK/min. This system will become a principal apparatus for obtaining some of the data required for the development of porosity characterization techniques via TPD. Software has been written for the analysis of small angle scattering (SAS) data, obtained with either X-rays (SAXS) or neutrons (SANS), which will be used in addition to gas adsorption techniques to characterize porosity for comparison with secondary reaction data.

  19. Direct determination of atom and radical concentrations in thermal reactions of hydrocarbons and other gases. Progress report, December 1, 1981-December 31, 1982

    International Nuclear Information System (INIS)

    Skinner, G.B.; Rao, V.S.; Wood, D.R.

    1983-01-01

    This is the seventh annual progress report on this project. During the period covered by the first six reports (June 1976 through December 1980) a shock tube and optical systems to measure H, D and O atom concentrations were built and fully characterized. The performance of our microwave discharge lamps were defined by numerous high-resolution spectroscopic profiles, while empirical calibrations were also made for all three of the above species. H, D and O atom concentrations were measured in gas mixtures containing H 2 , D 2 , O 2 , CD 4 , C 2 H 6 , C 2 D 6 , C 3 H 8 and C 3 D 8 in various proportions, and rate constants of several elementary reactions were deduced from the data. During the period covered by this report (December 1, 1981 to December 31, 1982) we have made kinetic modelling calculations to correlate H, D and O atom concentrations measured in shock-heated mixtures of C 2 H 6 -O 2 -Ar, C 2 D 6 -O 2 -Ar, C 3 H 8 -O 2 -Ar and C 3 D 8 -O 2 -Ar. These computations are difficult because there are several reactions for which rate constants are not known, so that it is necessary to do many calculations to completely optimize the results. Consequently, work is still going on with these calculations. We have completed an extensive series of measurements of H and D atom concentrations in pyrolysis experiments of benzene, toluene and neopentane and deuterium analogs, that have led to rate constants for the initial dissociation of these compounds, and for the reaction of H atoms with benzene and toluene

  20. Gold(I)/Gold(III)-Catalyzed Selective Synthesis of N-Sulfonyl Enaminone Isomers from Sulfonamides and Ynones via Two Distinct Reaction Pathways.

    Science.gov (United States)

    Lee, Dabon; Kim, Sang Min; Hirao, Hajime; Hong, Soon Hyeok

    2017-09-15

    Au-catalyzed chemoselective methods for synthesizing N-sulfonyl enaminones are developed. Two different isomers are obtained in a chemocontrolled manner by employing the different properties of Au(I) and Au(III) catalysts. Hydroamidation and proton-assisted carbonyl activation followed by Meyer-Schuster rearrangement are proposed as the working mechanisms for the reactions. A wide range of substrates afforded moderate to excellent yields and selectivities. These reactions represent the first examples of transition-metal-catalyzed enamine synthesis from sulfonamides and alkynes.

  1. Luminescence process, refractory stabilities, and new novel electronic states: scanning chemical reactions and novel products for laser induced isotope separation. Progress report, December 1, 1975--July 15, 1976

    International Nuclear Information System (INIS)

    Gole, J.L.

    1976-08-01

    The formulation, development, and use of versatile oven systems for high temperature metal vaporization at temperatures in excess of 2000 0 C are discussed. Refinements of an apparatus appropriate for the production and study of small metal aggregates M/sub n/(2 less than or equal to n less than or equal to 6) are discussed at length. Improvements in the argon ion and nitrogen pumped dye laser systems, and necessary additions for effective interfacing of these dye lasers to the aggregates apparatus are described. Internal calibration standards are discussed. Progress on the production of carbon vapor and the reaction of this vapor with metal atoms and metal dimers to form metal carbides is outlined. Metal sulfide chemistry is discussed. Several specific studies of the luminescence process are outlined. Included in these studies are completed work on aluminum oxidation. Studies of germanium and silicon oxidation are outlined, and new investigations of inorganic hydride oxidation are presented. The status of our efforts to form new and novel surfaces via aggregate deposition is outlined. Quantum chemical calculations on small metal aggregates are discussed. The first applications of dynamic laser induced fluorescence to the AlO molecule are presented

  2. Direct determination of atom and radical concentrations in thermal reactions of hydrocarbons and other gases. Progress report, January 1, 1977--December 31, 1977

    International Nuclear Information System (INIS)

    Skinner, G.B.; Lifshitz, A.; Wood, D.R.; Chiang, C.C.

    1978-01-01

    This is a second annual progress report on this project. The period covered by the first report (June through December, 1976) was devoted to building and testing a shock tube and an optical system to be used to measure H and D atom concentrations. During 1977 this apparatus was completed and used. The performance of our microwave discharge lamps was characterized by numerous high-resolution spectroscopic profiles, so that the shapes of the Lyman-alpha lines produced under various operating conditions are now quite well-known. Measurements of H or D atom concentrations in shock-heated mixtures of D 2 -N 2 O-Ar, D 2 -O 2 -Ar and H 2 -O 2 -Ar have been made. During the balance of the contract year (January 1 through May 31, 1978) measurements of H or D atom concentrations in shock-heated mixtures of CD 4 -Ar, C 8 H 18 (2,2,3,3, tetramethyl butane)-Ar, C 8 H 18 -CH 4 -Ar, C 3 H 8 -Ar and C 3 H 8 -CH 4 -Ar will be made, and kinetic data on reactions of H and D atoms deduced from the experimental results

  3. Development of protein biomarkers in cerebrospinal fluid for secondary progressive multiple sclerosis using selected reaction monitoring mass spectrometry (SRM-MS

    Directory of Open Access Journals (Sweden)

    Jia Yan

    2012-07-01

    Full Text Available Abstract Background Multiple sclerosis (MS is a chronic inflammatory disorder of the central nervous system (CNS. It involves damage to the myelin sheath surrounding axons and to the axons themselves. MS most often presents with a series of relapses and remissions but then evolves over a variable period of time into a slowly progressive form of neurological dysfunction termed secondary progressive MS (SPMS. The reasons for this change in clinical presentation are unclear. The absence of a diagnostic marker means that there is a lag time of several years before the diagnosis of SPMS can be established. At the same time, understanding the mechanisms that underlie SPMS is critical to the development of rational therapies for this untreatable stage of the disease. Results Using high performance liquid chromatography-coupled mass spectrometry (HPLC; we have established a highly specific and sensitive selected reaction monitoring (SRM assay. Our multiplexed SRM assay has facilitated the simultaneous detection of surrogate peptides originating from 26 proteins present in cerebrospinal fluid (CSF. Protein levels in CSF were generally ~200-fold lower than that in human sera. A limit of detection (LOD was determined to be as low as one femtomol. We processed and analysed CSF samples from a total of 22 patients with SPMS, 7 patients with SPMS treated with lamotrigine, 12 patients with non-inflammatory neurological disorders (NIND and 10 healthy controls (HC for the levels of these 26 selected potential protein biomarkers. Our SRM data found one protein showing significant difference between SPMS and HC, three proteins differing between SPMS and NIND, two proteins between NIND and HC, and 11 protein biomarkers showing significant difference between a lamotrigine-treated and untreated SPMS group. Principal component analysis (PCA revealed that these 26 proteins were correlated, and could be represented by four principal components. Overall, we established an

  4. Pd Metal Catalysts for Cross-Couplings and Related Reactions in the 21st Century: A Critical Review.

    Science.gov (United States)

    Biffis, Andrea; Centomo, Paolo; Del Zotto, Alessandro; Zecca, Marco

    2018-02-28

    Cross-couplings and related reactions are a class of highly efficient synthetic protocols that are generally promoted by molecular Pd species as catalysts. However, catalysts based on more or less highly dispersed Pd metal have been also employed for this purpose, and their use, which was largely limited to the Heck reaction until the turn of the century, has been extended in recent years to most reactions of this class. This review provides a critical overview on these recent applications of Pd metal catalysts. Particular attention is devoted to the discussion of the mechanistic pathways that have been proposed to explain the catalytic role of Pd metal. Furthermore, the most outstanding Pd metal based catalytic systems that have emerged are illustrated, together with the development of novel approaches to boost the reactivity of Pd metal. A section summarizing the current industrial applications of Pd metal catalyzed reactions of this kind concludes the review.

  5. Reaction mechanisms

    International Nuclear Information System (INIS)

    Nguyen Trong Anh

    1988-01-01

    The 1988 progress report of the Reaction Mechanisms laboratory (Polytechnic School, France), is presented. The research topics are: the valence bond methods, the radical chemistry, the modelling of the transition states by applying geometric constraints, the long range interactions (ion - molecule) in gaseous phase, the reaction sites in gaseous phase and the mass spectroscopy applications. The points of convergence between the investigations of the mass spectroscopy and the theoretical chemistry teams, as well as the purposes guiding the research programs, are discussed. The published papers, the conferences, the congress communications and the thesis, are also reported [fr

  6. Solving The Long-Standing Problem Of Low-Energy Nuclear Reactions At The Highest Microscopic Level. Annual Continuation And Progress Report, August 15, 2014 -- August 14, 2015

    Energy Technology Data Exchange (ETDEWEB)

    Quaglioni, Sofia [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2015-03-19

    The aim of this project is to develop a comprehensive framework that will lead to a fundamental description of both structural properties and reactions of light nuclei in terms of constituent protons and neutrons interacting through nucleon-nucleon (NN) and three-nucleon (3N) forces. This project will provide the research community with the theoretical and computational tools what will enable: an accurate prediction for fusion reactions that power stars and Earth-based fusion facilities; an improved description of the spectroscopy of exotic nuclei, including light Borromean systems; and, a fundamental understanding of the three-nucleon force in nuclear reaction and nuclei at the drip line.

  7. Nuclear excitations and reaction mechanisms. Progress report, 1 November 1979-30 September 1980. [Dept. of Physics, Brown Univ. , Providence, Rhode Island

    Energy Technology Data Exchange (ETDEWEB)

    1980-10-01

    Among the topics investigated were the following: photon scattering and consistency condition between seagull quadrupole terms and the absorption sum rule; Raman scattering to negative-parity states; nonlocal terms due to exchange and retardation effects in charge-transfer reactions; consistency and meaning of various approximate channel coupling array equations; derivation of equations used in empirical nuclear reaction analyses; multicluster, n-particle scattering theory; converged molecular bound state calculations; consistency of approximate channel coupling array equations; derivations of equations used in empirical nuclear reaction analyses; and WKB-type approximation in angular momenta for central potentials. References to publications are given.

  8. Neutron multiplicity distributions for 30 MeVu {sup 14}N reactions with the indicated targets. Progress in research, April 1, 1991--March 31, 1992

    Energy Technology Data Exchange (ETDEWEB)

    1992-06-01

    This report contains short papers on the following topics: Heavy ion reactions; nuclear structure and fundamental interactions; nuclear theory; atomic molecular and materials science; and superconducting cyclotron and instrumentation. (LSP)

  9. TORUS: Theory of Reactions for Unstable iSotopes Annual Continuation and Progress Report Year-2: March 1, 2011 - February 29, 2012

    Energy Technology Data Exchange (ETDEWEB)

    Arbanas, G; Elster, C; Escher, J; Mukhamedzanov, A; Nunes, F; Thompson, I J

    2012-02-24

    The TORUS collaboration derives its name from the research it focuses on, namely the Theory of Reactions for Unstable iSotopes. It is a Topical Collaboration in Nuclear Theory, and funded by the Nuclear Theory Division of the Office of Nuclear Physics in the Office of Science of the Department of Energy. The funding supports one postdoctoral researcher for the years 1 through 3. The collaboration brings together as Principal Investigators a large fraction of the nuclear reaction theorists currently active within the USA. The mission of the TORUS Topical Collaboration is to develop new methods that will advance nuclear reaction theory for unstable isotopes by using three-body techniques to improve direct-reaction calculations, and, by using a new partial-fusion theory, to integrate descriptions of direct and compound-nucleus reactions. This multi-institution collaborative effort is directly relevant to three areas of interest: the properties of nuclei far from stability; microscopic studies of nuclear input parameters for astrophysics, and microscopic nuclear reaction theory.

  10. Microglial and macrophage reactions mark progressive changes and define the penumbra in the rat neocortex and striatum after transient middle cerebral artery occlusion

    DEFF Research Database (Denmark)

    Lehrmann, E; Christensen, Thomas; Zimmer, J

    1997-01-01

    major histocompatibility complex (MHC) class II antigen expression. We interpret the present results as delineating two differentially progressing penumbral zones, which are likely to reflect differences in the underlying degenerative processes. Differences in the microglial/macrophage activation...... pattern attract special attention, as these cells may constitute specific targets for therapeutic intervention....

  11. Polyethersulfone hollow fiber modified with poly(styrenesulfonate) and Pd nanoparticles for catalytic reaction

    Science.gov (United States)

    Emin, C.; Gu, Y.; Remigy, J.-C.; Lahitte, J.-F.

    2015-07-01

    The aim of this work is the synthesis of polymer-stabilized Pd nanoparticles (PdNP) inside a functionalized polymeric porous membrane in order to develop hybrid catalytic membrane reactors and to test them in model metal-catalyzed organic reactions. For this goal, a polymeric membrane support (Polyethersulfone hollow fiber-shaped) was firstly functionalized with an ionogenic polymer (i.e. poly(styrenesulfonate) capable to retain PdNP precursors using an UV photo-grafting method. PdNP were then generated inside the polymeric matrix by chemical reduction of precursor salts (intermatrix synthesis). The catalytic performance of the PdNP catalytic membranes was evaluated using reduction of nitrophenol by sodium borohydride (NaBH4) in water.

  12. Progress on theoretical evaluation method of nuclear data calculation and applied nuclear reaction theory research at the theory group of CNDC

    International Nuclear Information System (INIS)

    Wang Shunnan

    1990-01-01

    The fields of theoretical evaluation method of nuclear data calculations and applied nuclear reaction theory research were described briefly. A global review of phenomenological and microscopic optical potential in nuclear data evaluation of 14 natural elements in the energy range of 0.1-24 MeV has been done. The nuclear fission is studied based on a new fission mechanism-the fission diffusion model. This model was proposed to explain the enhancement of neutron emission in heavy ion collisions

  13. Intermediate energy nuclear physics (Task C) and charge exchange reactions (Task W). Technical progress report, October 1, 1985-October 1, 1986

    International Nuclear Information System (INIS)

    Kraushaar, J.J.

    1986-10-01

    This report describes the experimental work in intermediate energy research carried out over the past year at the University of Colorado. The experimental program is very broad in nature, ranging from investigations in pion-nucleus interactions, nucleon charge exchange, inelastic electron scattering, and nucleon transfer reactions. The experiments were largely carried out at the Los Alamos Meson Physics Facility, but important programs were conducted at the Tri-University Meson Facility at the University of British Columbia, the Indiana University Cyclotron Facility and Netherlands Institute for Nuclear Physics Research (NIKHEF-K)

  14. Effects of mercaptans and disulfides on photochemical and high energy radiation induced reactions. Progress report, November 1, 1974--October 31, 1975

    International Nuclear Information System (INIS)

    Cohen, S.G.

    1975-10-01

    A chain reaction may be formulated at alkaline pH in terms of e - /sub aq/ acting as a source of - OH as a reactant and H. regenerating e - /sub aq/. This may account for radiolytic conversion of CO to formate with high G. 60 Co γ-radiolysis of alkaline aqueous acetonitrile and acetamide gave no evidence of a chain; extensive hydrolysis of methyl acetate is now attributed to non-radiolytic, normal hydrolysis. Aromatic mercaptans are found to retard photoreduction of a benzophenone by aliphatic amines, largely by hydrogen atom-transfer repair reactions. Aliphatic mercaptans accelerate photoreduction, apparently by affecting the reduction to quenching ratio in the intermediate charge-transfer complex. In photoreduction of a benzophenone by 2,3-butylene glycol at pH 3, the glycol is converted, not to 3-hydroxy-2-butanone, but to 2-butanone, and about 4 molecules of this are formed per molecule of ketone reduced. A short chain appears to be established. Mercaptan appears to accelerate the reduction of the ketone and retard the formation of 2-butanone

  15. [Transition metal mediated transformations of small molecules]. Progress report

    Energy Technology Data Exchange (ETDEWEB)

    Sen, A.

    1992-10-01

    Work on organotransition metal chemistry, homogeneous and heterogeneous catalysis is summarized. Several cationic palladium(II) complexes with bulky phosphine or pyridine ligands were discovered that are highly selective catalysts for linear dimerization of vinyl monomers and linear polymerization of p-divinylbenzene, the reactions proceeding through a carbocationic mechanism. Our studies were continued on alternating olefin-carbon monoxide copolymers. The copolymerization reaction and reactivity of copolymers were examined. New catalytic systems for alternating copolymerization of {alpha}-olefins with CO were discovered. In the case of styrene derivatives, tactic copolymers were obtained. Poly(ethylenepyrrolediyl) derivatives were synthesized from alternating ethylene-carbon monoxide copolymer and become electronic conductors when doped with iodine. A catalytic system for direct synthesis of polyureas and polyoxamides from and diamines was also discovered. Pt metal catalyzed the oxidation of ethers, esters, and amines to carboxylic acids and the oxidation of olefins to 1,2-diols. Anaerobic and aerobic decomposition of molybdenum(VI)-oxoalkyl compounds were studied for heterogeneous oxidation of alkanes and olefins on Mo(VI)-oxide surfaces. Synthesis of polymer-trapped metal, metal oxide, and metal sulfide nanoclusters (size <1--10 nm) was studied.

  16. Neutron-Induced Fission Cross Section of Uranium, Americium and Curium Isotopes. Progress report - Research Contract 14485, Coordinated Research Project on Minor Actinide Neutron Reaction Data (MANREAD)

    International Nuclear Information System (INIS)

    Alekseev, A.A.; Bergman, A.A.; Berlev, A.I.; Koptelov, E.A.; Samylin, B.F.; Trufanov, A.M.; Fursov, B.I.; Shorin, V.S.

    2009-12-01

    This report contains brief description of the Lead Slowing Down Spectrometer and results of measurements of neutron-induced fission cross sections for 236 U, 242m Am, 243 Cm, 244 Cm, 245 Cm and 246 Cm done at this spectrometer. The work was partially supported through the IAEA research contract RC-14485-RD in the framework of the IAEA Coordinated Research Project 'Minor Actinide Neutron Reaction Data (MANREAD)'. The detailed description of the experimental set up, measurements procedure and data treatment can be found in the JIA-1182 (2007) and JIA-1212 (2009) reports from the Institute of Nuclear Research of the Russian Academy of Science published in Russian. Part 1 contains the first year report of the research contract and part 2 the second year report. (author)

  17. Chapter K: Progress in the Evaluation of Alkali-Aggregate Reaction in Concrete Construction in the Pacific Northwest, United States and Canada

    Science.gov (United States)

    Shrimer, Fred H.

    2005-01-01

    The supply of aggregates suitable for use in construction and maintenance of infrastructure in western North America is a continuing concern to the engineering and resources-management community. Steady population growth throughout the region has fueled demand for high-quality aggregates, in the face of rapid depletion of existing aggregate resources and slow and difficult permitting of new sources of traditional aggregate types. In addition to these challenges, the requirement for aggregates to meet various engineering standards continues to increase. In addition to their physical-mechanical properties, other performance characteristics of construction aggregates specifically depend on their mineralogy and texture. These properties can result in deleterious chemical reactions when aggregate is used in concrete mixes. When this chemical reaction-termed 'alkali-aggregate reaction' (AAR)-occurs, it can pose a major problem for concrete structures, reducing their service life and requiring expensive repair or even replacement of the concrete. AAR is thus to be avoided in order to promote the longevity of concrete structures and to ensure that public moneys invested in infrastructure are well spent. Because the AAR phenomenon is directly related to the mineral composition, texture, and petrogenesis of the rock particles that make up aggregates, an understanding of the relation between the geology and the performance of aggregates in concrete is important. In the Pacific Northwest, some aggregates have a moderate to high AAR potential, but many others have no or only a low AAR potential. Overall, AAR is not as widespread or serious a problem in the Pacific Northwest as in other regions of North America. The identification of reactive aggregates in the Pacific Northwest and the accurate prediction of their behavior in concrete continue to present challenges for the assessment and management of geologic resources to the owners and operators of pits and quarries and to the

  18. Hydrogen-transfer and charge-transfer in photochemical and radiation induced reactions. Progress report, November 1, 1975--October 31, 1976

    International Nuclear Information System (INIS)

    Cohen, S.G.

    1976-10-01

    The relative importance of light absorption, quenching of triplet, and hydrogen transfer repair has been examined in retardation by mercaptans of photoreduction of aromatic ketones by alcohols. In the reduction of benzophenone by 2-propanol, retardation is efficient and, after correction for the first two effects, is due entirely to hydrogen-transfer repair, as indicated by deuterium labeling. In reduction of acetophenone by α-methylbenzyl alcohol, repair by hydrogen transfer is also operative. In reduction of benzophenone by benzhydrol, retardation is less efficient and is due to quenching, as the ketyl radical does not abstract hydrogen from mercaptan rapidly in competition with coupling. Deuterium isotope effects are discussed in terms of competitive reactions. Photoreduction of benzophenone by 2-butylamine and by triethylamine is retarded by aromatic mercaptans and disulfides. Of the retardation not due to light absorption and triplet quenching by the sulfur compounds, half is due to hydrogen-transfer repair, as indicated by racemization and deuterium labeling. The remainder is attributed to quenching by the sulfur compound of the charge-transfer-complex intermediate. Photoreduction by primary and secondary amines, but not by tertiary amines, is accelerated by aliphatic mercaptans. The acceleration is attributed to catalysis of hydrogen transfer by the mercaptan in the charge-transfer complex. The effect is large in hydrocarbon solvent, less in polar organic solvents and absent in water

  19. Cross-Coupling Reactions as Valuable Tool for the Preparation of PET Radiotracers

    Directory of Open Access Journals (Sweden)

    Marc Pretze

    2011-01-01

    Full Text Available The increasing application of positron emission tomography (PET in nuclear medicine has stimulated the extensive development of a multitude of new radiotracers and novel radiolabeling procedures with the most prominent short-lived positron emitters carbon-11 and fluorine-18. Radiolabeling with these radionuclides represents a remarkable challenge. Special attention has to be paid to synthesis time and specific labeling techniques due to the short physical half life of the respective radionuclides 11C (t1/2 = 20.4 min and 18F (t1/2 = 109.8 min. In the past, numerous transition metal-catalyzed reactions were employed in organic chemistry, even though only a handful of these coupling reactions were adopted in radiochemical practice. Thus, the implementation of modern synthesis methods like cross-coupling reactions offers the possibility to develop a wide variety of novel radiotracers. The introduction of catalysts based on transition metal complexes bears a high potential for rapid, efficient, highly selective and functional group-tolerating incorporation of carbon-11 and fluorine-18 into target molecules. This review deals with design, application and improvement of transition metal-mediated carbon-carbon as well as carbon-heteroatom cross-coupling reactions as a labeling feature with the focus on the preparation of radiolabeled compounds for molecular imaging.

  20. Nuclear excitations and reaction mechanisms: Progress report

    International Nuclear Information System (INIS)

    Fallieros, S.; Levin, F.S.

    1988-01-01

    This report describes activities of the Nuclear Theory Group at Brown University during the period 1 August 1987-31 July 1988, under Grant FG02-87ER40334. Completed and on-going research includes various theoretical and numerical studies on: parity non-conserving interactions in a relativistic system, processes involving virtual photons and real photons, deuteron-nucleus and neutron-deuteron collisions systems, and muon-catalyzed fusion

  1. Secondary Interactions Arrest the Hemiaminal Intermediate To Invert the Modus Operandi of Schiff Base Reaction: A Route to Benzoxazinones.

    Science.gov (United States)

    Patel, Ketan; Deshmukh, Satej S; Bodkhe, Dnyaneshwar; Mane, Manoj; Vanka, Kumar; Shinde, Dinesh; Rajamohanan, Pattuparambil R; Nandi, Shyamapada; Vaidhyanathan, Ramanathan; Chikkali, Samir H

    2017-04-21

    Discovered by Hugo Schiff, condensation between amine and aldehyde represents one of the most ubiquitous reactions in chemistry. This classical reaction is widely used to manufacture pharmaceuticals and fine chemicals. However, the rapid and reversible formation of Schiff base prohibits formation of alternative products, of which benzoxazinones are an important class. Therefore, manipulating the reactivity of two partners to invert the course of this reaction is an elusive target. Presented here is a synthetic strategy that regulates the sequence of Schiff base reaction via weak secondary interactions. Guided by the computational models, reaction between 2,3,4,5,6-pentafluoro-benzaldehyde with 2-amino-6-methylbenzoic acid revealed quantitative (99%) formation of 5-methyl-2-(perfluorophenyl)-1,2-dihydro-4H-benzo[d][1,3]oxazin-4-one (15). Electron donating and electron withdrawing ortho-substituents on 2-aminobenzoic acid resulted in the production of benzoxazinones 9-36. The mode of action was tracked using low temperature NMR, UV-vis spectroscopy, and isotopic ( 18 O) labeling experiments. These spectroscopic mechanistic investigations revealed that the hemiaminal intermediate is arrested by the hydrogen-bonding motif to yield benzoxazinone. Thus, the mechanistic investigations and DFT calculations categorically rule out the possibility of in situ imine formation followed by ring-closing, but support instead hydrogen-bond assisted ring-closing to prodrugs. This unprecedented reaction represents an interesting and competitive alternative to metal catalyzed and classical methods of preparing benzoxazinone.

  2. Reaction Automata

    OpenAIRE

    Okubo, Fumiya; Kobayashi, Satoshi; Yokomori, Takashi

    2011-01-01

    Reaction systems are a formal model that has been introduced to investigate the interactive behaviors of biochemical reactions. Based on the formal framework of reaction systems, we propose new computing models called reaction automata that feature (string) language acceptors with multiset manipulation as a computing mechanism, and show that reaction automata are computationally Turing universal. Further, some subclasses of reaction automata with space complexity are investigated and their la...

  3. Michaelis–Arbuzov reaction

    Indian Academy of Sciences (India)

    agriculture, medicine and synthetic chemistry as cata- lysts and synthetic ... ophile with an electrophilic carbon2 have been found in many synthetic ... problems. Catalytic methods play a special role in synthetic organic chemistry for progress of the reactions in sim- ple fashion. Therefore, researchers have developed var-.

  4. Progress Report

    DEFF Research Database (Denmark)

    Duer, Karsten

    1999-01-01

    Progress report describing the work carried out by the Danish participant in the ALTSET project in the period January 1999 to July 1999.......Progress report describing the work carried out by the Danish participant in the ALTSET project in the period January 1999 to July 1999....

  5. One-pot cascade michael.cyclization reactions of ο-hydroxycinnamaldehydes: Synthesis of functionalized 2,3-dihydrobenzofuranes

    Energy Technology Data Exchange (ETDEWEB)

    Gwon, Sung Hyuk; Kim, Sunggon [Kyonggi Univ., Suwon (Korea, Republic of)

    2012-04-15

    We described the cascade Michael.cyclization reaction of o-hydroxycinnamaldehydes with diethyl α-bromomalonate promoted by potassium carbonate. The reactions provided functionalized 2,3-dihydrobenzofurans in good yields for a variety of o-hydroxyaromatic α,β-unsaturated aldehydes. Current work focuses on expanding the scope of this reaction to other substrates such as sulfur yields, and on developing an efficient catalytic asymmetric variant. 2,3-Dihydrobenzofurans are found in numerous biologically active natural products and synthetic compounds. These are an attractive type of oxygenated compound because their basic core skeleton is present in neolignans, pterocarpans, and synthetic drugs used in the treatment of pulmonary hypertension, atherosclerotic peripheral arterial disease, and central nervous system trauma and ischemia. Owing to the importance of their structures, numerous synthetic methods for 2,3-dihydrobenzofurans have been developed, primarily: radical cyclizations, Lewis acid promoted reactions, anionic cyclizations, and transition-metal catalyzed processes. However, these methods cannot be generalized as much as is desirable, and they yielded poor chemo- and/or stereoselectivities. Hence, the development of an efficient enantioselective synthetic method for obtaining 2,3-dihydrobenzofuran scaffolds attracted our attention.

  6. One-pot cascade michael.cyclization reactions of ο-hydroxycinnamaldehydes: Synthesis of functionalized 2,3-dihydrobenzofuranes

    International Nuclear Information System (INIS)

    Gwon, Sung Hyuk; Kim, Sunggon

    2012-01-01

    We described the cascade Michael.cyclization reaction of o-hydroxycinnamaldehydes with diethyl α-bromomalonate promoted by potassium carbonate. The reactions provided functionalized 2,3-dihydrobenzofurans in good yields for a variety of o-hydroxyaromatic α,β-unsaturated aldehydes. Current work focuses on expanding the scope of this reaction to other substrates such as sulfur yields, and on developing an efficient catalytic asymmetric variant. 2,3-Dihydrobenzofurans are found in numerous biologically active natural products and synthetic compounds. These are an attractive type of oxygenated compound because their basic core skeleton is present in neolignans, pterocarpans, and synthetic drugs used in the treatment of pulmonary hypertension, atherosclerotic peripheral arterial disease, and central nervous system trauma and ischemia. Owing to the importance of their structures, numerous synthetic methods for 2,3-dihydrobenzofurans have been developed, primarily: radical cyclizations, Lewis acid promoted reactions, anionic cyclizations, and transition-metal catalyzed processes. However, these methods cannot be generalized as much as is desirable, and they yielded poor chemo- and/or stereoselectivities. Hence, the development of an efficient enantioselective synthetic method for obtaining 2,3-dihydrobenzofuran scaffolds attracted our attention

  7. Nuclear reactions

    International Nuclear Information System (INIS)

    Lane, A.M.

    1980-01-01

    In reviewing work at Harwell over the past 25 years on nuclear reactions it is stated that a balance has to be struck in both experiment and theory between work on cross-sections of direct practical relevance to reactors and on those relevant to an overall understanding of reaction processes. The compound nucleus and direct process reactions are described. Having listed the contributions from AERE, Harwell to developments in nuclear reaction research in the period, work on the optical model, neutron capture theory, reactions at doorway states with fine structure, and sum-rules for spectroscopic factors are considered in more detail. (UK)

  8. Progressive Business

    DEFF Research Database (Denmark)

    Christiansen, Christian O.

    2016-01-01

    Guest Post to the Society for U.S. Intellectual History Blog. Brief introduction to the book Progressive Business: An Intellectual History of the Role of Business in American Society, Oxford U.P., 2015.......Guest Post to the Society for U.S. Intellectual History Blog. Brief introduction to the book Progressive Business: An Intellectual History of the Role of Business in American Society, Oxford U.P., 2015....

  9. Tunable, Chemo- and Site-Selective Nitrene Transfer Reactions through the Rational Design of Silver(I) Catalysts.

    Science.gov (United States)

    Alderson, Juliet M; Corbin, Joshua R; Schomaker, Jennifer M

    2017-09-19

    Carbon-nitrogen (C-N) bonds are ubiquitous in pharmaceuticals, agrochemicals, diverse bioactive natural products, and ligands for transition metal catalysts. An effective strategy for introducing a new C-N bond into a molecule is through transition metal-catalyzed nitrene transfer chemistry. In these reactions, a metal-supported nitrene can either add across a C═C bond to form an aziridine or insert into a C-H bond to furnish the corresponding amine. Typical catalysts for nitrene transfer include Rh 2 L n and Ru 2 L n complexes supported by bridging carboxylate and related ligands, as well as complexes based on Cu, Co, Ir, Fe, and Mn supported by porphyrins and related ligands. A limitation of metal-catalyzed nitrene transfer is the ability to predictably select which specific site will undergo amination in the presence of multiple reactive groups; thus, many reactions rely primarily on substrate control. Achieving true catalyst-control over nitrene transfer would open up exciting possibilities for flexible installation of new C-N bonds into hydrocarbons, natural product-inspired scaffolds, existing pharmaceuticals or biorenewable building blocks. Silver-catalyzed nitrene transfer enables flexible control over the position at which a new C-N bond is introduced. Ag(I) supported by simple N-donor ligands accommodates a diverse range of coordination geometries, from linear to tetrahedral to seesaw, enabling the electronic and steric parameters of the catalyst to be tuned independently. In addition, the ligand, Ag salt counteranion, Ag/ligand ratio and the solvent all influence the fluxional and dynamic behavior of Ag(I) complexes in solution. Understanding the interplay of these parameters to manipulate the behavior of Ag-nitrenes in a predictable manner is a key design feature of our work. In this Account, we describe successful applications of a variety of design principles to tunable, Ag-catalyzed aminations, including (1) changing Ag/ligand ratios to influence

  10. Progressive brain compression

    International Nuclear Information System (INIS)

    Thuomas, K.AA.; Inst. of Surgical Research, National Hospital, Oslo; Vlajkovic, S.; Inst. of Surgical Research, National Hospital, Oslo; Ganz, J.C.; Inst. of Surgical Research, National Hospital, Oslo; Nilsson, P.; Inst. of Surgical Research, National Hospital, Oslo; Bergstroem, K.; Inst. of Surgical Research, National Hospital, Oslo; Ponten, U.; Inst. of Surgical Research, National Hospital, Oslo; Zwetnow, N.N.; Inst. of Surgical Research, National Hospital, Oslo

    1993-01-01

    Continuous recording of vital physiological variables and sequential MR imaging were performed simultaneously during continuous expansion of an epidural rubber balloon over the left hemisphere in anaesthetised dogs. Balloon expansion led to a progressive and slgithly nonlinear rise in intracranial CSF pressures and a full in local perfusion pressures. Changes in systemic arterial pressure, pulse rate, and respiration rate usually appeared at a balloon volume of 4% to 5% of the intracranial volume (reaction volume), together with a marked transtentorial pressure gradient and MR imaging changes consistent with tentorial herniation. Respiratory arrest occurred at a balloon volume of approximately 10% of the intracranial volume (apnoea volume), which was associated with occulsion of the cisterna magna, consistent with some degree of foramen magnum herniation. Increase in tissue water was observed beginning at approximately the reaction volume, presumably due to ischaemic oedema, due to the fall in perfusion pressures. (orig.)

  11. Nuclear chemistry progress report

    International Nuclear Information System (INIS)

    Viola, V.E.; Kwiatkowski, K.

    1993-08-01

    This is the annual progress report for the Indiana University nuclear chemistry program for the 1992/1993 year. Accomplishments include the construction, testing, and initial experimental runs of the Indiana Silicon Sphere (ISiS) 4π charged particle detector. ISiS is designed to study energy dissipation and multifragmentation phenomena in light-ion-induced nuclear reactions at medium-to-high energies. Its second test run was to examine 3.6 GeV 3 He beam reactions at Laboratoire National Saturne (LNS) in Saclay. The development and deployment of this system has occupied a great deal of the groups effort this reporting period. Additional work includes: calculations of isotopic IMF yields in the 4 He + 116,124 Sn reaction; cross sections for A = 6 - 30 fragments from the 4 He + 28 Si reaction at 117 and 198 MeV; charging effects of passivated silicon detectors; neck emission of intermediate-mass fragments in the fission of hot heavy nuclei

  12. Gas phase studies of the Pesci decarboxylation reaction: synthesis, structure, and unimolecular and bimolecular reactivity of organometallic ions.

    Science.gov (United States)

    O'Hair, Richard A J; Rijs, Nicole J

    2015-02-17

    CONSPECTUS: Decarboxylation chemistry has a rich history, and in more recent times, it has been recruited in the quest to develop cheaper, cleaner, and more efficient bond-coupling reactions. Thus, over the past two decades, there has been intense investigation into new metal-catalyzed reactions of carboxylic substrates. Understanding the elementary steps of metal-mediated transformations is at the heart of inventing new reactions and improving the performance of existing ones. Fortunately, during the same time period, there has been a convergence in mass spectrometry (MS) techniques, which allows these catalytic processes to be examined efficiently in the gas phase. Thus, electrospray ionization (ESI) sources have been combined with ion-trap mass spectrometers, which in turn have been modified to either accept radiation from tunable OPO lasers for spectroscopy based structural assignment of ions or to allow the study of ion-molecule reactions (IMR). The resultant "complete" gas-phase chemical laboratories provide a platform to study the elementary steps of metal-catalyzed decarboxylation reactions in exquisite detail. In this Account, we illustrate how the powerful combination of ion trap mass spectrometry experiments and DFT calculations can be systematically used to examine the formation of organometallic ions and their chemical transformations. Specifically, ESI-MS allows the transfer of inorganic carboxylate complexes, [RCO2M(L)n](x), (x = charge) from the condensed to the gas phase. These mass selected ions serve as precursors to organometallic ions [RM(L)n](x) via neutral extrusion of CO2, accessible by slow heating in the ion trap using collision induced dissociation (CID). This approach provides access to an array of organometallic ions with well-defined stoichiometry. In terms of understanding the decarboxylation process, we highlight the role of the metal center (M), the organic group (R), and the auxiliary ligand (L), along with cluster nuclearity, in

  13. Progressivity Enhanced

    Directory of Open Access Journals (Sweden)

    Marko Hren

    2013-09-01

    Full Text Available Rather than a scientific text, the author contributes a concise memorandum from the originator of the idea who has managed the campaign for the conversion of the military barracks into a creative cluster between 1988 and 2002, when he parted ways with Metelkova due to conflicting views on the center’s future. His views shed light on a distant period of time from a perspective of a participant–observer. The information is abundantly supported by primary sources, also available online. However, some of the presented hypotheses are heavily influenced by his personal experiences of xenophobia, elitism, and predatorial behavior, which were already then discernible on the so-called alternative scene as well – so much so that they obstructed the implementation of progressive programs. The author claims that, in spite of the substantially different reality today, the myths and prejudices concerning Metelkova must be done away with in order to enhance its progressive nature. Above all, the paper calls for an objective view on internal antagonisms, mainly originating in deep class divisions between the users. These make a clear distinction between truly marginal ndividuals and the overambitious beau-bourgeois, as the author labels the large part of users of Metelkova of »his« time. On these grounds, he argues for a robust approach to ban all forms of xenophobia and self-ghettoization.

  14. Progress report

    International Nuclear Information System (INIS)

    Brumovsky, M.

    1979-01-01

    Progress Report, covering the period up to the end of 1979 year, was sent to the IAEA according to the research agreement No. 1971 /CF. This work covered the following fields: preparation and dummy irradiation experiments with a new experimental capsule of ''CHOUCA-M'' type; measurement of temperature fields and design of specimen holders; measurement of neutron energy spectrum in the irradiation place in our experimental reactor of VVR-S type (Nuclear Research Institute) using a set of activation detectors; unification and calibration of the measurement of neutron fluence with the use of Fe, Cu, Mn-Mg and Co-Al monitors; development and improvement of the measuring apparatus and technique for the dynamic testing of pre-cracked specimens with determination of dynamic parameters of fracture mechanics; preparation and manufacture of testing specimens from the Japanese steels - forging, plate and weld metal; preparation of the irradiation capsule for assembling

  15. Progress report, 1982

    International Nuclear Information System (INIS)

    1982-01-01

    The report describes a number of areas of research at the TRIUMPH facility. Substantial progress has been made in the experiment to measure charge symmetry breaking in the n-p system. The investigations on polarized nucleon radiative capture on light nuclei have been ongoing with results of the excitation function for p + d→γ + 3 He reaction being published. Studies of the n + p→d + γ reactions are continuing. Results have been obtained in the determination of structure in the three nucleon system by studying the reaction anti d + p using tensor polarized deuterons. The Wolfenstein R-parameter in proton - 4 He elastic scattering has been measured at 500 MeV from 15 to 50 degrees (lab.) using the focal plane polarimeter on the MRS. Other experiments involving quasi-elastic scattering of polarized protons at 300 MeV, fission evaporation competition in heavy nuclei and proton-proton bremsstrahlung have been carried out. The status of the Bevelac heavy ion collaboration and the MWPC facility is also included

  16. Technical progress report

    International Nuclear Information System (INIS)

    1996-01-01

    This report summarizes experimental and theoretical work in basic nuclear physics carried out between October 1, 1995, the closing of our last Progress Report, and September 30, 1996 at the Nuclear Physics Laboratory of the University of Colorado, Boulder, under contracts DE-FG03-93ER-40774 and DE-FG03-95ER-40913 with the United States Department of Energy. The experimental contract supports broadly-based experimental research in intermediate energy nuclear physics. This report includes results from studies of Elementary Systems involving the study of the structure of the nucleon via polarized high-energy positron scattering (the HERMES experiment) and lower energy pion scattering from both polarized and unpolarized nucleon targets. Results from pion- and kaon-induced reactions in a variety of nuclear systems are reported under the section heading Meson Reactions; the impact of these and other results on understanding the nucleus is presented in the Nuclear Structure section. In addition, new results from scattering of high-energy electrons (from CEBAF/TJNAF) and pions (from KEK) from a broad range of nuclei are reported in the section on Incoherent Reactions. Finally, the development and performance of detectors produced by the laboratory are described in the section titled Instrumentation

  17. Capture reactions

    NARCIS (Netherlands)

    Endt, P.M.

    1956-01-01

    Capture reactions will be considered here from the viewpoint of the nuclear spectroscopist. Especially important to him are the capture of neutrons, protons, and alpha particles, which may proceed through narrow resonances, offering a well defined initial state for the subsequent deexcitation

  18. Allergic reactions

    Science.gov (United States)

    ... that don't bother most people (such as venom from bee stings and certain foods, medicines, and pollens) can ... person. If the allergic reaction is from a bee sting, scrape the ... more venom. If the person has emergency allergy medicine on ...

  19. cycloaddition reactions

    Indian Academy of Sciences (India)

    Unknown

    ... has shown very severe limitations in predicting the regioselectivity. In comparison,. DFT-based descriptors are better suited to model the regioselectivity of cycloaddition reactions. Acknowledgements. GG thanks the Council of Scientific and Industrial. Research for a fellowship. References. 1. Winkler J D 1996 Chem. Rev.

  20. Recent advances in osmium-catalyzed hydrogenation and dehydrogenation reactions.

    Science.gov (United States)

    Chelucci, Giorgio; Baldino, Salvatore; Baratta, Walter

    2015-02-17

    CONSPECTUS: A current issue in metal-catalyzed reactions is the search for highly efficient transition-metal complexes affording high productivity and selectivity in a variety of processes. Moreover, there is also a great interest in multitasking catalysts that are able to efficiently promote different organic transformations by careful switching of the reaction parameters, such as temperature, solvent, and cocatalyst. In this context, osmium complexes have shown the ability to catalyze efficiently different types of reactions involving hydrogen, proving at the same time high thermal stability and simple synthesis. In the catalytic reduction of C═X (X = O, N) bonds by both hydrogenation (HY) and transfer hydrogenation (TH) reactions, the most interest has been focused on homogeneous systems based on rhodium, iridium, and in particular ruthenium catalysts, which have proved to catalyze chemo- and stereoselective hydrogenations with remarkable efficiency. By contrast, osmium catalysts have received much less attention because they are considered less active on account of their slower ligand exchange kinetics. Thus, this area remained almost neglected until recent studies refuted these prejudices. The aim of this Account is to highlight the impressive developments achieved over the past few years by our and other groups on the design of new classes of osmium complexes and their applications in homogeneous catalytic reactions involving the hydrogenation of carbon-oxygen and carbon-nitrogen bonds by both HY and TH reactions as well as in alcohol deydrogenation (DHY) reactions. The work described in this Account demonstrates that osmium complexes are emerging as powerful catalysts for asymmetric and non-asymmetric syntheses, showing a remarkably high catalytic activity in HY and TH reactions of ketones, aldehydes, imines, and esters as well in DHY reactions of alcohols. Thus, for instance, the introduction of ligands with an NH function, possibly in combination with a

  1. Progress in nanophotonics 4

    CERN Document Server

    Yatsui, Takashi

    2017-01-01

    This book presents the recent progress in the field of nanophotonics. It contains review-like chapters focusing on various but mutually related topics in nanophotonics written by the world’s leading scientists. Following the elaboration of the idea of nanophotonics, much theoretical and experimental work has been carried out, and several novel photonic devices, high-resolution fabrication, highly efficient energy conversion, and novel information processing have been developed in these years. Novel theoretical models describing the nanometric light-matter interaction, nonequilibrium statistical mechanical models for photon breeding processes and near-field‐assisted chemical reactions as well as light‐matter interaction are also explained in this book. It describes dressed photon technology and its applications, including implementation of nanophotonic devices and systems, fabrication methods and performance characteristics of ultrathin, ultraflexible organic light‐emitting diodes, organic solar cells ...

  2. Spallation reactions

    International Nuclear Information System (INIS)

    Cugon, J.

    1996-01-01

    Spallation reactions dominate the interactions of hadrons with nuclei in the GeV range (from ∼ 0.1 to ∼ 10 GeV). They correspond to a sometimes important ejection of light particles leaving most of the time a residue of mass commensurate with the target mass. The main features of the experimental data are briefly reviewed. The most successful theoretical model, namely the intranuclear cascade + evaporation model, is presented. Its physical content, results and possible improvements are critically discussed. Alternative approaches are shortly reviewed. (author)

  3. Confined Catalysis in the g-C3N4/Pt(111) Interface: Feasible Molecule Intercalation, Tunable Molecule-Metal Interaction, and Enhanced Reaction Activity of CO Oxidation.

    Science.gov (United States)

    Wang, Shujiao; Feng, Yingxin; Yu, Ming'an; Wan, Qiang; Lin, Sen

    2017-09-27

    The deposition of a two-dimensional (2D) atomic nanosheet on a metal surface has been considered as a new route for tuning the molecule-metal interaction and surface reactivity in terms of the confinement effect. In this work, we use first-principles calculations to systematically explore a novel nanospace constructed by placing a 2D graphitic carbon nitride (g-C 3 N 4 ) nanosheet over a Pt(111) surface. The confined catalytic activity in this nanospace is investigated using CO oxidation as a model reaction. With the inherent triangular pores in the g-C 3 N 4 overlayer being taken advantage of, molecules such as CO and O 2 can diffuse to adsorb on the Pt(111) surface underneath the g-C 3 N 4 overlayer. Moreover, the mechanism of intercalation is also elucidated, and the results reveal that the energy barrier depends mainly on the properties of the molecule and the channel. Importantly, the molecule-catalyst interaction can be tuned by the g-C 3 N 4 overlayer, considerably reducing the adsorption energy of CO on Pt(111) and leading to enhanced reactivity in CO oxidation. This work will provide important insight for constructing a promising nanoreactor in which the following is observed: The molecule intercalation is facile; the molecule-metal interaction is efficiently tuned; the metal-catalyzed reaction is promoted.

  4. Progresses in Ab Initio QM/MM Free Energy Simulations of Electrostatic Energies in Proteins: Accelerated QM/MM Studies of pKa, Redox Reactions and Solvation Free Energies

    Energy Technology Data Exchange (ETDEWEB)

    Kamerlin, Shina C. L.; Haranczyk, Maciej; Warshel, Arieh

    2009-03-01

    Hybrid quantum mechanical / molecular mechanical (QM/MM) approaches have been used to provide a general scheme for chemical reactions in proteins. However, such approaches still present a major challenge to computational chemists, not only because of the need for very large computer time in order to evaluate the QM energy but also because of the need for propercomputational sampling. This review focuses on the sampling issue in QM/MM evaluations of electrostatic energies in proteins. We chose this example since electrostatic energies play a major role in controlling the function of proteins and are key to the structure-function correlation of biological molecules. Thus, the correct treatment of electrostatics is essential for the accurate simulation of biological systems. Although we will be presenting here different types of QM/MM calculations of electrostatic energies (and related properties), our focus will be on pKa calculations. This reflects the fact that pKa of ionizable groups in proteins provide one of the most direct benchmarks for the accuracy of electrostatic models of macromolecules. While pKa calculations by semimacroscopic models have given reasonable results in many cases, existing attempts to perform pKa calculations using QM/MM-FEP have led to large discrepancies between calculated and experimental values. In this work, we accelerate our QM/MM calculations using an updated mean charge distribution and a classical reference potential. We examine both a surface residue (Asp3) of the bovine pancreatic trypsin inhibitor, as well as a residue buried in a hydrophobic pocket (Lys102) of the T4-lysozyme mutant. We demonstrate that by using this approach, we are able to reproduce the relevant sidechain pKas with an accuracy of 3 kcal/mol. This is well within the 7 kcal/mol energy difference observed in studies of enzymatic catalysis, and is thus sufficient accuracy to determine the main contributions to the catalytic energies of enzymes. We also provide an

  5. Nuclear reactions

    International Nuclear Information System (INIS)

    Corner, J.; Richardson, K.; Fenton, N.

    1990-01-01

    Nuclear reactions' marks a new development in the study of television as an agency of public policy debate. During the Eighties, nuclear energy became a major international issue. The disasters at Three-mile Island and Chernobyl created a global anxiety about its risks and a new sensitivity to it among politicians and journalists. This book is a case-study into documentary depictions of nuclear energy in television and video programmes and into the interpretations and responses of viewers drawn from many different occupational groupings. How are the complex and specialist arguments about benefit, risk and proof conveyed through the different conventions of commentary, interview and film sequence? What symbolic associations does the visual language of television bring to portrayals of the issue? And how do viewers make sense of various and conflicting accounts, connecting what they see and hear on the screen with their pre-existing knowledge, experience and 'civic' expectations. The authors examine some of the contrasting forms and themes which have been used by programme makers to explain and persuade, and then give a sustained analysis of the nature and sources of viewers' own accounts. 'Nuclear Reactions' inquires into the public meanings surrounding energy and the environment, spelling out in its conclusion some of the implications for future media treatments of this issue. It is also a key contribution to the international literature on 'television knowledge' and the processes of active viewing. (author)

  6. About the role of physico-chemical properties and hydrodynamics on the progress of a precipitation reaction: the case of cerium oxalate particles produced during the coalescence of drops

    International Nuclear Information System (INIS)

    Jehannin, Marie

    2015-01-01

    The nucleation and growth of solid particles resulting from a precipitation process is an important topic both for fundamental science and industrial applications. In a precipitation process, different reactants, which are individually soluble in the same solvent, get in contact and react to form insoluble solid particles (the precipitate). The properties of the produced particles are the result of a strong coupling between the chemical reaction and the reactants feed and mixing rates. The latter are mainly provided by diffusive and convective transport through a reaction-diffusion-convection process. In the emulsion precipitation process considered here the reactants are enclosed into droplets. The local transport conditions can be modified in many ways by tuning the relevant parameters and thus be used to control the properties of the precipitated particles. The aim of this study is to investigate the impact of local flow and mixing conditions during the coalescence on the precipitates properties, mainly their size, morphology and distribution. The test system consists of two coalescing droplets: one drop contains oxalic acid dissolved in an aqueous solution, while the other one contains cerium nitrate. Upon contact of the two miscible solutions a precipitate of cerium oxalate is formed. Besides, by adding chosen amounts of diols into the droplets, their surface tensions can be adjusted. Differences in surface tension cause a surface tension gradient in the section where both drops get in contact. This can lead to a Marangoni flow directed from the low surface tension interface to the high surface tension interface. This local convective flow will modify the local mixing conditions of the two solutions. This study focuses on how, where, when, which precipitate forms as function of the initial stoichiometry of the reactants and of the process conditions (e.g. the mixing conditions affected by the Marangoni flow). For this purpose, two configurations of coalescing

  7. Applications of functionalized polymers in catalysis. Progress report 3, July 15, 1979-July 1, 1980

    Energy Technology Data Exchange (ETDEWEB)

    Bergbreiter, D.E.

    1980-07-01

    Research on applications of polymers in catalysis has encompassed three areas: the use of functionalized polymers to detect soluble intermediates in heterogeneous Group VIII metal catalyzed arene hydrogenations; a study of olefin isomerization and hydrogenations catalyzed by polystyrene supported bis(cyclopentadienyl)titanium dichloride and an alkylmagnesium halide; and the acceleration in rate of an olefin hydrogenation catalyzed by homogeneous rhodium and ruthenium complexes as a result of absorption of triphenylphosphine by silver (I) polystyrenesulfonate. The first project found that polymer bound trapping agents were unable to detect soluble intermediates such as dienes, free radicals, or reducing agents in platinum-catalyzed benzene hydrogenation at 60 psi H/sub 2/ and 30/sup 0/C. The inability to detect diene intermediates was shown to be the result of the lower reactivity of the polymeric reagent versus an active catalyst. The polymer-supported titanium catalysts studied were unusual in that immobilization of a catalyst in this case altered the catalyst's specificity relative to its homogeneous counterpart. Preliminary results from the third project demonstrate the potential of simple functionalized polymers to improve existing homogeneously catalyzed reactions. Rate increases for olefin hydrogenations using C1Rh(Ph/sub 3/P)/sub 3/, HRh(CO)(Ph/sub 3/)/sub 3/, HRu(OAc)(Ph/sub 3/P), H/sub 2/Ru(Ph/sub 3/P)/sub 4/, Cl/sub 2/Ru(Ph/sub 3/P)/sub 3/, and Cl/sub 2/Ru(Ph/sub 3/P)/sub 4/ ranged from 25 to 3000%.

  8. Chain reaction

    International Nuclear Information System (INIS)

    Balogh, Brian.

    1991-01-01

    Chain Reaction is a work of recent American political history. It seeks to explain how and why America came to depend so heavily on its experts after World War II, how those experts translated that authority into political clout, and why that authority and political discretion declined in the 1970s. The author's research into the internal memoranda of the Atomic Energy Commission substantiates his argument in historical detail. It was not the ravages of American anti-intellectualism, as so many scholars have argued, that brought the experts back down to earth. Rather, their decline can be traced to the very roots of their success after World War II. The need to over-state anticipated results in order to garner public support, incessant professional and bureaucratic specialization, and the sheer proliferation of expertise pushed arcane and insulated debates between experts into public forums at the same time that a broad cross section of political participants found it easier to gain access to their own expertise. These tendencies ultimately undermined the political influence of all experts. (author)

  9. Arithmetic Progressions on Conics

    OpenAIRE

    Ciss, Abdoul Aziz; Moody, Dustin

    2016-01-01

    In this paper, we look at long arithmetic progressions on conics. By an arithmetic progression on a curve, we mean the existence of rational points on the curve whose x-coordinates are in arithmetic progression. We revisit arithmetic progressions on the unit circle, constructing 3-term progressions of points in the first quadrant containing an arbitrary rational point on the unit circle. We also provide infinite families of three term progressions on the unit hyperbola, as well as conics ax2 ...

  10. Drug-induced progressive multifocal leukoencephalopathy

    DEFF Research Database (Denmark)

    Vermeer, N S; Straus, S M J M; Mantel-Teeuwisse, A K

    2015-01-01

    Progressive multifocal leukoencephalopathy (PML) has been identified as a serious adverse drug reaction (ADR) of several immunomodulatory biologicals. In this study, we contrasted the reporting patterns of PML for two biologicals for which the risk was identified at different points in their life......Progressive multifocal leukoencephalopathy (PML) has been identified as a serious adverse drug reaction (ADR) of several immunomodulatory biologicals. In this study, we contrasted the reporting patterns of PML for two biologicals for which the risk was identified at different points...

  11. Geothermal progress monitor. Progress report No. 1

    Energy Technology Data Exchange (ETDEWEB)

    1979-12-01

    Progress is reported on the following: electrical uses, direct-heat uses, drilling activities, leases, geothermal loan guarantee program, general activities, and legal, institutional, and regulatory activites. (MHR)

  12. Arithmetic Progressions on Conics.

    Science.gov (United States)

    Ciss, Abdoul Aziz; Moody, Dustin

    2017-01-01

    In this paper, we look at long arithmetic progressions on conics. By an arithmetic progression on a curve, we mean the existence of rational points on the curve whose x -coordinates are in arithmetic progression. We revisit arithmetic progressions on the unit circle, constructing 3-term progressions of points in the first quadrant containing an arbitrary rational point on the unit circle. We also provide infinite families of three term progressions on the unit hyperbola, as well as conics ax 2 + cy 2 = 1 containing arithmetic progressions as long as 8 terms.

  13. Communication of nuclear data progress

    International Nuclear Information System (INIS)

    2006-07-01

    This is the 30th issue of Communication of Nuclear Data Progress (CNDP), in which the progress and achievements in nuclear data field in China during 2004 are carried. It includes the evaluations and model calculations of neutron data for n+ 31 P, 59 Co, 92-106 Mo, Nat-116 Cd, 233 U and the covariance data evaluation of experimental data for 27 Al, update the decay data for radionuclide 7 Be. Some results of studies for nuclear evaluation tool and model are also included in this issue, i.e. reaction mechanism studies of 5 He, a new method of evaluating the discrepant data, linear fit of correlative data by least squared method et al. (authors)

  14. Progress in front propagation research

    Science.gov (United States)

    Fort, Joaquim; Pujol, Toni

    2008-08-01

    We review the progress in the field of front propagation in recent years. We survey many physical, biophysical and cross-disciplinary applications, including reduced-variable models of combustion flames, Reid's paradox of rapid forest range expansions, the European colonization of North America during the 19th century, the Neolithic transition in Europe from 13 000 to 5000 years ago, the description of subsistence boundaries, the formation of cultural boundaries, the spread of genetic mutations, theory and experiments on virus infections, models of cancer tumors, etc. Recent theoretical advances are unified in a single framework, encompassing very diverse systems such as those with biased random walks, distributed delays, sequential reaction and dispersion, cohabitation models, age structure and systems with several interacting species. Directions for future progress are outlined.

  15. Progress in front propagation research

    Energy Technology Data Exchange (ETDEWEB)

    Fort, Joaquim [Departament de Fisica, Campus de Montilivi, Universitat de Girona, 17071 Girona, Catalonia (Spain); Pujol, Toni [Departament de Mecanica, Campus de Montilivi, Universitat de Girona, 17071 Girona, Catalonia (Spain)

    2008-08-15

    We review the progress in the field of front propagation in recent years. We survey many physical, biophysical and cross-disciplinary applications, including reduced-variable models of combustion flames, Reid's paradox of rapid forest range expansions, the European colonization of North America during the 19th century, the Neolithic transition in Europe from 13 000 to 5000 years ago, the description of subsistence boundaries, the formation of cultural boundaries, the spread of genetic mutations, theory and experiments on virus infections, models of cancer tumors, etc. Recent theoretical advances are unified in a single framework, encompassing very diverse systems such as those with biased random walks, distributed delays, sequential reaction and dispersion, cohabitation models, age structure and systems with several interacting species. Directions for future progress are outlined.

  16. Nuclear theory. 1998 progress report

    International Nuclear Information System (INIS)

    1998-01-01

    Summaries of progress made on the following topics are given: (1) nonresonant contributions to inelastic N→Δ(1232) parity violation; (2) neutron distribution effects in elastic nuclear parity violation; (3) Wilson RG for scalar-plus-fermion field theories at finite density; (4) Perturbation theory for spin ladders using angular momentum coupled bases; (5) mean-field theory for spin ladders using angular momentum density; (6) finite temperature renormalization group effective potentials for the linear Sigma model; (7) negative-parity baryon resonances from lattice QCD; (8) the N→Δ electromagnetic transition amplitudes from QCD sum rules; and (9) higher nucleon resonances in exclusive reactions (γ, πN) on nuclei

  17. Fundamental studies of metal fluorination reactions. Fourth annual progress report

    Energy Technology Data Exchange (ETDEWEB)

    Rapp, R.A.

    1979-01-01

    In order to investigate the effects of oxygen on the electrical characteristics of the bulk and the electrode/electrolyte interface of CaF/sub 2/ electrochemical cells separately, the equivalent electrical circuits for the following cells were determined, and the geometric capacitances, the double-layer capacitances, the bulk conductivities and the interface conductivities were examined: Ni + NiF/sub 2//CaF/sub 2//Ni + NiF/sub 2/, Ni + NiO/CaF/sub 2//Ni + NiO, and Cu + Cu/sub 2/O/CaF/sub 2//Cu + Cu/sub 2/O. After understanding the behavior of oxygen at the electrode/electrolyte interface and in the bulk of a CaF/sub 2/ electrochemical cell, a theory was developed to rationalize the emf values of the Ni + NiO/CaF/sub 2//Cu + Cu/sub 2/O cell.

  18. Progress in all-order breakup reaction theories

    Indian Academy of Sciences (India)

    which are the starting points for a discussion on the theory of breakup processes. The ground state wave function of the projectile, φa(rbc), satisfies. (Tb + Tc + ..... constructive at smaller neutron angles, often being larger or almost equal to the individual nuclear terms. These results, thus, indicate that the CNI terms are not.

  19. Charged particle-induced nuclear fission reactionsProgress and ...

    Indian Academy of Sciences (India)

    of fission process for nuclei at moderately high excitation energies with large angular momentum values. ... model analysis of these data, the fission barrier can be determined for the fissioning com- pound nucleus. .... qualitative understanding of the various features of mass division are understood in terms of scission point ...

  20. 1984-85 ISN progress report

    International Nuclear Information System (INIS)

    1985-01-01

    This progress report ISN 1984-1985 deals with the following subjects: nuclear physics theory, peripheral and intermediate energy physics, characteristics of reaction mechanisms in heavy ion collisions, nuclear structure, fundamental interactions, experimental methods and new instrumentation, some interdisciplinary research activities and technical activities, the SARA cyclotron and finally, technology transfer and valorisation [fr

  1. Pelletron progress report, July 1 1978 - June 30 1979

    International Nuclear Information System (INIS)

    1979-01-01

    Progress is reported in research by the University of Melbourne Pelletron Accelerator Group. Areas covered include lifetime determination of nuclear states, reaction studies and nuclear astrophysics, elemental microanalysis and depth profiling and a report on the pelletron machine

  2. Progress in MELCOR development and assessment

    Energy Technology Data Exchange (ETDEWEB)

    Summers, R.M.; Kmetyk, L.N.; Cole, R.K. Jr.; Smith, R.C.; Elsbernd, A.E.; Stuart, D.S.; Thompson, S.L. [Sandia National Labs., Albuquerque, NM (United States). Modeling and Analysis Dept.

    1995-04-01

    MELCOR models the progression of severe accidents in light water reactor nuclear power plants. Recent efforts in MELCOR development to incorporate CORCON-Mod3 models for core-concrete interactions, new models for advanced reactors, and improvements to several other existing models have resulted in release of MELCOR 1.8.3. In addition, continuing efforts to expand the code assessment database have filled in many of the gaps in phenomenological coverage. Efforts are now under way to develop models for chemical interactions of fission products with structural surfaces and for reactions of iodine in the presence of water, and work is also in progress to improve models for the scrubbing of fission products by water pools, the chemical reactions of boron carbide with steam, and the coupling of flow blockages with the hydrodynamics. Several code assessment analyses are in progress, and more are planned.

  3. Progress in MELCOR development and assessment

    International Nuclear Information System (INIS)

    Summers, R.M.; Kmetyk, L.N.; Cole, R.K. Jr.; Smith, R.C.; Elsbernd, A.E.; Stuart, D.S.; Thompson, S.L.

    1995-01-01

    MELCOR models the progression of severe accidents in light water reactor nuclear power plants. Recent efforts in MELCOR development to incorporate CORCON-Mod3 models for core-concrete interactions, new models for advanced reactors, and improvements to several other existing models have resulted in release of MELCOR 1.8.3. In addition, continuing efforts to expand the code assessment database have filled in many of the gaps in phenomenological coverage. Efforts are now under way to develop models for chemical interactions of fission products with structural surfaces and for reactions of iodine in the presence of water, and work is also in progress to improve models for the scrubbing of fission products by water pools, the chemical reactions of boron carbide with steam, and the coupling of flow blockages with the hydrodynamics. Several code assessment analyses are in progress, and more are planned

  4. [Primary progressive apraxia].

    Science.gov (United States)

    Kondo, Masaki

    2011-10-01

    Similar to primary progressive aphasia, primary progressive apraxia has been considered to cause slowly progressive apraxia without dementia and to be a dependent disease. Of the 3 cases reported by De Renzi in 1986, 1 case showed slowly progressive apraxia without dementia. Since then, cases of primary progressive apraxia have been reported occasionally. Studies on primary progressive apraxia indicate that not only focal lesions caused by vascular disease or brain trauma but also lesions caused by neurodegenerative disease can cause apraxia alone, thereby supporting the hypothesis that apraxia-associated neurodegeneration may develop in cases of primary progressive apraxia. The pathogenesis of primary progressive apraxia is yet to be elucidated. Clinical features of primary progressive apraxia are not precisely distinguishable from those of corticobasal degeneration (CBD); further, previous studies have indicated that the brain pathology observed in primary progressive apraxia is consistent with that in Alzheimer disease (AD) or Pick disease. "Primary" progressive apraxia may be intrinsically different from slowly progressive apraxia that is associated with CBD, AD, or Pick disease and may show specific pathological findings. On the other hand, primary progressive apraxia may not be a dependent disease but a syndrome characterized by prolonged neurodegeneration that is observed in various degenetive dementias such as CBD, AD, or Pick disease.

  5. Catalysis of Photochemical Reactions.

    Science.gov (United States)

    Albini, A.

    1986-01-01

    Offers a classification system of catalytic effects in photochemical reactions, contrasting characteristic properties of photochemical and thermal reactions. Discusses catalysis and sensitization, examples of catalyzed reactions of excepted states, complexing ground state substrates, and catalysis of primary photoproducts. (JM)

  6. On Thermonuclear Reaction Rates

    OpenAIRE

    Haubold, H. J.; Mathai, A. M.

    1996-01-01

    Nuclear reactions govern major aspects of the chemical evolution of galaxies and stars. Analytic study of the reaction rates and reaction probability integrals is attempted here. Exact expressions for the reaction rates and reaction probability integrals for nuclear reactions in the cases of nonresonant, modified nonresonant, screened nonresonant and resonant cases are given. These are expressed in terms of H-functions, G-functions and in computable series forms. Computational aspects are als...

  7. Primary Progressive Aphasia

    Science.gov (United States)

    ... which cause different symptoms. Semantic variant primary progressive aphasia Symptoms include these difficulties: Comprehending spoken or written ... word meanings Naming objects Logopenic variant primary progressive aphasia Symptoms include: Having difficulty retrieving words Frequently pausing ...

  8. Progressive Pigmentary Purpura

    Science.gov (United States)

    ... Category: Share: Yes No, Keep Private Progressive Pigmentary Purpura Share | Progressive pigmentary purpura (we will call it PPP) is a group ... conditions ( Schamberg's disease , Lichenoid dermatitis of Gourgerot-Blum, purpura annularis telangiectodes of Majocchi and Lichen aureus). Schamberg's ...

  9. Progressive Supranuclear Palsy

    Science.gov (United States)

    ... alterations of mood and behavior, including depression and apathy as well as progressive mild dementia. The disorder's ... alterations of mood and behavior, including depression and apathy as well as progressive mild dementia. The disorder's ...

  10. Progress in K spectroscopy

    International Nuclear Information System (INIS)

    Leith, D.W.G.S.

    1977-07-01

    The progress in the field of K* spectroscopy is reviewed within the framework of the simple harmonic oscillator quark model, and contrasted with the recent progress made in the charmonium spectroscopy

  11. Progressive Multifocal Leukoencephalopathy

    Science.gov (United States)

    ... most prominent symptoms are clumsiness; progressive weakness; and visual, speech, and sometimes personality changes. The progression of deficits leads to life-threatening disability and (frequently) death. A diagnosis of PML can ...

  12. White matter lesion progression

    DEFF Research Database (Denmark)

    Hofer, Edith; Cavalieri, Margherita; Bis, Joshua C

    2015-01-01

    BACKGROUND AND PURPOSE: White matter lesion (WML) progression on magnetic resonance imaging is related to cognitive decline and stroke, but its determinants besides baseline WML burden are largely unknown. Here, we estimated heritability of WML progression, and sought common genetic variants...... and previous association studies. RESULTS: A total of 1085 subjects showed WML progression. The heritability estimate for WML progression was low at 6.5%, and no single-nucleotide polymorphisms achieved genome-wide significance (PFour loci were suggestive (P

  13. Removal of heavy metals and organic contaminants from aqueous streams by novel filtration methods. 1998 annual progress report

    International Nuclear Information System (INIS)

    Rodriguez, N.M.

    1998-01-01

    'Graphite nanofibers are a new type of material consisting of nanosized graphite platelets where only edges are exposed. Taking advantage of this unique configuration the authors objective is: (1) To produce graphite nanofibers with structural properties suitable for the removal of contaminants from water. (2) To test the suitability of the material in the removal of organic from aqueous solutions. (3) To determine the ability of the nanofibers to function as an electrochemical separation medium the selective removal of metal contaminants from solutions. This report summarizes work after 1.5 of a 3-year project. During this period, efforts have been concentrated on the production, characterization and optimization of graphite nanofibers (GNF). This novel material has been developed in the laboratory from the metal catalyzed decomposition of certain hydrocarbons (1). The structures possess a cross-sectional area that varies between 5 to 100 nm and have lengths ranging from 5 to 100 mm (2). High-resolution transmission electron microscopy studies have revealed that the nanofibers consist of extremely well-ordered graphite platelets, which are oriented in various directions with respect to the fiber axis (3). The arrangement of the graphene layers can be tailored to a desired geometry by choice of the correct catalyst system and reaction conditions, and it is therefore possible to generate structures where the layers are stacked in a ribbon, herring-bone, or stacked orientation. The research has been directed on two fronts: (a) the use of the material for the removal of organic contaminants, and (b) taking advantage of the high electrical conductivity as well as high surface area of the material to use it as electrode for the electrochemical removal of metal pollutants from aqueous streams.'

  14. Electrochemical promotion of catalytic reactions

    Science.gov (United States)

    Imbihl, R.

    2010-05-01

    The electrochemical promotion of heterogeneously catalyzed reactions (EPOC) became feasible through the use of porous metal electrodes interfaced to a solid electrolyte. With the O 2- conducting yttrium stabilized zirconia (YSZ), the Na + conducting β″-Al 2O 3 (β-alumina), and several other types of solid electrolytes the EPOC effect has been demonstrated for about 100 reaction systems in studies conducted mainly in the mbar range. Surface science investigations showed that the physical basis for the EPOC effect lies in the electrochemically induced spillover of oxygen and alkali metal, respectively, onto the surface of the metal electrodes. For the catalytic promotion effect general concepts and mechanistic schemes were proposed but these concepts and schemes are largely speculative. Applying surface analytical tools to EPOC systems the proposed mechanistic schemes can be verified or invalidated. This report summarizes the progress which has been achieved in the mechanistic understanding of the EPOC effect.

  15. Clozapine-associated extrapyramidal reaction.

    Science.gov (United States)

    Elliott, E S; Marken, P A; Ruehter, V L

    2000-05-01

    To report a case of extrapyramidal reaction associated with a dosage increase of clozapine. A 44-year-old white man with a 20-year history of chronic paranoid schizophrenia was admitted to an inpatient psychiatric facility. His prior medications restarted on admission were clozapine 650 mg at bedtime, haloperidol 10 mg at bedtime, clonazepam 2 mg/d, and aspirin 325 mg/d. Two days after admission (hospital day 3), clozapine and clonazepam were discontinued, and he was prescribed haloperidol 5 mg every morning and 10 mg every evening. Stabilization occurred over the following 24 days, with progressively lower dosages of haloperidol and increasing dosages of clozapine. Haloperidol was discontinued on day 24. On day 47, the patient was agitated and making bizarre statements; thus, the morning dose of clozapine was increased by 50 mg (total 450 mg/d). On day 48 at 2200, a dystonic reaction was diagnosed; he received intramuscular diphenhydramine 50 mg, which caused the reaction to subside. At the time of the adverse reaction, he was prescribed clozapine 450 mg/d, vitamin E 400 IU three times daily, aspirin 325 mg/d, and acetaminophen, milk of magnesia, and Maalox as needed. Although the risk of extrapyramidal symptoms (EPS) is significantly lower with clozapine than with conventional agents, elevated clozapine blood concentrations have been reported to cause EPS; other reports have cited severe dystonias and dyskinesias on abrupt clozapine withdrawal. Considering the medications prescribed at the time and the discontinuation of haloperidol 24 days before the event, clozapine was the most likely cause of the extrapyramidal reaction. Regardless of anticipated safety associated with novel antipsychotics such as clozapine, reports of dystonic reactions must be taken into account and patients monitored appropriately.

  16. Florid periosteal reaction and focal fibrocartilaginous dysplasia

    International Nuclear Information System (INIS)

    Nakase, T.; Yasui, Natsuo; Araki, Nobuhito; Tanaka, Makoto; Yoshikawa, Hideki; Ochi, Takahiro; Kuratsu, Shigeyuki

    1998-01-01

    Focal fibrocartilaginous dysplasia (FFCD) is a rare condition causing tibia vara in childhood. It is characterized by progressive tibia vara in young children with a characteristic radiographic lesion. This paper is thought to be the first to describe FFCD exhibiting florid periosteal reaction at the time of presentation with a subtle faint osteolytic lesion in the diametaphysis of the proximal tibia. (orig.)

  17. Biomarkers of adverse drug reactions.

    Science.gov (United States)

    Carr, Daniel F; Pirmohamed, Munir

    2018-02-01

    Adverse drug reactions can be caused by a wide range of therapeutics. Adverse drug reactions affect many bodily organ systems and vary widely in severity. Milder adverse drug reactions often resolve quickly following withdrawal of the casual drug or sometimes after dose reduction. Some adverse drug reactions are severe and lead to significant organ/tissue injury which can be fatal. Adverse drug reactions also represent a financial burden to both healthcare providers and the pharmaceutical industry. Thus, a number of stakeholders would benefit from development of new, robust biomarkers for the prediction, diagnosis, and prognostication of adverse drug reactions. There has been significant recent progress in identifying predictive genomic biomarkers with the potential to be used in clinical settings to reduce the burden of adverse drug reactions. These have included biomarkers that can be used to alter drug dose (for example, Thiopurine methyltransferase (TPMT) and azathioprine dose) and drug choice. The latter have in particular included human leukocyte antigen (HLA) biomarkers which identify susceptibility to immune-mediated injuries to major organs such as skin, liver, and bone marrow from a variety of drugs. This review covers both the current state of the art with regard to genomic adverse drug reaction biomarkers. We also review circulating biomarkers that have the potential to be used for both diagnosis and prognosis, and have the added advantage of providing mechanistic information. In the future, we will not be relying on single biomarkers (genomic/non-genomic), but on multiple biomarker panels, integrated through the application of different omics technologies, which will provide information on predisposition, early diagnosis, prognosis, and mechanisms. Impact statement • Genetic and circulating biomarkers present significant opportunities to personalize patient therapy to minimize the risk of adverse drug reactions. ADRs are a significant heath issue

  18. Hot atom chemistry: Three decades of progress

    International Nuclear Information System (INIS)

    Urch, D.S.

    1990-01-01

    The seminal experiments of Szilard and Chalmers indicated that the energy released in a nuclear transformation could be used to initiate chemical reaction. But basic studies of small molecules in the gas phase, from which reaction mechanisms could be elucidated, were not made until the late 50's. Since then theory and experiments have gone hand in hand in the study of the hot atom reactions of many recoil species. This review will present a broad overview of progress that has been made in understanding how the energy received by the atom (translation, ionization, electronic) in a nuclear transformation is used to drive chemical reactions. The limitations implied by concomitant radiation damage and ignorance of the exact state of the reacting species, upon fundamental studies and practical applications, will also be discussed

  19. Transition Metal-Catalyzed Regioselective Asymmetric Mono-hydrogenation of Dienes and Polyenes.

    Science.gov (United States)

    Margarita, Cristiana; Rabten, Wangchuk; Andersson, Pher G

    2018-02-28

    Organic compounds containing multiple C=C bonds are attractive substrates for catalytic asymmetric hydrogenation. The full saturation of prochiral double bonds, controlling the creation of two or more stereocenters in one step, is obviously a remarkable goal. However, another fascinating and useful option is to selectively introduce a new defined stereogenic center, while leaving other double bonds untouched. Thus, the retained functionalities can be further exploited in synthesis. Examples of regio- and enantioselective mono-hydrogenations of polyolefins are highlighted in this Concept article, and are divided according to the nature of the reduced double bond and the transition-metal catalyst used. Alkenes bearing coordinating functional groups are often preferentially hydrogenated by Rh- and Ru-complexes, while the more recently developed Ir-based catalysts promote the selective saturation on alkyl-substituted olefins. Relevant applications of this effective methodology in the synthesis of natural products are included to demonstrate its value in organic synthesis. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Metal ions, not metal-catalyzed oxidative stress, cause clay leachate antibacterial activity.

    Directory of Open Access Journals (Sweden)

    Caitlin C Otto

    Full Text Available Aqueous leachates prepared from natural antibacterial clays, arbitrarily designated CB-L, release metal ions into suspension, have a low pH (3.4-5, generate reactive oxygen species (ROS and H2O2, and have a high oxidation-reduction potential. To isolate the role of pH in the antibacterial activity of CB clay mixtures, we exposed three different strains of Escherichia coli O157:H7 to 10% clay suspensions. The clay suspension completely killed acid-sensitive and acid-tolerant E. coli O157:H7 strains, whereas incubation in a low-pH buffer resulted in a minimal decrease in viability, demonstrating that low pH alone does not mediate antibacterial activity. The prevailing hypothesis is that metal ions participate in redox cycling and produce ROS, leading to oxidative damage to macromolecules and resulting in cellular death. However, E. coli cells showed no increase in DNA or protein oxidative lesions and a slight increase in lipid peroxidation following exposure to the antibacterial leachate. Further, supplementation with numerous ROS scavengers eliminated lipid peroxidation, but did not rescue the cells from CB-L-mediated killing. In contrast, supplementing CB-L with EDTA, a broad-spectrum metal chelator, reduced killing. Finally, CB-L was equally lethal to cells in an anoxic environment as compared to the aerobic environment. Thus, ROS were not required for lethal activity and did not contribute to toxicity of CB-L. We conclude that clay-mediated killing was not due to oxidative damage, but rather, was due to toxicity associated directly with released metal ions.

  1. Metal-catalyzed growth of In2O3 nanotowers using thermal evaporation and oxidation method

    Science.gov (United States)

    Jian, Liu; Shihua, Huang; Lü, He

    2015-12-01

    Large-scale In2O3 nanotowers with different cross sections were synthesized by a thermal evaporation and oxidation technique using metal as the catalyst. The morphologies and structural characterizations of In2O3 nanotowers are dependent on growth processes, such as different metal (Au, Ag or Sn) catalysts, the relative position of the substrate and evaporation source, growth temperature, gas flow rate, and growth time. In2O3 nanotowers cannot be observed using Sn as the catalyst, which indicates that metal liquid droplets play an important role in the initial stages of the growth of In2O3 nanotowers. The formation of an In2O3 nanotower is attributed to the competitive growth model between a lateral growth controlled by vapor-solid mechanism and an axial vapor-liquid-solid growth mechanism mediated by metal liquid nanodroplets. The synthesized In2O3 nanostructures with novel tower-shaped morphology may have potential applications in optoelectronic devices and gas sensors. Project supported by the National Natural Science Foundation of China (No. 61076055), the Open Project Program of Surface Physics Laboratory (National Key Laboratory) of Fudan University (No. KF2015_02), the Zhejiang Provincial Science and Technology Key Innovation Team (No. 2011R50012), and the Zhejiang Provincial Key Laboratory (No. 2013E10022).

  2. Engineering catalyst microenvironments for metal-catalyzed hydrogenation of biologically derived platform chemicals.

    Science.gov (United States)

    Schwartz, Thomas J; Johnson, Robert L; Cardenas, Javier; Okerlund, Adam; Da Silva, Nancy A; Schmidt-Rohr, Klaus; Dumesic, James A

    2014-11-17

    It is shown that microenvironments formed around catalytically active sites mitigate catalyst deactivation by biogenic impurities that are present during the production of biorenewable chemicals from biologically derived species. Palladium and ruthenium catalysts are inhibited by the presence of sulfur-containing amino acids; however, these supported metal catalysts are stabilized by overcoating with poly(vinyl alcohol) (PVA), which creates a microenvironment unfavorable for biogenic impurities. Moreover, deactivation of Pd catalysts by carbon deposition from the decomposition of highly reactive species is suppressed by the formation of bimetallic PdAu nanoparticles. Thus, a PVA-overcoated PdAu catalyst was an order of magnitude more stable than a simple Pd catalyst in the hydrogenation of triacetic acid lactone, which is the first step in the production of biobased sorbic acid. A PVA-overcoated Ru catalyst showed a similar improvement in stability during lactic acid hydrogenation to propylene glycol in the presence of methionine. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Transition metal catalyzed oxidation of Alcell lignin, soda lignin, and lignin model compounds in ionic liquids

    NARCIS (Netherlands)

    Zakzeski, J.; Jongerius, A.L.; Weckhuysen, B.M.

    2013-01-01

    Lignin is a component of lignocellulosic biomass from which important aromatic compounds can potentially be obtained. In the present work, Alcell and soda lignin were dissolved in the ionic liquid 1-ethyl-3-methylimidazolium diethylphosphate (EMIM DEP) and subsequently oxidized using several

  4. Transition metal catalyzed polymerization of butadiene in supercritical CO{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Borkowsky, S. [Los Alamos National Lab., NM (United States)]|[Stanford Univ., CA (United States); Tumas, W. [Los Alamos National Lab., NM (United States); Waymouth, R.M. [Stanford Univ., CA (United States)

    1998-08-01

    A class of Ni(II) catalysts has been shown to stereoselectively catalyze the 1,4-polymerization of butadiene. The authors have been investigating the use of supercritical CO{sub 2} as an environmentally benign replacement solvent for conventional hydrocarbon and halocarbon solvents for a variety of chemical transformations. Above 31 C, CO{sub 2} enters a supercritical phase, where its physical properties are both liquid-like and gas-like. Importantly, the solvent properties such as dielectric constant for supercritical fluids can be varied by changing the pressure of the fluid. In this report, the authors present results of an investigation of the polymerization of 1,3-butadiene using [({pi}-allyl) Ni(CF{sub 3}CO{sub 2})]{sub 2} in supercritical CO{sub 2}. They conducted 1,3-butadiene polymerizations in CO{sub 2} to determine whether or not they could systematically and predictably adjust the regiochemistry/stereochemistry of the polybutadiene product by varying the solution properties at different pressures. They also mention experiments with CO catalysts that are known to give 1,2-syndiotactic polybutadiene, and with a Pd catalyst system that is known to copolymerize olefin with CO to give perfectly alternating copolymers.

  5. Exploratory study of nuclear reaction data utility framework of Japan charged particle reaction data group (JCPRG)

    Energy Technology Data Exchange (ETDEWEB)

    Masui, Hiroshi; Ohnishi, Akira; Kato, Kiyoshi [Hokkaido Univ., Graduate School of Science, Sapporo, Hokkaido (Japan); Ohbayasi, Yosihide [Hokkaido Univ., Meme Media Lab., Sapporo, Hokkaido (Japan); Aoyama, Shigeyoshi [Kitami Institute of Technology, Information Processing Center, Kitami, Hokkaido (Japan); Chiba, Masaki [Sapporo Gakuin Univ., Faculty of Social Information, Ebetsu, Hokkaido (Japan)

    2002-08-01

    Compilation, evaluation and dissemination are essential pieces of work for the nuclear data activities. We, Japan charged particle data group, have researched the utility framework for the nuclear reaction data on the basis of recent progress of computer and network technologies. These technologies will be not only for the data dissemination but for the compilation and evaluation assistance among the many corresponding researchers of all over the world. In this paper, current progress of our research and development is shown. (author)

  6. Exploratory study of nuclear reaction data utility framework of Japan charged particle reaction data group (JCPRG)

    International Nuclear Information System (INIS)

    Masui, Hiroshi; Ohnishi, Akira; Kato, Kiyoshi; Ohbayasi, Yosihide; Aoyama, Shigeyoshi; Chiba, Masaki

    2002-01-01

    Compilation, evaluation and dissemination are essential pieces of work for the nuclear data activities. We, Japan charged particle data group, have researched the utility framework for the nuclear reaction data on the basis of recent progress of computer and network technologies. These technologies will be not only for the data dissemination but for the compilation and evaluation assistance among the many corresponding researchers of all over the world. In this paper, current progress of our research and development is shown. (author)

  7. Progress in fusion

    International Nuclear Information System (INIS)

    1959-01-01

    Controlled thermonuclear fusion is now the biggest challenge before atomic science, not only because of the exceedingly difficult nature of the problem but also because of the virtually limitless benefit that, it is expected, will eventually flow from its solution. It might be pointed out that if some of the early optimism is now inevitably moderated, that is only because there is now a better understanding of the difficulties and, consequently, of the basic scientific and technical problems. The basic problem, as is now widely known, is to heat heavy hydrogen gas to a temperature at which the nuclei will fuse by moving so fast as to overcome their mutual electrical repulsion, and simultaneously to keep the gas in a state of extreme density so that the nuclei may collide against each other, fuse, release-energy in the form of heat, and thus set in a kind of thermal chain reaction. The temperature required is of a fantastically high order, but the scientists are confident that it can be obtained by fantastically powerful electrical discharges. More difficult seems to be the task of making the superheated gas, or the plasma as it is called when completely ionized, to behave obligingly. It must remain in a state of extreme density even when it is heated to a temperature of many millions of degrees. As a matter of fact, it must be contained, so to speak, by itself; it must not touch the walls of its material container and thereby lose some of its heat and, on top of that, evaporate the container. The pinch effect produces a kind of magnetic bottle for containing the plasma, but the trouble seems to be that it is difficult to make the bottle stable and leak-proof. The next task will be to ensure that the output of energy from this fusion is greater than the input of energy to heat the plasma. Intensive research and experiment on these problems have been going on in several countries, notably in the UK, the USA, and the USSR. In all the countries most advanced in

  8. [Adverse reactions to insulin].

    Science.gov (United States)

    Liñana, J J; Montoro, F J; Hernández, M D; Basomba, A

    1997-07-01

    The prevalence of allergic reactions to insuline has decreased during the last few years. Probably this is due to the use of the newly-developed recombinant human insuline. At present, adverse reactions to insuline occur in 5-10% of patients on therapy with insuline. Adverse reactions may be local (more frequent) or systemic (rare). Insuline resistance consists in a different type of immunological reaction. Diagnosis of allergy to insuline is based on clinical history and cutaneous and serological tests. Treatment depends upon the severity of the reaction. When insuline is indispensable despite a previous allergic reaction, a desensitization protocol may be implemented.

  9. Progressive osseous heteroplasia

    African Journals Online (AJOL)

    Progressive osseous heteroplasia is a rare genetic disorder characterized by cu- taneous ossification during infancy and progressive ossification of subcutane- ous and deep connective tissue including muscle and fascia during childhood. It is at the severe end of a spectrum of Guanine Nucleotide-binding protein,.

  10. Preequilibrium Nuclear Reactions

    International Nuclear Information System (INIS)

    Strohmaier, B.

    1988-01-01

    After a survey on existing experimental data on precompound reactions and a description of preequilibrium reactions, theoretical models and quantum mechanical theories of preequilibrium emission are presented. The 25 papers of this meeting are analyzed separately

  11. Microfluidic chemical reaction circuits

    Science.gov (United States)

    Lee, Chung-cheng [Irvine, CA; Sui, Guodong [Los Angeles, CA; Elizarov, Arkadij [Valley Village, CA; Kolb, Hartmuth C [Playa del Rey, CA; Huang, Jiang [San Jose, CA; Heath, James R [South Pasadena, CA; Phelps, Michael E [Los Angeles, CA; Quake, Stephen R [Stanford, CA; Tseng, Hsian-rong [Los Angeles, CA; Wyatt, Paul [Tipperary, IE; Daridon, Antoine [Mont-Sur-Rolle, CH

    2012-06-26

    New microfluidic devices, useful for carrying out chemical reactions, are provided. The devices are adapted for on-chip solvent exchange, chemical processes requiring multiple chemical reactions, and rapid concentration of reagents.

  12. Oral Hypersensitivity Reactions

    Science.gov (United States)

    ... such as cinnamon, peppermint, eugenol and menthol. Even dental floss and denture cleansers may contain ingredients known to cause a hypersensitivity reaction. Q: How can dental treatment trigger a hypersensitivity reaction? A: Some dental ...

  13. Chemical transport reactions

    CERN Document Server

    Schäfer, Harald

    2013-01-01

    Chemical Transport Reactions focuses on the processes and reactions involved in the transport of solid or liquid substances to form vapor phase reaction products. The publication first offers information on experimental and theoretical principles and the transport of solid substances and its special applications. Discussions focus on calculation of the transport effect of heterogeneous equilibria for a gas motion between equilibrium spaces; transport effect and the thermodynamic quantities of the transport reaction; separation and purification of substances by means of material transport; and

  14. Thermonuclear reaction rates. III

    International Nuclear Information System (INIS)

    Harris, M.J.; Fowler, W.A.; Caughlan, G.R.; Zimmerman, B.A.

    1983-01-01

    Stellar thermonuclear reaction rates are revised and updated, adding a number of new important reaction rates. Several reactions with large negative Q-values are included, and examples of them are discussed. The importance of the decay rates for Mg-26(p,n) exp 26 Al and Al-26(n,p) exp 26 Mg for stellar studies is emphasized. 19 references

  15. Cluster knockout reactions

    Indian Academy of Sciences (India)

    2014-04-07

    Apr 7, 2014 ... advancements in the area of (α, 2α) reactions and heavy cluster knockout reactions are discussed. Importance of the finite-range vertex and the final-state interactions are brought out. Keywords. Cluster knockout reactions; FR-DWIA calculations; t-matrix effective interaction. PACS Nos 14.20.Pt; 24.10.

  16. ORGANIC REACTION MECHANISM CONTROVERSY ...

    African Journals Online (AJOL)

    Preferred Customer

    However, there are so many chemical reactions notably in organic chemistry where reactions may not directly lead to products. ... There are concepts that support these ideas but can they be proven to the ... Reaction mechanism is one such issue in organic chemistry that has attracted a lot of controversial comments from ...

  17. Maillard Reaction: review

    Directory of Open Access Journals (Sweden)

    Júlia d'Almeida Francisquini

    2017-11-01

    Full Text Available Maillard reaction is an important subject of study in food science and technology and different areas of knowledge are involved such as chemistry, food engineering, nutrition and food technology. The objective of this paper is to present the basic concepts of the Maillard reaction, such as the reaction stages, the main compounds producced and some technological consequences for dairy products.

  18. Resonant thermonuclear reaction rate

    International Nuclear Information System (INIS)

    Haubold, H.J.; Mathai, A.M.

    1986-01-01

    Basic physical principles for the resonant and nonresonant thermonuclear reaction rates are applied to find their standard representations for nuclear astrophysics. Closed-form representations for the resonant reaction rate are derived in terms of Meijer's G-function. Analytic representations of the resonant and nonresonant nuclear reaction rates are compared and the appearance of Meijer's G-function is discussed in physical terms

  19. Progress report of the Nuclear Physics Department

    International Nuclear Information System (INIS)

    1981-01-01

    This progress report presents the experiments and the technological studies carried out at the Nuclear Physics Department of Saclay from October 1, 1979 to September 30, 1980. These studies concern the structure of nuclei and hypernuclei and various reaction mechanisms. They have been performed with the 8.5 MV tandem Van de Graaff, with the 600 MeV electron linac, at the synchrotron SATURNE and with different accelerators belonging to other laboratories [fr

  20. Van de Graaff Laboratory progress report [1974

    International Nuclear Information System (INIS)

    Bhatia, M.S.

    1977-01-01

    Research and development work carried out in the Van de Graaff Laboratory of the Bhabha Atomic Research Centre, Bombay, India during 1974 has been reported. Research programmes in the field of nuclear reactions and activities of the Indian Nuclear Data Group are described. Progress of developmental work on the low energy horizontal tandem accelerator, Dumas mass separator and ion implantation facility is reported. (K.M.)

  1. Renaissance of Sandmeyer-Type Reactions: Conversion of Aromatic C-N Bonds into C-X Bonds (X = B, Sn, P, or CF3).

    Science.gov (United States)

    Mo, Fanyang; Qiu, Di; Zhang, Yan; Wang, Jianbo

    2018-02-20

    The Sandmeyer reaction represents an important organic transformation that converts an arylamine to an aryl halide using Cu(I) halide via a diazonium salt intermediate. The reaction was first reported by Sandmeyer in 1884, and a number of named reactions closely related to it have been developed and widely applied in organic synthesis throughout the 20th century. These include the Pschorr reaction for the synthesis of biaryl tricycles, the Gomberg-Bachmann reaction for biaryl formations, the Balz-Schiemann reaction for C-F bond formations, and the Meerwein reaction for arylation of α,β-unsaturated carbonyl compounds. However, all these reactions were discovered before 1940. In 1977, Doyle and co-workers reported an organic phase diazotization process, and Kikukawa and Matsuda used aryldiazonium salts in transition metal-catalyzed cross-coupling reactions. However, completely new processes involving diazonium salts have been seldom reported since then, although aryldiazonium salts are widely utilized in modern organic synthesis. In the past few years, diazonium salt chemistry has been revisited and become a fast-growing research topic. Several novel transformations based on diazonium salts have been developed and have been practiced in organic synthesis. In 2010, we reported a direct conversion of arylamines to pinacol boronates through the reaction of in situ generated aryl diazonium salts with B 2 pin 2 . This new strategy is under metal-free conditions and thus completely avoids contamination by transition metals in the boron products. From readily available arylamines various functionalized arylboronates, some of which are difficult to access by other methods, can be easily obtained with this reaction. Mechanistic investigations indicate the reaction likely follows a radical mechanism, which is similar to traditional Sandmeyer-type reactions. Subsequently, modified reaction conditions for this transformation appeared in the literature, which include light

  2. Annual progress report 1976

    International Nuclear Information System (INIS)

    This report of the Nuclear Sciences Institute at Grenoble gives a general survey of the scientific and technical work done in 1976. The research areas are: nuclear reactions, gamma spectrometry, polarized neutrons, intermediate energy physics, theoretical physics, accelerators and technical means, the experimental physics at the cyclotron being essentially concerned with three fields: γ spectrometry, giant resonances, mechanisms of heavy ion induced reactions [fr

  3. Nietzsche, Pragmatism, and Progress

    OpenAIRE

    Harris, Daniel

    2010-01-01

    In this paper I argue that in Richard Rorty’s pragmatism we find a view of political progress at once at home in Nietzsche’s thought and in the Enlightenment tradition. If we think of progress as indexed to some permanent standard, and then agree that it is Nietzsche who dispels the authority of any such standard, then we may perhaps conclude that after Nietzsche, progress is ruled out. I want to show, however, that we find in Nietzsche comfort for a continued vision of human prog...

  4. Internationalisering og progression

    DEFF Research Database (Denmark)

    Wilken, Lisanne; Tange, Hanne

    2014-01-01

    education followed by two years of specialization within the same discipline. This idea is now being challenged on several fronts. For instance, it is becoming more common for Danish universities to offer interdisciplinary master programs. Also, the trend for greater internationalization in higher education...... sig til progression. Artiklen er skrevet på baggrund af semistrukturerede interviews med undervisere fra tværfaglige, internationale uddannelser ved Aarhus Universitet. University programs in Denmark have traditionally been perceived as a continuous education consisting of three years of basic...... universities reflect on progression in education. The article distinguishes between different forms of progression....

  5. Progress test utopia.

    Science.gov (United States)

    van der Vleuten, Cees; Freeman, Adrian; Collares, Carlos Fernando

    2018-04-01

    This paper discusses the advantages of progress testing. A utopia is described where medical schools would work together to develop and administer progress testing. This would lead to a significant reduction of cost, an increase in the quality of measurement and phenomenal feedback to learner and school. Progress testing would also provide more freedom and resources for more creative in-school assessment. It would be an educationally attractive alternative for the creation of cognitive licensing exams. A utopia is always far away in the future, but by formulating a vision for that future we may engage in discussions on how to get there.

  6. Controlled state-to-state atom-exchange reaction in an ultracold atom-dimer mixture

    OpenAIRE

    Rui, Jun; Yang, Huan; Liu, Lan; Zhang, De-Chao; Liu, Ya-Xiong; Nan, Jue; Zhao, Bo; Pan, Jian-Wei

    2016-01-01

    Ultracold molecules offer remarkable opportunities to study chemical reactions at nearly zero temperature. Although significant progresses have been achieved in exploring ultracold bimolecular reactions, the investigations are usually limited to measurements of the overall loss rates of the reactants. Detection of the reaction products will shed new light on understanding the reaction mechanism and provide a unique opportunity to study the state-to-state reaction dynamics. Here we report on t...

  7. Physicians’ Progress Notes

    DEFF Research Database (Denmark)

    Bansler, Jørgen; Havn, Erling C.; Mønsted, Troels

    2013-01-01

    This paper examines physicians’ progress notes, an artifact that, in spite of its obvious importance in the coordination of cooperative work in clinical settings, has not been subjected to systematic study under CSCW auspices. While several studies have addressed the role of the medical record...... in patient care, they have not dealt specifically with the role, structure, and content of the progress notes. As a consequence, CSCW research has not yet taken fully into account the fact that progress notes are coordinative artifacts of a rather special kind, an open-ended chain of prose texts, written...... sequentially by cooperating physicians for their own use as well as for that of their colleagues. We argue that progress notes are the core of the medical record, in that they marshal and summarize the overwhelming amount of data that is available in the modern hospital environment, and that their narrative...

  8. Progress report 1985

    International Nuclear Information System (INIS)

    1986-01-01

    This progress report of the nuclear physics institute includes five basic subjects: theoretical physics, high energy and intermediate energy physics, nuclear physics, combined research physics and instrumentation (microelectronics, imaging, multidetectors, scintillators,...) [fr

  9. Progress for the Paralyzed

    Science.gov (United States)

    ... Contents Latest Advances Help People Regain Function and Independence Founded in 2000, the National Institute for Biomedical ... More "NIBIB Robotics" Articles Progress for the Paralyzed / College Athlete Stands Again…On His Own! / Coffee to ...

  10. Progress report 1979

    International Nuclear Information System (INIS)

    1979-01-01

    Progress report on the meetings and working groups of DAF in 1979, e.g. engineering and industry, public and press, law and administration, business and industry, international cooperation in Europe and with the USA. (GL) [de

  11. Progress report, Physics Division

    International Nuclear Information System (INIS)

    1986-03-01

    This report reviews events and progress in the following areas: development of the TASCC facility; experimental and theoretical nuclear physics research; radionuclide standardization; condensed matter research; applied mathematics; and computer facility operation

  12. Progression of Liver Disease

    Science.gov (United States)

    ... Legacy Society Make Gifts of Stock Donate Your Car Personal Fundraising Partnership & Support Share Your Story Spread the Word Give While You Shop Contact Us Donate Now The Progression of Liver ...

  13. Progress report, 1978

    International Nuclear Information System (INIS)

    During the calendar year 1978 upgrading of the synchrocyclotron was completed and proton, deuteron and alpha beams were extensively used. Research continued into far-unstable nuclei, complex nuclear reaction and nuclear fission mechanisms, and positron tomography. (LL)

  14. Nuclear reaction studies

    International Nuclear Information System (INIS)

    Alexander, J.M.; Lacey, R.A.

    1994-01-01

    Research focused on the statistical and dynamical properties of ''hot'' nuclei formed in symmetric heavy-ion reactions. Theses included ''flow'' measurements and the mechanism for multifragment disassembly. Model calculations are being performed for the reactions C+C, Ne+Al, Ar+Sc, Kr+Nb, and Xe+La. It is planned to study 40 Ar reactions from 27 to 115 MeV/nucleon. 2 figs., 41 refs

  15. Sleeve reaction chamber system

    Science.gov (United States)

    Northrup, M Allen [Berkeley, CA; Beeman, Barton V [San Mateo, CA; Benett, William J [Livermore, CA; Hadley, Dean R [Manteca, CA; Landre, Phoebe [Livermore, CA; Lehew, Stacy L [Livermore, CA; Krulevitch, Peter A [Pleasanton, CA

    2009-08-25

    A chemical reaction chamber system that combines devices such as doped polysilicon for heating, bulk silicon for convective cooling, and thermoelectric (TE) coolers to augment the heating and cooling rates of the reaction chamber or chambers. In addition the system includes non-silicon-based reaction chambers such as any high thermal conductivity material used in combination with a thermoelectric cooling mechanism (i.e., Peltier device). The heat contained in the thermally conductive part of the system can be used/reused to heat the device, thereby conserving energy and expediting the heating/cooling rates. The system combines a micromachined silicon reaction chamber, for example, with an additional module/device for augmented heating/cooling using the Peltier effect. This additional module is particularly useful in extreme environments (very hot or extremely cold) where augmented heating/cooling would be useful to speed up the thermal cycling rates. The chemical reaction chamber system has various applications for synthesis or processing of organic, inorganic, or biochemical reactions, including the polymerase chain reaction (PCR) and/or other DNA reactions, such as the ligase chain reaction.

  16. Sodium-concrete reactions

    International Nuclear Information System (INIS)

    Gadd, P.G.

    1982-09-01

    Reaction products of all the major constituents of commercial concrete with liquid sodium have been identified using X-Ray Powder Diffraction. Eight different aggregate materials were chosen to represent the main rock classes available and Ordinary Portland Cement was used throughout. A Differential Thermal Analysis apparatus which enabled continuous stirring of the reactants was designed to improve contact between the powdered concrete components and the liquid sodium. Heats of reaction were calculated from peak areas, the apparatus having been calibrated using reactions of sodium with simple binary oxides whose heats of reaction were known. The heat evolution from aggregates was rationalised on the basis of their mineralogical composition, thus providing a means of choosing an optimum aggregate for use in the concrete of a LMFBR. The reaction of SiO 2 with liquid sodium was shown to depend on the oxygen concentration of the sodium. Reaction products are identified. The reaction of Al 2 O 3 with sodium has been shown also to depend on the oxygen concentration. Reaction products are identified. The evolution of hydrogen during a sodium-cement reaction has been studied using an electrochemical hydrogen meter and the penetration of the liquid metal into cement blocks was also investigated. (author)

  17. Tattoo reaction: Case series

    Directory of Open Access Journals (Sweden)

    Muneer Mohamed

    2018-04-01

    Full Text Available Tattoo is going to be a very common practice especially among young people and we are witnessing a gradual increase of numerous potential complications to tattoo placement which are often seen by physicians, but generally unknown to the public. The most common skin reactions to tattoo include a transient acute inflammatory reaction due to trauma of the skin with needles and medical complications such as superficial and deep local infections, systemic infections, allergic contact dermatitis, photodermatitis, granulomatous and lichenoid reactions, and skin diseases localized on tattooed area (eczema, psoriasis, lichen, and morphea. In this series we present three cases of tattoo reaction.

  18. Coupling reaction of thioamides with sulfonyl azides: an efficient catalyst-free click-type ligation under mild conditions.

    Science.gov (United States)

    Aswad, Muhammad; Chiba, Junya; Tomohiro, Takenori; Hatanaka, Yasumaru

    2013-11-11

    We report a coupling reaction of thioamides and sulfonyl azides to generate sulfonyl amidines in the absence of any activation additives. The reaction progresses in various solvents under mild conditions. Water exhibits the highest performance with respect to efficiency.

  19. Aqueous Biphasic Systems for the Synthesis of Formates by Catalytic CO2Hydrogenation: Integrated Reaction and Catalyst Separation for CO2-Scrubbing Solutions.

    Science.gov (United States)

    Scott, Martin; Blas Molinos, Beatriz; Westhues, Christian; Franciò, Giancarlo; Leitner, Walter

    2017-03-22

    Aqueous biphasic systems were investigated for the production of formate-amine adducts by metal-catalyzed CO 2 hydrogenation, including typical scrubbing solutions as feedstocks. Different hydrophobic organic solvents and ionic liquids could be employed as the stationary phase for cis-[Ru(dppm) 2 Cl 2 ] (dppm=bis-diphenylphosphinomethane) as prototypical catalyst without any modification or tagging of the complex. The amines were found to partition between the two phases depending on their structure, whereas the formate-amine adducts were nearly quantitatively extracted into the aqueous phase, providing a favorable phase behavior for the envisaged integrated reaction/separation sequence. The solvent pair of methyl isobutyl carbinol (MIBC) and water led to the most practical and productive system and repeated use of the catalyst phase was demonstrated. The highest single batch activity with a TOF av of approximately 35 000 h -1 and an initial TOF of approximately 180 000 h -1 was achieved in the presence of NEt 3 . Owing to higher stability, the highest productivities were obtained with methyl diethanolamine (Aminosol CST 115) and monoethanolamine (MEA), which are used in commercial scale CO 2 -scrubbing processes. Saturated aqueous solutions (CO 2 overpressure 5-10 bar) of MEA could be converted into the corresponding formate adducts with average turnover frequencies up to 14×10 3  h -1 with an overall yield of 70 % based on the amine, corresponding to a total turnover number of 150 000 over eleven recycling experiments. This opens the possibility for integrated approaches to carbon capture and utilization. © 2017 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.

  20. Chronic progressive multiple sclerosis

    International Nuclear Information System (INIS)

    Buffoli, A.; Micheletti, E.; Capra, R.; Mattioli, F.; Marciano', N.

    1991-01-01

    A long-lasting immunological suppression action seems to be produced by total lymphoid irradiation; some authors emphasize the favorable effect of this treatment on chronic progressive multiple sclerosis. In order to evaluate the actual role of TLI, 6 patients affected with chronic progressive multiple sclerosis were submitted to TLI with shaped and personalized fields at the Istituto del Radio, University of Brescia, Italy. The total dose delivered was 19.8 Gy in 4 weeks, 1.8 Gy/day, 5d/w; a week elapsed between the first and the second irradiation course. Disability according to Kurtzke scale was evaluated, together with blood lymphocyte count and irradiation side-effects, over a mean follow-up period of 20.8 months (range: 13-24). Our findings indicate that: a) disease progression was not markedly reduced by TLI; b) steroid hormones responsivity was restored after irradiation, and c) side-effects were mild and tolerable

  1. Calculation of the energetics of chemical reactions

    Energy Technology Data Exchange (ETDEWEB)

    Dunning, T.H. Jr.; Harding, L.B.; Shepard, R.L.; Harrison, R.J.

    1988-01-01

    To calculate the energetics of chemical reactions we must solve the electronic Schroedinger equation for the molecular conformations of importance for the reactive encounter. Substantial changes occur in the electronic structure of a molecular system as the reaction progresses from reactants through the transition state to products. To describe these changes, our approach includes the following three elements: the use of multiconfiguration self-consistent field wave functions to provide a consistent zero-order description of the electronic structure of the reactants, transition state, and products; the use of configuration interaction techniques to describe electron correlation effects needed to provide quantitative predictions of the reaction energetics; and the use of large, optimized basis sets to provide the flexibility needed to describe the variations in the electronic distributions. With this approach we are able to study reactions involving as many as 5--6 atoms with errors of just a few kcal/mol in the predicted reaction energetics. Predictions to chemical accuracy, i.e., to 1 kcal/mol or less, are not yet feasible, although continuing improvements in both the theoretical methodology and computer technology suggest that this will soon be possible, at least for reactions involving small polyatomic species. 4 figs.

  2. Clock Reaction: Outreach Attraction

    Science.gov (United States)

    Carpenter, Yuen-ying; Phillips, Heather A.; Jakubinek, Michael B.

    2010-01-01

    Chemistry students are often introduced to the concept of reaction rates through demonstrations or laboratory activities involving the well-known iodine clock reaction. For example, a laboratory experiment involving thiosulfate as an iodine scavenger is part of the first-year general chemistry laboratory curriculum at Dalhousie University. With…

  3. Nuclear Reaction Data Centers

    International Nuclear Information System (INIS)

    McLane, V.; Nordborg, C.; Lemmel, H.D.; Manokhin, V.N.

    1988-01-01

    The cooperating Nuclear Reaction Data Centers are involved in the compilation and exchange of nuclear reaction data for incident neutrons, charged particles and photons. Individual centers may also have services in other areas, e.g., evaluated data, nuclear structure and decay data, reactor physics, nuclear safety; some of this information may also be exchanged between interested centers. 20 refs., 1 tab

  4. Hydrogen evolution reaction catalyst

    Science.gov (United States)

    Subbaraman, Ram; Stamenkovic, Vojislav; Markovic, Nenad; Tripkovic, Dusan

    2016-02-09

    Systems and methods for a hydrogen evolution reaction catalyst are provided. Electrode material includes a plurality of clusters. The electrode exhibits bifunctionality with respect to the hydrogen evolution reaction. The electrode with clusters exhibits improved performance with respect to the intrinsic material of the electrode absent the clusters.

  5. Applications of Reaction Rate

    Science.gov (United States)

    Cunningham, Kevin

    2007-01-01

    This article presents an assignment in which students are to research and report on a chemical reaction whose increased or decreased rate is of practical importance. Specifically, students are asked to represent the reaction they have chosen with an acceptable chemical equation, identify a factor that influences its rate and explain how and why it…

  6. Degradations and Rearrangement Reactions

    Science.gov (United States)

    Zhang, Jianbo

    This section deals with recent reports concerning degradation and rearrangement reactions of free sugars as well as some glycosides. The transformations are classified in chemical and enzymatic ways. In addition, the Maillard reaction will be discussed as an example of degradation and rearrangement transformation and its application in current research in the fields of chemistry and biology.

  7. Study of reaction of benzo-1.4-dioxane with formaldehyde

    International Nuclear Information System (INIS)

    Tashbaev, G.A.; Turdialiev, M.Z.; Amonova, A.V.

    2015-01-01

    Present article is devoted to study of reaction of benzo-1.4-dioxane with formaldehyde. The reaction of oxy methylation of benzo-1.4-dioxane with aldehydes under various conditions was considered. The reaction progress and the purity of obtained products was controlled by means of thin-layer chromatography.

  8. Pop-It Beads to Introduce Catalysis of Reaction Rate and Substrate Depletion Effects

    Science.gov (United States)

    Gehret, Austin U.

    2017-01-01

    A kinesthetic classroom activity was designed to help students understand enzyme activity and catalysis of reaction rate. Students served the role of enzymes by manipulating Pop-It Beads as the catalytic event. This activity illuminates the relationship between reaction rate and reaction progress by allowing students to experience first-hand the…

  9. Progress in physical chemistry

    CERN Document Server

    Hempelmann, Rolf

    2008-01-01

    Progress in Physical Chemistry is a collection of recent ""Review Articles"" published in the ""Zeitschrift für Physikalische Chemie"". The second volume of Progress in Physical Chemistry is a collection of thematically closely related minireview articles written by the members of the Collaborative Research Centre (SFB) 277 of the German Research Foundation (DFG). These articles are based on twelve years of intense coordinated research efforts. Central topics are the synthesis and the characterization of interface-dominated, i.e. nanostructured materials, mainly in the solid state but also as

  10. Myopia: Prevalence and Progression

    Science.gov (United States)

    1989-01-01

    D~ L LL Myopia Prevalence and Progression DTIC ELECTE ! SEP 19 1989 C _ _ ’ l A 9 ,3 /5i MYOPIA: PREVALENCE AND PROGRESSION Working Group on Myopia... WALLMAN , Department of Biology, City University of New York AC"esiOf) For NTtSCF& DTjC T;,jE 0 ey ____ (:3 1U: or iii COMMITTEE ON VISION ANTHONY J. ADAMS...provided by Carol Metcalf and Gora P. Lerma, for which the working group is grateful. Christine L . McShane, editor of the Commission on Behavioral and

  11. 1985. Annual progress report

    International Nuclear Information System (INIS)

    1986-01-01

    This annual progress report of the CEA Protection and Nuclear Safety Institut outlines a description of the progress made in each sections of the Institut Research activities of the different departments include: reactor safety analysis, fuel cycle facilities analysis; and associated safety research programs (criticality, sites, transport ...), radioecology and environmental radioprotection techniques; data acquisition on radioactive waste storage sites; radiation effects on man, studies on radioprotection techniques; nuclear material security including security of facilities, security of nuclear material transport, and monitoring of nuclear material management; nuclear facility decommissioning; and finally the public information [fr

  12. Allergic reactions during anesthesia.

    Science.gov (United States)

    Levy, J H

    1988-01-01

    Any drug or blood product administered in the perioperative period has the potential to produce a life-threatening allergic (immune reaction) called anaphylaxis. Anaphylactic reactions represent adverse reactions mediated by immunospecific antibodies (IgE and IgG) that interact with mast cells, basophils, or the complement system to liberate vasoactive mediators and recruit other inflammatory cells. Activation of humoral and cellular pathways produces characteristic responses in the respiratory (bronchospasm and upper airway edema), cardiovascular (vasodilation and increased capillary permeability), and cutaneous systems (wheal and flare). Other predictable adverse drug reactions may mimic anaphylaxis to produce similar physiologic consequences independent of allergy (immune responses). Rapid and timely cardiopulmonary intervention with airway maintenance, epinephrine, and volume expansion is essential to avoid an adverse outcome. Severe reactions may be protracted, especially during anesthesia, requiring even larger doses of catecholamines and intensive care observation.

  13. Ofloxacin Induced Cutaneous Reactions in Children.

    Science.gov (United States)

    Ramani, Yerramalli Roja; Mishra, Sailen Kumar; Rath, Bandana; Rath, Saroj Sekhar

    2015-06-01

    Cutaneous adverse effects to antimicrobials are a major health problem. Though majority of them are mild and self-limiting, severe variants like Steven Johnson Syndrome (SJS), toxic epidermal necrolysis (TEN) are not uncommon. Ofloxacin, a fluoroquinolone widely used for the treatment of urinary tract infections, acute bacterial diarrheas, enteric fever, STDs and other soft tissue infections either as a single drug or in combination with other drugs. Earlier a case of mucocutaneous maculopapular rash with oral ofloxacin and was reported in an adult. In the present hospital set up there were few reports of such reactions to adults. Here we report three different variants of reactions associated with oral ofloxacin in chlidren. Early detection of cutaneous lesions and immediate withdrawal of the offending drug can prevent progression of such reactions to their severe variants as well as morbidity and mortality.

  14. Progressive Retirement Programme

    CERN Multimedia

    HR Department

    2007-01-01

    Following discussion at the Standing Concertation Committee at its meeting on 30 January 2007, the Director-General has approved the extension of the Progressive Retirement Programme with effect from 1 April 2007 until 31 March 2008. Human Resources Department Tel. 74484/74128

  15. [Progress on transgenic mosquitoes].

    Science.gov (United States)

    Yang, Pin

    2011-04-30

    The genetically modified mosquitoes have been developed aiming to control mosquito-borne diseases by either reducing population sizes or replacing existing populations with vectors unable to transmit the disease. introduces some progress on the generation of transgenic mosquitoes and their fitness in wild population. This paper

  16. Learning Progressions & Climate Change

    Science.gov (United States)

    Parker, Joyce M.; de los Santos, Elizabeth X.; Anderson, Charles W.

    2015-01-01

    Our society is currently having serious debates about sources of energy and global climate change. But do students (and the public) have the requisite knowledge to engage these issues as informed citizenry? The learning-progression research summarized here indicates that only 10% of high school students typically have a level of understanding…

  17. Scales of Progress

    Science.gov (United States)

    Jung, Lee Ann

    2018-01-01

    What is Goal Attainment Scaling? In this article, Lee Ann Jung defines it as a way to measure a student's progress toward an individualized goal. Instead of measuring a skill at a set time (for instance, on a test or other assignment), Goal Attainment Scaling tracks the steps a student takes over the course of a year in a targeted skill. Together,…

  18. Progress in optics

    CERN Document Server

    Wolf, Emil

    2015-01-01

    The Progress in Optics series contains more than 300 review articles by distinguished research workers, which have become permanent records for many important developments, helping optical scientists and optical engineers stay abreast of their fields. Comprehensive, in-depth reviewsEdited by the leading authority in the field

  19. Progress report 1981

    International Nuclear Information System (INIS)

    After giving a brief description of operations of an improvements to the University of Alberta nuclear physics facilities, this report summarizes the principal research programs. These include work on neutron scattering, thorium 232 fission, iodine 123 production. Progress towards the construction of MARIA, the Medical Accelerator Research Institute in Alberta, is described, and research on relativistic heavy ions is summarized

  20. Progress Report 1994

    International Nuclear Information System (INIS)

    1995-01-01

    This document is the 1994 annual progress report of the CEA-Direction of Waste Management (DGD). It comprises four chapters. The first chapter is a general presentation of radioactive wastes, of the management of liquid effluents, solid wastes, sealed sources, of the relations with the ANDRA (The French Agency for the Management of Radioactive Wastes), and of the research and development studies in progress for the improvement of waste management. The second chapter concerns the spent fuels and their reprocessing, in particular AGR and PWR type reactor fuels, the ''Caramel'' fuel from Osiris reactor and the cover elements from the Rapsodie reactor core. The long time storage of ancient fuels is also discussed. The third chapter concerns the dismantling of decommissioned installations, the actions in progress and the planning of dismantling actions up to the year 2000. Chapter four is devoted to the management of wastes from the Direction of Military Applications (DAM), the actions in progress in the different DAM centers and the cleansing projects at Marcoule plant. (J.S.). 5 figs., 28 tabs., 21 photos., 3 appendix

  1. Progressive dysarthria and ataxia

    African Journals Online (AJOL)

    Progressive dysarthria and ataxia. Lynsey McAlpinea, Fiona Cranb, Eluzai Hakimc a FY1 Stroke and Rehabilitation Medicine, St Mary's Hospital, Isle of Wight. b GPVST Stroke and Rehabilitation Medicine, St Mary's Hospital, Isle of Wight. c Consultant Physician Stroke and Rehabilitation Medicine, St Mary's Hospital, Isle of ...

  2. BARC progress report - 1997

    International Nuclear Information System (INIS)

    Kalyane, V.L.

    1998-07-01

    This report is a compilation of the progress in various major activities and Research and Development programmes of the different Divisions of the Bhabha Atomic Research Centre, Mumbai. The list of publications and papers presented at the various conferences, symposia, workshops and papers published in journal by the staff members of the Divisions are also given. (author)

  3. Progress report 1979

    International Nuclear Information System (INIS)

    1980-12-01

    This progress report deals with service oriented work performed at the AAEC Research Establishment in the twelve month period ending September 30, 1979. Services provided by the Engineering Services Division, the Safety Department, Site Information Services Department and Commercial Applications are described

  4. Annual progress report

    International Nuclear Information System (INIS)

    1976-04-01

    A summary is presented of research progress at the University of Illinois at Urbana, Illinois during the calendar year 1975. Included are listings of personnel, reports on facilities and operations, and a list of publications submitted or published and papers presented during 1975

  5. Progressive Retirement Programme

    CERN Multimedia

    HR Department

    2009-01-01

    Following the Standing Concertation Committee meeting of 2 December 2008, please note that the Progressive Retirement Programme has been extended by one year, i.e. until 31 March 2010. Further information is available on : https://hr-services.web.cern.ch/hr-services/services-Ben/prp/prp.asp HR Department, tel. 73903

  6. Assessing Pupils' Progress

    Science.gov (United States)

    Ollerton, Mike

    2010-01-01

    In this article, the author explores what Assessing Pupils' Progress (APP) is about. He contends that the predilection for testing is a catastrophe as far as the teaching and learning of mathematics is concerned; it is an outcome of the drive for collecting so-called "data" on pupils. What those people, who should know better, either choose to…

  7. MCNP Progress & Performance Improvements

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Forrest B. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Bull, Jeffrey S. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Rising, Michael Evan [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-04-14

    Twenty-eight slides give information about the work of the US DOE/NNSA Nuclear Criticality Safety Program on MCNP6 under the following headings: MCNP6.1.1 Release, with ENDF/B-VII.1; Verification/Validation; User Support & Training; Performance Improvements; and Work in Progress. Whisper methodology will be incorporated into the code, and run speed should be increased.

  8. Progressive Web applications

    CERN Multimedia

    CERN. Geneva

    2017-01-01

    Progressive Web Applications are native-like applications running inside of a browser context. In my presentation I would like describe their characteristics, benchmarks and building process using a quick and simple case study example with focus on Service Workers api.

  9. Recent progress in Biophysics

    International Nuclear Information System (INIS)

    Bemski, G.

    1980-03-01

    Recent progress in biophysics is reviewed, and three examples of the use of physical techniques and ideas in biological research are given. The first one deals with the oxygen transporting protein-hemoglobin, the second one with photosynthesis, and the third one with image formation, using nuclear magnetic resonance. (Author) [pt

  10. BARC progress report - 1998

    International Nuclear Information System (INIS)

    Kalyane, V.L.

    1999-04-01

    This report is a compilation of the progress in various major activities and Research and Development programmes of the different Divisions of the Bhabha Atomic Research Centre, Mumbai. The list of publications and papers presented at the various conferences, symposia, workshops and papers published in journal by the staff members of the Divisions are also given. (author)

  11. Response: Progress Takes Time.

    Science.gov (United States)

    Rist, Marilee C.

    1984-01-01

    Although declining enrollment and administrative seniority have hampered efforts to eliminate sex discrimination in employment practices in three Long Island, New York, school systems (Commack, Smithtown, and Bay Shore), progress is being made. Because of the Reagan administration's lack of support for affirmative action, however, litigation…

  12. Progress report 1979

    International Nuclear Information System (INIS)

    1980-12-01

    This progress report deals with technical and research work done at the AAEC Research Establishment in the twelve month period ending September 30, 1979. Work done in the following research divisions is reported: Applied Maths and Computing, Chemical Technology, Engineering Research, Environmental Science, Instrumentation and Control, Isotope, Materials and Physics

  13. Progression og underviserkompetencer

    Directory of Open Access Journals (Sweden)

    Lene Tortzen Bager

    2014-03-01

    Full Text Available På baggrund af en kvalitativ interviewundersøgelse af undervisere ved Aarhus Universitet lavet i 2012, tematiserer artiklen, hvordan undervisere udvikler deres faglige og pædagogiske kompetencer i forhold til at kunne skabe progression inden for innovation og entreprenørskab forstået enten som didaktik, arbejdsformer i faglige forløb eller som fag på universitetet. I arbejdet med progression er det en udfordring at integrere de nye faglige dimensioner i det kernefaglige felt. Den seneste model for progression inden for innovation og entreprenør-skab siger, at det er den lærendes generelle erfaringsniveau, der er den afgørende progressionsskabende faktor (Progressionsmodellen, Fonden for Entreprenørskab, 2013b. Samtidig skelner international forskning inden for studiekompetenceområdet mellem niveauer, hvor indlejret viden er det mest avancerede kompetenceniveau (Barrie, 2002.Ifølge progressionsmodellen og den nævnte kompetenceforskning er erfaring og dybt integreret læring altså centrale dimensioner i progression. Men hvad er underviserens rolle heri? Underviserens professionelle udviklingsarbejde forekommer at være underbelyst i forhold til, at underviseren er den legitime garant for integrationen af nye faglige dimensioner og for den studerendes kompetenceniveau. Interviewundersøgelsen forholder sig til spørgsmålet om progression gennem de deltagende underviseres beskrivelse af betydningslag i entreprenørskabsbegrebet koblet til de praksisformer i undervisningen, der knytter sig hertil samt et indblik i undervisernes refleksioner over deres kompetenceudviklingsprocesser. Artiklens bidrag til progression er at se underviserens motivation og kompetenceudvikling som forudsætninger herfor.  Based on a qualitative study of five teachers in the Faculty of Arts at Aarhus University that took place during 2012, the article thematizes how teachers develop their professional and educational qualifications in innovation and

  14. Progression og underviserkompetencer

    Directory of Open Access Journals (Sweden)

    Lene Tortzen Bager

    2014-03-01

    Full Text Available På baggrund af en kvalitativ interviewundersøgelse af undervisere ved Aarhus Universitet lavet i 2012, tematiserer artiklen, hvordan undervisere udvikler deres faglige og pædagogiske kompetencer i forhold til at kunne skabe progression inden for innovation og entreprenørskab forstået enten som didaktik, arbejdsformer i faglige forløb eller som fag på universitetet. I arbejdet med progression er det en udfordring at integrere de nye faglige dimensioner i det kernefaglige felt. Den seneste model for progression inden for innovation og entreprenør-skab siger, at det er den lærendes generelle erfaringsniveau, der er den afgørende progressionsskabende faktor (Progressionsmodellen, Fonden for Entreprenørskab, 2013b. Samtidig skelner international forskning inden for studiekompetenceområdet mellem niveauer, hvor indlejret viden er det mest avancerede kompetenceniveau (Barrie, 2002.Ifølge progressionsmodellen og den nævnte kompetenceforskning er erfaring og dybt integreret læring altså centrale dimensioner i progression. Men hvad er underviserens rolle heri? Underviserens professionelle udviklingsarbejde forekommer at være underbelyst i forhold til, at underviseren er den legitime garant for integrationen af nye faglige dimensioner og for den studerendes kompetenceniveau. Interviewundersøgelsen forholder sig til spørgsmålet om progression gennem de deltagende underviseres beskrivelse af betydningslag i entreprenørskabsbegrebet koblet til de praksisformer i undervisningen, der knytter sig hertil samt et indblik i undervisernes refleksioner over deres kompetenceudviklingsprocesser. Artiklens bidrag til progression er at se underviserens motivation og kompetenceudvikling som forudsætninger herfor.     Based on a qualitative study of five teachers in the Faculty of Arts at Aarhus University that took place during 2012, the article thematizes how teachers develop their professional and educational qualifications in innovation and

  15. Enhancing chemical reactions

    Science.gov (United States)

    Morrey, John R.

    1978-01-01

    Methods of enhancing selected chemical reactions. The population of a selected high vibrational energy state of a reactant molecule is increased substantially above its population at thermal equilibrium by directing onto the molecule a beam of radiant energy from a laser having a combination of frequency and intensity selected to pump the selected energy state, and the reaction is carried out with the temperature, pressure, and concentrations of reactants maintained at a combination of values selected to optimize the reaction in preference to thermal degradation by transforming the absorbed energy into translational motion. The reaction temperature is selected to optimize the reaction. Typically a laser and a frequency doubler emit radiant energy at frequencies of .nu. and 2.nu. into an optical dye within an optical cavity capable of being tuned to a wanted frequency .delta. or a parametric oscillator comprising a non-centrosymmetric crystal having two indices of refraction, to emit radiant energy at the frequencies of .nu., 2.nu., and .delta. (and, with a parametric oscillator, also at 2.nu.-.delta.). Each unwanted frequency is filtered out, and each desired frequency is focused to the desired radiation flux within a reaction chamber and is reflected repeatedly through the chamber while reactants are fed into the chamber and reaction products are removed therefrom.

  16. Respiratory transfusion reactions

    Directory of Open Access Journals (Sweden)

    Ivica Marić

    2017-11-01

    Full Text Available Respiratory transfusion-related reactions are not very frequent, partly also because recognition and reporting transfusion reactions is still underemphasized. Tis article describes the most important respiratory transfusion reactions, their pathophysiology, clinical picture and treatment strategies. Respiratory transfusion related reactions can be primary or secondary. The most important primary transfusion-related reactions are TRALI - transfusion-related acute lung injury, TACO – transfusion-associated circulatory overload, and TAD - transfusion-associated dyspnea. TRALI is immuneassociated injury of alveolar basal membrane, which becomes highly permeable and causes noncardiogenic pulmonary edema. Treatment of TRALI is mainly supportive with oxygen, fluids (in case of hypotension and in cases of severe acute respiratory failure also mechanic ventilation. TACO is caused by volume overload in predisposed individuals, such as patients with heart failure, the elderly, infants, patients with anemia and patients with positive fluid balance. Clinical picture is that of a typical pulmonary cardiogenic edema, and the therapy is classical: oxygen and diuretics, and in severe cases also non-invasive or invasive mechanical ventilation. TAD is usually a mild reaction of unknown cause and cannot be classified as TACO or TRALI, nor can it be ascribed to patient’s preexisting diseases. Although the transfusion-related reactions are not very common, knowledge about them can prevent serious consequences. On the one hand preventive measures should be sought, and on the other early recognition is beneficial, so that proper treatment can take place.

  17. Progressive Response Surfaces

    Science.gov (United States)

    Romero, V. J.; Swiler, L. P.

    2004-01-01

    Response surface functions are often used as simple and inexpensive replacements for computationally expensive computer models that simulate the behavior of a complex system over some parameter space. Progressive response surfaces are ones that are built up progressively as global information is added from new sample points in the parameter space. As the response surfaces are globally upgraded based on new information, heuristic indications of the convergence of the response surface approximation to the exact (fitted) function can be inferred. Sampling points can be incrementally added in a structured fashion, or in an unstructured fashion. Whatever the approach, at least in early stages of sampling it is usually desirable to sample the entire parameter space uniformly. At later stages of sampling, depending on the nature of the quantity being resolved, it may be desirable to continue sampling uniformly over the entire parameter space (Progressive response surfaces), or to switch to a focusing/economizing strategy of preferentially sampling certain regions of the parameter space based on information gained in early stages of sampling (Adaptive response surfaces). Here we consider Progressive response surfaces where a balanced indication of global response over the parameter space is desired.We use a variant of Moving Least Squares to fit and interpolate structured and unstructured point sets over the parameter space. On a 2-D test problem we compare response surface accuracy for three incremental sampling methods: Progressive Lattice Sampling; Simple-Random Monte Carlo; and Halton Quasi-Monte-Carlo sequences. We are ultimately after a system for constructing efficiently upgradable response surface approximations with reliable error estimates.

  18. Progress report 1984

    International Nuclear Information System (INIS)

    Wild, E.; Dirniger, G.

    1984-01-01

    A brief account is given on work in the fields: theoretical physics, experimental medium energy physics, nuclear model calculations, experimental nuclear physics, neutron induced reactions, instrumentation and detectors, evaluation of nuclear data and numerical data processing, radionuclide metrology, radioacitvity, dating and isotope geology, applications in medicine, application in geophysics and dosimetry and environmental studies. A list of publications is also included. (G.Q.)

  19. 1983. Annual progress report

    International Nuclear Information System (INIS)

    1984-01-01

    A beautiful experiment series for studying high energy excitation structures (10 to 80 MeV), concerning very heavy and asymmetric systems. CEV-Alice contributions to annual report concern Hg and Er high spin energy levels. About reaction mechanisms, the following contributions can be noticed: proton backward emission experiment results of high energy, at 200 MeV, on numerous targets; spectroscopic studies of direct transfer reactions by 18 O with measurement of angular distributions until 0 0 ; many heavy ion experiments around 30 MeV/u concerning the mechanism evolution between 10 and 100 MeV. Pion coherent production experiments have been made this year on energy dependence of the reaction 3 He+ 3 He → 6 Li+π + , considered as an existing model test. Cross section measurement of the elementary reactions (p,π + ) on three targets of very different masses, in a large energy scale and a wide angular domain, have been measured at the Synchrocyclotron. Concerning the nuclear structure in low and medium energy levels, elastic scattering and transfer studies are to be noticed particularly in transition nuclei region. Exotic nuclei rich in neutrons, with medium mass, Fe, Co, Ni, Zn have been studied using the 14 C beam of the Orsay tandem. The radiochemistry group work is essentially centered on actinides study [fr

  20. Annual progress report 1975

    International Nuclear Information System (INIS)

    This report gives a general survey of the activities and research work done in 1975 at Institut de Physique Nucleaire, Orsay. It is divided in 5 parts. The first one is concerned with the Nuclear Physics Division and the research fields are: nuclear reactions, nuclear spectroscopy (heavy ions, on-line analog isobaric states, transfer reactions), hyperfine interactions, exotic nuclei search... The second part is concerned with the work of the High Energy Physics Division and reports the creation in Annecy of the Particle Physics Laboratory (L.A.P.P.). The third one about the Radiochemistry Division reports the research work done in nuclear chemistry (new nuclear species research, fusion, quasi-elastic transfer reactions) and in radiochemistry (cis- and trans-uranium elements, natural superheavy element research). The fourth part is concerned with theoretical research in nuclear physics (nuclear structure, nuclear reactions, weak interactions, intermediate energies) and in particle physics (field theory, gauge theory, chiral symmetry, current algebra, off-shell amplitudes and strong interactions dynamics). The fifth part reports technical research about accelerators, separators, ion sources, semiconductors and the activities of the technical departments of the Institute [fr

  1. Annual progress report 1975

    International Nuclear Information System (INIS)

    This report of the Nuclear Sciences Institute at Grenoble gives a general survey of the scientific and technical work done in 1975. The research areas are: nuclear reactions, gamma spectroscopy, polarized neutrons, intermediate energy physics, theoretical physics, accelerators and technical means [fr

  2. Nuclear theory progress report

    International Nuclear Information System (INIS)

    1991-01-01

    This report discusses research performed at University of Washington in nuclear theory. Some of the topics discussed are: nuclear astrophysics; symmetry; time reversal invariance; quark matter; superallowed beta decay; exclusive reactions; nuclear probes; soliton model; relativistic heavy ion collisions; supernova explosions; neutrino processes in dense matter; field theories; weak interaction physics; and nuclear structure

  3. Nuclear chemistry progress report

    International Nuclear Information System (INIS)

    1976-01-01

    A brief administrative review is given of work in the following areas: investigations of the chemical effects accompanying muon capture in atoms and molecules, quadrupole interaction in metal and semimetal systems using perturbed gamma-ray angular correlation, and nuclear structure research using nuclear reaction spectroscopy. Detailed research reports were published in appropriate places; a publication list is included. 2 figures

  4. The Reaction Wheel Pendulum

    CERN Document Server

    Block, Daniel J; Spong, Mark W

    2007-01-01

    This monograph describes the Reaction Wheel Pendulum, the newest inverted-pendulum-like device for control education and research. We discuss the history and background of the reaction wheel pendulum and other similar experimental devices. We develop mathematical models of the reaction wheel pendulum in depth, including linear and nonlinear models, and models of the sensors and actuators that are used for feedback control. We treat various aspects of the control problem, from linear control of themotor, to stabilization of the pendulum about an equilibrium configuration using linear control, t

  5. Electron transfer reactions

    CERN Document Server

    Cannon, R D

    2013-01-01

    Electron Transfer Reactions deals with the mechanisms of electron transfer reactions between metal ions in solution, as well as the electron exchange between atoms or molecules in either the gaseous or solid state. The book is divided into three parts. Part 1 covers the electron transfer between atoms and molecules in the gas state. Part 2 tackles the reaction paths of oxidation states and binuclear intermediates, as well as the mechanisms of electron transfer. Part 3 discusses the theories and models of the electron transfer process; theories and experiments involving bridged electron transfe

  6. Progress of Jinping Underground laboratory for Nuclear Astrophysics experiment JUNA

    Science.gov (United States)

    Liu, Weiping

    2015-08-01

    Direct measurement of the cross sections for the key nuclear reactions in hydrostatic stellar evolution within Gamow window, which makes use of low background at deep underground laboratory, is crucial to solve key scientific questions in nuclear astrophysics. JUNA project aims at direct measurement of (α,γ), (α,n) reactions in hydrostatic helium burning and (p, γ), (p, α) reactions in hydrostatic hydrogen burning based on Jinping deep underground laboratory in China. The progress of experimental techniques, which include the accelerator system with high stability and high intensity, the detector system, and the shielding material with low background, will be presented.

  7. Communication of nuclear data progress: No.8 (1992)

    International Nuclear Information System (INIS)

    1992-12-01

    Communication of nuclear data progress (CNDP) in English is set up by Chinese Nuclear Data Center (CNDC). This is the eighth issue. It includes the measurements of secondary neutron spectra on 9 Be, the cross section and angular distribution of 40 Ca(n, α) reaction, 54 V decay data and 107 Ag(α, n) cross section; the theoretical calculations of neutron induced reaction data on 56 Fe, 238 U and proton induced reaction data on 89 Y and 241 Am; the charged particle data evaluation of 235 U; and some papers on atomic and molecular data and data processing

  8. Reactor for exothermic reactions

    Science.gov (United States)

    Smith, L.A. Jr.; Hearn, D.; Jones, E.M. Jr.

    1993-03-02

    A liquid phase process is described for oligomerization of C[sub 4] and C[sub 5] isoolefins or the etherification thereof with C[sub 1] to C[sub 6] alcohols wherein the reactants are contacted in a reactor with a fixed bed acid cation exchange resin catalyst at an LHSV of 5 to 20, pressure of 0 to 400 psig and temperature of 120 to 300 F. Wherein the improvement is the operation of the reactor at a pressure to maintain the reaction mixture at its boiling point whereby at least a portion but less than all of the reaction mixture is vaporized. By operating at the boiling point and allowing a portion of the reaction mixture to vaporize, the exothermic heat of reaction is dissipated by the formation of more boil up and the temperature in the reactor is controlled.

  9. Bad Reaction to Cosmetics?

    Science.gov (United States)

    ... Consumers Protect Yourself Health Fraud Bad Reactions to Cosmetics? Tell FDA! Share Tweet Linkedin Pin it More ... Radiation-Emitting Products Vaccines, Blood & Biologics Animal & Veterinary Cosmetics Tobacco Products

  10. Transfusion reaction - hemolytic

    Science.gov (United States)

    ... Names Blood transfusion reaction Images Surface proteins causing rejection References Choate JD, Maitta RW, Tormey CA, Wu ... PA: Elsevier Saunders; 2016:chap 177. Hall JE. Blood types; transfusion; tissue and organ transplantation. In: Hall JE, ...

  11. Reaction Qualifications Revisited

    DEFF Research Database (Denmark)

    Lippert-Rasmussen, Kasper

    2009-01-01

    to a person's effectiveness by causing a favourable reaction in customers, co-workers etc. (for short: recipients) - are involved, this assumption is false. Building on work by Wertheimer, Mason, and Miller, this paper proposes an account of the reaction qualifications that count, from the point of view...... preferences, recipients should not respond to the applicant actually hired on the basis of their (the recipients') racial preferences. My account decomposes the meritocratic ideal into four separate norms, one of which applies to recipients rather than to selectors. Finally, it defends the view that reaction...... qualifications based on antimeritocratic reactions, while not unproblematic, are not entirely irrelevant from the point of view of merit. Notably, selectors need not discount them when no one - including the targets of the objectionable preferences - is unfairly disadvantaged. Because not all problematic...

  12. Sequential charged particle reaction

    International Nuclear Information System (INIS)

    Hori, Jun-ichi; Ochiai, Kentaro; Sato, Satoshi; Yamauchi, Michinori; Nishitani, Takeo

    2004-01-01

    The effective cross sections for producing the sequential reaction products in F82H, pure vanadium and LiF with respect to the 14.9-MeV neutron were obtained and compared with the estimation ones. Since the sequential reactions depend on the secondary charged particles behavior, the effective cross sections are corresponding to the target nuclei and the material composition. The effective cross sections were also estimated by using the EAF-libraries and compared with the experimental ones. There were large discrepancies between estimated and experimental values. Additionally, we showed the contribution of the sequential reaction on the induced activity and dose rate in the boundary region with water. From the present study, it has been clarified that the sequential reactions are of great importance to evaluate the dose rates around the surface of cooling pipe and the activated corrosion products. (author)

  13. Firefighter Nozzle Reaction

    DEFF Research Database (Denmark)

    Chin, Selena K.; Sunderland, Peter B.; Jomaas, Grunde

    2017-01-01

    to anchor forces, the hose becomes straight. The nozzle reaction is found to equal the jet momentum flow rate, and it does not change when an elbow connects the hose to the nozzle. A forward force must be exerted by a firefighter or another anchor that matches the forward force that the jet would exert...... on a perpendicular wall. Three reaction expressions are derived, allowing it to be determined in terms of hose diameter, jet diameter, flow rate, and static pressure upstream of the nozzle. The nozzle reaction predictions used by the fire service are 56% to 90% of those obtained here for typical firefighting hand......Nozzle reaction and hose tension are analyzed using conservation of fluid momentum and assuming steady, inviscid flow and a flexible hose in frictionless contact with the ground. An expression that is independent of the bend angle is derived for the hose tension. If this tension is exceeded owing...

  14. Nucleon induced reactions

    International Nuclear Information System (INIS)

    Gmuca, S.; Antalik, R.; Kristiak, J.

    1988-01-01

    The collection contains full texts of 37 contributions; all fall within the INIS Subject Scope. The topics treated include some unsolved problems of nuclear reactions and relevant problems of nuclear structure at low and intermediate energies. (Z.S.)

  15. Jets in hadronic reactions

    Energy Technology Data Exchange (ETDEWEB)

    Paige, F.E.

    1983-01-01

    Recent experimental data on the properties of jets in hadronic reactions are reviewed and compared with theoretical expectations. Jets are clearly established as the dominant process for high E/sub T/ events in hadronic reactions. The cross section and the other properties of these events are in qualitative and even semiquantitative agreement with expectations based on perturbative QCD. However, we can not yet make precise tests of QCD, primarily because there are substantial uncertainties in the theoretical calculations. 45 references. (WHK)

  16. Oxygen evolution reaction catalysis

    Science.gov (United States)

    Haber, Joel A.; Jin, Jian; Xiang, Chengxiang; Gregoire, John M.; Jones, Ryan J.; Guevarra, Dan W.; Shinde, Aniketa A.

    2016-09-06

    An Oxygen Evolution Reaction (OER) catalyst includes a metal oxide that includes oxygen, cerium, and one or more second metals. In some instances, the cerium is 10 to 80 molar % of the metals in the metal oxide and/or the catalyst includes two or more second metals. The OER catalyst can be included in or on an electrode. The electrode can be arranged in an oxygen evolution system such that the Oxygen Evolution Reaction occurs at the electrode.

  17. Anaphylactic reaction to orthoiodohippurate

    Energy Technology Data Exchange (ETDEWEB)

    Stoeckel, M.; Roedbro, P.; Ennow, K.; Kristensen, K.

    1983-02-01

    A case of an anaphylactic reaction following administration of /sup 125/I- and /sup 131/-I-o-iodohippurate in a 32-year-old woman is reported. The patient had a renography performed because of hematuria. She was known to react to an intravenous pyelography previously performed with an anaphylactic shock. The importance of reporting all adverse reactions to radiopharmaceuticals for central registration is stressed.

  18. Direct studies of neutron-induced reactions in inverse kinematics

    Science.gov (United States)

    Mosby, Shea; Couture, Aaron; Mosby, Michelle; Reifarth, Rene

    2017-09-01

    Some of the major questions in both nuclear astrophysics and nuclear technology depend on neutron-induced reaction rates which are largely unknown, on nuclei which are too short-lived to directly measure with existing experimental methods. Indirect methods have progressed, by either attempting to determine the reaction rate explicitly or by constraining nuclear structure for reaction models. Despite this progress, systematic uncertainties associated with the techniques remain a persistent issue. It has been shown that the combination of a radioactive beam facility, ion storage ring, and spallation neutron source could enable direct measurements of neutron-induced reaction rates for nuclei with half-lives as short as minutes or less. We have analyzed the feasibility of this technique using the LANSCE accelerator complex as a baseline. The technique and initial results from the feasibility analysis will be presented.

  19. Adverse drug reactions.

    Science.gov (United States)

    Patton, K; Borshoff, D C

    2018-01-01

    Adverse drug reactions are a cause of significant morbidity and mortality to patients and a source of financial burden to the healthcare system. Of the wide spectrum of adverse drug reactions, the most concerning to the anaesthetist remain anaphylaxis and malignant hyperthermia. Although the incidence of anaphylaxis under anaesthesia is difficult to ascertain, it occurs commonly enough that most anaesthetists will manage at least one case in their career. The wide range of drugs given in the peri-operative period and the variable presentation in the anaesthetised patient can delay diagnosis and treatment, and adversely affect outcome. Furthermore, despite improvements in testing, causative drugs can still be difficult to identify, as adverse reactions may be mediated by mechanisms other than IgE activation. With an increase in the reporting of anaphylaxis to newer anaesthetic drugs such as sugammadex, combined with change over the recent decades in the most likely causative peri-operative agents, it is imperative anaesthetists remain up to date on recent developments. In addition, they should be vigilant to patient characteristics, including pharmacogenetic variations that may predispose to adverse drug reactions, in order to help minimise risks of a reaction. The severity of adverse drug reactions to peri-operative drugs means morbidity and mortality remain high. © 2018 The Association of Anaesthetists of Great Britain and Ireland.

  20. Progressive posterior cortical dysfunction

    Directory of Open Access Journals (Sweden)

    Fábio Henrique de Gobbi Porto

    Full Text Available Abstract Progressive posterior cortical dysfunction (PPCD is an insidious syndrome characterized by prominent disorders of higher visual processing. It affects both dorsal (occipito-parietal and ventral (occipito-temporal pathways, disturbing visuospatial processing and visual recognition, respectively. We report a case of a 67-year-old woman presenting with progressive impairment of visual functions. Neurologic examination showed agraphia, alexia, hemispatial neglect (left side visual extinction, complete Balint's syndrome and visual agnosia. Magnetic resonance imaging showed circumscribed atrophy involving the bilateral parieto-occipital regions, slightly more predominant to the right . Our aim was to describe a case of this syndrome, to present a video showing the main abnormalities, and to discuss this unusual presentation of dementia. We believe this article can contribute by improving the recognition of PPCD.

  1. Potential modulation of cancer progression by oxysterols.

    Science.gov (United States)

    Poli, Giuseppe; Biasi, Fiorella

    2016-06-01

    At least with regard to promotion and progression of cancer, oxysterols actually appear as typical Janus molecules, by inducing early inflammatory reaction against cancer expansion and apoptotic death of cancer cells, but on the other hand sustaining a complex survival signaling pathway that eventually turns in favor of the neoplastic process itself. The pro-tumoral and anti-tumoral properties of this class of compounds is mediated by both LXR-dependent and independent mechanisms. The extent of oxidative redox imbalance, moderate or extensive, likely plays a key role in determining the actual effects operated by oxysterols along the various steps of carcinogenesis. Copyright © 2016 Elsevier Ltd. All rights reserved.

  2. Neutrino-electron scattering. Progress report

    International Nuclear Information System (INIS)

    White, D.H.

    1982-01-01

    We present here a progress report on an experiment to measure the cross section for nu/sub μ/e scattering at the Brookhaven AGS. A wide band focussing horn is used with a neutrino beam energy centered at 1.5 GeV. We have in hand measurements with nu/sub μ/ and anti nu/sub μ/ beams but we present preliminary data on the nu/sub μ/ beam running only. We also measure the reactions: nu/sub μ/ + n → μ - + p and nu/sub e/ + n → e - + p which will be used in normalization and in background estimation

  3. [Progress in digital PCR technology and application].

    Science.gov (United States)

    Lin, Jiaqi; Su, Guocheng; Su, Wenjin; Zhou, Changyi

    2017-02-25

    Digital PCR is an emerging analysis technology for absolute quantification after realtime-PCR. Through digital PCR, single DNA molecules are distributed into isolated reactions, and the product with fluorescence signal can be detected and analyzed after amplification. With the advantages of higher sensitivity and accuracy, digital PCR, independent of a standard curve, is developing rapidly and applied widely to the next generation sequencing and detection fields, such as gene mutation, copy number variation, microorganism, and genetically modified food. In this article, we reviewed the quantitative method and research progress of digital PCR technology in the main application fields.

  4. Progress report of the nuclear physics department

    International Nuclear Information System (INIS)

    1987-01-01

    This progress report presents the experiments and the technological studies carried out at the Nuclear Physics Department of Saclay from October 1, 1985 to September 30, 1986. These studies concern the structure of nuclei, the nuclear reaction mechanisms and, more and more, mesic processes in nuclear dynamics. The experiments have been carried at the 700 MeV electron linac, the synchrotron SATURNE, the heavy ion accelerator GANIL, the SARA facility at Grenoble. An important technical activity has been devoted to the construction of the supraconducting booster of the 9 MV tandem [fr

  5. Progress report of the nuclear physics department

    International Nuclear Information System (INIS)

    1988-01-01

    This progress report presents the research programs and the technical developments carried out at the Nuclear Physics Department of Saclay from October 1, 1986 to September 30, 1987. The research programs concern the structure of nuclei and the general study of nuclear reaction mechanisms. Experiments use electromagnetic probes of the 700 Mev Saclay linear electron accelerator and hadronic probes, light polarised particles and heavy ions of the National Laboratories SATURNE and GANIL. The Nuclear Physics Department is also involved in development of accelerator technologies, especially in the field of superconducting cavities [fr

  6. Progress report of the nuclear physics department

    International Nuclear Information System (INIS)

    1986-01-01

    This progress report presents the experiments and the technological studies carried out at the Nuclear Physics Department of Saclay from October 1, 1984 to September 30, 1985. These studies concern the structure of nuclei, the nuclear reaction mechanisms and, more and more, mesic processes in nuclear dynamics. The experiments have been carried at the 700 MeV electron linac, the synchrotron SATURNE, the heavy ion accelerator GANIL, the SARA facility at Grenoble, and the antiproton beams at CERN. An important technical activity has been devoted to the construction of the supraconducting booster of the 9 MV tandem [fr

  7. ISABELLE: a progress report

    Energy Technology Data Exchange (ETDEWEB)

    Hahn, H

    1980-01-01

    This paper discusses the ISABELLE project, which has the objective of constructing a high-energy proton colliding beam facility at Brookhaven National Laboratory. The major technical features of the intersecting storage accelerators with their projected performance are described. Application of over 1000 superconducting magnets in the two rings represents the salient characteristic of the machine. The status of the entire project, the technical progress made so far, and difficulties encountered are reviewed.

  8. Three year progress report

    International Nuclear Information System (INIS)

    1977-07-01

    Progress is reported on the following studies: x-ray and uv effects in photosynthetic organisms; effects of alcohols and oxygen concentration on transforming DNA; free radical studies; sensitization by metal ions; role of the solvated electron in radiation damage to cells; effectiveness of organic and inorganic compounds in sensitizing bacterial spores to high energy radiation; oxygen effects; radiosensitivity of enzyme systems in Chlorella; and effects of pre-irradiation of solutions on spores

  9. Recent progress in microcalorimetry

    CERN Document Server

    Calvet, E; Skinner, H A

    2013-01-01

    Recent Progress in Microcalorimetry focuses on the methodologies, processes, and approaches involved in microcalorimetry, as well as heat flow, temperature constancy, and chemistry of alumina and cements.The selection first offers information on the different types of calorimeters; measurement of the heat flow between the calorimeter and jacket boundaries by means of a thermoelectric pile; and constructional details of the microcalorimeter. Discussions focus on classification of calorimeters, use of thermoelectric piles as thermometers, correct measurement of heat flow from a calorimeter conta

  10. Progress in optics

    CERN Document Server

    Wolf, Emil

    2008-01-01

    In the fourty-six years that have gone by since the first volume of Progress in Optics was published, optics has become one of the most dynamic fields of science. The volumes in this series which have appeared up to now contain more than 300 review articles by distinguished research workers, which have become permanent records for many important developments.- Metamaterials- Polarization Techniques- Linear Baisotropic Mediums- Ultrafast Optical Pulses- Quantum Imaging- Point-Spread Funcions- Discrete Wigner Functions

  11. Progress in optics

    CERN Document Server

    Wolf, Emil

    2009-01-01

    In the fourty-seven years that have gone by since the first volume of Progress in Optics was published, optics has become one of the most dynamic fields of science. The volumes in this series which have appeared up to now contain more than 300 review articles by distinguished research workers, which have become permanent records for many important developments.- Backscattering and Anderson localization of light- Advances in oliton manipulation in optical lattices- Fundamental quantum noise in optical amplification- Invisibility cloaks

  12. Clean Energy Progress Report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2011-07-01

    For the past several years, the IEA and others have been calling for a clean energy revolution to achieve global energy security, economic growth and climate change goals. This report analyses for the first time progress in global clean energy technology deployment against the pathways that are needed to achieve these goals. It provides an overview of technology deployment status, key policy developments and public spending on RDD&D of clean energy technologies.

  13. Progress in nanophotonics 1

    CERN Document Server

    Ohtsu, Motoichi

    2011-01-01

    This book focuses on the recent progress in nanophotonics technology to be used to develop novel nano-optical devices, fabrication technology, and security systems. It begins with a review of the concept of dressed photons and applications to devices, fabrication, and systems; principles and applications. Further topics include: DNA process for quantum dot chain, photon enhanced emission microscopy, near field spectroscopy of metallic nanostructure, self-organized fabrication of composite semiconductor quantum dots, formation of metallic nanostructure, and nanophotonic information systems with

  14. Progressive governance and globalisation

    OpenAIRE

    Jean Pisani-Ferry

    2008-01-01

    Jean Pisani-Ferry discusses the development of globalisation during the last decade and the challenges ahead. The speed and magnitude of the transformation affecting the world economy are larger than initially envisaged, while domestic policy reforms and redistribution have often been insufficient to cope with this adjustment challenge. Against this background, the definition of a renewed agenda that builds on the success of the initial one should be a priority for progressive governments. Th...

  15. Organic Reactions in Aqueous Media (by Chao-Jun Li and Tak-Hang Chan)

    Science.gov (United States)

    Rosan, Reviewed Alan M.

    2000-06-01

    This concise book joins the series of Wiley Interscience special topic publications. In seven chapters it selectively reviews the burgeoning literature on organic reactions conducted in water or in aqueous media as a reaction cosolvent, nicely complementing another recent book on the subject by Grieco. Following a short introduction there are six chapters that vary in length from 10 to 50 pages; they cover pericyclic reactions, nucleophilic additions and substitutions, metal-mediated reactions, transition metal-catalyzed reactions, oxidation and reduction reactions, and industrial applications. These chapters, each of which is prefaced with a short provocative quotation, also vary in depth, containing from 11 to more than 180 references. The literature is complete through 1996 and commendably includes citations of original papers by Barbier, Faraday, Frankland, Grignard, Kolbe, Lapworth, and Reformatsky as well as references to selected U.S. and foreign patents and the Russian literature. There is a subject index but no author index. This book is timely and effective. From the title, one might expect a broad discussion of the unique properties of water and water-soluble components (salts, surfactants, etc.) that would be thought to bear on organic reactivity. The first chapter opens by noting that water is the most abundant volatile material in comets and briefly describes those properties that suggest its utility as a solvent or cosolvent, summarizing the potential technical, economic, and environmental advantages. Also described are the remarkable changes in density, conductance, heat capacity, dielectric constant, and ionization constant that accompany the transition to the critical point, but the emphasis here is on the effect of water under non-critical conditions. Discussion of the structure of liquid water and the role of hydrogen bonding in mediating molecular recognition events is abbreviated. In fact, the term "hydrogen bond" is surprisingly absent from

  16. Environmental progress report

    International Nuclear Information System (INIS)

    1998-11-01

    Environmental progress made in 1997-1998 by member companies of the Mining Association of Canada (MAC) was described. MAC includes companies in the mineral exploration, mining, smelting, refining and semi-fabrication industries. Brief highlights from the action plans of participating companies are included, but the main focus is on those accomplishments which were undertaken as an association. The two issues which dominated MAC activities in 1997-1998 were tailings management and the role of metals in the environment. Ongoing activities in energy efficiency and water issues, as well as in reducing pollutant releases to the environment were also reported. Progress under programs such as the Mine Environment Neutral Drainage (MEND) and Metal Mining Liquid Effluent Regulations, both of which will continue in 1998, were reviewed. Completion of the Aquatic Effects Technology Evaluation field studies was announced. Issuance of updated guidelines for the National Pollutant Release Inventory and Accelerated Reduction/Elimination of Toxic Substances (ARET) was another milestone event in 1997. This progress report is based on the enhanced data submitted by participating companies prepared in accordance with the new guidance document. tabs., figs

  17. Nuclear data needs in nuclear astrophysics: Charged-particle reactions

    International Nuclear Information System (INIS)

    Smith, Michael S.

    2001-01-01

    Progress in understanding a diverse range of astrophysical phenomena - such as the Big Bang, the Sun, the evolution of stars, and stellar explosions - can be significantly aided by improved compilation, evaluation, and dissemination of charged-particle nuclear reaction data. A summary of the charged-particle reaction data needs in these and other astrophysical scenarios is presented, along with recommended future nuclear data projects. (author)

  18. Regioselective Reductive Cross-Coupling Reactions of Unsymmetrical Alkynes

    OpenAIRE

    Reichard, Holly A.; McLaughlin, Martin; Chen, Ming Z.; Micalizio, Glenn C.

    2010-01-01

    The present microreview summarizes our progress over the last few years in defining regioselective reductive cross-coupling reactions of unsymmetrical alkynes with terminal- and internal alkynes, aldehydes, and imines. We begin with a brief historical perspective of metal-mediated reductive dimerization reactions of aromatic alkynes and discuss the challenges associated with “crossed” versions of this mode of reactivity. Next, a collection of available methods that allow for regioselective re...

  19. Field theory of propagating reaction-diffusion fronts

    International Nuclear Information System (INIS)

    Escudero, C.

    2004-01-01

    The problem of velocity selection of reaction-diffusion fronts has been widely investigated. While the mean-field limit results are well known theoretically, there is a lack of analytic progress in those cases in which fluctuations are to be taken into account. Here, we construct an analytic theory connecting the first principles of the reaction-diffusion process to an effective equation of motion via field-theoretic arguments, and we arrive at results already confirmed by numerical simulations

  20. Progress report, 1980

    International Nuclear Information System (INIS)

    1980-01-01

    The operation and development of facilities in the Foster Radiation Laboratory and the research carried out from November 1979 to October 1980 are summarized. The upgrading process for the synchrocyclotron is continuing. The main research activities are the studies of nuclear properties far from beta stability, complex nuclear reactions, the nuclear fission mechanism, and positron emission tomography. A mini-cyclotron is being installed at the Montreal Neurological Institute. Lists of personnel and publications are included

  1. Removal of metallic and organic contaminants from aqueous streams by novel filtration methods. 1997 annual progress report

    International Nuclear Information System (INIS)

    Rodriguez, N.M.

    1997-01-01

    'Graphite nanofibers, are a novel material that has been developed in the laboratory from the metal catalyzed decomposition of certain hydrocarbons (1). These structures possess a cross-sectional area that varies between 5 to 100 nm and have lengths ranging from 5 to 100 mm (2). High-resolution transmission electron microscopy studies have revealed that the nanofibers consist of extremely well-ordered graphite platelets (3), which are oriented in various directions with respect to the fiber axis. The arrangement of the graphene layers can be tailored to a desired geometry by choice of the correct catalyst system and reaction conditions, and it is therefore possible to generate structures where the layers are stacked in a ribbon, herring-bone, or stacked orientation. An example of the later structure is shown in the high resolution electron micrograph, Figure 1a, where the lines across correspond to individual planes of graphite that are separated at a minimum distance of 0.34 nm. The structural features of the nanofiber can be better appreciated in the schematic renditions, Figures 1b and 1c. The unique combination of small cross-sectional area, which is estimated to be on average 20 nm, and the abundance of exposed edges makes the material an ideal solid for adsorption. The suitability of the material for the selective adsorption of a variety of molecules is illustrated in Figure 1c, where it can be seen that adsorption could be achieved upon access of the molecule to the inner regions of the solid. One the most outstanding features of graphite nanofibers, is that the solid consists entirely of non-rigid wall nanopores that extend across the entire solid. The process for the synthesis of graphite nanofibers produced from the decomposition of hydrocarbons and carbon monoxide over selected metal surfaces at temperatures over the range 450 to 700 C has been optimized and it is possible to produce relatively large quantities of high purity material in short periods of

  2. GEOMETRIC PROGRESSIONS ON ELLIPTIC CURVES.

    Science.gov (United States)

    Ciss, Abdoul Aziz; Moody, Dustin

    2017-01-01

    In this paper, we look at long geometric progressions on different model of elliptic curves, namely Weierstrass curves, Edwards and twisted Edwards curves, Huff curves and general quartics curves. By a geometric progression on an elliptic curve, we mean the existence of rational points on the curve whose x -coordinate (or y -coordinate) are in geometric progression. We find infinite families of twisted Edwards curves and Huff curves with geometric progressions of length 5, an infinite family of Weierstrass curves with 8 term progressions, as well as infinite families of quartic curves containing 10-term geometric progressions.

  3. Department of Nuclear Reactions - Overview

    International Nuclear Information System (INIS)

    Budzanowski, A.

    1999-01-01

    Full text: The year 1998 can be considered as very successful both in harvesting important results from the existing collaborations as well as establishing new ones. In the frame of the COSY-11 collaboration cross section for η' production in p-p collision close to the threshold has been measured. In the region of excess energy between 1.5 and 4.1 MeV the η' cross sections are much lower than those of the π 0 and η production. There seems to be no indication that N * resonance doorway-like state governs the reaction mechanisms. The determined coupling constant g η'pp appears to be consistent with the prediction of the simple quark model. Results were published in Phys. Rev. Letters. Using the GEM detector, investigations of the isospin symmetry breaking were performed. Two reactions channels 3 Heπ 0 and 3 Hπ + from the reaction at proton momenta 700, 767, and 825 MeV/c were measured. Data analysis is in progress. The model of the meson cloud in the nucleon which is a speciality of our department has been successfully applied to explain the leading proton and neutron cross sections from the e + or e - proton collisions at the HERA ring. General formulas to calculate polarization of the particles with spin transmitted through the barrier in the presence of strong magnetic fields were obtained. New collaboration between our laboratory and the Institute for Nuclear Research in Kiev has been established. One PhD thesis was completed in the frame of this collaboration. We joined the new collaboration with Lund University concerning studies of hot nuclear matter properties using heavy ions from CELSIUS ring. First test of the phoswich detector for the forward wall was performed in Uppsala. Isoscalar giant dipole resonance strength distribution 3 ℎω has been evaluated in 208 Pb in the space of 1p1h and 2p2h excitation. The centroid energy of this state can directly be related to the nuclear incompressibility module. Our result indicates rather large values of

  4. Psychological functioning in primary progressive versus secondary progressive multiple sclerosis

    DEFF Research Database (Denmark)

    Vleugels, L; Pfennings, L E; Pouwer, F

    1998-01-01

    Psychological functioning in two types of multiple sclerosis (MS) patients is assessed: primary progressive (PP) and secondary progressive (SP) patients. On the basis of differences in clinical course and underlying pathology we hypothesized that primary progressive patients and secondary......-MS scored significantly better on 5 out of 14 subscales than patients with SP-MS (p diagnosis of MS, amongst patients attending an MS unit, primary progressive...

  5. Cyclotron based nuclear science. Progress report, April 1, 1985-March 31, 1986

    International Nuclear Information System (INIS)

    Youngblood, D.H.

    1986-08-01

    Progress report for cyclotron based nuclear science cyclotron facility are summarized. Research is described under the headings heavy ion reactions, nuclear theory, atomic studies and activation analysis, superconducting cyclotron and instrumentation. Publications are listed

  6. Immediate reaction to clarithromycin.

    Science.gov (United States)

    Gangemi, S; Ricciardi, L; Fedele, R; Isola, S; Purello-D'Ambrosio, F

    2001-01-01

    We present the case of bronchospastic reaction to clarithromycin had during a drug challenge test. Personal allergic history was negative for respiratory allergies and positive for adverse drug reactions to general and regional anesthesia and to ceftriaxone. After the administration of 1/4 of therapeutic dose of clarithromycin the patient showed dyspnea, cough and bronchospasm in all the lung fields. The positivity of the test was confirmed by the negativity to the administration of placebo. The quickness and the clinical characteristic of the adverse reaction suggest a pathogenic mechanism of immediate-type hypersensitivity. On reviewing the literature we have found no reports of bronchospastic reaction to clarithromycin. Macrolides are a class of antibiotics mainly used in the last years in place of beta-lactams because of a broad spectrum of action and a low allergic power. In fact, there are few reports on allergic reactions to these molecules. Clarithromycin is one of the latest macrolides, characterised by the presence of a 14-carbon-atom lactone ring as erythromycin, active on a wide spectrum of pathogens.

  7. Chemical kinetics of gas reactions

    CERN Document Server

    Kondrat'Ev, V N

    2013-01-01

    Chemical Kinetics of Gas Reactions explores the advances in gas kinetics and thermal, photochemical, electrical discharge, and radiation chemical reactions. This book is composed of 10 chapters, and begins with the presentation of general kinetic rules for simple and complex chemical reactions. The next chapters deal with the experimental methods for evaluating chemical reaction mechanisms and some theories of elementary chemical processes. These topics are followed by discussions on certain class of chemical reactions, including unimolecular, bimolecular, and termolecular reactions. The rema

  8. Laboratory approaches of nuclear reactions involved in primordial and stellar nucleosynthesis

    International Nuclear Information System (INIS)

    Rolfs, C.; California Inst. of Tech., Pasadena

    1986-01-01

    Laboratory-based studies of primordial and stellar nucleosynthesis are reviewed, with emphasis on the nuclear reactions induced by charged particles. The analytical approach used to investigate nuclear reactions associated with stellar reactions is described, as well as the experimental details and procedures used to investigate nuclear reactions induced by charged particles. The present knowledge of some of the key reactions involved in primordial nucleosynthesis is discussed, along with the progress and problems of nuclear reactions involved in the hydrogen and helium burning phases of a star. Finally, a description is given of new experimental techniques which might be useful for future experiments in the field of nuclear astrophysics. (U.K.)

  9. Covering an arithmetic progression with geometric progressions and vice versa

    OpenAIRE

    Sanna, Carlo

    2013-01-01

    We show that there exists a positive constant C such that the following holds: Given an infinite arithmetic progression A of real numbers and a sufficiently large integer n (depending on A), there needs at least Cn geometric progressions to cover the first n terms of A. A similar result is presented, with the role of arithmetic and geometric progressions reversed.

  10. HSX progress report

    International Nuclear Information System (INIS)

    1994-01-01

    Brief statements on the progress of the design and construction of the HSX experiment are reported. Topics covered include the modular and auxiliary coil systems, the coil support structure, vacuum vessel, the ECH system, the magnet power supply and site. The proposed budget for Year 2 (August 1, 1994 through July 31, 1995) is presented. The effects of a flat funding profile (based on Year 2 budget level of $1137K) on out-years and the HSX project schedule are discussed. The stretching out of the program to accommodate the reduced funding profile should result in only a slight delay in HSX operations

  11. Progressive familial intrahepatic cholestasis

    International Nuclear Information System (INIS)

    Mirza, R.; Abbas, Z.; Luck, N.H.; Azam, S.M.Z.; Aziz, S.; Hassan, S.M; Somro, G.B.

    2006-01-01

    Progressive familial intrahepatic cholestasis (PFIC) is an important cause of cholestatic liver disease and biliary cirrhosis in pediatric population. Three cases of PFIC are described that were diagnosed on the basis of family history, pruritis, cirrhosis and / or paucity of interlobular bile ducts on liver biopsy and presence of extrahepatic biliary tree on imaging. These patients were initially labeled as suffering from extra-hepatic biliary atresia and neonatal hepatitis. PFIC-1 and 2 could not be differentiated on histological grounds, since these patients presented late and process of fibrosis was advanced. (author)

  12. [Progressive multifocal leukoencephalopathy].

    Science.gov (United States)

    Warnke, C; Wattjes, M P; Adams, O; Hartung, H-P; Martin, R; Weber, T; Stangel, M

    2016-12-01

    Progressive multifocal leukoencephalopathy (PML) is a disease of immunosuppressed patients caused by the JC polyomavirus (JCPyV). Due to the elevated risk in patients treated with natalizumab for multiple sclerosis (MS) and also treatment with other biologicals for different indications, the relevance of PML has increased in recent years. This article summarizes the published knowledge on the biology and pathogenesis of PML with a focus on the role of cerebrospinal fluid diagnostics in the work-up for PML and the current PML case definition. Current recommendations regarding risk management are discussed, as are possible therapies and prevention.

  13. TASCC Division progress report

    International Nuclear Information System (INIS)

    Hardy, J.C.

    1992-10-01

    The TASCC (Tandem Accelerator-Superconducting Cyclotron) facility is devoted to developing and providing beams for an experimental program of basic nuclear research. Beam was on target for 2901 hours during the period of interest. The cyclotron provided beam for 524 hours, and tandem beams were used for a total of 3940 hours. The most exciting experimental result was the first evidence of a rotational band with the characteristics of hyperdeformation: a ridge-valley structure in 152 Dy. This progress report details experimental results and instrumentation and facility development over the period. (L.L.) (refs., tabs., figs.)

  14. Progress in optics

    CERN Document Server

    Wolf, Emil

    2006-01-01

    In the thirty-seven years that have gone by since the first volume of Progress in Optics was published, optics has become one of the most dynamic fields of science. At the time of inception of this series, the first lasers were only just becoming operational, holography was in its infancy, subjects such as fiber optics, integrated optics and optoelectronics did not exist and quantum optics was the domain of only a few physicists. The term photonics had not yet been coined. Today these fields are flourishing and have become areas of specialisation for many science and engineering students and n

  15. Progress in optics

    CERN Document Server

    Wolf, Emil

    1977-01-01

    In the thirty-seven years that have gone by since the first volume of Progress in Optics was published, optics has become one of the most dynamic fields of science. At the time of inception of this series, the first lasers were only just becoming operational, holography was in its infancy, subjects such as fiber optics, integrated optics and optoelectronics did not exist and quantum optics was the domain of only a few physicists. The term photonics had not yet been coined. Today these fields are flourishing and have become areas of specialisation for many science and engineering students and n

  16. Progress in radiopharmacy

    International Nuclear Information System (INIS)

    Cox, P.H.; Mather, S.J.; Lazarus, C.R.

    1986-01-01

    Progress in Radiopharmacy is based on presentations to the Second European Symposium on Radiopharmacy and Radiopharmaceuticals, held at St. Catharine's College in Cambridge, England in March 1985. The aim of the meeting was to present an in-depth evaluation of the current status of radiopharmaceutical developments and usage within the European context, giving emphasis to European research in this area. Secondly, the professional aspects of the practice of radiopharmacy in Europe have been reviewed by experts from different countries. The scientific part of the meeting was divided into sessions devoted to generator systems for ultra short-lived nuclides, positron emitting radiopharmaceuticals, radiochemistry, radionuclides in drug formulation studies and radiopharmaceutical aerosols. (Auth.)

  17. Inflammatory reaction in chondroblastoma

    Energy Technology Data Exchange (ETDEWEB)

    Yamamura, Sigeki [Dept. of Orthopedic Surgery, Nagoya Univ. School of Medicine (Japan); Sato, Keiji [Dept. of Orthopedic Surgery, Nagoya Univ. School of Medicine (Japan); Sugiura, Hideshi [Dept. of Orthopedic Surgery, Nagoya Univ. School of Medicine (Japan); Iwata, Hisashi [Dept. of Orthopedic Surgery, Nagoya Univ. School of Medicine (Japan)

    1996-05-01

    The objective of this study was to evaluate the inflammatory reaction accompanying chondroblastoma and to define the value of the finding in clinical practice. We reviewed the clinical, radiographic, and magnetic resonance (MR) findings in six patients with histologically proven chondroblastoma. In all cases, MR imaging showered marrow and soft tissue edema. In four of six cases, periosteal reaction related to intra-osseous edema was more clearly demonstrated on MR imaging than on radiographs. Follow-up MR studies after surgery were available in three patients and all showed disappearance of inflammatory responses such as marrow and soft tissue edema, and reactive synovitis. We propose that these inflammatory reactions of chondroblastomas are inportant signs for detecting residual tumor in recurrences after surgery, as well as for making a precise diagnosis. The MR changes may also be valuable in demonstrating eradication of the tumor. (orig./MG)

  18. Nanoparticle Reactions on Chip

    Science.gov (United States)

    Köhler, J. M.; Kirner, Th.; Wagner, J.; Csáki, A.; Möller, R.; Fritzsche, W.

    The handling of heterogenous systems in micro reactors is difficult due to their adhesion and transport behaviour. Therefore, the formation of precipitates and gas bubbles has to be avoided in micro reaction technology, in most cases. But, micro channels and other micro reactors offer interesting possibilities for the control of reaction conditions and transport by diffusion and convection due to the laminar flow caused by small Reynolds numbers. This can be used for the preparation and modification of objects, which are much smaller than the cross section of microchannels. The formation of colloidal solutions and the change of surface states of nano particles are two important tasks for the application of chip reactors in nanoparticle technology. Some concepts for the preparation and reaction of nanoparticles in modular chip reactor arrangements will be discussed.

  19. Progress report 1983

    International Nuclear Information System (INIS)

    1984-01-01

    The facilities at the Studsvik Research Centre serve as a basis for fundamental research. The neutron diffraction work aiming at determining crystal structures has continued both with single crystals and with powders in collaboration with university groups from Lund, Goeteborg, Stockholm, Umeaa and Uppsala. Facilities for work on proteins and on liqiuds will be installed. Results for a number of compounds are reported. Neutron diffraction studies are made on molecular motion in liquid metals and salts, the determination of static and dynamic scattering factors in liqiuid metals and the diffusion of hydrogen in alloys. Another field is the elementary excitations in liquid 3 He, and studies of nuclear spin ordering in solid 3 He. On-line-isotope-separator experiments (OSIRIS) has been performed using a conventional target-ion source system. The main research activity has been on decay properties, including delayed neutrons, for short-lived, very neutron rich fission products. Other aspects of fission, and also heavy-ion induced reactions are studied in collaboration with Lawrence Berkeley Laboratory and Oregon State University. Work is done on construction of a high temperature ion-source. The Van der Graff-accelerator for various experiments in neutron physics, including reference work on scattering of neutrons from carbon. The accelerator is also used for inegral determinations of decay heat in nuclear fuel, for development of neutron diagnostical methods for use in fusion experiments, for study of (α,n)-processes of astrophysical importance, and as an analytical tool using the PIXE technique. The radiation chemical group has continued their studies of primary reactions in crystalline materials using pulse radiolysis and ESR spectrometry techniques. The optical properties and the reactions of trapped electrons have been investigated. Recently cationic species of hydrocarbons have been studied using ESR. (PAa)

  20. Progressive pseudorheumatoid dysplasia misdiagnosed as ...

    African Journals Online (AJOL)

    Progressive pseudorheumatoid dysplasia misdiagnosed as seronegative juvenile idiopathic arthritis. Ozgur Taspinar, Fatih Kelesoglu, Yasar Keskin, Murat Uludag. Abstract. Background: Progressive pseudorheumatoid dysplasia (PPD) is a rare spondylo- epi-metaphyseal dysplasia (SEMD). It can be confused with juvenile ...

  1. Progress report, 1979

    International Nuclear Information System (INIS)

    During 1979 the synchrocyclotron 3 He and alpha beam intensities have been improved and a stochastic beam stretcher for alpha and deuteron beams has been installed. The PDP-11 memory has been enlarged and a terminal for the PDP-15 installed at the cyclotron control desk. The angular correlation facility for on-line γ-spectrographic studies has been completed, and a microprocessor-controlled tape transport system integrated into the helium jet transport facilities. The main research interests continued to be the properties of nuclei far from beta stability, complex nuclear reactions, the fission mechanism, and positron tomography. (LL)

  2. Velocity pump reaction turbine

    Science.gov (United States)

    House, P.A.

    An expanding hydraulic/two-phase velocity pump reaction turbine including a dual concentric rotor configuration with an inter-rotor annular flow channel in which the inner rotor is mechanically driven by the outer rotor. In another embodiment, the inner rotor is immobilized and provided with gas recovery ports on its outer surface by means of which gas in solution may be recovered. This velocity pump reaction turbine configuration is capable of potential energy conversion efficiencies of up to 70%, and is particularly suited for geothermal applications.

  3. Reactions to dietary tartrazine.

    OpenAIRE

    David, T J

    1987-01-01

    Double blind challenges with tartrazine and benzoic acid were performed in hospital in 24 children whose parents gave a definite history of a purely behavioural immediate adverse reaction to one of these substances. The patients, whose ages ranged from 1.6 to 12.4 years, were on a diet that avoided these items, and in all there was a clear history that any lapse of the diet caused an obvious adverse behavioural reaction within two hours. In no patient was any change in behaviour noted either ...

  4. Allergic reactions in anaesthesia

    DEFF Research Database (Denmark)

    Krøigaard, M; Garvey, L H; Menné, T

    2005-01-01

    match, the right substance being suspected, but investigations showed an additional allergen or several substances, including the right substance being suspected. CONCLUSIONS: An informed guess is not a reliable way of determining the cause of a supposed allergic reaction during anaesthesia and may put...... a significant number of patients at unnecessary risk. Some patients may be labelled with a wrong allergy, leading to unnecessary warnings against harmless substances, and some patients may be put at risk of subsequent re-exposure to the real allergen. Patients with suspected allergic reactions during...

  5. Introduction to nuclear reactions

    International Nuclear Information System (INIS)

    Satchler, G.R.

    1980-01-01

    This introduction to nuclear reaction phenomena is aimed primarily but not exclusively at readers at the undergraduate student level. An overview of the subject is presented in the first two chapters entitled - Some background information and Introduction to nuclear reactions. The third chapter reviews scattering theory with emphasis on the underlying physical ideas and also provides schematic entrees to the more advanced topics. The physical models which have been developed to account for the various aspects of nuclear phenomena are described in more detail in chapter 4. References and exercises are appended to each chapter. (U.K.)

  6. Modeling of Reaction Calorimeter

    OpenAIRE

    Farzad, Reza

    2014-01-01

    The purpose of this project was to model the reaction calorimeter in order to calculate the heat of absorption which is the most important parameter in this work. Reaction calorimeter is an apparatus which is used in measuring the heat of absorption of CO2 as well as the total pressure in vapor phase based on vapor-liquid equilibrium state. Mixture of monoethanolamine (MEA) and water was used as a solvent to absorb the CO2.Project was divided in to three parts in order to make the programming...

  7. Anniversary reactions in therapists.

    Science.gov (United States)

    Granet, R B; Kalman, T P

    1982-12-01

    The authors provide three case examples of anniversary reactions in psychotherapists evoked in the course of treating patients. They note that psychotherapy has always been discussed in terms of time and phases, which lend themselves to periodicities and may provide the potential for anniversary phenomena. The authors recommend that therapists be aware of such phenomena; monitor their own losses, defenses, and dreams; and continue their own supervision. Possible positive aspects of identification of therapists' anniversary reactions are increased empathy with patients and help in completing unresolved therapeutic and personal issues.

  8. Malignant transformation of a potentially low risk lichenoid reaction

    International Nuclear Information System (INIS)

    Ashir, K.R.; Chatra, L.

    2012-01-01

    Lichenoid reaction represents a family of oral lesions identical, both clinically and histologically to oral lichen planus. The triggering factor for this lesion varies from medicines to dental materials, usually demonstrating a cause-effect relationship unlike lichen planus. We present a typical case of lichenoid reaction on the buccal mucosa that appeared in response to betel quid which progressed to carcinoma during a follow-up period of 6 months. Lichenoid reactions occurring in response to known carcinogens and that occurring in risk group population has to be observed more cautiously. (author)

  9. Cyclodextrin-Catalyzed Organic Synthesis: Reactions, Mechanisms, and Applications

    Directory of Open Access Journals (Sweden)

    Chang Cai Bai

    2017-09-01

    Full Text Available Cyclodextrins are well-known macrocyclic oligosaccharides that consist of α-(1,4 linked glucose units and have been widely used as artificial enzymes, chiral separators, chemical sensors, and drug excipients, owing to their hydrophobic and chiral interiors. Due to their remarkable inclusion capabilities with small organic molecules, more recent interests focus on organic reactions catalyzed by cyclodextrins. This contribution outlines the current progress in cyclodextrin-catalyzed organic reactions. Particular emphases are given to the organic reaction mechanisms and their applications. In the end, the future directions of research in this field are proposed.

  10. Cyclodextrin-Catalyzed Organic Synthesis: Reactions, Mechanisms, and Applications.

    Science.gov (United States)

    Bai, Chang Cai; Tian, Bing Ren; Zhao, Tian; Huang, Qing; Wang, Zhi Zhong

    2017-09-07

    Cyclodextrins are well-known macrocyclic oligosaccharides that consist of α-(1,4) linked glucose units and have been widely used as artificial enzymes, chiral separators, chemical sensors, and drug excipients, owing to their hydrophobic and chiral interiors. Due to their remarkable inclusion capabilities with small organic molecules, more recent interests focus on organic reactions catalyzed by cyclodextrins. This contribution outlines the current progress in cyclodextrin-catalyzed organic reactions. Particular emphases are given to the organic reaction mechanisms and their applications. In the end, the future directions of research in this field are proposed.

  11. Annual progress report 1980

    International Nuclear Information System (INIS)

    1981-01-01

    The technical support activities of the IPSN to competent administrations in 1980 has been marked: namely by the authorizations of divergence for 9 units EdF-PWR of 900 MW, the authorization project of creation and extension of reprocessing plant of COGEMA at the Hague UP 2 -800 and the authorization of starting up of the third unit of production of the EURODIF enrichment plant at Tricastin. On the other hand, IPSN has participated at the elaboration of a certain number of legislative and regulation texts relative to the control of nuclear matter, to radioprotection standards and to criteria of safety. For the safety of breeder, the test made at CABRI pile, in the international research program has given confirmation of the validity of theoretical models used in accidents calculations, hypothetical accidents which has allowed to reactualize safety criteria which have to be used for the development of this type of reactor. In worker radioprotection the results obtained in laboratory on the effect of radon, the progress made in personal dosimetry and the action of radioprotection undertaken in uranium mines constitutes a coherent effort. The deep drilling in granit (1000 m) and the experimental associated program which has finished the indispensable scientific data for the future policy in matter of storage of radioactives wastes. IPSN has contributed to progress made in the rules of exploitation of reactors, in the definition of wastes containment -specially at the output of reprocessing plant- in handling machines in hazardeous areas and in the study of environment [fr

  12. Slowly progressive fluent aphasia

    International Nuclear Information System (INIS)

    Sakurai, Yasuhisa; Momose, Toshimitsu; Watanabe, Toshiaki; Ishikawa, Takashi; Iwata, Makoto; Bando, Mitsuaki.

    1991-01-01

    Three patients with slowly progressive fluent aphasia are reported. One of the patients presented with memory disturbance. They were characterized clinically by having selective deficits in vocabulary, which resulted in impairment of confrontation naming, and auditory comprehension. MRI showed an atrophy not only in the left temporal lobe (including the superior, middle and inferior temporal gyri), hippocampus, parahippocampual gyrus, and fusiform gyrus, but also in the left parietal lobe. I-123 IMP SPECT and F-18 FDG PET were used to determine regional cerebral blood flow and regional cerebral metabolic rate, respectively. In addition to the decreased tracer uptake in the left temporal and/or parietal lobe, a decreased uptake was seen in the bilateral basal ganglia, the inner side of the temporal lobe (including the bilateral hippocampus), the right anterior temporal lobe, and the left thalamus. These findings may deny the previous thought that lesions are localized in slowly progressive fluent aphasia. Furthermore, noticeable difficulty in naming, i.e., patients unable to recognize the right answer, are considered attributable to widespread lesions from the whole left temporal lobe, including the hippocampus, to the right temporal lobe. (N.K.)

  13. Ghrelin and cancer progression.

    Science.gov (United States)

    Lin, Tsung-Chieh; Hsiao, Michael

    2017-08-01

    Ghrelin is a small peptide with 28 amino acids, and has been characterized as the ligand of the growth hormone secretagogue receptor (GHSR). In addition to its original function in stimulating pituitary growth hormone release, ghrelin is multifunctional and plays a role in the regulation of energy balance, gastric acid release, appetite, insulin secretion, gastric motility and the turnover of gastric and intestinal mucosa. The discovery of ghrelin and GHSR expression beyond normal tissues suggests its role other than physiological function. Emerging evidences have revealed ghrelin's function in regulating several processes related to cancer progression, especially in metastasis and proliferation. We further show the relative GHRL and GHSR expression in pan-cancers from The Cancer Genome Atlas (TCGA), suggesting the potential pathological role of the axis in cancers. This review focuses on ghrelin's biological function in cancer progression, and reveals its clinical significance especially the impact on cancer patient outcome. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

  14. Progress report 1999-2000

    International Nuclear Information System (INIS)

    2000-01-01

    This document presents the activities of the CENBG for the 1999 and 2000 years. The activities are arranged into 7 topics: 1) astro-particles, 2) high spins and big deformations, 3) fundamental interactions, 4) exotic nuclei, 5) the down end of the nuclear fuel cycle and ADS (accelerator driven system), 6) theoretical physics and 7) at the interface between physics and biology. Among a lot of achievements relevant to INIS we can note: -) the investigation of 2 new modes of decay: the bound internal conversion and the Pauli forbidden bound internal conversion, -) the progress made on the Nemo-3 experiment whose purpose is the possibility of detecting the neutrinoless double beta decay from the kinematics specificities of the 2 electrons released, -) the first observation of the doubly-magic nucleus Ni 48 , -) the beta delayed proton and gamma -ray spectroscopy of Mg 21 and Si 25 nuclei, -) the identification of the fundamental state of Li 10 , -) the measurement of the masses of nuclei close to N = Z line in the region A = 80, -) the measurement of the beta decay of Ga 62 (T = 116 ms), and concerning ADS technology: -) the neutron capture cross-section of Th 232 has been measured in the energy range from 60 keV to 2 MeV, -) the determination of neutron induced fission cross-section of Pa 233 in the fast neutron energy range from 0.5 to 10 MeV, and -) the measurement of isotopic distributions for all residual elements from Ti to Pb produced in the reaction 1 A.GeV Pb 208 on proton. (A.C.)

  15. Nuclear chemistry progress report

    International Nuclear Information System (INIS)

    1983-09-01

    The activities of the nuclear chemistry program at Indiana University during the period September 1, 1982 to August 31, 1983 are reviewed. As in the past, these investigations have focused on understanding the properties of nucleus-nucleus collisions at low-to-intermediate energies. During the past year new programs have been initiated at the National Superconducting Cyclotron Laboratory at Michigan State University and the Hollifield Heavy-Ion Research Facility at Oak Ridge. With the unique beams provided by these accelerators we have extended our previous studies of energy dissipation phenomena into new energy regimes. The MSU measurements, performed with E/A = 15 to 30 MeV 14 N beams, combined with recent results we have obtained at IUCF, have indicated the existence of a saturation in the average amount of linear momentum that can be transferred in nucleus-nucleus collisions. This saturation value is about 140 (MeV/C)/A and occurs at beam energies in the E/A approx. 30 to 50 MeV range for 3 He- to 20 Ne-projectiles. At HHIRF, studies of the 56 Fe + 56 Fe reaction at E/A = 14.6 MeV have provided additional evidence for structure in the energy spectra of projectile-like fragments formed in symmetric collisions. Studies of near-barrier 56 Fe-induced reactions have continued at the Lawrence Berkeley Laboratory SuperHILAC

  16. Reaction Decoder Tool (RDT): extracting features from chemical reactions

    OpenAIRE

    Rahman, Syed Asad; Torrance, Gilliean; Baldacci, Lorenzo; Mart?nez Cuesta, Sergio; Fenninger, Franz; Gopal, Nimish; Choudhary, Saket; May, John W.; Holliday, Gemma L.; Steinbeck, Christoph; Thornton, Janet M.

    2016-01-01

    Summary: Extracting chemical features like Atom?Atom Mapping (AAM), Bond Changes (BCs) and Reaction Centres from biochemical reactions helps us understand the chemical composition of enzymatic reactions. Reaction Decoder is a robust command line tool, which performs this task with high accuracy. It supports standard chemical input/output exchange formats i.e. RXN/SMILES, computes AAM, highlights BCs and creates images of the mapped reaction. This aids in the analysis of metabolic pathways and...

  17. Reaction Formulation: A Bibliography.

    Science.gov (United States)

    Pedrini, D. T.; Pedrini, Bonnie C.

    Reaction formation was studied by Sigmund Freud. This defense mechanism may be related to repression, substitution, reversal, and compensation (or over-compensation). Alfred Adler considered compensation a basic process in his individual psychology. Anna Freud discussed some defense mechanisms, and Bibring, Dwyer, Huntington, and Valenstein…

  18. Cluster knockout reactions

    Indian Academy of Sciences (India)

    2014-04-07

    Apr 7, 2014 ... Cluster knockout reactions are expected to reveal the amount of clustering (such as that of , d and even of heavier clusters such as 12C, 16O etc.) in the target nucleus. In simple terms, incident medium high-energy nuclear projectile interacts strongly with the cluster (present in the target nucleus) as if it ...

  19. Polymerase chain reaction system

    Science.gov (United States)

    Benett, William J.; Richards, James B.; Stratton, Paul L.; Hadley, Dean R.; Milanovich, Fred P.; Belgrader, Phil; Meyer, Peter L.

    2004-03-02

    A portable polymerase chain reaction DNA amplification and detection system includes one or more chamber modules. Each module supports a duplex assay of a biological sample. Each module has two parallel interrogation ports with a linear optical system. The system is capable of being handheld.

  20. Reaction product imaging

    Energy Technology Data Exchange (ETDEWEB)

    Chandler, D.W. [Sandia National Laboratories, Livermore, CA (United States)

    1993-12-01

    Over the past few years the author has investigated the photochemistry of small molecules using the photofragment imaging technique. Bond energies, spectroscopy of radicals, dissociation dynamics and branching ratios are examples of information obtained by this technique. Along with extending the technique to the study of bimolecular reactions, efforts to make the technique as quantitative as possible have been the focus of the research effort. To this end, the author has measured the bond energy of the C-H bond in acetylene, branching ratios in the dissociation of HI, the energetics of CH{sub 3}Br, CD{sub 3}Br, C{sub 2}H{sub 5}Br and C{sub 2}H{sub 5}OBr dissociation, and the alignment of the CD{sub 3} fragment from CD{sub 3}I photolysis. In an effort to extend the technique to bimolecular reactions the author has studied the reaction of H with HI and the isotopic exchange reaction between H and D{sub 2}.

  1. Explaining competitive reaction effects

    NARCIS (Netherlands)

    Leeflang, P.S.H.; Wittink, D.R.

    Changes in promotional expenditure decisions for a brand, as in other marketing decisions, should be based on the expected impact on purchase and consumption behavior as well as on the likely reactions by competitors. Purchase behavior may be predicted from estimated demand functions. Competitive

  2. Cutaneous adverse drug reactions

    African Journals Online (AJOL)

    limiting but they can be the initial presentation of more serious reactions such as Stevens-Johnson and drug hypersensitivity syndromes.3 It is thus important for the clinician to distinguish between self-limiting morbilliform drug eruptions that resolve solely with the withdrawal of the offending drug and the life-threatening ...

  3. Managing Your Emotional Reactions

    Science.gov (United States)

    ... this situation: Your friends have received promposals (or college acceptances, team places, etc.). But you haven't. Once you identify, ... each one. Which reaction would lead to the best outcome? We always have a ... that work out well. Learning to react well takes practice. But we all ...

  4. [Allergic reactions during anesthesia].

    Science.gov (United States)

    Escolano, F; Sierra, P

    1996-01-01

    Anaphylactic reaction during anesthesia is a constant source of concern for anesthesiologists, given that the rates of death and serious complications are high and predicting which patients will be susceptible is impossible. All substances used in the perioperative period carry a certain risk of releasing histamine and triggering an allergic reaction, though muscle relaxants are the drugs usually implicated. The incidence of serious anaphylaxis ranges between 1:4,000 and 1:23,000 anesthetic procedures, with mortality set at 3-9% and morbidity 10 times higher. Clinical signs vary from mild symptoms to anaphylactic shock and cardiac arrest. The diagnostic procedure to follow upon observing an allergic reaction is to first identify the responsible mechanism and later the responsible agent, as well as drugs that can be used safely. Prophylaxis is based mainly on recognizing predisposed patients before surgery and following recommendations and pharmacological protocols based on better understanding of the pathophysiological mechanisms that cause anaphylactic reaction and on experience in managing them.

  5. Transport description of heavy-ion reactions

    International Nuclear Information System (INIS)

    Weidenmueller, H.A.

    1980-01-01

    A guide is given of material presented by the author in his paper 'Transport Theories of Heavy-Ion Reactions' (Preprint MP1 H-1978-V29 and to appear in Progress in Particle and Nuclear Physics, Pergamon Press, Oxford) together with notes on the three lectures presented at the present International School of Nuclear Physics. The first of these contained a phenomenological introduction to the use of Fokker-Planck equations in heavy-ion reactions, the second discussed the validity of the use of transport equations in nuclei in terms of characteristic time scales and the third gave a summary of various approaches to calculate transport coefficients in the nuclear context. (UK)

  6. Directed Neutron Beams From Inverse Kinematic Reactions

    Science.gov (United States)

    Vanhoy, J. R.; Guardala, N. A.; Glass, G. A.

    2011-06-01

    Kinematic focusing of an emitted fairly mono-energetic neutron beam by the use of inverse-kinematic reactions, i.e. where the projectile mass is greater than the target atom's mass, can provide for the utilization of a significant fraction of the fast neutron yield and also provide for a safer radiation environment. We examine the merit of various neutron production reactions and consider the practicalities of producing the primary beam using the suitable accelerator technologies. Preliminary progress at the NSWC-Carderock Positive Ion Accelerator Facility is described. Possible important applications for this type of neutron-based system can be both advanced medical imaging techniques and active "stand-off" interrogation of contraband items.

  7. The application of reaction engineering to biocatalysis

    DEFF Research Database (Denmark)

    Ringborg, Rolf Hoffmeyer; Woodley, John

    2016-01-01

    Biocatalysis is a growing area of synthetic and process chemistry with the ability to deliver not only improved processes for the synthesis of existing compounds, but also new routes to new compounds. In order to assess the many options and strategies available to an engineer developing a new...... biocatalytic process,it is essential to carry out a systematic evaluation to progress rapidly and ensure decisions are madeon firm foundations. In this way, directed development can be carried out and the chances of implementation of a commercially successful process can be much improved. In this review we...... outline the benefits of reaction engineering in this development process, with particular emphasis of reaction kinetics. Future research needs to focus on rapid methods to collect such data at sufficient accuracy that it can be used forthe effective design of new biocatalytic processes....

  8. Transport description of damped nuclear reactions

    International Nuclear Information System (INIS)

    Randrup, J.

    1983-04-01

    Part I is an elementary introduction to the general transport theory of nuclear dynamics. It can be read without any special knowledge of the field, although basic quantum mechanics is required for the formal derivation of the general expression for the transport coefficients. The results can also be used in a wider context than the present one. Part II gives the student an up-to-date orientation about recent progress in the understanding of the angular-momentum variables in damped reactions. The emphasis is here on the qualitative understanding of the physics rather than the, at times somewhat tedious, formal derivations

  9. Reaction behaviour of reactor materials, including concrete during core meltdown

    International Nuclear Information System (INIS)

    Holleck, H.; Hofmann, P.; Skokan, A.

    1976-01-01

    The problems dealt with in the studies on the material behaviour of core meltdowns are sketched, and an outline is given on the experimental investigations now in progress. These studies aim at establishing a model which is as realistic as possible, and the paper tries to show that knowledge on the reaction behaviour is a basic prerequisite for this. (orig./TK) [de

  10. Bullous reactions to bed bug bites reflect cutaneous vasculitis

    Science.gov (United States)

    This study evaluates bullous cutaneous reactions and sequential histopathology in an individual sensitized to bed bug bites in an effort to better understand the allergic response and histology associated with these bites. There was a progression of the inflammatory response across time ranging from...

  11. Hypersensitivity Reaction and Tolerance Induction to Ethambutol

    Directory of Open Access Journals (Sweden)

    Josefina Rodrigues Cernadas

    2013-01-01

    Full Text Available Tuberculosis remains the leading cause of death worldwide from any infectious agent and the alarming increase in the annual incidence of new cases has been described as a global emergency. Mycobacterium infection requires simultaneous administration of multiple drugs. Although the majority of treatment courses progress with minor side effects, adverse reactions to antituberculosis drugs occur in about 5% of treated patients and can be responsible for cessation or switching the therapy. Both nonimmediate (mostly maculopapular rash and immediate reactions (urticarial reactions have been described with these drugs. The main problem is the occurrence of reactions while the patient is on treatment with multiple drugs. The diagnosis of the culprit drug is mostly based on stopping all medication, followed by the reintroduction of each drug with a time interval of four to five days. An alternative drug should be the first approach if it is equally effective. Most of the times, none of the alternative drugs are as effective as the culprit. If this is the case, a desensitization procedure should be performed. The authors describe a case of a woman with Mycobacterium avium complex (MAC infection, to whom treatment with ethambutol was crucial to recovery, and present a modified desensitization protocol to this drug.

  12. Fomepizole for severe disulfiram-ethanol reactions.

    Science.gov (United States)

    Sande, Margaret; Thompson, David; Monte, Andrew A

    2012-01-01

    Ingestion of ethanol in the presence of disulfiram may cause a histamine-like reaction due to accumulation of acetaldehyde. These disulfiram-ethanol reactions (DERs) are manifested by hypotension, tachycardia, gastritis, and angioedema. Fomepizole, an inhibitor of alcohol dehydrogenase, may halt progression of this reaction by blocking ethanol metabolism to acetaldehyde. We present 2 cases of disulfiram and alcohol overdose leading to severe reactions unresponsive to fluid resuscitation and treated with a single dose of fomepizole. Case 1: A 20-year-old woman presented after ingestion of vodka and disulfiram. After 11 hours of resuscitation, she had skin flushing, lip swelling, tachycardia, and hypotension. Antihistamines, steroids, and an additional 2 L of normal saline were given without improvement. Fomepizole 15 mg/kg was given with improvement within 1.5 hours, and she was ultimately discharged with no clinical sequelae. Case 2: A 47-year-old woman presented after overdose of vodka and disulfiram. She was tachycardic and hypotensive upon presentation. After administration of 3 L of normal saline, she remained hypotensive and tachycardic. One dose of fomepizole 15 mg/kg was given. Within 1 hour following fomepizole infusion, her blood pressure and heart rate normalized, and she had no further sequelae from her ingestion. Fomepizole may be a safe and effective treatment of severe DERs. We suggest that 1 dose of fomepizole for severe DERs with hypotension unresponsive to fluid resuscitation or for angioedema unresponsive to antihistamines be administered.

  13. Multicomponent reactions in polymer synthesis.

    Science.gov (United States)

    Kakuchi, Ryohei

    2014-01-03

    More participants, yet efficient reactions: Multicomponent reactions (MCRs) have found application in polymer chemistry both in the synthesis of multifunctional monomers and in post-polymerization modification. Examples include the Passerini three-component reaction, the Ugi four-component reaction, and the copper-catalyzed MCR. Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. What Is a Reaction Rate?

    Science.gov (United States)

    Schmitz, Guy

    2005-01-01

    The definition of reaction rate is derived and demonstrations are made for the care to be taken while using the term. Reaction rate can be in terms of a reaction property, the extent of reaction and thus it is possible to give a definition applicable in open and closed systems.

  15. Investigation of Multiscale and Multiphase Flow, Transport and Reaction in Heavy Oil Recovery Processes

    Energy Technology Data Exchange (ETDEWEB)

    Yorstos, Yannis C.

    2003-03-19

    The report describes progress made in the various thrust areas of the project, which include internal drives for oil recovery, vapor-liquid flows, combustion and reaction processes and the flow of fluids with yield stress.

  16. Engineering of enzymatic reactions and reactors for lipid modification and synthesis

    DEFF Research Database (Denmark)

    Xu, Xuebing

    2003-01-01

    Progress in enzymic lipid modification and synthesis in the past 20 yr is discussed, with particular reference to: enzymic hydrolysis; enzymic esterification; enzymic acidolysis; enzymic alcoholysis; enzymic ester-ester exchange; reaction and reactor optimization; product development; and process...

  17. Progress report 1981 - 1983

    International Nuclear Information System (INIS)

    Eder, G.; Rauch, H.; Balcar, E.; Buchtela, K.; Schwertfuehrer, W.; Vana, N.

    1984-06-01

    This progress report describes the research activities of the Atom-institute of the Austrian Universities of the period 1981-1983. The chapter headings are: (1) Electron- and X-ray physics, thermoluminescence and archeometry. (2) Nuclear physics. (3) Nuclear techniques, electronics and EDP. (4) Neutron- and solid state physics with neutron scattering, low temperature physics, theoretical solid state physics and preparation technique. (5) Radiation chemistry. (6) Radiation protection and dosimetry. Each chapter gives a comprimated overview about the research work done in the described period, illustrated by diagrams and tables, a comprehensive list of publications, each citation provided with an (mostly English) Abstract and a comprehensive list of thesis, which are completed or under preparation in the corresponding working group. Additional chapters give lists of educational work, verbal presentation, cooperations with other institutions and personnel. An annex of photos gives an additional impression of the institute. (A.N.)

  18. Progress in protein crystallography.

    Science.gov (United States)

    Dauter, Zbigniew; Wlodawer, Alexander

    2016-01-01

    Macromolecular crystallography evolved enormously from the pioneering days, when structures were solved by "wizards" performing all complicated procedures almost by hand. In the current situation crystal structures of large systems can be often solved very effectively by various powerful automatic programs in days or hours, or even minutes. Such progress is to a large extent coupled to the advances in many other fields, such as genetic engineering, computer technology, availability of synchrotron beam lines and many other techniques, creating the highly interdisciplinary science of macromolecular crystallography. Due to this unprecedented success crystallography is often treated as one of the analytical methods and practiced by researchers interested in structures of macromolecules, but not highly competent in the procedures involved in the process of structure determination. One should therefore take into account that the contemporary, highly automatic systems can produce results almost without human intervention, but the resulting structures must be carefully checked and validated before their release into the public domain.

  19. Muon collider progress

    Energy Technology Data Exchange (ETDEWEB)

    Noble, Robert J. FNAL

    1998-08-01

    Recent progress in the study of muon colliders is presented. An international collaboration consisting of over 100 individuals is involved in calculations and experiments to demonstrate the feasibility of this new type of lepton collider. Theoretical efforts are now concentrated on low-energy colliders in the 100 to 500 GeV center-of-mass energy range. Credible machine designs are emerging for much of a hypothetical complex from proton source to the final collider. Ionization cooling has been the most difficult part of the concept, and more powerful simulation tools are now in place to develop workable schemes. A collaboration proposal for a muon cooling experiment has been presented to the Fermilab Physics Advisory Committee, and a proposal for a targetry and pion collection channel experiment at Brookhaven National Laboratory is in preparation. Initial proton bunching and space-charge compensation experiments at existing hadron facilities have occurred to demonstrate proton driver feasibility.

  20. 1985. Progress annual report

    International Nuclear Information System (INIS)

    1986-06-01

    Tore Supra construction has been vigorously continued. The whole cryogenic system has been entirely delivered. On TFR priority has been given to electron cyclotron resonance heating; but also neutral heating mechanisms, pellet injection, plasma-wall interaction in the presence of pumped limiter, impurity transport and plasma turbulence have been studied and progress on diagnostics have been made. On Petula, with lower hybrid wave, the numerous results on ion heating, current drive, plasma stability in the presence of non-inductive current and on Tore Supra technical problems are important. At last, theoretical and numerical results are concerned with plasma equilibrium macroscopic evolution of plasma, RF heating, plasma instabilities, magnetic islands, turbulence, transport coefficients and spectroscopy [fr

  1. Progressing batch hydrolysis process

    Science.gov (United States)

    Wright, John D.

    1986-01-01

    A progressive batch hydrolysis process for producing sugar from a lignocellulosic feedstock, comprising passing a stream of dilute acid serially through a plurality of percolation hydrolysis reactors charged with said feedstock, at a flow rate, temperature and pressure sufficient to substantially convert all the cellulose component of the feedstock to glucose; cooling said dilute acid stream containing glucose, after exiting the last percolation hydrolysis reactor, then feeding said dilute acid stream serially through a plurality of prehydrolysis percolation reactors, charged with said feedstock, at a flow rate, temperature and pressure sufficient to substantially convert all the hemicellulose component of said feedstock to glucose; and cooling the dilute acid stream containing glucose after it exits the last prehydrolysis reactor.

  2. Vivitron - Progress report 1990

    International Nuclear Information System (INIS)

    1991-01-01

    The 1990 activity report of the Strasbourg Nuclear Research, concerning the Vivitron project, is presented. After having mounted all the Van de Graaff elements of the Vivitron needed for the generator tests, the tank was closed in July 1990. It was then put under vacuum, leaks were searched for and repaired. Voltage tests started in December and a voltage of 17.6 MV was reached in February. Modifications on the charging system and to improvement of the column protection against sparks are necessary before the voltage tests can be carried on. Great progress has been made in the setting up of the new Vivitron injector and analysing magnet. In this report are included the description of project different development steps, the Vivitron budget and the list of publications, congress contributions and internal reports. 18 figs

  3. Predicting periodontitis progression?

    Science.gov (United States)

    Ferraiolo, Debra M

    2016-03-01

    Cochrane Library, Ovid, Medline, Embase and LILACS were searched using no language restrictions and included information up to July 2014. Bibliographic references of included articles and related review articles were hand searched. On-line hand searching of recent issues of key periodontal journals was performed (Journal of Clinical Periodontology, Journal of Dental Research, Journal of Periodontal Research, Journal of Periodontology, Oral Health and Preventive Dentistry). Prospective and retrospective cohort studies were used for answering the question of prediction since there were no randomised controlled trials on this topic. Risk of bias was assessed using the validated Newcastle-Ottawa quality assessment scale for non-randomised studies. Cross-sectional studies were included in the summary of currently reported risk assessment tools but not for risk of progression of disease, due to the inability to properly assess bias in these types of studies. Titles and abstracts were scanned by two reviewers independently.Full reports were obtained for those articles meeting inclusion criteria or those with insufficient information in the title to make a decision. Any published risk assessment tool was considered. The tool was defined to include any composite measure of patient-level risk directed towards determining the probability for further disease progression in adults with periodontitis. Periodontitis was defined to include both chronic and aggressive forms in the adult population. Outcomes included changes in attachment levels and/or deepening of periodontal pockets in millimeters in study populations undergoing supportive periodontal therapy. Data extraction was performed independently and in collaboration by two reviewers; completed evidence tables were reviewed by three reviewers. Studies were each given a descriptive summary to assess the quantity of data as well as further assessment of study variations within study characteristics. This also allowed for

  4. Progressive amusia and aprosody.

    Science.gov (United States)

    Confavreux, C; Croisile, B; Garassus, P; Aimard, G; Trillet, M

    1992-09-01

    We report a case of slowly progressive amusia and aprosody in association with orofacial and eyelid apraxias. The patient was independent in daily living activities. Insight, judgment, and behavior were intact. Her language was normal, and she demonstrated no limb, dressing, or constructional apraxia. She had no prosopagnosia, no visuospatial disturbances, and no memory impairment. Imaging studies (computed tomography, magnetic resonance imaging, single photon emission computed tomography) indicated a selective disorder of the right frontal and temporal regions. Review of the literature shows an increasing number of reports of this degenerative syndrome affecting the left dominant hemisphere and language areas, whereas cases of the syndrome affecting the right hemisphere are rare. To our knowledge, this is the first case in which aprosody and amusia were associated with a focal cortical degeneration.

  5. Progress report 1998

    International Nuclear Information System (INIS)

    1999-01-01

    The O.P.R.I. is in charge of environmental general surveillance and follow-up of natural exposures; To monitor the nuclear installations, it carries out samples campaigns. The technical follow-up of medical installations concerns it too. The workers radiation protection as well as the public protection are in its attributions. We find in particular, three sanitary studies: about the North Cotentin, (the question of excess of leukemia or not, and due or not to the facility of La hague) Nogent-sur-Marne (the case of a nursery school built on a old factory using radium), and the situation of populations living in French Polynesia, areas that have worried the public with alarmist announcements published in newspapers. All the results relative to the radiations measurements for 1998 appear in this progress report. (N.C.)

  6. Methods for forming complex oxidation reaction products including superconducting articles

    International Nuclear Information System (INIS)

    Rapp, R.A.; Urquhart, A.W.; Nagelberg, A.S.; Newkirk, M.S.

    1992-01-01

    This patent describes a method for producing a superconducting complex oxidation reaction product of two or more metals in an oxidized state. It comprises positioning at least one parent metal source comprising one of the metals adjacent to a permeable mass comprising at least one metal-containing compound capable of reaction to form the complex oxidation reaction product in step below, the metal component of the at least one metal-containing compound comprising at least a second of the two or more metals, and orienting the parent metal source and the permeable mass relative to each other so that formation of the complex oxidation reaction product will occur in a direction towards and into the permeable mass; and heating the parent metal source in the presence of an oxidant to a temperature region above its melting point to form a body of molten parent metal to permit infiltration and reaction of the molten parent metal into the permeable mass and with the oxidant and the at least one metal-containing compound to form the complex oxidation reaction product, and progressively drawing the molten parent metal source through the complex oxidation reaction product towards the oxidant and towards and into the adjacent permeable mass so that fresh complex oxidation reaction product continues to form within the permeable mass; and recovering the resulting complex oxidation reaction product

  7. Stevens-Johnson syndrome progressing to toxic epidermal necrolysis with haloperidol and carbamazepine combination

    Directory of Open Access Journals (Sweden)

    Ajay Kumar

    2011-01-01

    Full Text Available Carbamazepine and other anticonvulsants are commoner cause of severe adverse cutaneous drug reactions such as erythema multiforme, toxic epidermal necrolysis (TEN, and Stevens-Johnson syndrome (SJS. We report a case of SJS rapidly progressing to TEN with a combination of haloperidol and carbamazepine in a patient with bipolar affective disorder. The pathophysiological mechanism underlying this reaction is discussed.

  8. Confronting Combat Stress Reactions

    Science.gov (United States)

    2010-03-22

    Making that culture shift will require constant attention and cooperation between myself and the Chiefs, and close work with the Office of the... deficit control. Consequently, defense programs will compete with domestic programs for a shrinking share of the budget. The politics of this debate...is “ stigmatizing ” in both our society and our military.74 Although the Veterans Affairs office is making progress in its efforts to meet the demands

  9. Nuclear reactions in astrophysics

    International Nuclear Information System (INIS)

    Cardenas, M.

    1976-01-01

    It is revised the nuclear reactions which present an interest in astrophysics regarding the explanation of some problems such as the relative quantity of the elements, the structure and evolution of the stars. The principal object of the study is the determination of the experimental possibilities in the field of astrophysics, of an accelerator Van de Graaff's 700 KeV type. Two hundred nuclear reactions approximately, were found, and nothing or very little has been done in the intervals of energy which are of interest. Since the bombardment energies and the involved sections are low in some cases, there are real possibilities, for the largest number of stars to obtain important statistical data with the above mentioned accelerator, taking some necessary precautions. (author)

  10. Reactions to dietary tartrazine.

    Science.gov (United States)

    David, T J

    1987-02-01

    Double blind challenges with tartrazine and benzoic acid were performed in hospital in 24 children whose parents gave a definite history of a purely behavioural immediate adverse reaction to one of these substances. The patients, whose ages ranged from 1.6 to 12.4 years, were on a diet that avoided these items, and in all there was a clear history that any lapse of the diet caused an obvious adverse behavioural reaction within two hours. In no patient was any change in behaviour noted either by the parents or the nursing staff after the administration of placebo or active substances. Twenty two patients returned to a normal diet without problems, but the parents of two children insisted on continuing the diet. While popular belief has it that additives may have harmful behavioural effects, objective verification is required to prevent overdiagnosis.

  11. Adverse reactions to antidepressants

    DEFF Research Database (Denmark)

    Uher, Rudolf; Farmer, Anne; Henigsberg, Neven

    2009-01-01

    (74%), constipation (33%) and weight gain (15%) were associated with nortriptyline treatment. Diarrhoea (9%), insomnia (36%) and yawning (16%) were more common during treatment with escitalopram. Problems with urination and drowsiness predicted discontinuation of nortriptyline. Diarrhoea and decreased......Background: Adverse drug reactions are important determinants of non-adherence to antidepressant treatment, but their assessment is complicated by overlap with depressive symptoms and lack of reliable self-report measures. Aims: To evaluate a simple self-report measure and describe adverse...... comparing escitalopram and nortriptyline. Results: There was good agreement between self-report and psychiatrists' ratings. Most complaints listed as adverse reactions in people with depression were more common when they were medication-free rather than during their treatment with antidepressants. Dry mouth...

  12. Concordant Chemical Reaction Networks

    Science.gov (United States)

    Shinar, Guy; Feinberg, Martin

    2015-01-01

    We describe a large class of chemical reaction networks, those endowed with a subtle structural property called concordance. We show that the class of concordant networks coincides precisely with the class of networks which, when taken with any weakly monotonic kinetics, invariably give rise to kinetic systems that are injective — a quality that, among other things, precludes the possibility of switch-like transitions between distinct positive steady states. We also provide persistence characteristics of concordant networks, instability implications of discordance, and consequences of stronger variants of concordance. Some of our results are in the spirit of recent ones by Banaji and Craciun, but here we do not require that every species suffer a degradation reaction. This is especially important in studying biochemical networks, for which it is rare to have all species degrade. PMID:22659063

  13. Enzyme catalysed tandem reactions.

    Science.gov (United States)

    Oroz-Guinea, Isabel; García-Junceda, Eduardo

    2013-04-01

    To transfer to the laboratory, the excellent efficiency shown by enzymes in Nature, biocatalysis, had to mimic several synthetic strategies used by the living organisms. Biosynthetic pathways are examples of tandem catalysis and may be assimilated in the biocatalysis field for the use of isolated multi-enzyme systems in the homogeneous phase. The concurrent action of several enzymes that work sequentially presents extraordinary advantages from the synthetic point of view, since it permits a reversible process to become irreversible, to shift the equilibrium reaction in such a way that enantiopure compounds can be obtained from prochiral or racemic substrates, reduce or eliminate problems due to product inhibition or prevent the shortage of substrates by dilution or degradation in the bulk media, etc. In this review we want to illustrate the developments of recent studies involving in vitro multi-enzyme reactions for the synthesis of different classes of organic compounds. Copyright © 2013 Elsevier Ltd. All rights reserved.

  14. Reactions to dietary tartrazine.

    Science.gov (United States)

    David, T J

    1987-01-01

    Double blind challenges with tartrazine and benzoic acid were performed in hospital in 24 children whose parents gave a definite history of a purely behavioural immediate adverse reaction to one of these substances. The patients, whose ages ranged from 1.6 to 12.4 years, were on a diet that avoided these items, and in all there was a clear history that any lapse of the diet caused an obvious adverse behavioural reaction within two hours. In no patient was any change in behaviour noted either by the parents or the nursing staff after the administration of placebo or active substances. Twenty two patients returned to a normal diet without problems, but the parents of two children insisted on continuing the diet. While popular belief has it that additives may have harmful behavioural effects, objective verification is required to prevent overdiagnosis. PMID:3548601

  15. Cluster knockout reactions

    Indian Academy of Sciences (India)

    2014-04-07

    Apr 7, 2014 ... (figure 2), the corresponding α–α t-matrix effective interactions are seen to be widely different (figure 3). 2. Formalism. The finite-range transition matrix element T n,l. BA in the triple differential cross-section [13], d3σ d 1d 2dE1. = Fkin × Sl × |T n,l. BA (kf 1, kf 2, ki)|2 for the (α, 2α) cluster knockout reactions is ...

  16. Flora rapid reaction forces

    Directory of Open Access Journals (Sweden)

    Виктор Васильевич Туганаев

    2015-10-01

    Full Text Available Flora rapid reaction forces ­– there are explerents that have high productivity and weak competitiveness. Their innately functional allocation is to plant disturbed acres as soon as possible preventing by that biosphere homeostasis disturbance. Disturbed acres were used to take place in geological history. Nowadays they take especially big areas. Considering a historical line of Dactylis glomerata L. authors suggest to separate out an especial group of anthropochores which they call medieophytes

  17. Photochemical reaction dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Moore, B.C. [Lawrence Berkeley Laboratory, Livermore, CA (United States)

    1993-12-01

    The purpose of the program is to develop a fundamental understanding of unimolecular and bimolecular reaction dynamics with application in combustion and energy systems. The energy dependence in ketene isomerization, ketene dissociation dynamics, and carbonyl substitution on organometallic rhodium complexes in liquid xenon have been studied. Future studies concerning unimolecular processes in ketene as well as energy transfer and kinetic studies of methylene radicals are discussed.

  18. Adverse cutaneous drug reaction

    Directory of Open Access Journals (Sweden)

    Nayak Surajit

    2008-01-01

    Full Text Available In everyday clinical practice, almost all physicians come across many instances of suspected adverse cutaneous drug reactions (ACDR in different forms. Although such cutaneous reactions are common, comprehensive information regarding their incidence, severity and ultimate health effects are often not available as many cases go unreported. It is also a fact that in the present world, almost everyday a new drug enters market; therefore, a chance of a new drug reaction manifesting somewhere in some form in any corner of world is unknown or unreported. Although many a times, presentation is too trivial and benign, the early identification of the condition and identifying the culprit drug and omit it at earliest holds the keystone in management and prevention of a more severe drug rash. Therefore, not only the dermatologists, but all practicing physicians should be familiar with these conditions to diagnose them early and to be prepared to handle them adequately. However, we all know it is most challenging and practically difficult when patient is on multiple medicines because of myriad clinical symptoms, poorly understood multiple mechanisms of drug-host interaction, relative paucity of laboratory testing that is available for any definitive and confirmatory drug-specific testing. Therefore, in practice, the diagnosis of ACDR is purely based on clinical judgment. In this discussion, we will be primarily focusing on pathomechanism and approach to reach a diagnosis, which is the vital pillar to manage any case of ACDR.

  19. Modelling Tethered Enzymatic Reactions

    Science.gov (United States)

    Solis Salas, Citlali; Goyette, Jesse; Coker-Gordon, Nicola; Bridge, Marcus; Isaacson, Samuel; Allard, Jun; Maini, Philip; Dushek, Omer

    Enzymatic reactions are key to cell functioning, and whilst much work has been done in protein interaction in cases where diffusion is possible, interactions of tethered proteins are poorly understood. Yet, because of the large role cell membranes play in enzymatic reactions, several reactions may take place where one of the proteins is bound to a fixed point in space. We develop a model to characterize tethered signalling between the phosphatase SHP-1 interacting with a tethered, phosphorylated protein. We compare our model to experimental data obtained using surface plasmon resonance (SPR). We show that a single SPR experiment recovers 5 independent biophysical/biochemical constants. We also compare the results between a three dimensional model and a two dimensional model. The work gives the opportunity to use known techniques to learn more about signalling processes, and new insights into how enzyme tethering alters cellular signalling. With support from the Mexican Council for Science and Technology (CONACyT), the Public Education Secretariat (SEP), and the Mexican National Autonomous University's Foundation (Fundacion UNAM).

  20. Are feldspar-to-mica reactions necessarily reaction-softening processes in fault zones?

    Science.gov (United States)

    Wibberley, Christopher

    1999-08-01

    Reaction-softening by mineralogical changes from feldspars to sericite has been documented from many fault zones. During external crystalline basement deformation in the Alpine orogeny, the Ser Barbier thrust and splay faults in the Pelvoux Massif experienced ultracataclasis and sericitisation. Microstructural information and geochemical data from the fault rocks suggest that different muscovitisation reactions occurred at different times within the evolution of the fault zone, and each reaction had its own impact on fault rheology. Early cataclasis aided chemical breakdown of orthoclase feldspars to muscovite, yet quartz release accompanying this process resulted in local cementation and consequent hardening of the ultracataclasite. Continued deformation was accompanied by muscovitisation of the albite feldspar, and resulted in the formation of mica-rich fault rocks which experienced progressive silica removal by the fluid with increasing deformation. At this stage, reaction-enhanced ductility dominated. Much of the early cemented ultracataclasites escaped later deformation, and their low permeability allowed preservation of their early geochemical characteristics by preventing later fluid access. Such findings demonstrate how the complex interplay between deformation processes and geochemical reactions may result in a changing rheology during fault zone evolution.

  1. Polyneutron Chain Reactions

    International Nuclear Information System (INIS)

    John C. Fisher

    2000-01-01

    Although helium atoms do not form molecules, a sufficiently large number will bind into a stable liquid droplet. A comparable situation is expected for neutrons, with a sufficiently large number binding into a stable droplet of neutron matter. Such polyneutron droplets can be viewed as isotopes of an element with nuclear charge Z=0, tentatively denoted neutrium, symbol Nt. Because of the relatively weak binding of neutrons compared with that of a mix of neutrons and protons, the minimum number of neutrons required for stability of a droplet is fairly large. Early estimates of ∼60 may be reduced to a dozen or so by the BCS pairing interaction. The Nt entries with N≥12 are new to the table of isotopes. Because all of them are beta-unstable, none is expected to persist as a free particle. Yet, some may occasionally be produced by means to be described below, and it is of interest to examine their decay chains and their interactions with charged nuclei to ascertain how their presence might be revealed. Although these reactions are interesting, they cannot be taken seriously without identifying a source for the initial Nt isotope that begins the chain. Here, we consider possible interactions between 16 O and A Nt. Although there is no strong interaction between them, we can expect a very weak residual attraction that can form a loosely bound 16 O A Nt nuclear molecule. This is not a compound nucleus in the usual sense because, considered as fluids, the 16 O and A Nt droplets are immiscible. For a droplet with fewer than about 60 neutrons, beta decay of A Nt is prevented by the buildup of Coulomb energy associated with transforming A Nt into A H in close proximity to 16 O. Thus, it is possible that 16 O A Nt molecules can persist indefinitely and that a few of them may be present in ordinary water as supermassive oxygen nuclei. Because the binding of these molecules is weak, the A Nt component can tunnel to an adjacent nucleus, and if the adjacent nucleus is 18 O, a

  2. PVUSA progress report, 1991

    Energy Technology Data Exchange (ETDEWEB)

    Ellyn, W. [ed.] [Nesbit (William) and Associates, Santa Rosa, CA (United States); Jennings, C. [ed.] [Pacific Gas and Electric Co., San Ramon, CA (United States)

    1991-12-31

    Photovoltaics for Utility Scale Applications (PVUSA) is a national public-private partnership that is assessing and demonstrating the viability of utility-scale photovoltaic (PV) electric generating systems. PVUSA participants include Pacific Gas & Electric (PG&E), the US Department of Energy (DOE), the Electric Power Research Institute (EPRI), the California Energy Commission (CEC), and eight utilities and other agencies. This report updates the progress of the PVUSA project, reviews the status and performance of the various PV installations during 1991, and summarizes key findings and conclusions from work to date. PVUSA offers utilities hands-on experience needed to evaluate and utilize maturing PV technology. The project also provides manufacturers a test bed for their products, encourages technology improvement and cost reductions in PV modules and other system components, and establishes communication channels between utilities and the PV industry. The project consists of two types of demonstrations: Emerging Module Technology (EMT) arrays, which are unproven but promising state-of-the-art PV technologies in 20-kW (nominal) arrays; and Utility Scale (US) systems, which represent more mature PV technologies in 200- to 500-kW turnkey systems.

  3. Resistance to technological progress

    International Nuclear Information System (INIS)

    Isensee, J.

    1983-01-01

    This article deals with the tolerance test the constitutional system (Basic Law) of the Federal Republic of Germany is currently put to as a consequence of the resistance to the power structure of this country, which is expressed in the name of protection and defense for the environment and world peace. This biopacifistic resistance movment, the author says, has nothing to do with the legal right to resist, as laid down in art. 20 (4) of the Basic Law. According to the author, this attitude is an offspring of fear of the hazards of technological progress, primarily of nuclear hazards. Practical resistance, the author states, is preceded by theoretical resistance in speech: De-legitimation of the democratic legality, of the parliamentary functions, of the supreme power of the government, and denial of the citizens duty of obedience. The author raises the question as to whether this attitude of disobedience on ecological grounds marks the onset of a fourth stage of development of the modern state, after we have passed through stages characterised by fear of civil war, of tyranny, and of social privation and suffering. There are no new ideas brought forward by the ecologically minded movement, the author says, for re-shaping our institutions or constitutional system. (HP) [de

  4. Progress in neuromorphic photonics

    Science.gov (United States)

    Ferreira de Lima, Thomas; Shastri, Bhavin J.; Tait, Alexander N.; Nahmias, Mitchell A.; Prucnal, Paul R.

    2017-03-01

    As society's appetite for information continues to grow, so does our need to process this information with increasing speed and versatility. Many believe that the one-size-fits-all solution of digital electronics is becoming a limiting factor in certain areas such as data links, cognitive radio, and ultrafast control. Analog photonic devices have found relatively simple signal processing niches where electronics can no longer provide sufficient speed and reconfigurability. Recently, the landscape for commercially manufacturable photonic chips has been changing rapidly and now promises to achieve economies of scale previously enjoyed solely by microelectronics. By bridging the mathematical prowess of artificial neural networks to the underlying physics of optoelectronic devices, neuromorphic photonics could breach new domains of information processing demanding significant complexity, low cost, and unmatched speed. In this article, we review the progress in neuromorphic photonics, focusing on photonic integrated devices. The challenges and design rules for optoelectronic instantiation of artificial neurons are presented. The proposed photonic architecture revolves around the processing network node composed of two parts: a nonlinear element and a network interface. We then survey excitable lasers in the recent literature as candidates for the nonlinear node and microring-resonator weight banks as the network interface. Finally, we compare metrics between neuromorphic electronics and neuromorphic photonics and discuss potential applications.

  5. Progress report: physics division

    International Nuclear Information System (INIS)

    1980-11-01

    The isotope separator is being used to prepare targets of rare and expensive isotopes using natural element feedstock. Research in the Nuclear Physics branch included studies of gamma-ray muliplicities and intensities of gamma rays in the continuum feeding high spin states in 147 Gd, 6 Li parity non-conservation, and the 6 Li + 6 Li reaction. A catalogue of (n,γ) γ-rays has been compiled and submitted for publication, and a portable source for the calibration of gamma ray spectrometers has been developed. Construction of the superconducting cyclotron and development of the high current proton accelerator are continuing. The electron test accelerator is being used in experiments to investigate bremsstrahlung angular distributions. Fertile-to-fissile conversion work is being done at TRIUMF, and fusion blanket studies are being carried out at Chalk River. The Solid State Physics branch has carried out neutron scattering studies of solid Cs 2 , measurements of the structure factor for liquid 4 He, neutron powder diffraction studies of Mnsub(0.6) Znsub(0.4) Te, measurements of the transverse magnetic response in CsCoCl 3 , and analysis of structure data for UPd 3 . The Applied Mathematics and Computation branch has developed new face seal dynamics models. Expansion of the computing centre has been completed. (L.L.)

  6. Scientific Progress in Strategic Management

    DEFF Research Database (Denmark)

    Foss, Nicolai Juul

    Does the RBV represent a case of scientific progress? And has it emerged as the dominant approach to the analysis of competitive advantage for this reason? Conventional criteria for scientific progress, notably those of the growth of knowledge literature, are not particularly helpful...... for understanding this. Instead, it is argued that in order to understand why the RBV is an instance of scientific progress, we should begin from the notion that reduction is at the heart of progress in science, and that many scientists implicitly or explicitly hold this view. The RBV is a case of scientific...

  7. Integrating Conceptions of Human Progress

    Directory of Open Access Journals (Sweden)

    Rick Szostak

    2013-06-01

    Full Text Available This paper applies interdisciplinary techniques toward the investigation of the idea of human progress. It argues that progress needs to be considered with respect to an ethical evaluation of a host of different phenomena. Some of these have displayed progress in human history, others regress, and still others neither. It is argued that it is possible to achieve progress on all fronts in the future, but only if we engage constructively with the true complexity of the world we inhabit. Classification is seen as a critical complement to interdisciplinary analysis.

  8. Arsenate stabilized Cu₂O nanoparticle catalyst for one-electron transfer reversible reaction.

    Science.gov (United States)

    Sahoo, Ramkrishna; Dutta, Soumen; Pradhan, Mukul; Ray, Chaiti; Roy, Anindita; Pal, Tarasankar; Pal, Anjali

    2014-05-14

    The befitting capping capabilities of AsO4(3-) provide a stable Cu2O nanocatalyst from a galvanic reaction between a Cu(II) precursor salt and As(0) nanoparticles. This stable Cu2O hydrosol appears to be a suitable catalyst for the one-electron transfer reversible redox reaction between Eosin Y and NaBH4. The progress of the reaction relates to three different kinetic stages. In the presence of the new catalyst the reversible redox reaction of Eosin Y in air shows a periodic color change providing a new crowd-pleasing demonstration, i.e. a "clock reaction".

  9. ISMP Adverse Drug Reactions: Pregabalin-Induced Stuttering Nitroglycerine-Induced Bradycardia Progressing to Asystole Minocycline-Induced DRESS Leading to Liver Transplantation and Type 1 Diabetes Increased Risk of Vertebral Fractures in Women Receiving Thiazide or Loop Diuretics Gambling Disorder and Impulse Control Disorder with Aripiprazole.

    Science.gov (United States)

    Mancano, Michael A

    2017-04-01

    The purpose of this feature is to heighten awareness of specific adverse drug reactions (ADRs), discuss methods of prevention, and promote reporting of ADRs to the US Food and Drug Administration's (FDA's) MedWatch program (800-FDA-1088). If you have reported an interesting, preventable ADR to MedWatch, please consider sharing the account with our readers. Write to Dr. Mancano at ISMP, 200 Lakeside Drive, Suite 200, Horsham, PA 19044 (phone: 215-707-4936; e-mail: mmancano@temple.edu). Your report will be published anonymously unless otherwise requested. This feature is provided by the Institute for Safe Medication Practices (ISMP) in cooperation with the FDA's MedWatch program and Temple University School of Pharmacy. ISMP is an FDA MedWatch partner.

  10. Reactions of secondary propargylamines with heteroallenes for the synthesis of diverse heterocycles

    KAUST Repository

    Peshkov, Vsevolod A.

    2018-03-16

    This focused review aims to summarize recent developments in the processes involving additions of secondary propargylamines to various heteroallenes and subsequent transition metal-catalyzed or electrophile-mediated cyclizations. The utility of this convenient and tunable strategy spans from the carbon dioxide fixation and target-oriented synthesis of complex natural and biologically active products to the generation of extended synthetic libraries of diverse oxygen-, nitrogen- and sulfur-containing heterocycles. For comparative purposes, the analogous transformations of propargylic alcohols are also highlighted in this account.

  11. HYLIFE-2 progress report

    International Nuclear Information System (INIS)

    Moir, R.W.; Adamson, M.G.; Bangerter, R.O.; Bieri, R.L.; Condit, R.H.; Hartman, C.W.; House, P.A.; Langdon, A.B.; Logan, B.G.; Orth, C.D.; Petzoldt, R.W.; Pitts, J.H.; Post, R.F.; Sacks, R.A.; Tobin, M.T.; Williams, W.H.; Dolan, T.J.; Longhurst, G.R.; Hoffman, M.A.; Meier, W.R.

    1991-12-01

    LIFE-II inertial confinement fusion power plant design study uses a liquid fall, in the form of jets to protect the first structural wall from neutron damage, x rays, and blast to provide a 30-y lifetime. This is a progress report of an incomplete and ongoing study. HYLIFE-I used liquid lithium. HYLIFE-11 avoids the fire hazard of lithium by using a molten salt composed of fluorine, lithium, and beryllium (Li 2 Be 4 ) called Flibe. Access for heavy-ion beams is provided. Calculations for assumed heavy-ion beam performance show a nominal gain of 70 at 5 MJ producing 350 MJ, about 5.2 times less yield than the 1.8 GJ from a driver energy of 4.5 MJ with gain of 400 for HYLIFE-I. The nominal 1 GWe of power can be maintained by increasing the repetition rate by a factor of about 5.2, from 1.5 to 8 Hz. A higher repetition rate requires faster re-establishment of the jets after a shot, which can be accomplished in part by decreasing the jet fall height and increasing the jet flow velocity. Multiple chambers may be required.In addition, although not considered for HYLIFE-I there is undoubtedly liquid splash that must be forcibly cleared because gravity is too slow, especially at high repetition rates. Splash removal can be accomplished by either pulsed or oscillating jet flows. The cost of electricity is estimated to be 0.10 $/kW· in constant 1990 dollars, about twice that of future coal and light water reactor nuclear power. The driver beam cost is about one-half the total cost

  12. The Thermochronologist's Progress

    Science.gov (United States)

    Zeitler, P. K.

    2011-12-01

    We owe our current understanding of thermochronology less to a series of revolutionary insights than to a somewhat uneven intellectual pilgrimage that over fifty years has progressed in fits and starts. Though hampered at times by overenthusiasm, oversimplification, and misunderstandings, on balance the field advanced thanks to a blend of curiosity-driven research, tool-building motivated by new ideas about Earth science, and improvements in technology. But now that we've exploited most radiogenic systems and the major minerals that host them, and now that our models can devour CPU time along with the best of them, are we done? Have we reached peak thermochron? The answer of course is no, and papers in this session will demonstrate what new technologies and techniques might have to offer in the coming years. However, I will argue that the discipline as a whole has matured to a point where if thermochronology is to remain a mainstream tool as opposed to a weekend sport, we need to get serious about several challenges. The most fundamental challenge is that current geodynamic models (and even more complex models we can envision coding) have outpaced our meagre stockpile of kinetic calibrations, our understanding of detailed isotope systematics, and our ability to generate data with sufficient throughput. These issues will not be addressed adequately through the business-as-usual approach that brought us to our current knowledge, and some community effort will probably be needed to coordinate the hard work that will be required. But any serious attempt to answer important questions with accurate thermal histories that have low and well-defined uncertainties will require that we actually know the kinetics for the specific samples we are analyzing, that we fully understand scatter in the data, that we work with the large sample numbers that are required for some problems like landscape evolution, and that inversion tools fully explore the important aspects of both the

  13. Progress report 2000

    International Nuclear Information System (INIS)

    2001-01-01

    Clean Air Hamilton is the new name of the Hamilton-Wentworth Air Quality Initiative and its implementation committee, which began in 1995 as a collaborative, multi-sectoral effort to identify and examine important air quality issues and to implement strategies to reduce many of the harmful emissions that endanger human health. During the year 2000 Clean Air Hamilton focused on nine program areas. Strategies were initiated to (1) reduce single occupancy auto trips, (2) purchase low emission vehicles, (3) model transportation emissions, (4) reduce smog-causing emissions, (5) plant trees, (6) provide advice on air quality related land use and transportation issues for consideration in city-wide planning, (7) promote public awareness through social marketing, (8) study fugitive road dust, and (9) reduce transboundary air pollution. A number of indicators to measure progress in efforts to improve air quality have been developed; many of these indicators show significant improvements which, taken collectively, show a positive trend toward cleaner air. The report highlights major accomplishment of Clean Air Hamilton; reports trends in ambient air quality data; assesses human health impacts of air quality, and recommends strategies for further improvements. Among major improvements, inhalable particulate (PM10) levels have decreased by about 20 per cent since 1991; sulphur dioxide levels dropped by 40 per cent since 1989 at industrial sampling sites and 20 per cent at the downtown sampling site; the air pollution index has remained under the advisory level of 32 at all API stations in Hamilton since June 1996. Benzene levels in air decreased by over 50 per cent near the Dofasco plant compared to the five-year composite average from 1994-1998. Given these accomplishments, participants in Clean Air Hamilton believe that while there is much room for improvement, the efforts to date have been worthwhile and provide encouragement for the future. 14 figs., 4 appendices

  14. 2004 Progress Report

    International Nuclear Information System (INIS)

    Batistoni, Paola; De Marco, Francesco; Pieroni, Leonardo

    2005-01-01

    Fusion research is undertaken all over the world with the objective of realising an environmentally responsible source of energy with essentially unlimited and widely distributed fuel reserves. The results of the worldwide efforts made in recent years are now embodied in ITER, the International Thermonuclear Experimental Reactor, designed to produce at least 500 MW of fusion power with a power gain of ten. ITER will test for the first time the interaction of fusion plasma physics with power station technology. In this international framework, during 2004 Fusion Technical and Scientific Unit of ENEA obtained important results in several keys areas. At the Frascati Tokamak Upgrade the lower hybrid microwave system was fully exploited to study the generation and control of the plasma current, and the electron cyclotron heating system reached full power (1.5 MW). With the simultaneous injection of the two waves, good energy confinement regimes with internal transport barriers were obtained at the highest plasma densities ever achieved. Advanced scenario regimes were also addressed in the activities of ENEA at JET. The engineering design of the IGNITOR machine was finalised, and significant progress was made in understanding the plasma physics regimes. Among the technology activities, the qualification of the deposition process of a copper liner on carbon fibre composite (CFC) hollow tiles may be mentioned as the most important achievement. This innovative pre brazed casting process is a competitive candidate for the fabrication of the CFCbased ITER divertor components. ENEA participated in the European activity for the definition and production on an industrial scale of an advanced Nb3Sn strand for the ITER superconducting central solenoid and toroidal field coils. Contributions were also made to the design of the final conductor layout and the characterisation tests. Inertial fusion studies continued along the previous lines, namely, the study of the implosion

  15. 1997 Progress report

    International Nuclear Information System (INIS)

    Cecchini, M.; Crescentini, L.; Ghezzi, L.

    1997-01-01

    1997 was another year of intense activity for the ENEA Nuclear Fusion Division in the evolving scenario of fusion research. With respect to the International Thermonuclear Experimental Reactor (ITER), a major review process has started, originate by the wide perception that the difficult financial situation affecting some of the parties would make it very difficult, practically impossible, to secure funding for the project as it stands. To scale down the size and cost of the machine by reducing the technical objectives, while keeping to the programmatic goal of constructing a demonstration reactor (DEMO) as the following step, appears achievable. Progress in physics was substantial during 1997. Analysis of the huge existing database, complemented by the latest results, had led to a better, more accurate scaling for the confinement time on which to base extrapolation to ITER. Studies of the very promising advanced regimes have been pursued on many tokamaks. The Frascati Tokamak Upgrade (FTU) is well placed in this respect since it is equipped with the right tools, lower hybrid and electron cyclotron radiofrequency heating and current drive systems, to explore the new promised land of low transport from the plasma core. The main highlights of FTU operation in 1997 were related to providing information relevant to these future developments. Transient production of low transport regimes with electron temperatures of 8-9 keV at the plasma center was obtained by taking advantage of the plasma skin effect and precise electron cyclotron power deposition. High-efficiency current drive at high density using lower hybrid waves was demonstrated. High-confinement pellet-enhanced modes of operation and good ion Bernstein wave coupling through the waveguide-type coupler were also achieved. Concerning the IGNITOR experiment, funds were made available only for continuation of the engineering design activities, and nothing has been released so far for manufacturing the additional

  16. 2004 Progress Report

    Energy Technology Data Exchange (ETDEWEB)

    Batistoni, Paola; De Marco, Francesco; Pieroni, Leonardo (ed.)

    2005-07-01

    Fusion research is undertaken all over the world with the objective of realising an environmentally responsible source of energy with essentially unlimited and widely distributed fuel reserves. The results of the worldwide efforts made in recent years are now embodied in ITER, the International Thermonuclear Experimental Reactor, designed to produce at least 500 MW of fusion power with a power gain of ten. ITER will test for the first time the interaction of fusion plasma physics with power station technology. In this international framework, during 2004 Fusion Technical and Scientific Unit of ENEA obtained important results in several keys areas. At the Frascati Tokamak Upgrade the lower hybrid microwave system was fully exploited to study the generation and control of the plasma current, and the electron cyclotron heating system reached full power (1.5 MW). With the simultaneous injection of the two waves, good energy confinement regimes with internal transport barriers were obtained at the highest plasma densities ever achieved. Advanced scenario regimes were also addressed in the activities of ENEA at JET. The engineering design of the IGNITOR machine was finalised, and significant progress was made in understanding the plasma physics regimes. Among the technology activities, the qualification of the deposition process of a copper liner on carbon fibre composite (CFC) hollow tiles may be mentioned as the most important achievement. This innovative pre brazed casting process is a competitive candidate for the fabrication of the CFCbased ITER divertor components. ENEA participated in the European activity for the definition and production on an industrial scale of an advanced Nb3Sn strand for the ITER superconducting central solenoid and toroidal field coils. Contributions were also made to the design of the final conductor layout and the characterisation tests. Inertial fusion studies continued along the previous lines, namely, the study of the implosion

  17. 1997 Progress report

    Energy Technology Data Exchange (ETDEWEB)

    Cecchini, M.; Crescentini, L.; Ghezzi, L. [ENEA, Centro Ricerche Frascati, Rome (Italy). Nuclear fusion division

    1997-12-31

    1997 was another year of intense activity for the ENEA Nuclear Fusion Division in the evolving scenario of fusion research. With respect to the International Thermonuclear Experimental Reactor (ITER), a major review process has started, originate by the wide perception that the difficult financial situation affecting some of the parties would make it very difficult, practically impossible, to secure funding for the project as it stands. To scale down the size and cost of the machine by reducing the technical objectives, while keeping to the programmatic goal of constructing a demonstration reactor (DEMO) as the following step, appears achievable. Progress in physics was substantial during 1997. Analysis of the huge existing database, complemented by the latest results, had led to a better, more accurate scaling for the confinement time on which to base extrapolation to ITER. Studies of the very promising advanced regimes have been pursued on many tokamaks. The Frascati Tokamak Upgrade (FTU) is well placed in this respect since it is equipped with the right tools, lower hybrid and electron cyclotron radiofrequency heating and current drive systems, to explore the new promised land of low transport from the plasma core. The main highlights of FTU operation in 1997 were related to providing information relevant to these future developments. Transient production of low transport regimes with electron temperatures of 8-9 keV at the plasma center was obtained by taking advantage of the plasma skin effect and precise electron cyclotron power deposition. High-efficiency current drive at high density using lower hybrid waves was demonstrated. High-confinement pellet-enhanced modes of operation and good ion Bernstein wave coupling through the waveguide-type coupler were also achieved. Concerning the IGNITOR experiment, funds were made available only for continuation of the engineering design activities, and nothing has been released so far for manufacturing the additional

  18. Progress Report for 1947

    Energy Technology Data Exchange (ETDEWEB)

    Authors, Various

    1947-11-01

    The year 1947 has witnessed the dawn of a new era of atomic science, a flowering of fundamental knowledge of the nature of matter which appears to be unsurpassed even by that period of the 1930's which led to the age of plutonium. A great new cyclotron, an atom-smasher ten times more powerful than the one which brought plutonium into the world, has carried mankind over a new horizon of sub-atomic space. It has brought scientists at last to grips with the infinitely small and rapid forces, until now beyond reach, which operate within the incredibly tiny distances of nuclear space. On the new energy frontier created by the giant machine, now laws govern nuclear reactions. methods are at hand, heretofore unavailable, which permit the measurement and determination of the nature of sub-atomic forces. Under ultra-high energy bombardment, the nucleus presents a different appearance from the nucleus of Bohr and Rutherford, the nucleus of atomic energy fission. The new exploration of the atom has been sponsored by the Atomic Energy Commission with the giant, new 4000-ton cyclotron in the Radiation Laboratory of the University of California. This is the thirdmajor machine built by the Director of the Laboratory and inventor of the cyclotron, Professor Ernest O. Lawrence. Whether the new knowledge will be of immediate practical consequence cannot now be predicted. Nor could Professor Lawrence predict, when in 1934 he established a new atomic energy range for that day with his first cyclotron, that the fundamental knowledge he pursued would be climaxed with the discovery of plutonium. What can be predicted is this: without the new basic knowledge, practical atomic developments of the future would be limited to the applicability of the fundamental information which made possible the initial release of atomic energy. In short, the nation's atomic potential has been greatly expanded.

  19. Boron atom reactions

    International Nuclear Information System (INIS)

    Estes, R.; Tabacco, M.B.; Digiuseppe, T.G.; Davidovits, P.

    1982-01-01

    The reaction rates of atomic boron with various epoxides have been measured in a flow tube apparatus. The bimolecular rate constants, in units of cm 3 molecule -1 s -1 , are: 1,2-epoxypropane (8.6 x 10 -11 ), 1,2-epoxybutane (8.8 x 10 -11 ), 1,2,3,4-diepoxybutane (5.5 x 10 -11 ), 1-chloro-2,3-epoxypropane (5.7 x 10 -11 ), and 1,2-epoxy-3,3,3-trichloropropane (1.5 x 10 -11 ). (orig.)

  20. Microfluidic polymerase chain reaction

    Science.gov (United States)

    Maltezos, George; Gomez, Alvaro; Zhong, Jiang; Gomez, Frank A.; Scherer, Axel

    2008-12-01

    We implement microfluidic technology to miniaturize a thermal cycling system for amplifying DNA fragments. By using a microfluidic thermal heat exchanger to cool a Peltier junction, we have demonstrated rapid heating and cooling of small volumes of solution. We use a miniature K-type thermocouple to provide a means for in situ sensing of the temperature inside the microrefrigeration system. By combining the thermocouple, two power supplies controlled by a relay system, and computer automation, we reproduce the function of a commercial polymerase chain reaction thermal cycler and demonstrate amplification of a DNA sample of about 1000 base pairs.

  1. Low Energy Nuclear Reactions?

    CERN Multimedia

    CERN. Geneva; Faccini, R.

    2014-01-01

    After an introduction to the controversial problem of Low Energy Nuclear Reactions (LENR) catalyzed by neutrons on metallic hydride surfaces we present the results of an experiment, made in collaboration with ENEA Labs in Frascati, to search neutrons from plasma discharges in electrolytic cells. The negative outcome of our experiment goes in the direction of ruling out those theoretical models expecting LENR to occur in condensed matter systems under specific conditions. Our criticism on the theoretical foundations of such models will also be presented.

  2. Catalytic enantioselective synthesis of chiral organic compounds of ultra-high purity of >99% ee.

    Science.gov (United States)

    Negishi, Ei-ichi; Xu, Shiqing

    2015-01-01

    Shortly after the discovery of Zr-catalyzed carboalumination of alkynes in 1978, we sought expansion of the scope of this reaction so as to develop its alkene version for catalytic asymmetric C-C bond formation, namely the ZACA (Zr-catalyzed asymmetric carboalumination of alkenes). However, this seemingly easy task proved to be quite challenging. The ZACA reaction was finally discovered in 1995 by suppressing three competitive side reactions, i.e., (i) cyclic carbometalation, (ii) β-H transfer hydrometalation, and (iii) alkene polymerization. The ZACA reaction has been used to significantly modernize and improve syntheses of various natural products including deoxypolypropionates and isoprenoids. This review focuses on our recent progress on the development of ZACA-lipase-catalyzed acetylation-transition metal-catalyzed cross-coupling processes for highly efficient and enantioselective syntheses of a wide range of chiral organic compounds with ultra-high enantiomeric purities.

  3. (d,pγ) Reactions and the surrogate reaction technique

    International Nuclear Information System (INIS)

    Cizewski, J.A.; Hatarik, R.; Jones, K.L.; Pain, S.D.; Thomas, J.S.; Johnson, M.S.; Bardayan, D.W.; Blackmon, J.C.; Smith, M.S.; Kozub, R.L.

    2007-01-01

    Neutron-capture reactions on neutron-rich nuclei are important to understand r-process nucleosynthesis, as well as applied needs such as stewardship science and nuclear energy. Because of the short half-lives of these species, it is not possible to measure these reactions directly with neutron beams on unstable targets. The (d,pγ) reaction with radioactive ion beams has been proposed as a surrogate reaction for (n,γ). Experiments to develop (d,pγ) techniques with radioactive ion beams and to demonstrate the efficacy of the (d,pγ) reaction as a surrogate for (n,γ) are discussed

  4. Detection Progress of Selected Drugs in TLC

    Science.gov (United States)

    Pyka, Alina

    2014-01-01

    This entry describes applications of known indicators and dyes as new visualizing reagents and various visualizing systems as well as photocatalytic reactions and bioautography method for the detection of bioactive compounds including drugs and compounds isolated from herbal extracts. Broadening index, detection index, characteristics of densitometric band, modified contrast index, limit of detection, densitometric visualizing index, and linearity range of detected compounds were used for the evaluation of visualizing effects of applied visualizing reagents. It was shown that visualizing effect depends on the chemical structure of the visualizing reagent, the structure of the substance detected, and the chromatographic adsorbent applied. The usefulness of densitometry to direct detection of some drugs was also shown. Quoted papers indicate the detection progress of selected drugs investigated by thin-layer chromatography (TLC). PMID:24551853

  5. Hydrogen isotope exchange reactions

    International Nuclear Information System (INIS)

    Jones, J.R.

    1980-01-01

    The two most widely used methods for following hydrogen isotope exchange reactions, namely dedeuteriation and detritiation, involve in the first place the synthesis of an appropriately labelled compound. Rates of dedeuteriation are usually followed by measuring changes in the 1 H n.m.r. spectrum of the substrate (examples are given); the method not only gives the rate but also the site(s) of exchange. It is limited to rather slow reactions and is not as accurate as some of the other methods. The development of deuterium n.m.r. spectroscopy means that changes in the 2 H n.m.r. spectrum can also be used to measure rates of dedeuteriation. The development of liquid scintillation counting greatly eased the problem of how to detect weak β emitters; the attractions of tritium as a tracer were thereby much enhanced. Nowadays the study of rates of detritiation constitutes one of the most versatile and accurate methods of following hydrogen isotope exchange. Examples of the technique are given. (U.K.)

  6. The nuclear reaction matrix

    International Nuclear Information System (INIS)

    Krenciglowa, E.M.; Kung, C.L.; Kuo, T.T.S.; Osnes, E.; and Department of Physics, State University of New York at Stony Brook, Stony Brook, New York 11794)

    1976-01-01

    Different definitions of the reaction matrix G appropriate to the calculation of nuclear structure are reviewed and discussed. Qualitative physical arguments are presented in support of a two-step calculation of the G-matrix for finite nuclei. In the first step the high-energy excitations are included using orthogonalized plane-wave intermediate states, and in the second step the low-energy excitations are added in, using harmonic oscillator intermediate states. Accurate calculations of G-matrix elements for nuclear structure calculations in the Aapprox. =18 region are performed following this procedure and treating the Pauli exclusion operator Q 2 /sub p/ by the method of Tsai and Kuo. The treatment of Q 2 /sub p/, the effect of the intermediate-state spectrum and the energy dependence of the reaction matrix are investigated in detail. The present matrix elements are compared with various matrix elements given in the literature. In particular, close agreement is obtained with the matrix elements calculated by Kuo and Brown using approximate methods

  7. Nuclear reaction matrix

    International Nuclear Information System (INIS)

    Krenciglowa, E.M.; Kung, C.L.; Kuo, T.T.S.; Osnes, E.

    1975-01-01

    Different definitions of the reaction matrix G appropriate to the calculation of nuclear structure are reviewed and discussed. Qualitative physical arguments are presented in support of a two-step calculation of the G-matrix for finite nuclei. In the first step the high-energy excitations are included using orthogonalized plane-wave intermediate states, and in the second step the low-energy excitations are added in, using harmonic oscillator intermediate states. Accurate calculations of G-matrix elements for nuclear structure calculations in the A approximately 18 region are performed following this procedure and treating the Pauli exclusion operator Q/sub 2p/ by the method of Tsai and Kuo. The treatment of Q/sub 2p/, the effect of the intermediate-state spectrum and the energy dependence of the reaction matrix are investigated in detail. The present matrix elements are compared with various matrix elements given in the literature. In particular, close argument is obtained with the matrix elements calculated by Kuo and Brown using approximate methods

  8. [Extensive swelling reaction after a pentavalent vaccination].

    Science.gov (United States)

    Gébus, M; Barbier, C; Bost-Bru, C; Michard-Lenoir, A P; Plantaz, D

    2015-09-01

    Injection site reactions (ISRs) are quite common side effects defined by a local adverse drug reaction directly caused by a vaccine. Twenty-four hours after an intramuscular injection (in the deltoid muscle) of the diphtheria, tetanus, acellular pertussis, inactivated poliomyelitis, Haemophilus influenza type b (DTPCa-Hib) combined vaccine, a 3-year-old boy developed fever. A few hours later, local redness and swelling appeared at the injection site, with rapid extension to the entire limb, it was pain-free, and no other clinical anomalies were present. The patient received intravenous antibiotics for suspected cellulitis. The progression was favorable in 12h (apyrexia and decreased limb swelling), allowing the intravenous antibiotic treatment to be discontinued. Since the child was in excellent general health and recovery was fast, an ISR was diagnosed. Extensive limb swelling is frequent, mostly after the fourth dose of DTPCa-Hib. Deltoid muscle injection of DTP vaccine increases the risk of ISR compared to injection in the thigh, before the age of 3 years. The introduction of acellular pertussis vaccine decreased the risk of general side effects but may increase the risk of ISR. These reactions disappear with symptomatic treatment and do not contraindicate the product. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  9. [Recent progress in mycobacteriology].

    Science.gov (United States)

    Okada, Masaji; Kobayashi, Kazuo

    2007-10-01

    Mycobacterium tuberculosis is one of the most successful bacterial parasites of humans, infecting over one-third of the population of the world as latent infection without clinical manifestations. Over 8.8 million new cases and nearly 2 million deaths by tuberculosis (TB) occur annually. TB poses a significant health threat to the world population. The goal of this symposium is to open new avenues for combating tuberculosis. The speakers have presented their data and provided control strategies against tuberculosis and pulmonary disease due to M. avium complex (MAC) from aspects of molecular epidemiology, pathogenesis, serodiagnosis, new anti-TB drugs, and vaccine development. Drs. Maeda and Murase have reported that the 12-locus VNTR analysis is very useful for molecular epidemiology of M. tuberculosis strains isolated in Japan better than IS6110-RFLP and suggested that the analysis is powerful tool for the molecular epidemiology. Drs. Matsumoto and Kobayashi have discovered a protein, mycobacterial DNA-binding protein 1 (MDPl), overproduced in dormant M. tuberculosis that plays key roles in latent/ persistent infection, disease progression, and host protection. They have concluded that MDP1 may be a possible target for anti-tuberculosis drugs and vaccines. Drs. Kitada and Maekura have developed serodiagnosis of MAC disease based on enzyme immunoassay (EIA) by detecting anti-glycopeptidolipid (GPL) antibody in sera of human patients. GPL is specific for MAC. The EIA is a simple, rapid and accurate measure with high sensitivity and specificity. The levels of antibody also reflect disease activity. A large-scale clinical multicenter study is currently in progress. Dr. Makoto Matsumoto has discovered an innovative new anti-TB drug, OPC-67683 that is a derivative of nitroimidazole compounds. OPC-67683 inhibited mycolic acid synthesis and exerted potent antimycobacterial activity, including multidrug-resistant M. tuberculosis. Multidrug therapy using OPC-67683 could

  10. Mechanistic interpretation of glass reaction: Input to kinetic model development

    International Nuclear Information System (INIS)

    Bates, J.K.; Ebert, W.L.; Bradley, J.P.; Bourcier, W.L.

    1991-05-01

    Actinide-doped SRL 165 type glass was reacted in J-13 groundwater at 90 degree C for times up to 278 days. The reaction was characterized by both solution and solid analyses. The glass was seen to react nonstoichiometrically with preferred leaching of alkali metals and boron. High resolution electron microscopy revealed the formation of a complex layer structure which became separated from the underlying glass as the reaction progressed. The formation of the layer and its effect on continued glass reaction are discussed with respect to the current model for glass reaction used in the EQ3/6 computer simulation. It is concluded that the layer formed after 278 days is not protective and may eventually become fractured and generate particulates that may be transported by liquid water. 5 refs., 5 figs. , 3 tabs

  11. The Progressive in Modal Semantics.

    Science.gov (United States)

    Portner, Paul

    1998-01-01

    Presents a semantic analysis of English progressive as an intentional operator within the framework of modal semantics. The treatment allows a combination of the central idea that the progressive's meaning has a major modal component with insights of other theories. Using a more sophisticated background theory of modality allows natural solutions…

  12. Current progress on zeolite membrane reactor for CO2 hydrogenation

    Science.gov (United States)

    Makertiharta, I. G. B. N.; Dharmawijaya, P. T.; Wenten, I. G.

    2017-01-01

    Carbon capture and storage via catalytic hydrogenation into methanol have been recognized as the most promising solution to not only global warming issue but also high fuel and methanol demand worldwide. However, methanol synthesis from CO2 involves equilibrium limited reaction that can be optimized using membrane reactor (MR). Among all selective membrane layer, the zeolite is the most promising material because it can selectively remove water and methanol from reaction mixture component, especially H2. To present a clear background of zeolite membrane reactor, this paper will bring the brief discussion on the recent progress towards utilization of zeolite membrane reactor for CO2 hydrogenation. The progress of selective layer used in said MR will be examined in detail. Critical issues related to zeolite membrane reactor will also be discussed to develop it further.

  13. Reaction Decoder Tool (RDT): extracting features from chemical reactions.

    Science.gov (United States)

    Rahman, Syed Asad; Torrance, Gilliean; Baldacci, Lorenzo; Martínez Cuesta, Sergio; Fenninger, Franz; Gopal, Nimish; Choudhary, Saket; May, John W; Holliday, Gemma L; Steinbeck, Christoph; Thornton, Janet M

    2016-07-01

    Extracting chemical features like Atom-Atom Mapping (AAM), Bond Changes (BCs) and Reaction Centres from biochemical reactions helps us understand the chemical composition of enzymatic reactions. Reaction Decoder is a robust command line tool, which performs this task with high accuracy. It supports standard chemical input/output exchange formats i.e. RXN/SMILES, computes AAM, highlights BCs and creates images of the mapped reaction. This aids in the analysis of metabolic pathways and the ability to perform comparative studies of chemical reactions based on these features. This software is implemented in Java, supported on Windows, Linux and Mac OSX, and freely available at https://github.com/asad/ReactionDecoder : asad@ebi.ac.uk or s9asad@gmail.com. © The Author 2016. Published by Oxford University Press.

  14. Metal-catalyzed activation of ethers via C-O bond cleavage: a new strategy for molecular diversity.

    Science.gov (United States)

    Cornella, Josep; Zarate, Cayetana; Martin, Ruben

    2014-12-07

    In 1979, the seminal work of Wenkert set the standards for the utilization of aryl and vinyl ethers as coupling partners via C-O bond-cleavage. Although the topic remained dormant for almost three decades, the last few years have witnessed a renaissance in this area of expertise, experiencing an exponential growth and becoming a significant discipline within the cross-coupling arena. The means to utilize readily accessible aryl or vinyl ethers as counterparts does not only represent a practical, powerful and straightforward alternative to organic halides, but also constitutes an excellent opportunity to improve our chemical knowledge about a relatively unexplored area of expertise. This review summarizes the most significant developments in the area of C-O bond-cleavage when employing aryl or vinyl ethers, providing a detailed overview of the current state of the art and including future aspects, when applicable.

  15. Base-free non-noble-metal-catalyzed hydrogen generation from formic acid: scope and mechanistic insights.

    Science.gov (United States)

    Mellmann, Dörthe; Barsch, Enrico; Bauer, Matthias; Grabow, Kathleen; Boddien, Albert; Kammer, Anja; Sponholz, Peter; Bentrup, Ursula; Jackstell, Ralf; Junge, Henrik; Laurenczy, Gábor; Ludwig, Ralf; Beller, Matthias

    2014-10-13

    The iron-catalyzed dehydrogenation of formic acid has been studied both experimentally and mechanistically. The most active catalysts were generated in situ from cationic Fe(II) /Fe(III) precursors and tris[2-(diphenylphosphino)ethyl]phosphine (1, PP3 ). In contrast to most known noble-metal catalysts used for this transformation, no additional base was necessary. The activity of the iron catalyst depended highly on the solvent used, the presence of halide ions, the water content, and the ligand-to-metal ratio. The optimal catalytic performance was achieved by using [FeH(PP3 )]BF4 /PP3 in propylene carbonate in the presence of traces of water. With the exception of fluoride, the presence of halide ions in solution inhibited the catalytic activity. IR, Raman, UV/Vis, and EXAFS/XANES analyses gave detailed insights into the mechanism of hydrogen generation from formic acid at low temperature, supported by DFT calculations. In situ transmission FTIR measurements revealed the formation of an active iron formate species by the band observed at 1543 cm(-1) , which could be correlated with the evolution of gas. This active species was deactivated in the presence of chloride ions due to the formation of a chloro species (UV/Vis, Raman, IR, and XAS). In addition, XAS measurements demonstrated the importance of the solvent for the coordination of the PP3 ligand. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Growth and characterization of gold catalyzed SiGe nanowires and alternative metal-catalyzed Si nanowires

    Science.gov (United States)

    Potié, Alexis; Baron, Thierry; Dhalluin, Florian; Rosaz, Guillaume; Salem, Bassem; Latu-Romain, Laurence; Kogelschatz, Martin; Gentile, Pascal; Oehler, Fabrice; Montès, Laurent; Kreisel, Jens; Roussel, Hervé

    2011-12-01

    The growth of semiconductor (SC) nanowires (NW) by CVD using Au-catalyzed VLS process has been widely studied over the past few years. Among others SC, it is possible to grow pure Si or SiGe NW thanks to these techniques. Nevertheless, Au could deteriorate the electric properties of SC and the use of other metal catalysts will be mandatory if NW are to be designed for innovating electronic. First, this article's focus will be on SiGe NW's growth using Au catalyst. The authors managed to grow SiGe NW between 350 and 400°C. Ge concentration ( x) in Si1- x Ge x NW has been successfully varied by modifying the gas flow ratio: R = GeH4/(SiH4 + GeH4). Characterization (by Raman spectroscopy and XRD) revealed concentrations varying from 0.2 to 0.46 on NW grown at 375°C, with R varying from 0.05 to 0.15. Second, the results of Si NW growths by CVD using alternatives catalysts such as platinum-, palladium- and nickel-silicides are presented. This study, carried out on a LPCVD furnace, aimed at defining Si NW growth conditions when using such catalysts. Since the growth temperatures investigated are lower than the eutectic temperatures of these Si-metal alloys, VSS growth is expected and observed. Different temperatures and HCl flow rates have been tested with the aim of minimizing 2D growth which induces an important tapering of the NW. Finally, mechanical characterization of single NW has been carried out using an AFM method developed at the LTM. It consists in measuring the deflection of an AFM tip while performing approach-retract curves at various positions along the length of a cantilevered NW. This approach allows the measurement of as-grown single NW's Young modulus and spring constant, and alleviates uncertainties inherent in single point measurement.

  17. Metal-catalyzed oxidation and cleavage of octopus glutathione transferase by the Cu(II)-ascorbate system.

    Science.gov (United States)

    Tang, S S; Lin, C C; Chang, G G

    1996-01-01

    Glutathione transferase (GST) from octopus hepatopancreas was rapidly inactivated by micromolar concentration of Cu(II) in the presence of ascorbate at neutral pH and 0 degree C. Omitting the metal ion or ascorbate, or replacing the Cu(II) with Fe(II) did not result in any inactivation. Glutathione or the conjugation product of glutathione and 1-chloro-2,4-dinitrobenzene offered complete protection of the enzyme from Cu(II)-induced inactivation. 1-Chloro-2,4-dinitrobenzene, however, did not provide any protection. The inactivation was time and Cu(II) concentration dependent. The dependence of inactivation rate on Cu(II) concentration displayed saturation kinetics, which suggests that the inactivation occurs in two steps with Cu(II) binding with the enzyme first (KdCu = 260 microM), then the locally generated free radicals modify the essential amino acid residues in the active center, which results in enzyme inactivation. The Cu(II)-ascorbate system is, thus, an affinity reagent for the octopus GST. The enzyme inactivation was demonstrated to be followed by protein cleavage. Native octopus GST has a subunit M(r) of 24,000. The inactivated enzyme was cleaved at the C-terminal domain (domain II) of the enzyme molecule and resulted in the formation of peptide fragment of M(r) 15,300, which has the identical N-terminal amino acid sequence as the native enzyme. The other half of the peptide with M(r) approximately 7700 was visible in the gels only after silver staining, which also revealed a minor cleavage site, also located at the domain II, to produce peptide fragments of M(r) approximately 11,300 and 8300. The oxygen carrier molecule in the cephalopods' blood is the copper-containing hemocyanin, which during turnover will release Cu(II). Our results indicate that Cu(II) catalyzes a site-specific oxidation of the essential amino acid residues at the C-terminus of GST causing enzyme inactivation. The modified-enzyme is then affinity cleaved at the putative metal binding site. The ability of octopus GST to bind with free Cu(II) may have important biological implications to enable cephalopods to avoid copper-induced cellular toxicity.

  18. Progressive outer retinal necrosis and immunosuppressive therapy in myasthenia gravis.

    Science.gov (United States)

    Coisy, Solène; Ebran, Jean-Marc; Milea, Dan

    2014-01-01

    Progressive outer retinal necrosis (PORN) is a rare but devastating infectious retinitis associated with varicella zoster virus (VZV) and responsible for severe visual loss. A 59-year-old man treated for generalized myasthenia with oral azathioprine and prednisone presented with severe unilateral necrotizing retinitis. Polymerase chain reaction of the aqueous and vitreous humors was diagnostic for VZV PORN. VZV PORN is a severe potential ocular complication of immunosuppression, prompting urgent diagnosis and appropriate treatment.

  19. Progressive Outer Retinal Necrosis and Immunosuppressive Therapy in Myasthenia Gravis

    Directory of Open Access Journals (Sweden)

    Solène Coisy

    2014-04-01

    Full Text Available Introduction: Progressive outer retinal necrosis (PORN is a rare but devastating infectious retinitis associated with varicella zoster virus (VZV and responsible for severe visual loss. Case Report: A 59-year-old man treated for generalized myasthenia with oral azathioprine and prednisone presented with severe unilateral necrotizing retinitis. Polymerase chain reaction of the aqueous and vitreous humors was diagnostic for VZV PORN. Conclusion: VZV PORN is a severe potential ocular complication of immunosuppression, prompting urgent diagnosis and appropriate treatment.

  20. Progress report, Physics Division, July 1 to September 30, 1975

    International Nuclear Information System (INIS)

    1975-10-01

    Progress in the Physics Division, CRNL, for the period July 1 to September 30, 1975 is reported. Operation of the MP tandem accelerator and design studies for a superconducting heavy ion cyclotron are summarized. Research on nuclear reactions and radioisotope decay is reported. Studies of neutron scattering on liquid helium and properties of ferromagnetic alloys are presented. A summary of computing centre operations is also provided. (O.T.)

  1. Nuclear Physics Laboratory, University of Colorado, Final Progress Report

    Energy Technology Data Exchange (ETDEWEB)

    Kinney, E.R., ed.

    2004-05-12

    OAK-B135 The results and progress of research funded by DOE grant number DOE-FG03-95ER40913 at the University of Colorado at Boulder is described. Includes work performed at the HERMES experiment at DESY to study the quark structure of the nucleon and the hadronization process in nuclei, as well as hadronic reactions studied at LAMPF, KEK, and Fermilab.

  2. Progress report 1986-1987 Department of Physics

    International Nuclear Information System (INIS)

    1988-01-01

    This progress report 1986-1987 deals with the first two years operation of the TANDAR electrostatic accelerator and also describes the research work in the following fields: nuclear physics (nuclear structure, nuclear reactions, intermediate energies, applied nuclear physics); solid state physics (crystallography and phase transitions, Mossbauer spectroscopy, condensed matter theory, crystals growth, instrumentation); atomic physics and computational physics. Finally, the staff, a list of publications and activities related to international agencies is included [es

  3. Monte Carlos of the new generation: status and progress

    International Nuclear Information System (INIS)

    Frixione, Stefano

    2005-01-01

    Standard parton shower monte carlos are designed to give reliable descriptions of low-pT physics. In the very high-energy regime of modern colliders, this is may lead to largely incorrect predictions of the basic reaction processes. This motivated the recent theoretical efforts aimed at improving monte carlos through the inclusion of matrix elements computed beyond the leading order in QCD. I briefly review the progress made, and discuss bottom production at the Tevatron

  4. The 1989 progress report: Polytechnic school laboratories' Direction

    International Nuclear Information System (INIS)

    1989-01-01

    The 1989 progress report of the laboratories' Direction of the Polytechnic School (France) is presented. The research activities carried out in each laboratory are summarized. Scientific and technical cooperation, financial and employement aspects are included. The main fields of research are: biochemistry, chemistry, reaction mechanisms, organic synthesis, mechanics of solids, meteorology, irradiated solids, optics, physics, biophysics, lasers, mathematics, econometrics, epistemology, management and computer science [fr

  5. Progress report, August 1, 1980-May 31, 1982

    Energy Technology Data Exchange (ETDEWEB)

    Rawitscher, G.H.

    1982-02-10

    Progress is briefly described on the following topics: (1) effect of deuteron breakup on elastic deuteron scattering cross sections and polarizations; (2) the validity of the discretization method; (3) the effect of breakup on rearrangement reactions; (4) formulation in terms of hyperspherical harmonics of the effect of breakup in deuteron-nucleous collisions; and (5) formulation of scattering theory in terms of a basis of positive energy Weinberg functions. (WHK)

  6. Thermodynamic Activity-Based Progress Curve Analysis in Enzyme Kinetics.

    Science.gov (United States)

    Pleiss, Jürgen

    2018-03-01

    Macrokinetic Michaelis-Menten models based on thermodynamic activity provide insights into enzyme kinetics because they separate substrate-enzyme from substrate-solvent interactions. Kinetic parameters are estimated from experimental progress curves of enzyme-catalyzed reactions. Three pitfalls are discussed: deviations between thermodynamic and concentration-based models, product effects on the substrate activity coefficient, and product inhibition. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. The US nuclear reaction data network. Summary of the first meeting, March 13 ampersand 14 1996

    International Nuclear Information System (INIS)

    1996-03-01

    The first meeting of the US Nuclear Reaction Data Network (USNRDN) was held at the Colorado School of Mines, March 13-14, 1996 chaired by F. Edward Cecil. The Agenda of the meeting is attached. The Network, its mission, products and services; related nuclear data and data networks, members, and organization are described in Attachment 1. The following progress reports from the members of the USNRDN were distributed prior to the meeting and are given as Attachment 2. (1) Measurements and Development of Analytic Techniques for Basic Nuclear Physics and Nuclear Applications; (2) Nuclear Reaction Data Activities at the National Nuclear Data Center; (3) Studies of nuclear reactions at very low energies; (4) Nuclear Reaction Data Activities, Nuclear Data Group; (5) Progress in Neutron Physics at Los Alamos - Experiments; (6) Nuclear Reaction Data Activities in Group T2; (7) Progress Report for the US Nuclear Reaction Data Network Meeting; (8) Nuclear Astrophysics Research Group (ORNL); (9) Progress Report from Ohio University; (10) Exciton Model Phenomenology; and (11) Progress Report for Coordination Meeting USNRDN

  8. The US nuclear reaction data network. Summary of the first meeting, March 13 & 14 1996

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-03-01

    The first meeting of the US Nuclear Reaction Data Network (USNRDN) was held at the Colorado School of Mines, March 13-14, 1996 chaired by F. Edward Cecil. The Agenda of the meeting is attached. The Network, its mission, products and services; related nuclear data and data networks, members, and organization are described in Attachment 1. The following progress reports from the members of the USNRDN were distributed prior to the meeting and are given as Attachment 2. (1) Measurements and Development of Analytic Techniques for Basic Nuclear Physics and Nuclear Applications; (2) Nuclear Reaction Data Activities at the National Nuclear Data Center; (3) Studies of nuclear reactions at very low energies; (4) Nuclear Reaction Data Activities, Nuclear Data Group; (5) Progress in Neutron Physics at Los Alamos - Experiments; (6) Nuclear Reaction Data Activities in Group T2; (7) Progress Report for the US Nuclear Reaction Data Network Meeting; (8) Nuclear Astrophysics Research Group (ORNL); (9) Progress Report from Ohio University; (10) Exciton Model Phenomenology; and (11) Progress Report for Coordination Meeting USNRDN.

  9. [Domestic violence: any progress?].

    Science.gov (United States)

    Henrion, Roger

    2014-01-01

    Since the publication of the French national survey of violence against women in 2000, the fight against domestic violence has made steady progress. Knowledge of the phenomenon has significantly improved. A nationwide study of murders and manslaughters perpetrated by one partner of a couple against the other has been published annually since 2006. In 2012, domestic violence resulted in the deaths of 314 persons: 166 women, 31 men, 25 children, 9 collateral victims, 14 rivals, and two former spouses killed by their ex-fathers in law. In addition, 67 perpetrators committed suicide (51 men and3 women). The number of victims fluctuates from year to year but has remained fairly stable since 2006 (n=168). Legislation has improved significantly: eight new laws have been passed since 2004, all designed to protect women and to ensure that violent men are restrained and treated. New measures to inform and protect women have been implemented and others have been improved, such as the anonymous helpline (phone no 3919, "domestic violence information"). An inter-ministerial committee on the protection of women from violence and the prevention of human trafficking (MIPROF) was created on 3 January 2013. A website entitled "Stop violence against women " (Stop violences faites aux femmes) is now available. The "Imminent Danger" mobile phone system, designed to alert police if a suspected or known perpetrator breaches restraint conditions, will be extended to the entire country from January 2014. Referees charged with coordinating comprehensive long-tern care of women victims have been deployed at the county level. Information centers on the rights of women and families (CIDFF) now form a local nationwide network. Routine interviews with a midwife during the fourth month of pregnancy, focusing on the woman's emotional, economic and social conditions, have been implemented in 21 % of maternity units and should gradually be generalized. The authorities who have enforced the law have

  10. CBM progress report 2007

    Energy Technology Data Exchange (ETDEWEB)

    Herrmann, N.; Rami, F.; Roehrich, D.; Stroth, J.; Wessels, J.; Zaitsev, Yu

    2008-02-15

    This report documents the activities within the CBM project in 2007. Significant progress has been made in the optimization of the simulation software, the layout and development of detectors, the design of front-end electronics, and the concepts for data acquisition. The simulation and analysis routines have been completely integrated into the software framework (FAIRoot and CBMroot), and can be used now easily by users outside GSI. A breakthrough has been achieved in the development of fast algorithms for track and vertex reconstruction which have been improved in speed by a factor of 10{sup 5}. These fast routines permit to perform high-statistics simulations for detailed detector layout optimization. Full event reconstruction based on realistic detector properties and particle multiplicities as given by microscopic transport models are routinely used in the feasibility studies. A version of the Silicon Tracking System is now implemented in the simulation software comprising 8 detector layers based on microstrip technology only, including the readout cables, and the mechanical detector structure. The studies of open charm detection have been extended to D{sub s}{sup +} and {lambda}{sub c}, taking into account a realistic layout of the Silicon Pixel Microvertex detector. The identification of electrons has been optimized by improved ring recognition algorithms and transition radiation simulations. The Ring Imaging Cherenkov (RICH) detector has been redesigned, resulting in a reduction by a factor of two in mirror size and number of readout channels without reducing the pion rejection capability. The muon detection system has been optimized with respect to the number of detector layers. The muon simulations take into account detector inefficiencies and a segmentation of the muon chambers into pads according to a nominal occupancy of 5% for central Au+Au collisions. Studies for a dimuon trigger show promising results. Radiation dose simulations using the FLUKA

  11. CBM progress report 2007

    International Nuclear Information System (INIS)

    Herrmann, N.; Rami, F.; Roehrich, D.; Stroth, J.; Wessels, J.; Zaitsev, Yu

    2008-02-01

    This report documents the activities within the CBM project in 2007. Significant progress has been made in the optimization of the simulation software, the layout and development of detectors, the design of front-end electronics, and the concepts for data acquisition. The simulation and analysis routines have been completely integrated into the software framework (FAIRoot and CBMroot), and can be used now easily by users outside GSI. A breakthrough has been achieved in the development of fast algorithms for track and vertex reconstruction which have been improved in speed by a factor of 10 5 . These fast routines permit to perform high-statistics simulations for detailed detector layout optimization. Full event reconstruction based on realistic detector properties and particle multiplicities as given by microscopic transport models are routinely used in the feasibility studies. A version of the Silicon Tracking System is now implemented in the simulation software comprising 8 detector layers based on microstrip technology only, including the readout cables, and the mechanical detector structure. The studies of open charm detection have been extended to D s + and Λ c , taking into account a realistic layout of the Silicon Pixel Microvertex detector. The identification of electrons has been optimized by improved ring recognition algorithms and transition radiation simulations. The Ring Imaging Cherenkov (RICH) detector has been redesigned, resulting in a reduction by a factor of two in mirror size and number of readout channels without reducing the pion rejection capability. The muon detection system has been optimized with respect to the number of detector layers. The muon simulations take into account detector inefficiencies and a segmentation of the muon chambers into pads according to a nominal occupancy of 5% for central Au+Au collisions. Studies for a dimuon trigger show promising results. Radiation dose simulations using the FLUKA transport code have been

  12. Communication of nuclear data progress: No.7 (1992)

    International Nuclear Information System (INIS)

    1992-06-01

    This is the seventh issue of communication of Nuclear Data Progress (CNDP), in which the nuclear data progress in china during the last year is presented. It includes 14 MeV neutron activation cross section nuclear decay data inelastic angular distribution integral prompt spontaneous fission neutron spectrum and α spectrum measurements of reaction 40 Ca(n, α); programs UNF-for fast neutron data calculation of structural materials, APCOM and APOM for searching optimal charged particle and neutron optical potential parameters respectively; P + 63 Cu reaction calculation in energy region 3 ∼ 55 MeV; evaluation of 197 Au (n, Zn) 196 Au cross section, progress on nuclear structure and decay data evaluation for A-chain a database on ion-atom collision processes, and evaluation of trapping and desorption data, systematics calculation of nuclear data for radiation damage assessment and related safety aspects, and systematics of (n, t) and (n, 3 He) reaction cross sections at 14 MeV, construction of covariance matrix for experimental data, Spline fit for multi-sets of correlative data etc

  13. Ion-Molecule Reaction Dynamics.

    Science.gov (United States)

    Meyer, Jennifer; Wester, Roland

    2017-05-05

    We review the recent advances in the investigation of the dynamics of ion-molecule reactions. During the past decade, the combination of single-collision experiments in crossed ion and neutral beams with the velocity map ion imaging detection technique has enabled a wealth of studies on ion-molecule reactions. These methods, in combination with chemical dynamics simulations, have uncovered new and unexpected reaction mechanisms, such as the roundabout mechanism and the subtle influence of the leaving group in anion-molecule nucleophilic substitution reactions. For this important class of reactions, as well as for many fundamental cation-molecule reactions, the information obtained with crossed-beam imaging is discussed. The first steps toward understanding micro-solvation of ion-molecule reaction dynamics are presented. We conclude with the presentation of several interesting directions for future research.

  14. Kinetics of Bio-Reactions

    DEFF Research Database (Denmark)

    Villadsen, John

    2015-01-01

    . The models can be used in mass balances for design of processes under process conditions not yet studied experimentally. The value of the predictive kinetic model depends on the quality of the experimental data on which the model is based, and well-founded kinetic models for enzyme reactions have...... a considerable predictive power. This is also true for cell reaction models, when the model is used in its proper context. The chapter first discusses the kinetics for enzymatically catalyzed reactions (“enzyme reactions”). The kinetics can be derived from a mechanistic model. Then, the chapter derives empirical......his chapter predicts the specific rates of reaction by means of a mathematical expression, the kinetics of the reaction. This expression can be derived through a mechanistic interpretation of an enzymatically catalyzed reaction, but it is essentially of empirical nature for cell reactions...

  15. The Glaser–Hay reaction

    DEFF Research Database (Denmark)

    Vilhelmsen, Mie Højer; Jensen, Jonas; Tortzen, Christian

    2013-01-01

    . This unfavorable change in reaction profile could be avoided by adding molecular sieves to the reaction mixture, thereby removing the water that is accumulated from the air and produced in the reaction in which dioxygen acts as the oxidizing agent. Not unexpectedly, the stirring rate, and hence uptake of air (O2......), was found to have a significant effect on the rate of the reaction: The percentage of alkyne remaining after a certain time decreased linearly with the rate of stirring. On the basis of systematic studies, the optimized conditions for the coupling reaction using CuCl/TMEDA as the catalyst system......The oxidative Glaser–Hay coupling of two terminal alkynes to furnish a butadiyne is a key reaction for acetylenic scaffolding. Although the reaction is performed under rather simple conditions [CuCl/TMEDA/O2 (air)], the mechanism is still under debate. Herein we present detailed studies...

  16. Nuclear reactions an introduction

    CERN Document Server

    Paetz gen. Schieck, Hans

    2014-01-01

    Nuclei and nuclear reactions offer a unique setting for investigating three (and in some cases even all four) of the fundamental forces in nature. Nuclei have been shown – mainly by performing scattering experiments with electrons, muons, and neutrinos – to be extended objects with complex internal structures: constituent quarks; gluons, whose exchange binds the quarks together; sea-quarks, the ubiquitous virtual quark-antiquark pairs and, last but not least, clouds of virtual mesons, surrounding an inner nuclear region, their exchange being the source of the nucleon-nucleon interaction.   The interplay between the (mostly attractive) hadronic nucleon-nucleon interaction and the repulsive Coulomb force is responsible for the existence of nuclei; their degree of stability, expressed in the details and limits of the chart of nuclides; their rich structure and the variety of their interactions. Despite the impressive successes of the classical nuclear models and of ab-initio approaches, there is clearly no ...

  17. Chemical Reactions in Nanoparticles

    Czech Academy of Sciences Publication Activity Database

    Levdansky, V.V.; Smolík, Jiří; Moravec, Pavel

    2010-01-01

    Roč. 83, č. 2 (2010), s. 401-405 ISSN 1062-0125 R&D Projects: GA ČR GA101/09/1633; GA AV ČR(CZ) IAA400720804; GA MPO(CZ) FR-TI1/548 Institutional research plan: CEZ:AV0Z40720504 Keywords : nanoparticle * chemical reaction * size effect Subject RIV: CF - Physical ; Theoretical Chemistry http://www.scopus.com/record/display.url?eid=2-s2.0-77955925089&origin=resultslist&sort=plf-f& src =s&st1=smolik%2cj&sid=j7atgxrpM26F0dojYSZsugJ%3a170&sot=b&sdt=b&sl=21&s=AUTHOR-NAME%28smolik%2cj%29&relpos=10&relpos=10&searchTerm=AUTHOR-NAME(smolik,j)

  18. Thermophysicochemical Reaction of ZrCo-Hydrogen-Helium System

    Science.gov (United States)

    Jung, Kwangjin; Kang, Hee-Seok; Yun, Sei-Hun; Chung, Hongsuk

    2017-11-01

    Nuclear fusion energy, which is clean and infinite, has been studied for more than half a century. Efforts are in progress worldwide for the demonstration and validation of nuclear fusion energy. Korea has been developing hydrogen isotope storage and delivery system (SDS) technologies including a basic scientific study on a hydrogen storage medium. An SDS bed, which is a key component of the SDS, is used for storing hydrogen isotopes in a metal hydride form and supplying them to a tokamak. Thermophysicochemical properties of the ZrCo-H2-He system are investigated for the practical utilization of a hydriding alloy system. The hydriding reaction, in which ZrCoHx is composed as ZrCo absorbing hydrogen, is exothermic. The dehydriding reaction, in which ZrCoHx decomposes into ZrCo and hydrogen, is endothermic. The heat generated through the hydriding reaction interrupts the hydriding progress. The heat loss by a dehydriding reaction impedes the dehydriding progress. The tritium decay product, helium-3, covers the ZrCo and keeps the hydrogen from contact with ZrCo in the SDS bed. In this study, we designed and fabricated a ZrCo bed and its performance test rig. The helium blanketing effect on a ZrCo hydrogen reaction with 0 % to 20 % helium content in a gaseous phase and a helium blanket removal method were studied experimentally. In addition, the volumetric flow rates and temperature at the beginning of a ZrCo hydrogen reaction in a hydrogen or helium atmosphere, and the cooling of the SDS bed by radiation only and by both radiation and natural convection related to the reuse cycle, were obtained.

  19. Psychological functioning in primary progressive versus secondary progressive multiple sclerosis

    DEFF Research Database (Denmark)

    Vleugels, L; Pfennings, L E; Pouwer, F

    1998-01-01

    progressive patients might have different psychological functioning. Seventy patients treated in an MS centre were examined cross-sectionally. Forty had an SP course of MS and 30 a PP course. The 33 male and 37 female patients had a mean age of 48.4 years (SD 11.2) and mean age of onset of MS of 30.7 years......Psychological functioning in two types of multiple sclerosis (MS) patients is assessed: primary progressive (PP) and secondary progressive (SP) patients. On the basis of differences in clinical course and underlying pathology we hypothesized that primary progressive patients and secondary...... (SD 11.1). Patients completed questionnaires measuring among others the following aspects of psychological functioning: depression (BDI, SCL-90), anxiety (STAI, SCL-90), agoraphobia (SCL-90), somatic complaints (SCL-90), hostility (SCL-90) and attitude towards handicap (GHAS). Patients with a PP...

  20. Defining active progressive multiple sclerosis.

    Science.gov (United States)

    Sellebjerg, Finn; Börnsen, Lars; Ammitzbøll, Cecilie; Nielsen, Jørgen Erik; Vinther-Jensen, Tua; Hjermind, Lena Elisabeth; von Essen, Marina; Ratzer, Rikke Lenhard; Soelberg Sørensen, Per; Romme Christensen, Jeppe

    2017-11-01

    It is unknown whether disease activity according to consensus criteria (magnetic resonance imaging activity or clinical relapses) associate with cerebrospinal fluid (CSF) changes in progressive multiple sclerosis (MS). To compare CSF biomarkers in active and inactive progressive MS according to consensus criteria. Neurofilament light chain (NFL), myelin basic protein (MBP), IgG-index, chitinase-3-like-1 (CHI3L1), matrix metalloproteinase-9 (MMP-9), chemokine CXCL13, terminal complement complex, leukocyte counts and nitric oxide metabolites were measured in primary ( n = 26) and secondary progressive MS ( n = 26) and healthy controls ( n = 24). Progressive MS patients had higher CSF cell counts, IgG-index, CHI3L1, MMP-9, CXCL13, NFL and MBP concentrations. Active patients were younger and had higher NFL, CXCL13 and MMP-9 concentrations than inactive patients. Patients with active disease according to consensus criteria or detectable CXCL13 or MMP-9 in CSF were defined as having combined active progressive MS. These patients had increased CSF cell counts, IgG-index and MBP, NFL and CHI3L1 concentrations. Combined inactive patients only had increased IgG-index and MBP concentrations. Patients with combined active progressive MS show evidence of inflammation, demyelination and neuronal/axonal damage, whereas the remaining patients mainly show evidence of active demyelination. This challenges the idea that neurodegeneration independent of inflammation is crucial in disease progression.

  1. Taking the plunge: chemical reaction dynamics in liquids.

    Science.gov (United States)

    Orr-Ewing, Andrew J

    2017-12-11

    The dynamics of chemical reactions in liquid solutions are now amenable to direct study using ultrafast laser spectroscopy techniques and advances in computer simulation methods. The surrounding solvent affects the chemical reaction dynamics in numerous ways, which include: (i) formation of complexes between reactants and solvent molecules; (ii) modifications to transition state energies and structures relative to the reactants and products; (iii) coupling between the motions of the reacting molecules and the solvent modes, and exchange of energy; (iv) solvent caging of reactants and products; and (v) structural changes to the solvation shells in response to the changing chemical identity of the solutes, on timescales which may be slower than the reactive events. This article reviews progress in the study of bimolecular chemical reaction dynamics in solution, concentrating on reactions which occur on ground electronic states. It illustrates this progress with reference to recent experimental and computational studies, and considers how the various ways in which a solvent affects the chemical reaction dynamics can be unravelled. Implications are considered for research in fields such as mechanistic synthetic chemistry.

  2. Bibliographic index to photonuclear reaction data (1955--1992)

    Energy Technology Data Exchange (ETDEWEB)

    Asami, Tetsuo [Data Engineering, Inc., Yokohama (Japan); Nakagawa, Tsuneo [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Dept. of Reactor Engineering

    1993-10-01

    Japanese Nuclear Data Committee (JNDC) has a plan to compile the evaluated data library for photon-induced nuclear reaction cross sections, and the work on the data evaluation is in progress at the present. In the evaluations for these data a bibliographic index for neutron nuclear data is required. As the bibliographic index to photonuclear reactions, several excellent compilations have been done at some research institutes in the world, and have contributed to various basic and applied researches on the photonuclear reactions. For example, there are the abstract sheets published by US National Bureau of Standards and the data index published regularly in Russia. On the other hand, the four-center network on nuclear data (US National Nuclear Data Center at Brookhaven, Russian Nuclear Data Center at Obninsk, NEA Data Bank at Paris and IAEA Nuclear Data Section at Vienna) compiles and exchanges the numerical data on photonuclear reactions as well as on neutron-induced ones, in the EXFOR format. Those numerical data are available for users. There is, however, no bibliographic index to photonuclear reactions, available for general users. Therefore, the present work to make a photonuclear reaction data index has been done urgently to contribute to the above-mentioned data evaluation. Although these data might be still incomplete and have some defects, we have decided to serve this as the first edition of our photonuclear reaction index.

  3. High-temperature gas-cooled reactor base-technology program. Progress report, January 1, 1974--June 30, 1975

    International Nuclear Information System (INIS)

    Coobs, J.H.; Kasten, P.R.

    1976-11-01

    Progress is reported in the following areas: PCRV development, studies on structural materials, fission product technology studies, kernel migration and irradiated fuel chemistry, coolant chemistry (steam-graphite reactions), fuel qualification, and characterization and standardization of graphite

  4. High-temperature gas-cooled reactor base-technology program. Progress report, January 1, 1974--June 30, 1975

    Energy Technology Data Exchange (ETDEWEB)

    Coobs, J.H.; Kasten, P.R.

    1976-11-01

    Progress is reported in the following areas: PCRV development, studies on structural materials, fission product technology studies, kernel migration and irradiated fuel chemistry, coolant chemistry (steam-graphite reactions), fuel qualification, and characterization and standardization of graphite.

  5. Federal Facility Agreement progress report

    Energy Technology Data Exchange (ETDEWEB)

    1993-10-01

    The (SRS) Federal Facility Agreement (FFA) was made effective by the US. Environmental Protection Agency Region IV (EPA) on August 16, 1993. To meet the reporting requirements in Section XXV of the Agreement, the FFA Progress Report was developed. The FFA Progress Report is the first of a series of quarterly progress reports to be prepared by the SRS. As such this report describes the information and action taken to September 30, 1993 on the SRS units identified for investigation and remediation in the Agreement. This includes; rubble pits, runoff basins, retention basin, seepage basin, burning pits, H-Area Tank 16, and spill areas.

  6. Federal Facility Agreement progress report

    International Nuclear Information System (INIS)

    1993-10-01

    The (SRS) Federal Facility Agreement (FFA) was made effective by the US. Environmental Protection Agency Region IV (EPA) on August 16, 1993. To meet the reporting requirements in Section XXV of the Agreement, the FFA Progress Report was developed. The FFA Progress Report is the first of a series of quarterly progress reports to be prepared by the SRS. As such this report describes the information and action taken to September 30, 1993 on the SRS units identified for investigation and remediation in the Agreement. This includes; rubble pits, runoff basins, retention basin, seepage basin, burning pits, H-Area Tank 16, and spill areas

  7. Communication of nuclear data progress No.22 (1999)

    International Nuclear Information System (INIS)

    1999-12-01

    The 22th issue of Communication of Nuclear Data Progress (CNDP) is presented, in which the achievements in nuclear data field for last year in China are carried. It includes the reaction mechanism and energy balance of light nuclei; the calculation of n+ 90,91,92,94,96,Nat Zr, and γ+ 9 Be reaction; the evaluations of complete data for n+ 233 U, 239 Pu, 65 Cu, 90,91,92,94,96,Nat Zr, 69,71 Ga, γ + Al, Cr and the cross sections of 89,88 Y (n, 2n) 88,87 Y reactions; the evaluation of reference fission yield data and prompt γ-ray induced by thermal neutron capture; wavelength calculation of high stripped ions; and benchmark testing of CEND-2.1 for heavy water reactor

  8. Reversible and irreversible reaction fronts in two competing reactions system

    International Nuclear Information System (INIS)

    Sinder, M.; Taitelbaum, H.; Pelleg, J.

    2002-01-01

    A modeling of the non-equilibrium diffusion phenomena of the impurities in the semiconductors is based on the reaction-diffusion equations for local concentrations of the components. Through this approach a new feature, a reaction front, may be caused by reaction in diffusion profiles of the components. The asymptotic long-time properties of the reaction fronts in the system with initially separated components and two competing reactions: reversible A 1 +B↔C 1 and irreversible A 2 +B→C 2 are studied in this work. It is assumed that the backward constant of the reaction A 1 +B↔C 1 is small. The dynamics of the system is described as a cross-over between the 'irreversible' regime for small times and the 'reversible' regime for large times. It is shown that the 'irreversible' regime is characterized by single reaction zone, in which both reactions occur. The two reaction fronts, reversible A 1 +B↔C 1 and irreversible A 2 +C 1 →A 1 +C 2 appear in the 'reversible' regime. Numerical computing of the mean-field kinetics equations confirms these asymptotic results. The experimental tests of the theoretical predictions relating to the diffusion phenomena in semiconductors are discussed

  9. Preventing Breast Cancer: Making Progress

    Science.gov (United States)

    ... Home Current Issue Past Issues Preventing Breast Cancer: Making Progress Past Issues / Fall 2006 Table of Contents ... the time a woman is taking the pills, notes Leslie Ford, M.D., associate director for NCI's ...

  10. Early detection of emphysema progression

    DEFF Research Database (Denmark)

    Gorbunova, Vladlena; Jacobs, Sander S. A. M.; Lo, Pechin Chien Pau

    2010-01-01

    Emphysema is one of the most widespread diseases in subjects with smoking history. The gold standard method for estimating the severity of emphysema is a lung function test, such as forced expiratory volume in first second (FEV1). However, several clinical studies showed that chest CT scans offer...... more sensitive estimates of emphysema progression. The standard CT densitometric score of emphysema is the relative area of voxels below a threshold (RA). The RA score is a global measurement and reflects the overall emphysema progression. In this work, we propose a framework for estimation of local...... emphysema progression from longitudinal chest CT scans. First, images are registered to a common system of coordinates and then local image dissimilarities are computed in corresponding anatomical locations. Finally, the obtained dissimilarity representation is converted into a single emphysema progression...

  11. Zolpidem in Progressive Supranuclear Palsy

    Directory of Open Access Journals (Sweden)

    Sandip K. Dash

    2013-01-01

    Full Text Available Progressive supranuclear palsy (PSP is a progressive neurodegenerative disorder, characterized by motor symptoms, postural instability, personality changes, and cognitive impairment. There is no effective treatment for this disorder. Reduced neurotransmission of GABA in the striatum and globus pallidus may contribute to the symptoms of motor and cognitive symptoms seen in PSP. Zolpidem is a GABA agonist of the benzodiazepine subreceptor BZ1. Here a nondiabetic, normotensive case of PSP is (Progressive Supranuclear Palsy described, which showed improvement in swallowing, speech, and gaze paresis after zolpidem therapy and possible mechanism of actions are discussed. However, more trials are needed with large number of patients to confirm the effectiveness of zolpidem in progressive supranuclear palsy.

  12. Progresses in proton radioactivity studies

    Energy Technology Data Exchange (ETDEWEB)

    Ferreira, L. S., E-mail: flidia@ist.utl.pt [Center of Physics and Engineering of Advanced Materials, CeFEMA and Departamento de Física, Instituto Superior Técnico, Universidade de Lisboa, Avenida Rovisco Pais, P1049-001 Lisbon (Portugal); Maglione, E. [Dipartimento di Fisica e Astronomia “G. Galilei”, Via Marzolo 8, I-35131 Padova, Italy and Istituto Nazionale di Fisica Nucleare, Padova (Italy)

    2016-07-07

    In the present talk, we will discuss recent progresses in the theoretical study of proton radioactivity and their impact on the present understanding of nuclear structure at the extremes of proton stability.

  13. Arsenic | Cancer Trends Progress Report

    Science.gov (United States)

    The Cancer Trends Progress Report, first issued in 2001, summarizes our nation's advances against cancer in relation to Healthy People targets set forth by the Department of Health and Human Services.

  14. Cadmium | Cancer Trends Progress Report

    Science.gov (United States)

    The Cancer Trends Progress Report, first issued in 2001, summarizes our nation's advances against cancer in relation to Healthy People targets set forth by the Department of Health and Human Services.

  15. Defining active progressive multiple sclerosis

    DEFF Research Database (Denmark)

    Sellebjerg, Finn; Börnsen, Lars; Ammitzbøll, Cecilie

    2017-01-01

    BACKGROUND: It is unknown whether disease activity according to consensus criteria (magnetic resonance imaging activity or clinical relapses) associate with cerebrospinal fluid (CSF) changes in progressive multiple sclerosis (MS). OBJECTIVE: To compare CSF biomarkers in active and inactive...

  16. Radon | Cancer Trends Progress Report

    Science.gov (United States)

    The Cancer Trends Progress Report, first issued in 2001, summarizes our nation's advances against cancer in relation to Healthy People targets set forth by the Department of Health and Human Services.

  17. Benzene | Cancer Trends Progress Report

    Science.gov (United States)

    The Cancer Trends Progress Report, first issued in 2001, summarizes our nation's advances against cancer in relation to Healthy People targets set forth by the Department of Health and Human Services.

  18. Periodic progress report, 6 months

    DEFF Research Database (Denmark)

    Juhl, Thomas Winther; Nielsen, Jakob Skov

    This is the first progress report of the BriteEuram project named "High Power Laser Cutting for Heavy Industry" ("Powercut"). The report contains a summary of the objectives of the first period, an overview of the technical progress, a comparison between the planed and the accomplished work......, a description of the planned activities for the next period, and last comments on management and coordination....

  19. Progressive technologies in furniture design

    OpenAIRE

    Šebková, Martina

    2014-01-01

    Šebková, M. Progressive technologies in furniture design. Diploma thesis, Brno, Mendel University in Brno, 2014 Diploma thesis 'Progressive technologies in furniture design' is focused on the use of modern technologies in furniture production. The theoretical part explains the basic terms, technology and material options. It focuses mainly on the production of 3D printed furniture and possibilities of virtual testing, measurements, scanning and rapid prototyping. Practical part of diploma the...

  20. Predicting progression of Alzheimer's disease.

    Science.gov (United States)

    Doody, Rachelle S; Pavlik, Valory; Massman, Paul; Rountree, Susan; Darby, Eveleen; Chan, Wenyaw

    2010-02-23

    Clinicians need to predict prognosis of Alzheimer's disease (AD), and researchers need models of progression to develop biomarkers and clinical trials designs. We tested a calculated initial progression rate to see whether it predicted performance on cognition, function and behavior over time, and to see whether it predicted survival. We used standardized approaches to assess baseline characteristics and to estimate disease duration, and calculated the initial (pre-progression) rate in 597 AD patients followed for up to 15 years. We designated slow, intermediate and rapidly progressing groups. Using mixed effects regression analysis, we examined the predictive value of a pre-progression group for longitudinal performance on standardized measures. We used Cox survival analysis to compare survival time by progression group. Patients in the slow and intermediate groups maintained better performance on the cognitive (ADAScog and VSAT), global (CDR-SB) and complex activities of daily living measures (IADL) (P values < 0.001 slow versus fast; P values < 0.003 to 0.03 intermediate versus fast). Interaction terms indicated that slopes of ADAScog and PSMS change for the slow group were smaller than for the fast group, and that rates of change on the ADAScog were also slower for the intermediate group, but that CDR-SB rates increased in this group relative to the fast group. Slow progressors survived longer than fast progressors (P = 0.024). A simple, calculated progression rate at the initial visit gives reliable information regarding performance over time on cognition, global performance and activities of daily living. The slowest progression group also survives longer. This baseline measure should be considered in the design of long duration Alzheimer's disease clinical trials.