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Sample records for benzyne-furan cycloadditions total

  1. Remote Stereoinductive Intramolecular Nitrile Oxide Cycloaddition: Asymmetric Total Synthesis and Structure Revision of (-)-11β-Hydroxycurvularin.

    Science.gov (United States)

    Choe, Hyeonjeong; Pham, Thuy Trang; Lee, Joo Yun; Latif, Muhammad; Park, Haeil; Kang, Young Kee; Lee, Jongkook

    2016-03-18

    The first total synthesis and structure revision of (-)-11β-hydroxycurvularin (1b), a macrolide possessing a β-hydroxyketone moiety, were accomplished. The β-hydroxyketone moiety in this natural product was introduced by cleavage of the N-O bond in an isoxazoline ring that was formed diastereoselectively in a 1,5-remote stereocontrolled fashion by employing intramolecular nitrile oxide cycloaddition.

  2. Asymmetric Organocatalytic Cycloadditions

    DEFF Research Database (Denmark)

    Mose, Rasmus

    2016-01-01

    has gained broad recognition as it has found several applications in academia and industry. The [4+2] cycloaddition has also been performed in an enantioselective aminocatalytic fashion which allows the generation of optically active products. In this thesis it is demonstrated how trienamines can......Since the onset of the new millennium the field of organocatalysis has undergone a great expansion led by investigations in the field of aminocatalysis. This thesis will address some recent developments in aminocatalyzed cycloadditions and provide a theoretical background hereto. Cycloadditions...... undergo cascade reactions with different electron deficient dienophiles in Diels Alder – nucleophilic ring closing reactions. This methodology opens up for the direct asymmetric formation of hydroisochromenes and hydroisoquinolines which may possess interesting biological activities. It is also...

  3. Exo selective enantioselective nitrone cycloadditions.

    Science.gov (United States)

    Sibi, Mukund P; Ma, Zhihua; Jasperse, Craig P

    2004-01-28

    We have developed a novel method for accessing exo adducts with high enantioselectivity in nitrone cycloadditions to enoates. Pyrazolidinones proved to be effective achiral templates in the cycloadditions, providing exo adducts typically in >15:1 selectivity and 90-98% ee. The use of Lewis acids that form square planar complexes, such as copper triflate, was important for obtaining high exo selectivity.

  4. Cycloadditions in modern polymer chemistry.

    Science.gov (United States)

    Delaittre, Guillaume; Guimard, Nathalie K; Barner-Kowollik, Christopher

    2015-05-19

    Synthetic polymer chemistry has undergone two major developments in the last two decades. About 20 years ago, reversible-deactivation radical polymerization processes started to give access to a wide range of polymeric architectures made from an almost infinite reservoir of functional building blocks. A few years later, the concept of click chemistry revolutionized the way polymer chemists approached synthetic routes. Among the few reactions that could qualify as click, the copper-catalyzed azide-alkyne cycloaddition (CuAAC) initially stood out. Soon, many old and new reactions, including cycloadditions, would further enrich the synthetic macromolecular chemistry toolbox. Whether click or not, cycloadditions are in any case powerful tools for designing polymeric materials in a modular fashion, with a high level of functionality and, sometimes, responsiveness. Here, we wish to describe cycloaddition methodologies that have been reported in the last 10 years in the context of macromolecular engineering, with a focus on those developed in our laboratories. The overarching structure of this Account is based on the three most commonly encountered cycloaddition subclasses in organic and macromolecular chemistry: 1,3-dipolar cycloadditions, (hetero-)Diels-Alder cycloadditions ((H)DAC), and [2+2] cycloadditions. Our goal is to briefly describe the relevant reaction conditions, the advantages and disadvantages, and the realized polymer applications. Furthermore, the orthogonality of most of these reactions is highlighted because it has proven highly beneficial for generating unique, multifunctional polymers in a one-pot reaction. The overview on 1,3-dipolar cycloadditions is mostly centered on the application of CuAAC as the most travelled route, by far. Besides illustrating the capacity of CuAAC to generate complex polymeric architectures, alternative 1,3-dipolar cycloadditions operating without the need for a catalyst are described. In the area of (H)DA cycloadditions

  5. Regio and stereoselectivity in ionic cycloadditions

    Indian Academy of Sciences (India)

    WINTEC

    Though the reactions have both electrostatic control and frontier orbital control the former dominates in the initial stages of the reaction. Keywords. Stereoselectivity; ionic cycloaddition; density functional theory; acridizinium ion; methyl vinyl ether; 2,3-dimethylisoquinolinium ion. 1. Introduction. In polar or ionic cycloadditions ...

  6. Iron Catalyzed Cycloaddition of Alkynenitriles and Alkynes

    Science.gov (United States)

    D’Souza, Brendan R.; Lane, Timothy K.

    2011-01-01

    The combination of Fe(OAc)2 and an electron-donating, sterically-hindered pyridyl bisimine ligand catalyzes the cycloaddition of alkynenitriles and alkynes. A variety of substituted pyridines were obtained in good yields. PMID:21557582

  7. Bioorthogonal Cycloadditions with Sub-Millisecond Intermediates.

    Science.gov (United States)

    Qing, Yujia; Pulcu, Gökçe Su; Bell, Nicholas A W; Bayley, Hagan

    2018-01-26

    Tetrazine- and sydnone-based click reactions have emerged as important bioconjugation strategies with fast kinetics and N 2 or CO 2 as the only byproduct. Mechanistic studies of these reactions have focused on the initial rate-determining cycloaddition steps. The subsequent N 2 or CO 2 release from the bicyclic intermediates has been approached mainly through computational studies, which have predicted lifetimes of femtoseconds. In the present study, bioorthogonal cycloadditions involving N 2 or CO 2 extrusion have been examined experimentally at the single-molecule level by using a protein nanoreactor. At the resolution of this approach, the reactions appeared to occur in a single step, which places an upper limit on the lifetimes of the intermediates of about 80 μs, which is consistent with the computational work. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Hydrazones as substrates for cycloaddition reactions

    International Nuclear Information System (INIS)

    Belskaya, N P; Eliseeva, A I; Bakulev, V A

    2015-01-01

    The [2+2]-, [4+2]- and [3+2]-cycloaddition reactions of hydrazones and 1,2-diazabuta-1,3-dienes, azomethine imines, nitrile imines and azomethine ylides formed upon hydrazone transformations with dienophiles, dipolarophiles and dienes are considered. The principal issues of structure and reactivity of active substrates and the influence of the reaction conditions and catalysts on the reaction regioselectivity and efficiency are discussed. The bibliography includes 288 references

  9. Nitrone Cycloadditions of 1,2-Cyclohexadiene

    OpenAIRE

    Barber, Joyann S.; Styduhar, Evan D.; Pham, Hung V.; McMahon, Travis C.; Houk, K. N.; Garg, Neil K.

    2016-01-01

    We report the first 1,3-dipolar cycloadditions of 1,2-cyclohexadiene, a rarely exploited strained allene. 1,2-Cyclohexadiene is generated in situ under mild conditions and trapped with nitrones to give isoxazolidine products in synthetically useful yields. The reactions occur regioselectively and exhibit a notable endo preference, thus resulting in the controlled formation of two new bonds and two stereogenic centers. DFT calculations of stepwise and concerted reaction pathways are used to ra...

  10. Cycloaddition of nitrones to metal-activated nitriles and isocyanides

    International Nuclear Information System (INIS)

    Bokach, Nadejda A

    2010-01-01

    1,3-Dipolar cycloaddition reactions of nitrones to nitriles and isocyanides are considered. Attention is focused on metal-mediated processes and the role played by the nature of the metal centre and its oxidation state. The published data on the selectivity of metal-mediated cycloaddition of nitrones to nitriles and the new data on the cycloaddition of nitrones to coordinated isocyanide ligands are summarized and analyzed.

  11. (4 + 3) Cycloadditions of Nitrogen-Stabilized Oxyallyl Cations

    Science.gov (United States)

    Lohse, Andrew G.; Hsung, Richard P.

    2011-01-01

    The use of heteroatom-substituted oxyallyl cations in (4 + 3) cycloadditions has had a tremendous impact on the development of cycloaddition chemistry. Extensive efforts have been exerted toward investigating the effect of oxygen-, sulfur-, and halogen-substituents on the reactivity of oxyallyl cations. Most recently, the use of nitrogen-stabilized oxyallyl cations has gained prominence in the area of (4 + 3) cycloadditions. The following article will provide an overview of this concept utilizing nitrogen-stabilized oxyallyl cations. PMID:21384451

  12. Nitrile ylides: diastereoselective cycloadditions using chiral oxazolidinones without Lewis acid.

    Science.gov (United States)

    Sibi, Mukund P; Soeta, Takahiro; Jasperse, Craig P

    2009-12-03

    Lewis acid complexation is generally required for chiral-auxiliary-controlled stereoselectivity, and chiral Lewis acid catalysis is frequently optimal for introducing asymmetry. In this work, we show that nitrile ylide cycloadditions to electron-poor acceptors attached to chiral auxiliaries proceed in high yield and stereoselectivity in the absence of Lewis acids. In contrast, chiral Lewis acids are inferior in these cycloadditions.

  13. Mechanism and regioselectivity of 1,3-dipolar cycloaddition ...

    Indian Academy of Sciences (India)

    1,3-Dipolar cycloaddition; sulphur-centred 1,3-dipoles; regioselectivity; DFT reactivity indices;. FMO theory. 1. Introduction. Five-membered heterocyclic compounds can be gene- rated by addition of a 1,3-dipole to a dipolarophile under a 1,3-dipolar cycloaddition (1,3-DC) reaction which is well known as pericyclic reaction.

  14. Biomimetic Syntheses of Callistrilones A-E via an Oxidative [3 + 2] Cycloaddition.

    Science.gov (United States)

    Guo, Yonghong; Zhang, Yuhan; Xiao, Mingxing; Xie, Zhixiang

    2018-04-16

    Concise total syntheses of callistrilones A-E have been achieved from 7 and commercially available α-phellandrene (8). The synthetic strategy, which was primarily inspired by the biogenetic hypothesis, was enabled by an oxidative [3 + 2] cycloaddition followed by a Michael addition and an intramolecular nucleophilic addition to construct the target molecules. Moreover, viminalin I was also synthesized, and its absolute configuration was unambiguously confirmed.

  15. Enatioselective[2+2+2] Cycloaddition as A Synthetic Tool

    Institute of Scientific and Technical Information of China (English)

    T.Shibata; S.Yoshida; M.Otsuka; Y.Arai; K.Endo

    2007-01-01

    1 Results Transition metal-catalyzed [2+2+2] cycloaddition is one of the most efficient protocols for the construction of six-membered ring system.Our group has comprehensively studied various types of highly enantioselective [2+2+2] cycloaddition for the synthesis of chiral cycloadducts; we already reported an iridium-catalyzed intermolecular [2+2+2] cycloaddition between α,ω-diynes,having various tethers and substituents on the alkyne termini,and monoalkynes,possessing oxygen or/and nitrogen functiona...

  16. Nitrone Cycloadditions of 1,2-Cyclohexadiene

    Science.gov (United States)

    Barber, Joyann S.; Styduhar, Evan D.; Pham, Hung V.; McMahon, Travis C.; Houk, K. N.; Garg, Neil K.

    2016-01-01

    We report the first 1,3-dipolar cycloadditions of 1,2-cyclohexadiene, a rarely exploited strained allene. 1,2-Cyclohexadiene is generated in situ under mild conditions and trapped with nitrones to give isoxazolidine products in synthetically useful yields. The reactions occur regioselectively and exhibit a notable endo preference, thus resulting in the controlled formation of two new bonds and two stereogenic centers. DFT calculations of stepwise and concerted reaction pathways are used to rationalize the observed selectivities. Moreover, the strategic manipulation of nitrone cycloadducts demonstrates the utility of this methodology for the assembly of compounds bearing multiple heterocyclic units. These studies showcase the exploitation of a traditionally avoided reactive intermediate in chemical synthesis. PMID:26854652

  17. Chiral lewis Acid catalysis in nitrile oxide cycloadditions.

    Science.gov (United States)

    Sibi, Mukund P; Itoh, Kennosuke; Jasperse, Craig P

    2004-05-05

    We describe examples of highly regio- and enantioselective nitrile oxide cycloadditions to unsaturated alkenes using substoichiometric amounts of a chiral Lewis acid. Pyrazolidinones proved to be effective achiral templates in the cycloadditions providing C-adducts typically in >30:1 selectivity and 80-99% ee. To avoid potential problems involving coordination of the Lewis acid by amine bases, we have devised a novel method for the generation of unstable nitrile oxides from hydroximinoyl chlorides using Amberlyst 21 as the base.

  18. Cycloaddition Reaction of Hydrogen-Bonded Zn(II)

    Indian Academy of Sciences (India)

    Solid-state Photochemical [2+2] Cycloaddition Reaction of ... and free bpe and lattice water molecules shows face-to-face, π ··· π stacking of two of the four free bpe molecules with coordinated .... were decanted and dried in air. [Yield: 0.068 g ...

  19. Recent developments in gold-catalyzed cycloaddition reactions

    Directory of Open Access Journals (Sweden)

    Fernando López

    2011-08-01

    Full Text Available In the last years there have been extraordinary advances in the development of gold-catalyzed cycloaddition processes. In this review we will summarize some of the most remarkable examples, and present the mechanistic rational underlying the transformations.

  20. Enantioselective cycloadditions with alpha,beta-disubstituted acrylimides.

    Science.gov (United States)

    Sibi, Mukund P; Ma, Zhihua; Itoh, Kennosuke; Prabagaran, Narayanasamy; Jasperse, Craig P

    2005-06-09

    [reaction: see text] The use of N-H imide templates provides a solution to the problem of rotamer control in Lewis acid catalyzed reactions of alpha,beta-disubstituted acryloyl imides. Reactions proceed through the s-cis rotamer and with improved reactivity because A(1,3) strain is avoided. Enantioselective nitrone, nitrile oxide, and Diels-Alder cycloadditions demonstrate the principle.

  1. Functionalization of Graphene via 1,3-Dipolar Cycloaddition

    NARCIS (Netherlands)

    Quintana, Mildred; Spyrou, Konstantinos; Grzelczak, Marek; Browne, Wesley R.; Rudolf, Petra; Prato, Maurizio

    Few-layer graphenes (FLG) produced by dispersion and exfoliation of graphite in N-methylpyrrolidone were successfully functionalized using the 1,3-dipolar cycloaddition of azomethine ylides. The amino functional groups attached to graphene sheets were quantified by the Kaiser test. These amino

  2. Copper-catalyzed azide alkyne cycloaddition polymer networks

    Science.gov (United States)

    Alzahrani, Abeer Ahmed

    -CuAAC reaction and a chain-growth acrylate homopolymerization were demonstrated and used to form branched polymer structures. A bulk, organic soluble initiation system consisting of a Cu(II) salt and a primary amine was also examined in both model reactions and in bulk polymerizations. The system was shown to be highly efficient, leading to nearly complete CuAAC polymerization at ambient temperature. Increasing the ratio of amine to copper from 1 to 4 increases the CuAAC reaction rate significantly from 4 mM/min for 1:1 ratio of Cu(II):hexyalmine to 14mM/min for 1:4 ratio. The concentration dependence of the amine on the reaction rate enables the polymerization rate to be controlled simply by manipulating the hexylamine concentration. Sequential thiol--acrylate and photo-CuAAC click reactions were utilized to form two-stage reactive polymer networks capable of generating wrinkles in a facile manner. The click thiol-Michael addition reaction was utilized to form a cross-linked polymer with residual, reactive alkyne sites that remained tethered throughout the network. The latent, unreacted alkyne sites are subsequently reacted with diazide monomers via a photoinduced Cu(I)-catalyzed alkyne-azide cycloaddition (CuAAC) reaction to increase the cross-link density. Increased cross-linking raised the modulus and glass transition temperature from 1.6 MPa and 2 °C after the thiol-acrylate reaction to 4.4 MPa and 22 °C after the CuAAC reaction, respectively. The double click reaction approach led to micro-wrinkles with well-controlled wavelength and amplitude of 8.50 +/- 1.6 and 1.4 μm, respectively, for a polymer with a 1280 μm total film thickness. Additionally, this approach further enables spatial selectivity of wrinkle formation by photo-patterning. The CuAAC-based polymerization was also used to design smart, responsive porous materials from well-defined CuAAC networks, which possesses a high glass transition temperature (Tg= 115°C) due to the formation of the triazole linkages

  3. Rapid cycloaddition of a diazo group with an unstrained dipolarophile.

    Science.gov (United States)

    Aronoff, Matthew R; Gold, Brian; Raines, Ronald T

    2016-06-01

    The cycloaddition of a diazoacetamide with ethyl 4,4,4-trifluorocrotonate proceeds with k = 0.1 M -1 s -1 . This second-order rate constant rivals those of optimized strain-promoted azide- alkyne cycloadditions, even though the reaction does not release strain. The regioselectivity and a computational distortion/interaction analysis of the reaction energetics are consistent with the formation of an N-H…F-C hydrogen bond in the transition state and the electronic character of the trifluorocrotonate. Analogous reactions with an azidoacetamide dipole or with an acrylate or crotonate dipolarophile were much slower. These findings suggest a new strategy for the design of diazo-selective reagents for chemical biology.

  4. Synthesis of Spiroisoxazolines by 1,3-Dipolar Cycloaddition

    Directory of Open Access Journals (Sweden)

    Peter Ertl

    1997-04-01

    Full Text Available The cycloaddition of the chiral nitrile oxide 1 to 1-R-substituted 3,3-methylene-5,5-dimethyl-2-pyrrolidinones 2 (where R is H, n-butyl-, 1,1-dimethylethoxycarbonyl-, 1-methylethenyl- and acetyl- proceeds regioselectively under the formation of spiroisoxazolines, namely 7-R-substituted-6-oxo-8,8-dimethyl-1-oxa-2,7-diazaspiro[4,4]non-2-enes 5 and 6. The asymmetric induction expected by the a-chiral centre of the nitrile oxide 1 was not very effective, diastereoisomers 5 and 6 were formed in an approximate 50:50 ratio. The stereoselectivity of the 1,3-dipolar cycloaddition of the arylnitrile oxide 7 with the chiral lactam 3 and the achiral lactone 4 are investigated. The attack of the 1,3-dipole occurred from the less hindered face of the dipolarophile 3 and 4, giving the major isomer 8 and 10, respectively.

  5. Nitrogen heteroaromatic cations by [2+2+2] cycloaddition

    Czech Academy of Sciences Publication Activity Database

    Čížková, Martina; Kolivoška, Viliam; Císařová, I.; Šaman, David; Pospíšil, Lubomír; Teplý, Filip

    2011-01-01

    Roč. 9, č. 2 (2011), s. 450-462 ISSN 1477-0520 R&D Projects: GA ČR GA203/09/1614; GA ČR GA203/09/0705; GA MŠk OC 140 Institutional research plan: CEZ:AV0Z40550506; CEZ:AV0Z40400503 Keywords : modular synthesis * N-heteroaromatic cation * [2+2+2] cycloaddition Subject RIV: CC - Organic Chemistry Impact factor: 3.696, year: 2011

  6. Criss-cross Cycloadditions on Ketazines Derived from Alicyclic Ketones

    Directory of Open Access Journals (Sweden)

    Milan Potacek

    2006-01-01

    Full Text Available The reactivity of alicyclic ketazines in criss-cross cycloadditions was investigated. They react with potassium cyanate and ammonium thiocyanate in the presence of acetic acid to form spirocyclic perhydro[1,2,4]triazolo[1,2-a][1,2,4]triazole-1,5-diones and perhydro[1,2,4]triazolo[1,2-a][1,2,4]triazole-1,5-dithiones, respectively, in relatively high yields.

  7. Enantioselective 1,3-dipolar cycloadditions of diazoacetates with electron-deficient olefins.

    Science.gov (United States)

    Sibi, Mukund P; Stanley, Levi M; Soeta, Takahiro

    2007-04-12

    [reaction: see text] A general strategy for highly enantioselective 1,3-dipolar cycloaddition of diazoesters to beta-substituted, alpha-substituted, and alpha,beta-disubstituted alpha,beta-unsaturated pyrazolidinone imides is described. Cycloadditions utilizing less reactive alpha,beta-disubstituted dipolarophiles require elevated reaction temperatures, but still provide the corresponding pyrazolines with excellent enantioselectivities. Finally, an efficient synthesis of (-)-manzacidin A employing this cycloaddition methodology as a key step is illustrated.

  8. Intramolecular ketenimine-ketenimine [2 + 2] and [4 + 2] cycloadditions.

    Science.gov (United States)

    Alajarín, Mateo; Bonillo, Baltasar; Sanchez-Andrada, Pilar; Vidal, Angel; Bautista, Delia

    2007-07-20

    Bis(ketenimines), in which the two heterocumulenic functions are placed in close proximity on a carbon skeleton to allow their mutual interaction, show a rich and not easily predictable chemistry. Intramolecular [2 + 2] or [4 + 2] cycloadditions are, respectively, observed when both ketenimine functions are supported on either ortho-benzylic or 2,2'-biphenylenic scaffolds. In addition, nitrogen-to-carbon [1,3] and [1,5] shifts of arylmethyl groups in N-arylmethyl-C,C-diphenyl ketenimines are also disclosed.

  9. Mechanism-Based Fluorogenic trans-Cyclooctene-Tetrazine Cycloaddition

    Czech Academy of Sciences Publication Activity Database

    Vázquez, Arcadio; Dzijak, Rastislav; Dračínský, Martin; Rampmaier, Robert; Siegl, Sebastian J.; Vrábel, Milan

    2017-01-01

    Roč. 56, č. 5 (2017), s. 1334-1337 ISSN 1433-7851 R&D Projects: GA ČR GJ15-06020Y; GA ČR GA15-11223S EU Projects: European Commission(XE) 677465 - SWEETOOLS Institutional support: RVO:61388963 Keywords : bioorthogonal chemistry * cycloaddition * click reactions * heterocycles * imaging agents Subject RIV: CC - Organic Chemistry OBOR OECD: Organic chemistry Impact factor: 11.994, year: 2016 http://onlinelibrary.wiley.com/doi/10.1002/anie.201610491/full

  10. Site-Specific Antibody Functionalization Using Tetrazine-Styrene Cycloaddition.

    Science.gov (United States)

    Umlauf, Benjamin J; Mix, Kalie A; Grosskopf, Vanessa A; Raines, Ronald T; Shusta, Eric V

    2018-05-03

    Biologics, such as antibody-drug conjugates, are becoming mainstream therapeutics. Consequently, methods to functionalize biologics without disrupting their native properties are essential for identifying, characterizing, and translating candidate biologics from the bench to clinical practice. Here, we present a method for site-specific, carboxy-terminal modification of single-chain antibody fragments (scFvs). ScFvs displayed on the surface of yeast were isolated and functionalized by combining intein-mediated expressed protein ligation (EPL) with inverse electron-demand Diels-Alder (IEDDA) cycloaddition using a styrene-tetrazine pair. The high thiol concentration required to trigger EPL can hinder the subsequent chemoselective ligation reactions; therefore, the EPL reaction was used to append styrene to the scFv, limiting tetrazine exposure to damaging thiols. Subsequently, the styrene-functionalized scFv was reacted with tetrazine-conjugated compounds in an IEDDA cycloaddition to generate functionalized scFvs that retain their native binding activity. Rapid functionalization of yeast surface-derived scFv in a site-directed manner could find utility in many downstream laboratory and preclinical applications.

  11. Synthesis of Functionalized Pyrazoles via 1,3-Dipolar Cycloaddition of α-Diazo-β-ketophosphonates, Sufones and Esters with Electron-Deficient Alkenes.

    Science.gov (United States)

    Baiju, T V; Namboothiri, Irishi N N

    2017-10-01

    1,3-Dipolar cycloaddition of diazo compounds with olefinic substrates is a promising atom-economic strategy for the construction of functionalized pyrazoles. Over the last few years, our group has been engaged in the synthesis of phosphonyl/sulfonylpyrazoles and pyrazole esters by employing Bestmann-Ohira Reagent (BOR) and its sulfur and ester analogs as 1,3-dipole precursors with various dipolarophiles. This account describes the novel synthetic methods developed in our laboratory, in the perspective of closely related work by others, for the synthesis of phosphonyl/sulfonylpyrazoles, pyrazole esters and the total synthesis of Withasomnine, a natural product, by using 1,3-dipolar cycloaddition as the key step. © 2017 The Chemical Society of Japan & Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Selectivity in Ketenimine Cycloadditions. Photoelectron Hel Spectra of Ketenimines

    Science.gov (United States)

    Bernardi, Fernando; Bottoni, Andrea; Ballaglia, Arturo; Distefano, Giuseppe; Dondoni, Alessandro

    1980-05-01

    The first few bands in the photoelectron (Hel) spectra of ketenimines R1R2C-C=NR3(R1,R2=H, CH3, C5H6, CH2=CH; R3=alkyl or aryl group) are assigned to the corresponding molecular orbitals. The assignment is based on SCF-MO calculations made at three different levels (CNDO/2, ab-initio STO-3C and 4-31G) coupled with perturbational molecular orbital analyses. The π-orbitals of the unsaturated substituents are found to interact with one of the two perpendicular π-electron systems of the>C=C=N- residue, the critical factor being the position of attack of the substituent. The relevance of these results on the site selectivity observed in cycloaddition reactions of these species is discussed.

  13. Intramolecular Azide to Alkene Cycloadditions for the Construction of Pyrrolobenzodiazepines and Azetidino-Benzodiazepines

    Czech Academy of Sciences Publication Activity Database

    Hemming, K.; Chambers, Christopher S.; Jamshaid, F.; O´Gorman, Paul A.

    2014-01-01

    Roč. 19, č. 10 (2014), s. 16737-16756 ISSN 1420-3049 Institutional support: RVO:61388971 Keywords : azide * cycloadditions * benzodiazepines Subject RIV: CC - Organic Chemistry Impact factor: 2.416, year: 2014

  14. Regio- and stereochemistry of 1,3-dipolar cycloaddition of nitrile oxides to alkenes

    International Nuclear Information System (INIS)

    Litvinovskaya, Raisa P; Khripach, Vladimir A

    2001-01-01

    The published data on the chemistry of intermolecular 1,3-dipolar cycloaddition of nitrile oxides to different types of alkene derivatives are systematised. Various aspects of stereo- and regiochemistry of this reaction are considered. The bibliography includes 182 references.

  15. Preparation of dispersible graphene through organic functionalization of graphene using a zwitterion intermediate cycloaddition approach

    NARCIS (Netherlands)

    Zhang, Xiaoyan; Browne, Wesley R.; Feringa, Ben L.

    2012-01-01

    Highly functionalized graphene were obtained through a zwitterion intermediate cycloaddition onto exfoliated graphene flakes under new reaction conditions. The functionalized graphene obtained formed stable dispersions in common solvents, including dimethylformamide (DMF), CHCl3 and water. Its

  16. Iron-catalyzed intermolecular cycloaddition of diazo surrogates with hexahydro-1,3,5-triazines.

    Science.gov (United States)

    Liu, Pei; Zhu, Chenghao; Xu, Guangyang; Sun, Jiangtao

    2017-09-26

    We report here an unprecedented iron-catalyzed cycloaddition reaction of diazo surrogates with hexahydro-1,3,5-triazines, providing five-membered heterocycles in moderate to high yields under mild reaction conditions. This cycloaddition features C-N and C-C bond formation using a cheap iron catalyst. Importantly, different to our former report on a gold-catalyzed system, both donor/donor and donor/acceptor diazo substrates are tolerated in this iron-catalyzed protocol.

  17. Functionalized MIL-101 with imidazolium-based ionic liquids for the cycloaddition of CO2 and epoxides under mild condition

    Science.gov (United States)

    Liu, Dan; Li, Gang; Liu, Haiou

    2018-01-01

    A kind of multi-functional sites metal-organic framework (MOF) composite (MIL-101-IMBr) was successfully prepared by post-synthesis modification of MIL-101 with imidazolium-based ionic liquids. The ionic liquids not only functionalize as basic sites but also provide halide anions, which serve as a nucleophile in cycloaddition reaction. The prepared functional MOF materials were characterized by X-ray diffraction, fourier transform infrared spectroscopy, scanning electron microscopy, energy dispersive spectroscopy, N2 adsorption-desorption and CO2 temperature programmed desorption. The results of fourier transform infrared spectroscopy and energy dispersive spectroscopy show that the MIL-101-IMBr composite was successfully synthesized. The N2 adsorption-desorption results clearly demonstrated that the modified composites still preserve high BET surface area and total pore volume. The composite exhibits high catalytic activity for the cycloaddition of CO2 with epoxides under mild and co-catalyst free conditions. The conversion of propylene oxide was 95.8% and the selectivity of cyclic carbonate was 97.6% under 0.8 MPa at 80 °C for 4 h. Moreover, the catalyst can be used for at least five times.

  18. Fluorogenic Strain-Promoted Alkyne-Diazo Cycloadditions.

    Science.gov (United States)

    Friscourt, Frédéric; Fahrni, Christoph J; Boons, Geert-Jan

    2015-09-28

    Fluorogenic reactions, in which non- or weakly fluorescent reagents produce highly fluorescent products, are attractive for detecting a broad range of compounds in the fields of bioconjugation and material sciences. Herein, we report that a dibenzocyclooctyne derivative modified with a cyclopropenone moiety (Fl-DIBO) can undergo fast strain-promoted cycloaddition reactions under catalyst-free conditions with azides, nitrones, nitrile oxides, as well as mono- and disubstituted diazo-derivatives. Although the reaction with nitrile oxides, nitrones, and disubstituted diazo compounds gave cycloadducts with low quantum yield, monosubstituted diazo reagents produced 1H-pyrazole derivatives that exhibited an approximately 160-fold fluorescence enhancement over Fl-DIBO combined with a greater than 10,000-fold increase in brightness. Concluding from quantum chemical calculations, fluorescence quenching of 3H-pyrazoles, which are formed by reaction with disubstituted diazo-derivatives, is likely due to the presence of energetically low-lying (n,π*) states. The fluorogenic probe Fl-DIBO was successfully employed for the labeling of diazo-tagged proteins without detectable background signal. Diazo-derivatives are emerging as attractive reporters for the labeling of biomolecules, and the studies presented herein demonstrate that Fl-DIBO can be employed for visualizing such biomolecules without the need for probe washout. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Coordinatively unsaturated ruthenium complexes as efficient alkyneazide cycloaddition catalysts

    KAUST Repository

    Lamberti, Marina; Fortman, George C.; Poater, Albert; Broggi, Julie; Slawin, Alexandra M. Z.; Cavallo, Luigi; Nolan, Steven P.

    2012-01-01

    The performance of 16-electron ruthenium complexes with the general formula Cp*Ru(L)X (in which L = phosphine or N-heterocyclic carbene ligand; X = Cl or OCH2CF3) was explored in azidealkyne cycloaddition reactions that afford the 1,2,3- triazole products. The scope of the Cp*Ru(PiPr 3)Cl precatalyst was investigated for terminal alkynes leading to new 1,5-disubstituted 1,2,3-triazoles in high yields. Mechanistic studies were conducted and revealed a number of proposed intermediates. Cp*Ru- (PiPr3)(2-HCCPh)Cl was observed and characterized by 1H, 13C, and 31P NMR at temperatures between 273 and 213 K. A rare example of N,N-κ2-phosphazide complex, Cp*Ru(κ2- iPr3PN3Bn)Cl, was fully characterized, and a single-crystal X-ray diffraction structure was obtained. DFT calculations describe a complete map of the catalytic reactivity with phenylacetylene and/or benzylazide. © 2012 American Chemical Society.

  20. Coordinatively unsaturated ruthenium complexes as efficient alkyneazide cycloaddition catalysts

    KAUST Repository

    Lamberti, Marina

    2012-01-23

    The performance of 16-electron ruthenium complexes with the general formula Cp*Ru(L)X (in which L = phosphine or N-heterocyclic carbene ligand; X = Cl or OCH2CF3) was explored in azidealkyne cycloaddition reactions that afford the 1,2,3- triazole products. The scope of the Cp*Ru(PiPr 3)Cl precatalyst was investigated for terminal alkynes leading to new 1,5-disubstituted 1,2,3-triazoles in high yields. Mechanistic studies were conducted and revealed a number of proposed intermediates. Cp*Ru- (PiPr3)(2-HCCPh)Cl was observed and characterized by 1H, 13C, and 31P NMR at temperatures between 273 and 213 K. A rare example of N,N-κ2-phosphazide complex, Cp*Ru(κ2- iPr3PN3Bn)Cl, was fully characterized, and a single-crystal X-ray diffraction structure was obtained. DFT calculations describe a complete map of the catalytic reactivity with phenylacetylene and/or benzylazide. © 2012 American Chemical Society.

  1. Chemoselective Switch in the Asymmetric Organocatalysis of 5 H -Oxazol-4-ones and N -Itaconimides: Addition-Protonation or [4+2] Cycloaddition

    KAUST Repository

    Zhu, Bo; Lee, Richmond; Li, Jiangtao; Ye, Xinyi; Hong, San-Ni; Qiu, Shuai; Coote, Michelle L.; Jiang, Zhiyong

    2015-01-01

    -tert-leucine-derived tertiary amine-urea compounds. The reaction was modulated to harness either tandem conjugate addition-protonation or [4+2] cycloaddition as major product with excellent enantio- and diastereoselectivities. Subjecting the enantio-enriched cycloaddition

  2. An intramolecular [2 + 2] cycloaddition of ketenimines via palladium-catalyzed rearrangements of N-allyl-ynamides.

    Science.gov (United States)

    DeKorver, Kyle A; Hsung, Richard P; Song, Wang-Ze; Wang, Xiao-Na; Walton, Mary C

    2012-06-15

    A cascade of Pd-catalyzed N-to-C allyl transfer-intramolecular ketenimine-[2 + 2] cycloadditions of N-allyl ynamides is described. This tandem sequence is highly stereoselective and the [2 + 2] cycloaddition could be rendered in a crossed or fused manner depending on alkene substitutions, leading to bridged and fused bicycloimines.

  3. Stepwise π-extension of meso-alkylidenyl porphyrins through sequential 1,3-dipolar cycloaddition and redox reactions.

    Science.gov (United States)

    Park, Dowoo; Jeong, Seung Doo; Ishida, Masatoshi; Lee, Chang-Hee

    2014-08-25

    Several regioselectively π-extended, pyrrole fused porphyrinoids have been synthesized by the 1,3-dipolar cycloaddition of meso-alkylidene-(benzi)porphyrins. Pd(II) complexes gave oxidation resistant, bis-pyrrole fused adducts. The repeated 1,3-dipolar cycloaddition followed by oxidation-reduction of pentaphyrin analogs afforded π-extended porphyrin analogs.

  4. Citrus Peel Additives for One-Pot Triazole Formation by Decarboxylation, Nucleophilic Substitution, and Azide-Alkyne Cycloaddition Reactions

    Science.gov (United States)

    Mendes, Desiree E.; Schoffstall, Allen M.

    2011-01-01

    This undergraduate organic laboratory experiment consists of three different reactions occurring in the same flask: a cycloaddition reaction, preceded by decarboxylation and nucleophilic substitution reactions. The decarboxylation and cycloaddition reactions occur using identical Cu(I) catalyst and conditions. Orange, lemon, and other citrus fruit…

  5. Gold-Catalyzed Formal [4+1]/[4+3] Cycloadditions of Diazo Esters with Triazines.

    Science.gov (United States)

    Zhu, Chenghao; Xu, Guangyang; Sun, Jiangtao

    2016-09-19

    Reported herein is the unprecedented gold-catalyzed formal [4+1]/[4+3] cycloadditions of diazo esters with hexahydro-1,3,4-triazines, thus providing five- and seven-membered heterocycles in moderate to high yields under mild reaction conditions. These reactions feature the use of a gold complex to accomplish the diverse annulations and the first example of the involvement of a gold metallo-enolcarbene in a cycloaddition. It is also the first utilization of stable triazines as formal dipolar adducts in the carbene-involved cycloadditions. Mechanistic investigations reveal that the triazines reacted directly, rather than as formaldimine precursors, in the reaction process. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Phosphine-catalyzed cycloadditions of allenic ketones: new substrates for nucleophilic catalysis.

    Science.gov (United States)

    Wallace, Debra J; Sidda, Rachel L; Reamer, Robert A

    2007-02-02

    A range of phosphine-catalyzed cycloaddition reactions of allenic ketones have been studied, extending the scope of these processes from the more widely used 2,3-butadienoates to allow access to a number of synthetically useful products. Reaction of allenyl methyl ketone 4 with exo-enones afforded spirocyclic compounds in good regioselectivity and promising enantioselectivity via a [2 + 3] cycloaddtion. Aromatic allenyl ketones undergo a phosphine-promoted dimerization to afford functionalized pyrans, leading to a formal [2 + 4] Diels-Alder product, but did not react in the [2 + 3] cycloaddition. The results from other reactions that had found utility with 2,3-butadienoates are also reported.

  7. Diazo Esters as Dienophiles in Intramolecular (4 + 2) Cycloadditions: Computational Explorations of Mechanism.

    Science.gov (United States)

    Duan, Abing; Yu, Peiyuan; Liu, Fang; Qiu, Huang; Gu, Feng Long; Doyle, Michael P; Houk, K N

    2017-02-22

    The first experimental examples of Diels-Alder (DA) reactions of diazo compounds as heterodienophiles with dienes have been studied with density functional theory (DFT) using the M06-2X functional. For comparison, the reactivities of diazo esters as dienophiles or 1,3-dipoles with 1,3-dienes in intermolecular model systems have been analyzed by the distortion/interaction model. The 1,3-dipolar cycloaddition is strongly favored for the intermolecular system. The intramolecular example is unique because the tether strongly favors the (4 + 2) cycloaddition.

  8. Diazo Compounds as Highly Tunable Reactants in 1,3-Dipolar Cycloaddition Reactions with Cycloalkynes†

    Science.gov (United States)

    McGrath, Nicholas A.

    2012-01-01

    Diazo compounds, which can be accessed directly from azides by deimidogenation, are shown to be extremely versatile dipoles in 1,3-dipolar cycloaddition reactions with a cyclooctyne. The reactivity of a diazo compound can be much greater or much less than its azide analog, and is enhanced markedly in polar-protic solvents. These reactivities are predictable from frontier molecular orbital energies. The most reactive diazo compound exhibited the highest known second-order rate constant to date for a dipolar cycloaddition with a cycloalkyne. These data provide a new modality for effecting chemoselective reactions in a biological context. PMID:23227302

  9. 1,3-Dipolar Cycloadditions of Diazo Compounds in the Presence of Azides.

    Science.gov (United States)

    Aronoff, Matthew R; Gold, Brian; Raines, Ronald T

    2016-04-01

    The diazo group has untapped utility in chemical biology. The tolerance of stabilized diazo groups to cellular metabolism is comparable to that of azido groups. However, chemoselectivity has been elusive, as both groups undergo 1,3-dipolar cycloadditions with strained alkynes. Removing strain and tuning dipolarophile electronics yields diazo group selective 1,3-dipolar cycloadditions that can be performed in the presence of an azido group. For example, diazoacetamide but not its azido congener react with dehydroalanine residues, as in the natural product nisin.

  10. The Cycloaddition of the Benzimidazolium Ylides with Alkynes: New Mechanistic Insights.

    Directory of Open Access Journals (Sweden)

    Costel Moldoveanu

    Full Text Available New insights concerning the reaction mechanism in the cycloaddition reaction of benzimidazolium ylides to activated alkynes are presented. The proposed pathway leading both to 2-(1H-pyrrol-1-ylanilines and to pyrrolo[1,2-a]quinoxalin-4(5H-ones involves an opening of the imidazole ring from the cycloaddition product, followed by a nucleophilic attack of the aminic nitrogen to a proximal carbonyl group and the elimination of a leaving group. The mechanistic considerations are fully supported by experimental data, including the XRD resolved structure of the key reaction intermediate.

  11. The Cycloaddition of the Benzimidazolium Ylides with Alkynes: New Mechanistic Insights.

    Science.gov (United States)

    Moldoveanu, Costel; Zbancioc, Gheorghita; Mantu, Dorina; Maftei, Dan; Mangalagiu, Ionel

    2016-01-01

    New insights concerning the reaction mechanism in the cycloaddition reaction of benzimidazolium ylides to activated alkynes are presented. The proposed pathway leading both to 2-(1H-pyrrol-1-yl)anilines and to pyrrolo[1,2-a]quinoxalin-4(5H)-ones involves an opening of the imidazole ring from the cycloaddition product, followed by a nucleophilic attack of the aminic nitrogen to a proximal carbonyl group and the elimination of a leaving group. The mechanistic considerations are fully supported by experimental data, including the XRD resolved structure of the key reaction intermediate.

  12. An Unprecedented [2+3] Cycloadditive Dimerization of a Transient Thiocarbonyl S-Ylide

    DEFF Research Database (Denmark)

    El-Sayed, Ibrahim; Hazell, Rita Grønbæk; Madsen, Jørgen Øgaard

    2003-01-01

    4-Chlorophenyl C-(phenylsulfonyl)dithioformate reacts with diazo(trimethylsilyl)methane to form 2-(4-chlorophenylthio)-2-phenylsulfonyl-4,5-bis(trimethylsilyl)-1,3-dithiolan-1-ium(4-chlorophenylthio)(phenylsulfonyl)methylide. It is assumed that this product is formed by [2+3] cycloadditive...

  13. A kinetic study of 1,3-dipolar cycloadditions in micellar media

    NARCIS (Netherlands)

    Rispens, T; Engberts, JBFN

    2003-01-01

    The kinetics of the 1,3-dipolar cycloadditions (DC) of benzonitrile oxide with a series of N-substituted maleimides in micellar media have been investigated. Surfactants studied include anionic sodium dodecyl sulfate, cationic cetyltrimethylammonium bromide, and a series of nonionic alkyl

  14. Synthesis and Diels–Alder cycloaddition reaction of norbornadiene and benzonorbornadiene dimers

    Directory of Open Access Journals (Sweden)

    Bilal Nişancı

    2009-08-01

    Full Text Available Dimeric forms of norbornadiene and benzonorbornadiene were synthesized starting with known monobromide derivatives. The Diels–Alder cycloaddition reaction of dimers with TCNE and PTAD was investigated and new norbornenoid polycyclics were obtained. All compounds were characterized properly using NMR spectroscopy.

  15. Cycloadditions of ketene acetals under microwave irradiation in solvent-free conditions

    International Nuclear Information System (INIS)

    Diaz-Ortiz, A.; Diez-Barra, E.; La Hoz, A. De; Prieto, P.; Moreno, A.

    1994-01-01

    When subjected to microwave irradiation ketene acetals undergo 1.3-dipolar and hetero-Diels-Alder cycloadditions within 5-12 min to give excellent yields of easily purified heterocyclic products. This efficient and rapid synthesis has the advantage of employing milder reaction conditions than those of classical thermal heating. (author)

  16. Copper(II)-catalyzed exo and enantioselective cycloadditions of azomethine imines.

    Science.gov (United States)

    Sibi, Mukund P; Rane, Digamber; Stanley, Levi M; Soeta, Takahiro

    2008-07-17

    A strategy for exo and enantioselective 1,3-dipolar cycloaddition of azomethine imines to 2-acryloyl-3-pyrazolidinone is described. The corresponding cycloadducts are isolated with high diastereoselectivities (up to >96:4 exo/endo) and enantioselectivities (up to 98% ee).

  17. An entry to a chiral dihydropyrazole scaffold: enantioselective [3 + 2] cycloaddition of nitrile imines.

    Science.gov (United States)

    Sibi, Mukund P; Stanley, Levi M; Jasperse, Craig P

    2005-06-15

    We have developed a versatile strategy to access dihydropyrazoles in highly enantioenriched form. Dipolar cycloaddition of electron-deficient acceptors and in situ-generated nitrile imines proceeds with high regio- and enantioselectivity using 10 mol % chiral Lewis acid catalyst. A variety of dihydropyrazoles that incorporate functionality for further manipulation have been prepared.

  18. Diels-Alder cycloaddition strategy for kinetic resolution of chiral pyrazolidinones.

    Science.gov (United States)

    Sibi, Mukund P; Kawashima, Keisuke; Stanley, Levi M

    2009-09-03

    A rare example of the application of a catalytic, enantioselective Diels-Alder cycloaddition to affect a kinetic resolution has been developed. Chiral pyrazolidinones are resolved with high selectivity through a process that utilizes a relay of stereochemical information from a permanent chiral center to a fluxional chiral center to enhance the inherent selectivity of the chiral Lewis acid catalyst.

  19. Pressure-accelerated azide-alkyne cycloaddition: micro capillary versus autoclave reactor performance.

    Science.gov (United States)

    Borukhova, Svetlana; Seeger, Andreas D; Noël, Timothy; Wang, Qi; Busch, Markus; Hessel, Volker

    2015-02-01

    Pressure effects on regioselectivity and yield of cycloaddition reactions have been shown to exist. Nevertheless, high pressure synthetic applications with subsequent benefits in the production of natural products are limited by the general availability of the equipment. In addition, the virtues and limitations of microflow equipment under standard conditions are well established. Herein, we apply novel-process-window (NPWs) principles, such as intensification of intrinsic kinetics of a reaction using high temperature, pressure, and concentration, on azide-alkyne cycloaddition towards synthesis of Rufinamide precursor. We applied three main activation methods (i.e., uncatalyzed batch, uncatalyzed flow, and catalyzed flow) on uncatalyzed and catalyzed azide-alkyne cycloaddition. We compare the performance of two reactors, a specialized autoclave batch reactor for high-pressure operation up to 1800 bar and a capillary flow reactor (up to 400 bar). A differentiated and comprehensive picture is given for the two reactors and the three methods of activation. Reaction speedup and consequent increases in space-time yields is achieved, while the process window for favorable operation to selectively produce Rufinamide precursor in good yields is widened. The best conditions thus determined are applied to several azide-alkyne cycloadditions to widen the scope of the presented methodology. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Exploring strain-promoted 1,3-dipolar cycloadditions of end functionalized polymers

    NARCIS (Netherlands)

    Ledin, Petr A; Kolishetti, Nagesh; Hudlikar, Manish S; Boons, Geert-Jan

    2014-01-01

    Strain-promoted 1,3-dipolar cycloaddition of cyclooctynes with 1,3-dipoles such as azides, nitrones, and nitrile oxides, are of interest for the functionalization of polymers. In this study, we have explored the use of a 4-dibenzocyclooctynol (DIBO)-containing chain transfer agent in reversible

  1. Phosphoramidite accelerated copper(I)-catalyzed [3+2] cycloadditions of azides and alkynes

    NARCIS (Netherlands)

    Campbell-Verduyn, Lachlan S.; Mirfeizi, Leila; Dierckx, Rudi A.; Elsinga, Philip H.; Feringa, Ben L.

    2009-01-01

    Monodentate phosphoramidite ligands are used to accelerate the copper(I)-catalyzed 1,3-dipolar cycloaddition of azides and alkynes (CuAAC) rapidly yielding a wide variety of functionalized 1,4-disubstituted-1,2,3-triazoles; Cu(I) and Cu(II) salts both function as the copper source in aqueous

  2. Cycloadditions in mixed aqueous solvents : the role of the water concentration

    NARCIS (Netherlands)

    Rispens, Theo; Engberts, Jan B. F. N.

    We examined the kinetics of a series of cycloaddition reactions in mixtures of water with methanol, acetonitrile and poly(ethylene glycol) (MW 1000). The reactions include the Diels-Alder (DA) reaction between cyclopentadiene and N-n-butylmaleimide or acridizinium bromide, the retro-Diels-Alder

  3. Thermal and catalytic intramolecular [4+2]-cycloaddition in 2-alkenylfurans

    International Nuclear Information System (INIS)

    Zubkov, Fedor I; Nikitina, Evgenia V; Varlamov, Alexey V

    2005-01-01

    The published data on the intramolecular Diels-Alder reaction in compounds of the 2-alkenylfuran series are generalised. The methods and conditions for the preparation of tricyclic systems are considered. The effects of the substituents in the furan and the unsaturated fragments on the cycloaddition are discussed. The application of this reaction to the synthesis of alkaloids and terpenoids is exemplified.

  4. Undergraduate Organic Experiment: Tetrazole Formation by Microwave Heated (3 + 2) Cycloaddition in Aqueous Solution

    Science.gov (United States)

    DeFrancesco, Heather; Dudley, Joshua; Coca, Adiel

    2018-01-01

    An undergraduate experiment for the organic laboratory is described that utilizes microwave heating to prepare 5- substituted 1H-tetrazole derivatives through a (3 + 2) cycloaddition between aryl nitriles and sodium azide. The reaction mixture is analyzed by thin layer chromatography. The products are purified through an acid-base extraction and…

  5. Cycloadditions to Epoxides Catalyzed by GroupIII-V Transition-Metal Complexes

    KAUST Repository

    D'Elia, Valerio

    2015-05-25

    Complexes of groupIII-V transition metals are gaining increasing importance as Lewis acid catalysts for the cycloaddition of dipolarophiles to epoxides. This review examines the latest reports, including homogeneous and heterogeneous applications. The pivotal step for the cycloaddition reactions is the ring opening of the epoxide following activation by the Lewis acid. Two modes of cleavage (C-C versus C-O) have been identified depending primarily on the substitution pattern of the epoxide, with lesser influence observed from the Lewis acid employed. The widely studied cycloaddition of CO2 to epoxides to afford cyclic carbonates (C-O bond cleavage) has been scrutinized in terms of catalytic efficiency and reaction mechanism, showing that unsophisticated complexes of groupIII-V transition metals are excellent molecular catalysts. These metals have been incorporated, as well, in highly performing, recyclable heterogeneous catalysts. Cycloadditions to epoxides with other dipolarophiles (alkynes, imines, indoles) have been conducted with scandium triflate with remarkable performances (C-C bond cleavage). © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. One-Pot Functionalization of Graphene with Porphyrin through Cycloaddition Reactions

    NARCIS (Netherlands)

    Zhang, Xiaoyan; Hou, Lili; Cnossen, Arjen; Coleman, Anthony C.; Ivashenko, Oleksii; Rudolf, Petra; Wees, Bart J. van; Browne, Wesley R.; Feringa, Ben L.

    Two types of graphene-based hybrid materials, graphene-TPP (TPP=tetraphenylporphyrin) and graphene-PdTPP (PdTPP=palladium tetraphenylporphyrin), were prepared directly from pristine graphene through one-pot cycloaddition reactions. The hybrid materials were characterized by thermogravimetric

  7. Pressure-accelerated azide-alkyne cycloaddition : micro capillary versus autoclave reactor performance

    NARCIS (Netherlands)

    Borukhova, S.; Seeger, A.D.; Noël, T.; Wang, Q.; Busch, M.; Hessel, V.

    2015-01-01

    Pressure effects on regioselectivity and yield of cycloaddition reactions have been shown to exist. Nevertheless, high pressure synthetic applications with subsequent benefits in the production of natural products are limited by the general availability of the equipment. In addition, the virtues and

  8. Copper on Chitosan: A Recyclable Heterogeneous Catalyst for Azide-alkyne Cycloaddition Reactions in Water

    Science.gov (United States)

    Copper sulfate is immobilized over chitosan by simply stirring an aqueous suspension of chitosan in water with copper sulfate; the ensuing catalyst has been utilized for the azide-alkyne cycloaddition in aqueous media and it can be recycled and reused many time without loosing it...

  9. Thermal and catalytic intramolecular [4+2]-cycloaddition in 2-alkenylfurans

    Energy Technology Data Exchange (ETDEWEB)

    Zubkov, Fedor I; Nikitina, Evgenia V; Varlamov, Alexey V [Department of Physical, Mathematical and Natural Sciences, Peoples' Friendship University of Russia (Russian Federation)

    2005-07-31

    The published data on the intramolecular Diels-Alder reaction in compounds of the 2-alkenylfuran series are generalised. The methods and conditions for the preparation of tricyclic systems are considered. The effects of the substituents in the furan and the unsaturated fragments on the cycloaddition are discussed. The application of this reaction to the synthesis of alkaloids and terpenoids is exemplified.

  10. Novel synthesis of 4(5)-monosubstituted imidazoles via cycloaddition of tosylmethyl isocyanide to aldimines

    NARCIS (Netherlands)

    ten Have, Ronald; Huisman, M; Meetsma, A; van Leusen, A.M.

    1997-01-01

    4(5)-Monosubstituted imidazoles (9) have been prepared via base-induced cycloaddition of tosylmethyl isocyanide (TosMIC) to N-(dimethylsulfamoyl)aldimines (2) or N-tosylaldimines (3). In the first case, N-(dimethylsulfamoyl)imidazoles 8 are the initial reaction products, from which the

  11. Cycloadditions to Epoxides Catalyzed by GroupIII-V Transition-Metal Complexes

    KAUST Repository

    D'Elia, Valerio; Pelletier, Jeremie; Basset, Jean-Marie

    2015-01-01

    Complexes of groupIII-V transition metals are gaining increasing importance as Lewis acid catalysts for the cycloaddition of dipolarophiles to epoxides. This review examines the latest reports, including homogeneous and heterogeneous applications. The pivotal step for the cycloaddition reactions is the ring opening of the epoxide following activation by the Lewis acid. Two modes of cleavage (C-C versus C-O) have been identified depending primarily on the substitution pattern of the epoxide, with lesser influence observed from the Lewis acid employed. The widely studied cycloaddition of CO2 to epoxides to afford cyclic carbonates (C-O bond cleavage) has been scrutinized in terms of catalytic efficiency and reaction mechanism, showing that unsophisticated complexes of groupIII-V transition metals are excellent molecular catalysts. These metals have been incorporated, as well, in highly performing, recyclable heterogeneous catalysts. Cycloadditions to epoxides with other dipolarophiles (alkynes, imines, indoles) have been conducted with scandium triflate with remarkable performances (C-C bond cleavage). © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Visible Light Photocatalysis of [2+2] Styrene Cycloadditions via Energy Transfer

    Science.gov (United States)

    Lu, Zhan; Yoon, Tehshik P.

    2012-01-01

    Hip to be square: Styrenes participate in [2+2] cycloadditions upon irradiation with visible light in the presence of an iridium(III) polypyridyl complex. In contrast to previous reports of visible light photoredox catalysis, the mechanism of this process involves photosensitization by energy transfer and not electron transfer. PMID:22965321

  13. A Palladium-Catalyzed Vinylcyclopropane (3 + 2) Cycloaddition Approach to the Melodinus Alkaloids

    KAUST Repository

    Goldberg, Alexander F. G.

    2011-08-19

    A palladium-catalyzed (3+2) cycloaddition of a vinylcyclopropane and a β-nitrostyrene is employed to rapidly assemble the cyclopentane core of the Melodinus alkaloids. The ABCD ring system of the natural product family is prepared in six steps from commercially available materials.

  14. Chiral four-membered cyclic nitrones; asymmetric induction in the (4+2)-cycloaddition reaction of chiral ynamines and nitroalkenes

    NARCIS (Netherlands)

    van Elburg, P.A.; Honig, G.W.N.; Reinhoudt, David

    1987-01-01

    Chiral four-membered cyclic nitrones were synthesized by the asymmetric (4+2)-cycloaddition of nitroalkenes 1 and chiral ynamines 2. The subsequent stereoselective addition of nucleophiles to these nitrones enabled the synthesis of chiral N-hydroxyazetidines.

  15. 1,3-Dipolar cycloaddition reactions of nitrile oxides in the synthesis of natural compounds and their analogues

    International Nuclear Information System (INIS)

    Kotyatkina, Anna I; Zhabinsky, Vladimir N; Khripach, Vladimir A

    2001-01-01

    The published data on the use of 1,3-dipolar cycloaddition reactions of nitrile oxides in the synthesis of natural compounds and their analogues are systematised and reviewed. The bibliography includes 145 references.

  16. Multicomponent synthesis of spiropyrrolidine analogues derived from vinylindole/indazole by a 1,3-dipolar cycloaddition reaction

    Directory of Open Access Journals (Sweden)

    Manjunatha Narayanarao

    2016-12-01

    Full Text Available A new series of spiropyrrolidine compounds containing indole/indazole moieties as side chains have been accomplished via a one-pot multicomponent synthesis. The method uses the 1,3-dipolar cycloaddition reaction between N-alkylvinylindole/indazole and azomethine ylides, prepared in situ from cyclic/acyclic amino acids. The 1,3-dipolar cycloaddition proceeds efficiently under thermal conditions to afford the regio- and stereospecific cyclic adducts.

  17. Photo- and radiation chemical cycloaddition of maleic acid derivatives to ethylene and acetylene under elavated pressure

    International Nuclear Information System (INIS)

    Mirbach, M.

    1975-01-01

    Based on spectroscopic and kinetic measurements the influence of high pressure on some selected photochemical cycloaddition-reactions is studied. The photo-cycloaddition-reaction of maleic acid anhydride with ethylen has been performed under high ethylen pressures ( 90%). Surprisingly the quantum yield of the cyclo aduct decreases with increasing ethylene pressure from PHI = 0.06 at p = 1 bar to PHI = 0.022 at p = 42 bar. Based on Stern-Volmer quenching experiments, the decrease in ring formation with increasing ethylene concentrations could be explained by an endoergic triplet energy transfer from maleic acid anhydride to ethylene. The type II dissociation of butyrophenone has been quenched also with ethylene. With a lifetime for the first excited butyrophenone triplett state of tau = 6.8 x 10 -8 sec, obtained from kinetic data, the velocity constant can be calculated for this reaction with the result k 5 = 3 x 10 6 M -1 sec -1 . (orig./HK) [de

  18. Investigation of the Pyridinium Ylide—Alkyne Cycloaddition as a Fluorogenic Coupling Reaction

    Directory of Open Access Journals (Sweden)

    Simon Bonte

    2016-03-01

    Full Text Available The cycloaddition of pyridinium ylides with alkynes was investigated under mild conditions. A series of 13 pyridinium salts was prepared by alkylation of 4-substituted pyridines. Their reactivity with propiolic ester or amide in various reaction conditions (different temperatures, solvents, added bases was studied, and 11 indolizines, with three points of structural variation, were, thus, isolated and characterized. The highest yields were obtained when electron-withdrawing groups were present on both the pyridinium ylide, generated in situ from the corresponding pyridinium salt, and the alkyne (X, Z = ester, amide, CN, carbonyl, etc.. Electron-withdrawing substituents, lowering the acid dissociation constant (pKa of the pyridinium salts, allow the cycloaddition to proceed at pH 7.5 in aqueous buffers at room temperature.

  19. A facile regioselective synthesis of novel spiroacenaphthene pyrroloisoquinolines through 1,3-dipolar cycloaddition reactions

    International Nuclear Information System (INIS)

    Sarrafi, Yaghoub; Asghari, Asieh; Sadatshahabi, Marzieh; Hamzehloueian, Mahshid; Alimohammadi, Kamal

    2013-01-01

    An efficient one-pot three-component procedure for the synthesis of novel spiroacenaphthene pyrroloisoquinolines with high regioselectivity is described. These compounds were prepared from 1,3-dipolar cycloaddition of an azomethine ylide generated from acenaphthenequinone and 1,2,3,4-tetrahydroisoquinoline via [1,5]-H shift, with chalcone and nitrostyrene derivatives as dipolarophiles. The structure and stereochemistry of the cycloadducts have been established by single crystal X-ray structure and spectroscopic techniques. (author)

  20. (4+2) Cycloaddition reactions with inverse electron demand of nitrogen bearing, heteroaromatic cations

    International Nuclear Information System (INIS)

    Ritzberger-Baumgartner, W.

    1996-06-01

    Three cationic, heteroaromatic diene-systems (1, 2, 3, 4-tetramethoxycarbonyl-quinolizinium-tetrafluoroborate (M), 8, 9, 10, 11-tetrarnethoxycarbonylpyrido[2,1-a]-isoquinolinium-TFB and triazolo[1,5-b]isoquinolinium-TFBs) and a cationic, non-aromatic diene (2,5,5-trimethyl-3-oxo-1, 2, 4-triazolium-TFB) were synthesized. The dienes were employed successfully in cycloaddition reactions with a number ofconjugated dienophiles (including norbornene). The mechanism underlying these cycloaddition reactions was discussed in the theoretical section. At first quantumchemical calculations of the frontier orbital energies provided the proof, that the reactions followed the pattern of reactions with inverse electron demand. Calculation of the charge distribution and of the orbital coefficients led to the conclusion, that these reactions are mainly orbital controlled. Two mechanistic variants were in discussion. Either the reactions proceed in a concerted manner resembling the Diels-Alder reaction with inverse electron demand or in two distinct steps with the formation of a cationic intermediate following the attack of the heterodienes acting as weak electrophiles at the dienophiles being weak nucleophiles. Calculations of a possible transition state of these cycloaddition reactions revealed a pronounced preference for the formation of the bond between the logical reaction centers in the first step of a two-step reaction. However, experimental and theoretical findings led to the conviction, that cationic polar cycloaddition reactions proceed exactly along the crossroad between a concerted and a two-step mechanism and depending on the electrophilic strength of the diene and the nucleophilic strength of the dienophile these reactions show more characteristics of one of the two mechanistic possibilities. The high regioselectivity as well as the high stereoselectivity could be explained satisfactory with the help of the calculated orbital coefficients. (author)

  1. Mechanistic rationalization of unusual sigmoidal kinetic profiles in the Machetti-De Sarlo cycloaddition reaction.

    Science.gov (United States)

    Mower, Matthew P; Blackmond, Donna G

    2015-02-18

    Unusual sigmoidal kinetic profiles in the Machetti-De Sarlo base-catalyzed 1,3-dipolar cycloaddition of acrylamide to N-methylnitroacetamide are rationalized by detailed in situ kinetic analysis. A dual role is uncovered in which a substrate acts as a precursor to catalyze its own reaction. Such kinetic studies provide a general protocol for distinguishing among different mechanistic origins of induction periods in complex organic reactions.

  2. [3 + 2]-Cycloadditions of nitrile ylides after photoactivation of vinyl azides under flow conditions

    Directory of Open Access Journals (Sweden)

    Stephan Cludius-Brandt

    2013-08-01

    Full Text Available The photodenitrogenation of vinyl azides to 2H-azirines by using a photoflow reactor is reported and compared with thermal formation of 2H-azirines. Photochemically, the ring of the 2H-azirines was opened to yield the nitrile ylides, which underwent a [3 + 2]-cycloaddition with 1,3-dipolarophiles. When diisopropyl azodicarboxylate serves as the dipolarophile, 1,3,4-triazoles become directly accessible starting from the corresponding vinyl azide.

  3. NMR studies on 1,3-dipolar cycloaddition of nitrile oxides to norbornenes

    International Nuclear Information System (INIS)

    Gucma, Mirosław; Gołębiewski, W. Marek; Krawczyk, Maria

    2013-01-01

    The 1,3-dipolar cycloaddition reaction of nitrile oxides to norbornenes substituted with an acrylate-derived moiety was examined. Only adducts to norbornene system were formed with a good exo selectivity and complete site-selectivity. Structures of the products were elucidated by an extensive application of electrospray ionization-mass spectrometry (ESI-MS) and 2D 1 H and 13 C nuclear magnetic resonance (NMR). (author)

  4. Intramolecular Azide to Alkene Cycloadditions for the Construction of Pyrrolobenzodiazepines and Azetidino-Benzodiazepines

    Directory of Open Access Journals (Sweden)

    Karl Hemming

    2014-10-01

    Full Text Available The coupling of proline- and azetidinone-substituted alkenes to 2-azidobenzoic and 2-azidobenzenesulfonic acid gives precursors that undergo intramolecular azide to alkene 1,3-dipolar cycloadditions to give imine-, triazoline- or aziridine-containing pyrrolo[1,4]benzodiazepines (PBDs, pyrrolo[1,2,5]benzothiadiazepines (PBTDs, and azetidino[1,4]benzodiazepines. The imines and aziridines are formed after loss of nitrogen from a triazoline cycloadduct. The PBDs are a potent class of antitumour antibiotics.

  5. Rhodium-Catalyzed Linear Codimerization and Cycloaddition of Ketenes with Alkynes

    Directory of Open Access Journals (Sweden)

    Teruyuki Kondo

    2010-06-01

    Full Text Available A novel rhodium-catalyzed linear codimerization of alkyl phenyl ketenes with internal alkynes to dienones and a novel synthesis of furans by an unusual cycloaddition of diaryl ketenes with internal alkynes have been developed. These reactions proceed smoothly with the same rhodium catalyst, RhCl(PPh33, and are highly dependent on the structure and reactivity of the starting ketenes.

  6. NMR studies on 1,3-dipolar cycloaddition of nitrile oxides to norbornenes

    Energy Technology Data Exchange (ETDEWEB)

    Gucma, Miroslaw; Golebiewski, W. Marek; Krawczyk, Maria, E-mail: golebiewski@ipo.waw.pl [Institute of Industrial Organic Chemistry, Warsaw (Poland)

    2013-05-15

    The 1,3-dipolar cycloaddition reaction of nitrile oxides to norbornenes substituted with an acrylate-derived moiety was examined. Only adducts to norbornene system were formed with a good exo selectivity and complete site-selectivity. Structures of the products were elucidated by an extensive application of electrospray ionization-mass spectrometry (ESI-MS) and 2D {sup 1}H and {sup 13}C nuclear magnetic resonance (NMR). (author)

  7. A facile regioselective synthesis of novel spiroacenaphthene pyrroloisoquinolines through 1,3-dipolar cycloaddition reactions

    Energy Technology Data Exchange (ETDEWEB)

    Sarrafi, Yaghoub; Asghari, Asieh; Sadatshahabi, Marzieh, E-mail: ysarrafi@umz.ac.ir [Department of Organic Chemistry, Faculty of Chemistry, University of Mazandaran (Iran, Islamic Republic of); Hamzehloueian, Mahshid [Department of Chemistry, Jouybar Branch, Islamic Azad University, Jouybar (Iran, Islamic Republic of); Alimohammadi, Kamal [Department of Chemistry, Dr. Shariati Branch, University of Farhangian, Sari (Iran, Islamic Republic of)

    2013-12-01

    An efficient one-pot three-component procedure for the synthesis of novel spiroacenaphthene pyrroloisoquinolines with high regioselectivity is described. These compounds were prepared from 1,3-dipolar cycloaddition of an azomethine ylide generated from acenaphthenequinone and 1,2,3,4-tetrahydroisoquinoline via [1,5]-H shift, with chalcone and nitrostyrene derivatives as dipolarophiles. The structure and stereochemistry of the cycloadducts have been established by single crystal X-ray structure and spectroscopic techniques. (author)

  8. Mechanism, reactivity, and selectivity of nickel-catalyzed [4 + 4 + 2] cycloadditions of dienes and alkynes.

    Science.gov (United States)

    Hong, Xin; Holte, Dane; Götz, Daniel C G; Baran, Phil S; Houk, K N

    2014-12-19

    Density functional theory (DFT) calculations with B3LYP and M06 functionals elucidated the reactivities of alkynes and Z/E selectivity of cyclodecatriene products in the Ni-catalyzed [4 + 4 + 2] cycloadditions of dienes and alkynes. The Ni-mediated oxidative cyclization of butadienes determines the Z/E selectivity. Only the oxidative cyclization of one s-cis to one s-trans butadiene is facile and exergonic, leading to the observed 1Z,4Z,8E-cyclodecatriene product. The same step with two s-cis or s-trans butadienes is either kinetically or thermodynamically unfavorable, and the 1Z,4E,8E- and 1Z,4Z,8Z-cyclodecatriene isomers are not observed in experiments. In addition, the competition between the desired cooligomerization and [2 + 2 + 2] cycloadditions of alkynes depends on the coordination of alkynes. With either electron-deficient alkynes or alkynes with free hydroxyl groups, the coordination of alkynes is stronger than that of dienes, and alkyne trimerization prevails. With alkyl-substituted alkynes, the generation of alkyne-coordinated nickel complex is much less favorable, and the [4 + 4 + 2] cycloaddition occurs.

  9. Cu(OAc)2/TFA-promoted formal [3 + 3] cycloaddition/oxidation of enamines and enones for synthesis of multisubstituted aromatic amines.

    Science.gov (United States)

    Li, Liang; Zhao, Mi-Na; Ren, Zhi-Hui; Li, Jian-Li; Guan, Zheng-Hui

    2012-07-06

    New strategies for the oxidative cycloaddition of enones with enamines are developed. These cycloaddition reactions directly afford substituted aromatic amines, which are important in organic chemistry, in moderate to good yield. Cu(OAc)(2)/TFA is shown to be essential to achieve high reaction efficiency.

  10. Theoretical studies of mechanisms of cycloaddition reaction between difluoromethylene carbene and acetone

    Science.gov (United States)

    Lu, Xiu Hui; Yu, Hai Bin; Wu, Wei Rong; Xu, Yue Hua

    Mechanisms of the cycloaddition reaction between singlet difluoromethylene carbene and acetone have been investigated with the second-order Møller-Plesset (MP2)/6-31G* method, including geometry optimization and vibrational analysis. Energies for the involved stationary points on the potential energy surface (PES) are corrected by zero-point energy (ZPE) and CCSD(T)/6-31G* single-point calculations. From the PES obtained with the CCSD(T)//MP2/6-31G* method for the cycloaddition reaction between singlet difluoromethylene carbene and acetone, it can be predicted that path B of reactions 2 and 3 should be two competitive leading channels of the cycloaddition reaction between difluoromethylene carbene and acetone. The former consists of two steps: (i) the two reactants first form a four-membered ring intermediate, INT2, which is a barrier-free exothermic reaction of 97.8 kJ/mol; (ii) the intermediate INT2 isomerizes to a four-membered product P2b via a transition state TS2b with an energy barrier of 24.9 kJ/mol, which results from the methyl group transfer. The latter proceeds in three steps: (i) the two reactants first form an intermediate, INT1c, through a barrier-free exothermic reaction of 199.4 kJ/mol; (ii) the intermediate INT1c further reacts with acetone to form a polycyclic intermediate, INT3, which is also a barrier-free exothermic reaction of 27.4 kJ/mol; and (iii) INT3 isomerizes to a polycyclic product P3 via a transition state TS3 with an energy barrier of 25.8 kJ/mol.

  11. Novel quinazoline ring synthesis by cycloaddition of N-arylketenimines with N,N-disubstituted cyanamides.

    Science.gov (United States)

    Shimizu, Masao; Oishi, Akihiro; Taguchi, Yoichi; Gama, Yasuo; Shibuya, Isao

    2002-03-01

    The reaction of N-aryl-substituted ketenimines with N,N-disubstituted cyanamides or (MeS)2C=N-CN under high pressure afforded 4-(N,N-disubstituted amino) or 4-(MeS)2C=N-substituted quinazoline derivatives, respectively. These products were formed by [4+2] cycloaddition between the aza-diene moieties of the N-arylsubstituted ketenimines and cyano groups. A 4-(unsubstituted amino)quinazoline derivative was synthesized by hydrolysis of the latter product.

  12. Synthesis and Intramolecular [4+2] Cycloaddition Reactions of 4-Pyridazinecarbonitriles with Alkyne Side Chains

    Directory of Open Access Journals (Sweden)

    Norbert Haider

    1998-01-01

    Full Text Available The preparation of a series of new 3-(alkynyl-X-substituted 4-pyridazinecarbonitriles 2-5 (X = O, NH is described. The compounds are shown to undergo thermally induced intramolecular Diels-Alder reactions with inverse electron demand, affording the fused benzonitriles 6-8. Incorporation of a 1,2-phenylene unit into the side chain, as in the case of compounds 10 and 13, results in a more favorable conformation of the dienophilic substructure and thus to a pronounced acceleration of the [4+2] cycloaddition reaction.

  13. Synthesis and 1,3-Dipolar Cycloaddition Reactions of Chiral Maleimides

    Directory of Open Access Journals (Sweden)

    Lubor Fisera

    1997-02-01

    Full Text Available New routes to the synthesis of various novel chiral maleimides are described. The oxabicyclic anhydride 2 readily available exo-Diels-Alder adduct of furan and maleic anhydride was used as a vehicle, which in turn reacted with hydrochlorides of amino acids 3a-f in the presence of Et3N with release of furan to give the requisite novel chiral imides 4a-f in good to moderate yields. The stereoselectivity of 1,3-dipolar cycloaddition of nitrile oxides with prepared chiral imides 4a-f is investigated.

  14. Predictable and Regioselective Insertion of Internal Unsymmetrical Alkynes in Rhodium-Catalyzed Cycloadditions with Alkenyl Isocyanates

    Science.gov (United States)

    Friedman, Rebecca Keller; Rovis, Tomislav

    2009-01-01

    A regioselective, rhodium-catalyzed cycloaddition between a variety of internal, unsymmetrical alkynes is described. We document the impact of both steric and electronic properties of the alkyne on reaction course, efficiency and enantioselectivity. The substituent that better stabilizes a positive charge or the larger group, all else being equal, inserts distal to the carbonyl moiety in a predictable and controllable fashion. The reaction scope is broad and the enantioselectivities are high, providing an ‘instruction manual’ for substrate choice when utilizing this reaction as a synthetic tool. PMID:19569692

  15. Synthesis of 1,4-naphthoquinone derivatives using 1,3-dipolar cycloaddition and Sonogashira reactions

    Directory of Open Access Journals (Sweden)

    Wilson Silva do Nascimento

    2010-04-01

    Full Text Available Naphthoquinones are known according to their important bio-activities, such as their antitumoral and topoisomerase inhibition properties. From 2-azido (3 or 2,3-diacetylene-1,4-naphthoquinone (4 it was possible to obtain triazole derivatives (naphthoquinonic. This work describes the synthesis of two novel molecules, with triazole groups linked to 1,4-naphthoquinone using the 1,3-dipolar cycloaddition and Sonogashira reactions. The synthetic strategy followed two routes (Scheme 1. First, we synthesized the 2-bromo-1,4-naphthoquinone (2, yield 98% by using Br2 and CH3CO2H, and then used it to obtain 2-azido-1,4-naphthoquinone (3, yield 62% from compound 1, along with ethanolic solution (reflux and NaN3. Finally, we prepared 1,2,3-triazole compounds (4a, b by 1,3-dipolar cycloaddition, involving compound (3 and terminal acetylenes (phenylacetylene, a and glycoside (b using Cu(OAc2 and ascorbate, under argon atmosphere. During the second step, 2,3-dibromo-1,4-naphthoquinone was prepared using Br2/CH2Cl2 at room temperature. From compound (5 it was possible to synthesize (6, catalyzed by Pd(PPh32Cl2/CuI/Et3N, under argon atmosphere, in 40% yield. The 1,3-dipolar cycloaddition reactions involving 2-azido-1,4-naphthoquinone (3 and alkynes (a, yield 23% and b, yield 30% were conducted using the solvent system, (1:1 terc-BuOH/H2O/r.t/ 20 mol% of Cu(OAc2 and sodium ascorbate, under stirring during 24 hours. The reaction involving 2,3-dibromo-1,4-naphthoquinone (5, yield 65% and phenylacetylene was prepared using the solvent mixture (2:1 DMSO/CHCl3 and catalytic amount of CuI/Pd(PPh32Cl2. The final products were characterized by elemental analysis and spectrometric techniques (IR, NMR 1H and 13C. Two novel triazole compounds were synthesized from naphthoquinones by 1,3-dipolar cycloaddition from suitable 1,4-naphthoquinones obtained by Sonogashira couplings.

  16. Triazol-substituted titanocenes by strain-driven 1,3-dipolar cycloadditions

    Directory of Open Access Journals (Sweden)

    Andreas Gansäuer

    2014-07-01

    Full Text Available An operationally simple, convenient, and mild strategy for the synthesis of triazole-substituted titanocenes via strain-driven 1,3-dipolar cycloadditions between azide-functionalized titanocenes and cyclooctyne has been developed. It features the first synthesis of titanocenes containing azide groups. These compounds constitute ‘second-generation’ functionalized titanocene building blocks for further synthetic elaboration. Our synthesis is modular and large numbers of the complexes can in principle be prepared in short periods of time. Some of the triazole-substituted titanocenes display high cyctotoxic activity against BJAB cells. Comparison of the most active complexes allows the identification of structural features essential for biological activity.

  17. Easy access to heterobimetallic complexes for medical imaging applications via microwave-enhanced cycloaddition

    Directory of Open Access Journals (Sweden)

    Nicolas Desbois

    2015-11-01

    Full Text Available The Cu(I-catalysed Huisgen cycloaddition, known as “click” reaction, has been applied to the synthesis of a range of triazole-linked porphyrin/corrole to DOTA/NOTA derivatives. Microwave irradiation significantly accelerates the reaction. The synthesis of heterobimetallic complexes was easily achieved in up to 60% isolated yield. Heterobimetallic complexes were easily prepared as potential MRI/PET (SPECT bimodal contrast agents incorporating one metal (Mn, Gd for the enhancement of contrast for MRI applications and one “cold” metal (Cu, Ga, In for future radionuclear imaging applications. Preliminary relaxivity measurements showed that the reported complexes are promising contrast agents (CA in MRI.

  18. Diels–Alder cycloaddition of 2-methylfuran and ethylene for renewable toluene

    Energy Technology Data Exchange (ETDEWEB)

    Green, Sara K.; Patet, Ryan E.; Nikbin, Nima; Williams, C. Luke; Chang, Chun-Chih; Yu, Jingye; Gorte, Raymond J.; Caratzoulas, Stavros; Fan, Wei; Vlachos, Dionisios G.; Dauenhauer, Paul J.

    2016-01-01

    Diels–Alder cycloaddition of biomass-derived 2-methylfuran and ethylene provides a thermochemical pathway to renewable toluene. In this work, the kinetics and reaction pathways of toluene formation have been evaluated with H-BEA and Sn-BEA catalysts. Kinetic analysis of the main reaction chemistries reveals the existence of two rate-controlling reactions: (i) Diels–Alder cycloaddition of 2-methylfuran and ethylene where the production rate is independent of the Brønsted acid site concentration, and (ii) dehydration of the Diels–Alder cycloadduct where the production rate is dependent on the Brønsted acid site concentration. Application of a reduced kinetic model supports the interplay of these two regimes with the highest concentration of toluene measured at a catalyst loading equal to the transition region between the two kinetic regimes. Selectivity to toluene never exceeded 46%, as 2-methylfuran was consumed by several newly identified reactions to side products, including dimerization of 2-methylfuran, the formation of a trimer following hydrolysis and ring-opening of 2-methylfuran, and the incomplete dehydration of the Diels–Alder cycloadduct of 2-methylfuran and ethylene.

  19. Ratiometric Fluorescence Azide-Alkyne Cycloaddition for Live Mammalian Cell Imaging.

    Science.gov (United States)

    Fu, Hongxia; Li, Yanru; Sun, Lingbo; He, Pan; Duan, Xinrui

    2015-11-17

    Click chemistry with metabolic labeling has been widely used for selectively imaging biomacromolecules in cells. The first example of azide-alkyne cycloaddition for ratiometric fluorescent imaging of live cells is reported. The precursor of the azido fluorophore (cresyl violet) has a fluorescence emission peak at 620 nm. The electron-rich nitrogen of the azido group blue-shifts the emission peak to 566 nm. When the click reaction occurs, an emission peak appears at 620 nm due to the lower electronic density of the newly formed triazole ring, which allows us to ratiometrically record fluorescence signals. This emission shift was applied to ratiometric imaging of propargylcholine- and dibenzocyclooctyne-labeled human breast cancer cells MCF-7 under laser confocal microscopy. Two typical triazole compounds were isolated for photophysical parameter measurements. The emission spectra presented a fluorescence emission peak around 620 nm for both click products. The results further confirmed the emission wavelength change was the result of azide-alkyne cycloaddition reaction. Since nearly all biomolecules can be metabolically labeled by reported alkyne-functionalized derivatives of native metabolites, our method can be readily applied to image these biomacromolecules.

  20. Mild and modular surface modification of cellulose via hetero Diels-Alder (HDA) cycloaddition.

    Science.gov (United States)

    Goldmann, Anja S; Tischer, Thomas; Barner, Leonie; Bruns, Michael; Barner-Kowollik, Christopher

    2011-04-11

    A combination of reversible addition-fragmentation chain transfer (RAFT) polymerization and hetero Diels-Alder (HDA) cycloaddition was used to effect, under mild (T ≈ 20 °C), fast, and modular conditions, the grafting of poly(isobornyl acrylate) (M(n) = 9800 g mol(-1), PDI = 1.19) onto a solid cellulose substrate. The active hydroxyl groups expressed on the cellulose fibers were converted to tosylate leaving groups, which were subsequently substituted by a highly reactive cyclopentadienyl functionality (Cp). By employing the reactive Cp-functionality as a diene, thiocarbonyl thio-capped poly(isobornyl acrylate) synthesized via RAFT polymerization (mediated by benzyl pyridine-2-yldithioformiate (BPDF)) was attached to the surface under ambient conditions by an HDA cycloaddition (reaction time: 15 h). The surface-modified cellulose samples were analyzed in-depth by X-ray photoelectron spectroscopy, scanning electron microscopy, elemental analysis, Fourier transform infrared (FT-IR) spectroscopy as well as Fourier transform infrared microscopy employing a focal plane array detector for imaging purposes. The analytical results provide strong evidence that the reaction of suitable dienophiles with Cp-functional cellulose proceeds under mild reaction conditions (T ≈ 20 °C) in an efficient fashion. In particular, the visualization of individual modified cellulose fibers via high-resolution FT-IR microscopy corroborates the homogeneous distribution of the polymer film on the cellulose fibers.

  1. Asymmetric 1,3-Dipolar Cycloadditions to 5-(R)-Menthyloxy-2(5H)-Furanone

    NARCIS (Netherlands)

    Rispens, Minze T.; Keller, Erik; Lange, Ben de; Zijlstra, Robert W.J.; Feringa, Bernard

    Various diazo compounds, nitrile oxides, nitrones and azomethine ylides were examined in 1,3-dipolar cycloadditions to enantiomerically pure 5-(R)-menthyloxy-2(5H)-furanone 1a. Pyrazoline 9 was obtained in 100% c.y. as a mixture of 2 diastereoisomers in ratios up to 72 : 28, whereas pyrazoline 16

  2. Tandem electrophilic cyclization-[3+2] cycloaddition-rearrangement reactions of 2-alkynylbenzaldoxime, DMAD, and Br2.

    Science.gov (United States)

    Ding, Qiuping; Wang, Zhiyong; Wu, Jie

    2009-01-16

    Tandem electrophilic cyclization-[3+2] cycloaddition-rearrangement reactions of 2-alkynylbenzaldoximes, DMAD, and bromine are described, which afford the unexpected isoquinoline-based azomethine ylides in good to excellent yields. The products could be further elaborated via palladium-catalyzed cross-coupling reactions to generate highly functionalized isoquinoline-based stable azomethine ylides.

  3. Selective Halogen-Lithium Exchange of 1,2-Dihaloarenes for Successive [2+4] Cycloadditions of Arynes and Isobenzofurans

    Directory of Open Access Journals (Sweden)

    Shohei Eda

    2015-10-01

    Full Text Available Successive [2+4] cycloadditions of arynes and isobenzofurans by site-selective halogen-lithium exchange of 1,2-dihaloarenes were developed, allowing the rapid construction of polycyclic compounds which serve as a useful synthetic intermediates for the preparation of various polyacene derivatives.

  4. Visible light-photocatalysed carbazole synthesis via a formal (4+2) cycloaddition of indole-derived bromides and alkynes.

    Science.gov (United States)

    Yuan, Zhi-Guang; Wang, Qiang; Zheng, Ang; Zhang, Kai; Lu, Liang-Qiu; Tang, Zilong; Xiao, Wen-Jing

    2016-04-14

    We successfully developed an unprecedented route to carbazole synthesis through a visible light-photocatalysed formal (4+2) cycloaddition of indole-derived bromides and alkynes. This novel protocol features extremely mild conditions, a broad substrate scope and high reaction efficiency.

  5. Microwave-Enhanced Organic Syntheses for the Undergraduate Laboratory: Diels-Alder Cycloaddition, Wittig Reaction, and Williamson Ether Synthesis

    Science.gov (United States)

    Baar, Marsha R.; Falcone, Danielle; Gordon, Christopher

    2010-01-01

    Microwave heating enhanced the rate of three reactions typically performed in our undergraduate organic chemistry laboratory: a Diels-Alder cycloaddition, a Wittig salt formation, and a Williamson ether synthesis. Ninety-minute refluxes were shortened to 10 min using a laboratory-grade microwave oven. In addition, yields improved for the Wittig…

  6. cycloaddition reactions

    Indian Academy of Sciences (India)

    Unknown

    Molecular Modeling Group, Organic Chemical Sciences, Indian Institute of Chemical Technology,. Hyderabad ... thus obtained are helpful to model the regioselectivity ... compromise to model Diels–Alder reactions involving ...... acceptance.

  7. An unprecedented chemospecific and stereoselective tandem nucleophilic addition/cycloaddition reaction of nucleophilic carbenes with ketenimines.

    Science.gov (United States)

    Cheng, Ying; Ma, Yang-Guang; Wang, Xiao-Rong; Mo, Jun-Ming

    2009-01-16

    The first study of the reaction between nucleophilic carbenes and ketenimines is reported. The interaction of thiazole and benzothiazole carbenes with ketenimines proceeded in a chemospecific and stereoselective manner to produce thiazole- and benzothiazole-spiro-pyrrole derivatives generally in good yields. The reaction was proposed to proceed via a tandem nucleophilic addition of carbene to the C=N bond of ketenimine followed by a stepwise [3+2] cycloaddition of the 1,3-dipolar intermediate with the C=C bond of ketenimine. This reaction provides a powerful protocol for the construction of novel polyfunctional thiazole-spiro-pyrrole or benzothiazole-spiro-pyrrole compounds that are not readily accessible by other methods.

  8. Azide-Alkyne Huisgen [3+2] Cycloaddition Using CuO Nanoparticles

    Directory of Open Access Journals (Sweden)

    Hyunjoon Song

    2012-11-01

    Full Text Available Recent developments in the synthesis of CuO nanoparticles (NPs and their application to the [3+2] cycloaddition of azides with terminal alkynes are reviewed. With respect to the importance of click chemistry, CuO hollow NPs, CuO hollow NPs on acetylene black, water-soluble double-hydrophilic block copolymer (DHBC nanoreactors and ZnO–CuO hybrid NPs were synthesized. Non-conventional energy sources such as microwaves and ultrasound were also applied to these click reactions, and good catalytic activity with high regioselectivity was observed. CuO hollow NPs on acetylene black can be recycled nine times without any loss of activity, and water-soluble DHBC nanoreactors have been developed for an environmentally friendly process.

  9. Relative Performance of Alkynes in Copper-Catalyzed Azide-Alkyne Cycloaddition

    Science.gov (United States)

    Kislukhin, Alexander A.; Hong, Vu P.; Breitenkamp, Kurt E.; Finn, M.G.

    2013-01-01

    Copper-catalyzed azide–alkyne cycloaddition (CuAAC) has found numerous applications in a variety of fields. We report here only modest differences in the reactivity of various classes of terminal alkynes under typical bioconjugative and preparative organic conditions. Propargyl compounds represent an excellent combination of azide reactivity, ease of installation, and cost. Electronically activated propiolamides are slightly more reactive, at the expense of increased propensity for Michael addition. Certain alkynes, including tertiary propargyl carbamates, are not suitable for bioconjugation due to copper-induced fragmentation. A fluorogenic probe based on such reactivity is available in one step from rhodamine 110 and can be useful for optimization of CuAAC conditions. PMID:23566039

  10. In Situ generation of difluoromethyl diazomethane for [3+2] cycloadditions with alkynes.

    Science.gov (United States)

    Mykhailiuk, Pavel K

    2015-05-26

    A novel approach to agrochemically important difluoromethyl-substituted pyrazoles has been developed based on the elusive reagent CF2 HCHN2 , which was synthesized (generated in situ) for the first time and employed in [3+2] cycloaddition reactions with alkynes. The reaction is extremely practical as it is a one-pot process, does not require a catalyst or the isolation of the potentially toxic and explosive gaseous intermediate, and proceeds in a common solvent, namely chloroform, in air. The reaction is also scalable and allows for the preparation of the target pyrazoles on gram scale. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Electronic effects of ruthenium-catalyzed [3+2]-cycloaddition of alkynes and azides

    KAUST Repository

    Hou, Duenren

    2010-11-01

    A combined experimental and theoretical study of ruthenium-catalyzed azide-alkyne cycloaddition (RuAAC) reactions is presented and various electronic analyses were conducted to provide a basis in understanding the observed regioselectivity of the 1,2,3-triazole products. Computational studies using density functional theory (DFT) and atoms in molecules quantum theory (AIM) further yield fresh details on the electronic factors that determine the regioselectivity in the RuAAC. It is found that the formation of 1,2,3-triazole products is irreversible and from the Hammett study, the pathway involving a vinyl cationic intermediate is ruled out. The electronic effect favors the formation of 5-electron-donating-group substituted-1,2,3-trizoles. © 2010 Elsevier Ltd. All rights reserved.

  12. Synthesis of chitosan-PEO hydrogels via mesylation and regioselective Cu(I)-catalyzed cycloaddition.

    Science.gov (United States)

    Tirino, Pasquale; Laurino, Rosaria; Maglio, Giovanni; Malinconico, Mario; d'Ayala, Giovanna Gomez; Laurienzo, Paola

    2014-11-04

    In this work, a well-defined hydrogel was developed by coupling chitosan with PEO through "click chemistry". Azide functionalities were introduced onto chitosan, through mesylation of C-6 hydroxyl groups, and reacted with a di-alkyne PEO by a regioselective Cu(I)-catalyzed cycloaddition. This synthetic approach allowed us to obtain a hydrogel with a controlled crosslinking degree. In fact, the extent of coupling is strictly dependent on the amount of azido groups on chitosan, which in turn can be easily modulated. The obtained hydrogel, with a crosslinking degree of around 90%, showed interesting swelling properties. With respect to chitosan hydrogels reported in literature, a considerably higher equilibrium uptake was reached (940%). The possibility to control the crosslinking degree of hydrogel and its capability to rapidly absorb high amounts of water make this material suitable for several applications, such as controlled drug release and wound healing. Copyright © 2014. Published by Elsevier Ltd.

  13. Solid-state polymerisation via [2+2] cycloaddition reaction involving coordination polymers.

    Science.gov (United States)

    Medishetty, Raghavender; Park, In-Hyeok; Lee, Shim Sung; Vittal, Jagadese J

    2016-03-14

    Highly crystalline metal ions containing organic polymers are potentially useful to manipulate the magnetic and optical properties to make advanced multifunctional materials. However, it is challenging to synthesise monocrystalline metal complexes of organic polymers and single-phase hybrid materials made up of both coordination and organic polymers by traditional solution crystallisation. This requires an entirely different approach in the solid-state by thermal or photo polymerisation of the ligands. Among the photochemical methods available, [2+2] cycloaddition reaction has been recently employed to generate cyclobutane based coordination polymers from the metal complexes. Cyclobutane polymers have also been integrated into coordination polymers in this way. Recent advancements in the construction of polymeric chains of cyclobutane rings through photo-dimerisation reaction in the monocrystalline solids containing metal complexes, coordination polymers and metal-organic framework structures are discussed here.

  14. Electronic effects of ruthenium-catalyzed [3+2]-cycloaddition of alkynes and azides

    KAUST Repository

    Hou, Duenren; Kuan, Tingchun; Li, YuKai; Lee, Richmond; Huang, Kuo-Wei

    2010-01-01

    A combined experimental and theoretical study of ruthenium-catalyzed azide-alkyne cycloaddition (RuAAC) reactions is presented and various electronic analyses were conducted to provide a basis in understanding the observed regioselectivity of the 1,2,3-triazole products. Computational studies using density functional theory (DFT) and atoms in molecules quantum theory (AIM) further yield fresh details on the electronic factors that determine the regioselectivity in the RuAAC. It is found that the formation of 1,2,3-triazole products is irreversible and from the Hammett study, the pathway involving a vinyl cationic intermediate is ruled out. The electronic effect favors the formation of 5-electron-donating-group substituted-1,2,3-trizoles. © 2010 Elsevier Ltd. All rights reserved.

  15. Chain-growth cycloaddition polymerization via a catalytic alkyne [2 + 2 + 2] cyclotrimerization reaction and its application to one-shot spontaneous block copolymerization.

    Science.gov (United States)

    Sugiyama, Yu-ki; Kato, Rei; Sakurada, Tetsuya; Okamoto, Sentaro

    2011-06-29

    A cobalt-catalyzed alkyne [2 + 2 + 2] cycloaddition reaction has been applied to polymerizations yielding linear polymers via selective cross-cyclotrimerization of yne-diyne monomers, which occurs in a chain-growth manner. Additionally, through control of the alkyne reactivity of the two monomers, this method was efficiently applied to the spontaneous block copolymerization of their mixture. Here we present the proposed mechanism of the catalyst transfer process of this cycloaddition polymerization.

  16. A new approach to produce amino-carbon nanotubes as plasmid transfection vector by [2 + 1] cycloaddition of nitrenes

    International Nuclear Information System (INIS)

    Jiang Yongjian; Jin Chen; Yang Feng; Yu Xianjun; Wang Guojian; Cheng Si; Di, Yang; Li, Ji; Fu, Deliang; N, Quanxing

    2011-01-01

    Amino-carbon nanotubes (amino-CNTs) can conjugate with the DNA by electrostatic interactions and shuttle the DNA to the cell cytoplasm or even the nucleus. Here we report a new approach to produce amino-CNTs by cycloaddition of nitrenes. Fourier transform infrared spectroscopy was used to verify the success of the functionalization, and the functionalization degree was calculated by thermal gravity analysis. Transmission electron microscope (TEM) was used to observe the solubility of the CNTs and the interactions of the amino-CNTs with the plasmids. Cell ultrathin sections were made and observed under the TEM to confirm the amino-CNTs enter the cells. Transfection experiments ultimately verify the amino-CNTs produced through cycloadditions of nitrenes can serve as plasmid vector.

  17. Copper-catalyzed azide–alkyne cycloaddition (CuAAC) and beyond: new reactivity of copper(i) acetylides†

    OpenAIRE

    Hein, Jason E.; Fokin, Valery V.

    2010-01-01

    Copper-catalyzed azide–alkyne cycloaddition (CuAAC) is a widely utilized, reliable, and straightforward way for making covalent connections between building blocks containing various functional groups. It has been used in organic synthesis, medicinal chemistry, surface and polymer chemistry, and bioconjugation applications. Despite the apparent simplicity of the reaction, its mechanism involves multiple reversible steps involving coordination complexes of copper(i) acetylides of varying nucle...

  18. Recent Advances in Recoverable Systems for the Copper-Catalyzed Azide-Alkyne Cycloaddition Reaction (CuAAC

    Directory of Open Access Journals (Sweden)

    Alessandro Mandoli

    2016-09-01

    Full Text Available The explosively-growing applications of the Cu-catalyzed Huisgen 1,3-dipolar cycloaddition reaction between organic azides and alkynes (CuAAC have stimulated an impressive number of reports, in the last years, focusing on recoverable variants of the homogeneous or quasi-homogeneous catalysts. Recent advances in the field are reviewed, with particular emphasis on systems immobilized onto polymeric organic or inorganic supports.

  19. Growth of Fullerene Fragments Using the Diels-Alder Cycloaddition Reaction: First Step towards a C60 Synthesis by Dimerization

    Directory of Open Access Journals (Sweden)

    Julio A. Alonso

    2013-02-01

    Full Text Available Density Functional Theory has been used to model the Diels-Alder reactions of the fullerene fragments triindenetriphenilene and pentacyclopentacorannulene with ethylene and 1,3-butadiene. The purpose is to prove the feasibility of using Diels-Alder cycloaddition reactions to grow fullerene fragments step by step, and to dimerize fullerene fragments, as a way to obtain C60. The dienophile character of the fullerene fragments is dominant, and the reaction of butadiene with pentacyclopentacorannulene is favored.

  20. Nucleophile-directed selectivity towards linear carbonates in the niobium pentaethoxide-catalysed cycloaddition of CO2 and propylene oxide

    KAUST Repository

    Dutta, Barnali

    2014-01-01

    Homoleptic Nb-complexes combined with selected organic nucleophiles generate very active catalytic systems for the cycloaddition of propylene oxide and CO2 under ambient conditions. An unprecedented reaction pathway towards an acyclic organic carbonate is observed when extending the study to [Nb(OEt)5] in combination with 4-dimethylamino-pyridine (DMAP) or tetra-n-butylammonium bromide (TBAB). Mechanistic insights of the reaction are provided based on experimental and spectroscopic evidences. This journal is © the Partner Organisations 2014.

  1. Synthesis of 2-azaspiro[4.4]nonan-1-ones via phosphine-catalysed [3+2]-cycloadditions

    Energy Technology Data Exchange (ETDEWEB)

    Yong, Sarah R.; Williams, Morwenna C.; Pyne, Stephen G.; Ung, Alison T.; Skelton, Brian W.; White, Allan H.; Turner, Peter (UWA); (Wollongong); (Sydney)

    2008-10-03

    The phosphine-catalyzed [3+2]-cycloaddition of the 2-methylene {gamma}-lactams 4 and 5 and the acrylate 6 with the ylides derived from the ethyl ester, the amide or the chiral camphor sultam derivative of 2-butynoic acid (7a-c) give directly, or indirectly after reductive cyclization, spiro-heterocyclic products. The acid 32 underwent Curtius rearrangement and then acid hydrolysis to give two novel spiro-cyclic ketones, 41 and 42.

  2. Efficient assembly of polysubstituted pyrroles via a (3 + 2) cycloaddition/skeletal rearrangement/redox isomerization cascade reaction.

    Science.gov (United States)

    Yu, Yuanyuan; Wang, Chunyu; He, Xinze; Yao, Xiaotong; Zu, Liansuo

    2014-07-03

    An unprecedented cascade strategy, used in conjunction with a redox isomerization, for the synthesis of 3-allyl pyrroles is reported. In a single step, readily accessible simple starting materials are transformed into highly substituted pyrroles with high efficiency. The products obtained contain allyl substituents, which can be readily elaborated to other useful functional groups. The reaction proceeds through an unusual (3 + 2) cycloaddition/skeletal rearrangement/redox isomerization pathway.

  3. Decreasing Distortion Energies without Strain: Diazo-Selective 1,3-Dipolar Cycloadditions.

    Science.gov (United States)

    Gold, Brian; Aronoff, Matthew R; Raines, Ronald T

    2016-07-15

    The diazo group has attributes that complement those of the azido group for applications in chemical biology. Here, we use computational analyses to provide insights into the chemoselectivity of the diazo group in 1,3-dipolar cycloadditions. Dipole distortion energies are responsible for ∼80% of the overall energetic barrier for these reactions. Here, we show that diazo compounds, unlike azides, provide an opportunity to decrease that barrier substantially without introducing strain into the dipolarophile. The ensuing rate enhancement is due to the greater nucleophilic character of a diazo group compared to that of an azido group, which can accommodate decreased distortion energies without predistortion. The tuning of distortion energies with substituents in a diazo compound or dipolarophile can enhance reactivity and selectivity in a predictable manner. Notably, these advantages of diazo groups are amplified in water. Our findings provide a theoretical framework that can guide the design and application of both diazo compounds and azides in "orthogonal" contexts, especially for biological investigations.

  4. Improved metal-adhesive polymers from copper(I)-catalyzed azide-alkyne cycloaddition.

    Science.gov (United States)

    Accurso, Adrian A; Delaney, Mac; O'Brien, Jeff; Kim, Hyonny; Iovine, Peter M; Díaz Díaz, David; Finn, M G

    2014-08-18

    Electrically conductive adhesive polymers offer many potential advantages relative to Sn-Pb solders, including reduced toxicity, low cost, low processing temperatures, and the ability to make application-specific formulations. Polymers generated from the copper(I)-catalyzed cycloaddition (CuAAC) reaction between multivalent azides and alkynes have previously been identified as strong metal-binding adhesives. Herein we demonstrate that the performance of these materials can be remarkably improved by the incorporation of a flexibility-inducing difunctionalized component and a tertiary amine additive in optimized concentrations. The best formulations were identified by means of rapid adhesion testing of a library of potential candidates by using a custom-built instrument and validated in an American Society for Testing and Materials (ASTM)-standard lap-shear test. Characteristic phase transitions were identified by differential scanning calorimetry (DSC) for adhesives with and without the additives as a function of curing temperature. The incorporation of flexible components was found to more than double the strength of the adhesive. Moreover, the adhesive was made electrically conductive by the inclusion of 20 wt% silver-coated copper flakes and further improved in this regard by the incorporation of multiwalled carbon nanotubes in the formulation. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. The cobalt-mediated [2+2+2]cycloaddition of thiophenes and benzofurans to alkynes

    Energy Technology Data Exchange (ETDEWEB)

    Malaska, M.J.

    1991-01-01

    The cobalt-mediated [2+2+2]cycloaddition of thiophenes and benzofurans to alkynes was investigated. The cocyclization of 2-propynyloxymethylthiophenes provided two types of cyclohexadiene complexes. It was found that one of these complexes could be converted to the other by a thermal rearrangement. This novel transformation was investigated by deuterium-labelling and kinetic studies, and a mechanism was proposed. The complexes could be oxidatively demetallated to provide the liberated organic framework. Further reorganization of these dienes were observed during the decomplexation process and in the presence of CpCo(C[sub 2]H[sub 4])[sub 2]. In this manner several new heterocyclic ring systems could be constructed from 2-substituted thiophenes. Following the success of the thiophene cyclizations, the cocyclization of the benzofuran nucleus was examined. Reagents and conditions were developed that provide an efficient synthesis of alkynols from carboxylic acids; other functional group interconversions of the alkynols were briefly studied. The synthesis and cyclization of 1-[7-methoxy-4-benzofuranyl]-3-butyn-2-ol produced a cobalt complex containing the A,B,C, and D rings of the morphine skeleton. A synthetic advantage of this methodology would be the ease of substitution at pharmaco-logically relevant C-6 and C-7 positions of the morphine framework. Synthetic routes using a cobalt cyclization strategy were proposed.

  6. Structural Determinants of Alkyne Reactivity in Copper-Catalyzed Azide-Alkyne Cycloadditions

    Directory of Open Access Journals (Sweden)

    Xiaoguang Zhang

    2016-12-01

    Full Text Available This work represents our initial effort in identifying azide/alkyne pairs for optimal reactivity in copper-catalyzed azide-alkyne cycloaddition (CuAAC reactions. In previous works, we have identified chelating azides, in particular 2-picolyl azide, as “privileged” azide substrates with high CuAAC reactivity. In the current work, two types of alkynes are shown to undergo rapid CuAAC reactions under both copper(II- (via an induction period and copper(I-catalyzed conditions. The first type of the alkynes bears relatively acidic ethynyl C-H bonds, while the second type contains an N-(triazolylmethylpropargylic moiety that produces a self-accelerating effect. The rankings of reactivity under both copper(II- and copper(I-catalyzed conditions are provided. The observations on how other reaction parameters such as accelerating ligand, reducing agent, or identity of azide alter the relative reactivity of alkynes are described and, to the best of our ability, explained.

  7. Oxidative removal of quinclorac by permanganate through a rate-limiting [3 + 2] cycloaddition reaction.

    Science.gov (United States)

    Song, Dean; Cheng, Hanyang; Jiang, Xiaohua; Sun, Huiqing; Kong, Fanyu; Liang, Rongning; Qiang, Zhimin; Liu, Huijuan; Qu, Jiuhui

    2018-04-05

    Quinclorac, a widely used herbicide in agriculture, has been recognized as an emerging environmental pollutant owing to its long persistence and potential risk to humans. However, no related information is available on the degradation of quinclorac by employing oxidants. Herein, the reactivity of quinclorac with permanganate was systematically investigated in water by combining experimental and computational approaches. The reaction followed overall second-order kinetics pointing to a bimolecular rate-limiting step. The second-order rate constant was found to be 3.47 × 10-3 M-1 s-1 at 25 °C, which was independent of pH over the range from 5 to 9 and was dependent on temperature over the range from 19 to 35 °C. The initial product was identified by UPLC-Q-TOF-MS to be mono-hydroxylated quinclorac, which was more susceptible to further oxidation. The result could be supported by the complete simulation of the reaction process in DFT calculations, indicating the [3 + 2] cycloaddition oxidation of the benzene ring in the rate-limiting step. The plausible mechanism was then proposed, accompanied by the analysis of the HOMO indicating the hydroxylation position and of the ESP suggesting a more electron-rich moiety. Considering the high effectiveness and low toxicity, permanganate oxidation was considered to be a very promising technique for removing quinclorac from aquatic environments.

  8. Highly Regio- and Stereoselective Diels-Alder Cycloadditions via Two-Step and Multicomponent Reactions Promoted by Infrared Irradiation under Solvent-Free Conditions

    Science.gov (United States)

    Flores-Conde, Maria Ines; Reyes, Leonor; Herrera, Rafael; Rios, Hulme; Vazquez, Miguel A.; Miranda, Rene; Tamariz, Joaquin; Delgado, Francisco

    2012-01-01

    Infrared irradiation promoted the Diels-Alder cycloadditions of exo-2-oxazolidinone dienes 1–3 with the Knoevenagel adducts 4–6, as dienophiles, leading to the synthesis of new 3,5-diphenyltetrahydrobenzo[d]oxazol-2-one derivatives (7, 9, 11 and 13–17), under solvent-free conditions. These cycloadditions were performed with good regio- and stereoselectivity, favoring the para-endo cycloadducts. We also evaluated the one-pot three-component reaction of active methylene compounds 20, benzaldehydes 21 and exo-2-oxazolidinone diene 2 under the same reaction conditions. A cascade Knoevenagel condensation/Diels-Alder cycloaddition reaction was observed, resulting in the final adducts 13–16 in similar yields. These procedures are environmentally benign, because no solvent and no catalyst were employed in these processes. The regioselectivity of these reactions was rationalized by Frontier Molecular Orbital (FMO) calculations. PMID:22489113

  9. Highly Regio- and Stereoselective Diels-Alder Cycloadditions via Two-Step and Multicomponent Reactions Promoted by Infrared Irradiation under Solvent-Free Conditions

    Directory of Open Access Journals (Sweden)

    Francisco Delgado

    2012-02-01

    Full Text Available Infrared irradiation promoted the Diels-Alder cycloadditions of exo-2-oxazolidinone dienes 1–3 with the Knoevenagel adducts 4–6, as dienophiles, leading to the synthesis of new 3,5-diphenyltetrahydrobenzo[d]oxazol-2-one derivatives (7, 9, 11 and 13–17, under solvent-free conditions. These cycloadditions were performed with good regio- and stereoselectivity, favoring the para-endo cycloadducts. We also evaluated the one-pot three-component reaction of active methylene compounds 20, benzaldehydes 21 and exo-2-oxazolidinone diene 2 under the same reaction conditions. A cascade Knoevenagel condensation/Diels-Alder cycloaddition reaction was observed, resulting in the final adducts 13–16 in similar yields. These procedures are environmentally benign, because no solvent and no catalyst were employed in these processes. The regioselectivity of these reactions was rationalized by Frontier Molecular Orbital (FMO calculations.

  10. Intramolecular Parallel [4+3] Cycloadditions of Cyclopropane 1,1-Diesters with [3]Dendralenes: Efficient Construction of [5.3.0]Decane and Corresponding Polycyclic Skeletons.

    Science.gov (United States)

    Zhang, Chi; Tian, Jun; Ren, Jun; Wang, Zhongwen

    2017-01-26

    Aiming to develop efficient and general strategies for construction of complex and diverse polycyclic skeletons, we have successfully developed [4+3]IMPC (intramolecular parallel cycloaddition) of cyclopropane 1,1-diesters with [3]dendralenes. With a combination of the [4+3]IMPC and subsequent [4+n] cycloadditions, trans-[5.3.0]decane skeleton and its corresponding structurally complex and diverse polycyclic variants could be constructed efficiently. This novel [4+3] cycloaddition reaction mode of donor-acceptor cyclopropanes proceeds as a result of the ring-strain relief of a trans-[3.3.0]octane. We strongly believe that the developed methods will demonstrate potential applications in natural products synthesis and drug discovery. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. A DFT study on the mechanisms for the cycloaddition reactions between 1-aza-2-azoniaallene cations and acetylenes.

    Science.gov (United States)

    Wang, Jing-mei; Li, Zhi-ming; Wang, Quan-rui; Tao, Feng-gang

    2013-01-01

    The mechanisms of cycloaddition reactions between 1-aza-2-azoniaallene cations 1 and acetylenes 2 have been investigated using the global electrophilicity and nucleophilicity of the corresponding reactants as global reactivity indexes defined within the conceptual density functional theory. The reactivity and regioselectivity of these reactions were predicted by analysis of the energies, geometries, and electronic nature of the transition state structures. The theoretical results revealed that the reaction features a tandem process: an ionic 1,3-dipolar cycloaddition to produce the cycloadducts 3 H-pyrazolium salts 3 followed by a [1,2]-shift affording the thermodynamically more stable adducts 4 or 5. The mechanism of the cycloaddition reactions can be described as an asynchronous concerted pathway with reverse electron demand. The model reaction has also been investigated at the QCISD/6-31++G(d,p) and CCSD(T)/6-31++G(d,p)//B3LYP/6-31++G(d,p) levels as well as by the DFT. The polarizable continuum model, at the B3LYP/6-31++G(d,p) level of theory, was used to study solvent effects on all the studied reactions. In solvent dichloromethane, all the initial cycloadducts 3 were obtained via direct ionic process as the result of the solvent effect. The consecutive [1,2]-shift reaction, in which intermediates 3 are rearranged to the five-membered heterocycles 4/5, is proved to be a kinetically controlled reaction, and the regioselectivity can be modulated by varying the migrant. The LOL function and RDG function based on localized electron analysis were used to analysis the covalent bond and noncovalent interactions in order to unravel the mechanism of the title reactions.

  12. Advances in heterocycle synthesis via [3+m]-cycloaddition reactions involving an azaoxyallyl cation as the key intermediate.

    Science.gov (United States)

    Xuan, Jun; Cao, Xia; Cheng, Xiao

    2018-05-17

    Heterocyclic compounds are widely found in many natural isolates and medicinally relevant compounds, as well as some fine chemicals. The development of general and efficient methods for the construction of heterocyclic compounds is one of the most important tasks in synthetic organic chemistry. Along these lines, [3+m]-cycloaddition reactions involving in situ generated azaoxyallyl cations as the 3-atom units have emerged as a powerful method for the synthesis of nitrogen-containing heterocycles. In this feature article, we highlight recent advances in this rapidly growing area, mainly focusing on the reaction design as well as the reaction mechanism.

  13. Regio- and Stereoselective Cascades via Aldol Condensation and 1,3-Dipolar Cycloaddition for Construction of Functional Pyrrolizidine Derivatives.

    Science.gov (United States)

    Mao, Zhuo-Ya; Liu, Yi-Wen; Han, Pan; Dong, Han-Qing; Si, Chang-Mei; Wei, Bang-Guo; Lin, Guo-Qiang

    2018-02-16

    An efficient and step-economical approach to access functionalized pyrrolizidine derivatives by a one-pot tandem sequence, including an aldol condensation and subsequent 1,3-dipolar cycloaddition process, has been developed, starting from acetone, aldehyde, and proline. A number of substituted aromatic aldehydes were amenable to this transformation, and the desired products, racemic 7a-7w and chiral 9a-9m, were obtained with excellent regioselectivities and outstanding diastereoselectivities. Moreover, in situ NMR studies revealed MgSO 4 could effectively promote the aldol condensation pathway in this tandem process.

  14. Sequential One-Pot Ruthenium-Catalyzed Azide−Alkyne Cycloaddition from Primary Alkyl Halides and Sodium Azide

    KAUST Repository

    Johansson, Johan R.

    2011-04-01

    An experimentally simple sequential one-pot RuAAC reaction, affording 1,5-disubstituted 1H-1,2,3-triazoles in good to excellent yields starting from an alkyl halide, sodium azide, and an alkyne, is reported. The organic azide is formed in situ by treating the primary alkyl halide with sodium azide in DMA under microwave heating. Subsequent addition of [RuClCp*(PPh 3) 2] and the alkyne yielded the desired cycloaddition product after further microwave irradiation. © 2011 American Chemical Society.

  15. Synthesis of Carbocyclic Hydantocidins via Regioselective and Diastereoselective Phosphine-Catalyzed [3 + 2]-Cycloadditions to 5-Methylenehydantoins

    Energy Technology Data Exchange (ETDEWEB)

    Pham, Tien Q.; Pyne, Stephen G.; Skelton, Brian W.; White, Allan H. (UWA); (Wollongong)

    2010-07-20

    The phosphine-catalyzed [3 + 2]-cycloaddition of 5-methylenehydantoins 4 with the ylides 5, derived from addition of tributylphosphine to the 2-butynoic acid derivatives, 6a-d, gives spiro-heterocyclic products. The camphor sultam derivative 6b gives optically active products. Noteable was that the ylides derived from ethyl 2-butynoate and the 3-(2-butynoyl)-1,3-oxazolidin-2-one derivatives 6c and 6d gave spiro-heterocyclic products with reverse regioselectivities. The N,N-dibenzylprotected cycloadduct has been converted to carbocyclic hydantocidin and 6,7-diepi-carbocyclic hydantocidin.

  16. CO2 Conversion: The Potential of Porous–Organic Polymers (POPs) for the cycloaddition of CO2 and epoxides

    KAUST Repository

    Alkordi, Mohamed Helmi

    2016-03-30

    Novel porous organic polymers (POPs) have been synthesized using functionalized Cr and Co-salen complexes as molecular building blocks. The integration of metalosalen catalysts into the porous polymers backbone permits the successful utilization of the materials as solid-state catalysts for CO2-epoxide cycloadditions reactions with excellent catalytic performance under mild conditions of temperature and pressure. The catalyst proved to be fully recyclable and robust thus showing the potential of POPs as smart functional materials for the heterogenization of key catalytic elements.

  17. The divergent synthesis of nitrogen heterocycles by rhodium(II)-catalyzed cycloadditions of 1-sulfonyl 1,2,3-triazoles with 1,3-dienes.

    Science.gov (United States)

    Shang, Hai; Wang, Yuanhao; Tian, Yu; Feng, Juan; Tang, Yefeng

    2014-05-26

    The first rhodium(II)-catalyzed aza-[4+3] cycloadditions of 1-sulfonyl 1,2,3-triazoles with 1,3-dienes have been developed, and enable the efficient synthesis of highly functionalized 2,5-dihydroazepines from readily available precursors. In some cases, the reaction pathway could divert to formal aza-[3+2] cycloadditions, thus leading to 2,3-dihydropyrroles. In this context, the titled reaction represents a capable tool for the divergent synthesis of two types of synthetically valuable aza-heterocycles from common rhodium(II) iminocarbene intermediates. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Site-Specific Antibody Labeling by Covalent Photoconjugation of Z Domains Functionalized for Alkyne-Azide Cycloaddition Reactions.

    Science.gov (United States)

    Perols, Anna; Arcos Famme, Melina; Eriksson Karlström, Amelie

    2015-11-01

    Antibodies are extensively used in research, diagnostics, and therapy, and for many applications the antibodies need to be labeled. Labeling is typically performed by using amine-reactive probes that target surface-exposed lysine residues, resulting in heterogeneously labeled antibodies. An alternative labeling strategy is based on the immunoglobulin G (IgG)-binding protein domain Z, which binds to the Fc region of IgG. Introducing the photoactivable amino acid benzoylphenylalanine (BPA) into the Z domain makes it possible for a covalent bond to be be formed between the Z domain and the antibody on UV irradiation, to produce a site-specifically labeled product. Z32 BPA was synthesized by solid-phase peptide synthesis and further functionalized to give alkyne-Z32 BPA and azide-Z32 BPA for Cu(I) -catalyzed cycloaddition, as well as DBCO-Z32 BPA for Cu-free strain-promoted cycloaddition. The Z32 BPA variants were conjugated to the human IgG1 antibody trastuzumab and site-specifically labeled with biotin or fluorescein. The fluorescently labeled trastuzumab showed specific staining of the membranes of HER2-expressing cells in immunofluorescence microscopy. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Activation-Strain Analysis Reveals Unexpected Origin of Fast Reactivity in Heteroaromatic Azadiene Inverse-Electron-Demand Diels-Alder Cycloadditions

    NARCIS (Netherlands)

    Talbot, Austin; Devarajan, Deepa; Gustafson, Samantha J.; Fernandez, Israel; Bickelhaupt, F. Matthias; Ess, Daniel H.

    2014-01-01

    Heteroaromatic azadienes, especially 1,2,4,5-tetrazines, are extremely reactive partners with alkenes in inverse-electron-demand Diels–Alder reactions. Azadiene cycloaddition reactions are used to construct heterocycles in synthesis and are popular as bioorthogonal reactions. The origin of fast

  20. Synthesis, molecular docking and biological evaluation as HDAC inhibitors of cyclopeptide mimetics by a tandem three-component reaction and intramolecular [3+2] cycloaddition.

    Science.gov (United States)

    Pirali, Tracey; Faccio, Valeria; Mossetti, Riccardo; Grolla, Ambra A; Di Micco, Simone; Bifulco, Giuseppe; Genazzani, Armando A; Tron, Gian Cesare

    2010-02-01

    Novel macrocyclic peptide mimetics have been synthesized by exploiting a three-component reaction and an azide-alkyne [3 + 2] cycloaddition. The prepared compounds were screened as HDAC inhibitors allowing us to identify a new compound with promising biological activity. In order to rationalize the biological results, computational studies have also been performed.

  1. Copper-Catalyzed Sulfonyl Azide-Alkyne Cycloaddition Reactions: Simultaneous Generation and Trapping of Copper-Triazoles and -Ketenimines for the Synthesis of Triazolopyrimidines.

    Science.gov (United States)

    Nallagangula, Madhu; Namitharan, Kayambu

    2017-07-07

    First simultaneous generation and utilization of both copper-triazole and -ketenimine intermediates in copper-catalyzed sulfonyl azide-alkyne cycloaddition reactions is achieved for the one-pot synthesis of triazolopyrimidines via a novel copper-catalyzed multicomponent cascade of sulfonyl azides, alkynes, and azirines. Significantly, the reaction proceeds under very mild conditions in good yields.

  2. Adhesion of Photon-Driven Molecular Motors to Surfaces via 1,3-Dipolar Cycloadditions : Effect of Interfacial Interactions on Molecular Motion

    NARCIS (Netherlands)

    Carroll, Gregory T.; London, Gabor; Fernández Landaluce, Tatiana; Rudolf, Petra; Feringa, Ben L.

    We report the attachment of altitudinal light-driven molecular motors to surfaces using 1,3-dipolar cycloaddition reactions. Molecular motors were designed containing azide or alkyne groups for attachment to alkyne- or azide-modified surfaces. Surface attachment was characterized by UV-vis, IR, XPS,

  3. Traceless Azido Linker for the Solid-Phase Synthesis of NH-1,2,3-Triazoles via Cu-Catalyzed Azide-Alkyne Cycloaddition Reactions

    DEFF Research Database (Denmark)

    Cohrt, Anders Emil; Jensen, Jakob Feldthusen; Nielsen, Thomas Eiland

    2010-01-01

    A broadly useful acid-labile traceless azido linker for the solid-phase synthesis of NH-1,2,3-triazoles is presented. A variety of alkynes were efficiently immobilized on a range of polymeric supports by Cu(I)-mediated azide-alkyne cycloadditions. Supported triazoles showed excellent compatibility...

  4. Visible-light photoredox catalyzed synthesis of pyrroloisoquinolines via organocatalytic oxidation/[3 + 2] cycloaddition/oxidative aromatization reaction cascade with Rose Bengal

    Directory of Open Access Journals (Sweden)

    Carlos Vila

    2014-05-01

    Full Text Available Pyrrolo[2,1-a]isoquinoline alkaloids have been prepared via a visible light photoredox catalyzed oxidation/[3 + 2] cycloaddition/oxidative aromatization cascade using Rose Bengal as an organo-photocatalyst. A variety of pyrroloisoquinolines have been obtained in good yields under mild and metal-free reaction conditions.

  5. Teaching Experiment to Elucidate a Cation-Pi Effect in an Alkyne Cycloaddition Reaction and Illustrate Hypothesis-Driven Design of Experiments

    Science.gov (United States)

    St.Germain, Elijah J.; Horowitz, Andrew S.; Rucco, Dominic; Rezler, Evonne M.; Lepore, Salvatore D.

    2017-01-01

    An organic chemistry experiment is described that is based on recent research to elucidate a novel cation-pi interaction between tetraalkammonium cations and propargyl hydrazines. This nonbonded interaction is a key component of the mechanism of ammonium-catalyzed intramolecular cycloaddition of nitrogen to the terminal carbon of a C-C triple bond…

  6. Mono and dinuclear arene ruthenium(II) triazoles by 1,3-dipolar cycloadditions to a coordinated azide in ruthenium(II) compounds

    Digital Repository Service at National Institute of Oceanography (India)

    Singh, K.S.; Svitlyk, V.; Mozharivskyj, Y.

    = Me, 3 or Et, 4). In contrast, a similar 1,3-dipolar cycloaddition reaction of (((Eta sup(6)-C sub(6)Me sub(6))Ru(L sub(2))N sub(3))) (2) (where; L sub(2) = tropolone) with acetylene yielded the monomeric triazole compound ((Eta sup(6)-C sub(6)Me sub(6...

  7. Asymmetric Domino Aza-Michael Addition/[3+2] Cycloaddition Reactions as a Versatile Approach to alpha,beta,gamma,-Triamino Acid Derivatives

    Czech Academy of Sciences Publication Activity Database

    Kapras, Vojtěch; Pohl, Radek; Císařová, I.; Jahn, Ullrich

    2014-01-01

    Roč. 16, č. 4 (2014), s. 1088-1091 ISSN 1523-7060 Institutional support: RVO:61388963 Keywords : 1,3-dipolar cycloaddition * lithium amides * aza-Michael addition * amino acids * pyrazoles Subject RIV: CC - Organic Chemistry Impact factor: 6.364, year: 2014

  8. Total protein

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/article/003483.htm Total protein To use the sharing features on this page, please enable JavaScript. The total protein test measures the total amount of two classes ...

  9. A 11-Steps Total Synthesis of Magellanine through a Gold(I)-Catalyzed Dehydro Diels-Alder Reaction.

    Science.gov (United States)

    McGee, Philippe; Bétournay, Geneviève; Barabé, Francis; Barriault, Louis

    2017-05-22

    We have developed an innovative strategy for the formation of angular carbocycles via a gold(I)-catalyzed dehydro Diels-Alder reaction. This transformation provides rapid access to a variety of complex angular cores in excellent diastereoselectivities and high yields. The usefulness of this Au I -catalyzed cycloaddition was further demonstrated by accomplishing a 11-steps total synthesis of (±)-magellanine. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Synthesis with Perfect Atom Economy: Generation of Furan Derivatives by 1,3-Dipolar Cycloaddition of Acetylenedicarboxylates at Cyclooctynes

    Directory of Open Access Journals (Sweden)

    Klaus Banert

    2014-09-01

    Full Text Available Cyclooctyne and cycloocten-5-yne undergo, at room temperature, a 1,3-dipolar cycloaddition with dialkyl acetylenedicarboxylates 1a,b to generate furan-derived short-lived intermediates 2, which can be trapped by two additional equivalents of 1a,b or alternatively by methanol, phenol, water or aldehydes to yield polycyclic products 3b–d, orthoesters 4a–c, ketones 5 or epoxides 6a,b, respectively. Treatment of bis(trimethylsilyl acetylenedicarboxylate (1c with cyclooctyne leads to the ketone 7 via retro-Brook rearrangement of the dipolar intermediate 2c. In all cases, the products are formed with perfect atom economy.

  11. Diels-Alder cyclo-addition as an efficient tool for linking π-donors onto fullerene C60

    International Nuclear Information System (INIS)

    Hudhomme, P.

    2006-01-01

    Diels-Alder reaction of endo-cyclic, acyclic 1,3-dienes or (hetero) o-quinodimethanes with the dienophilic fullerene C 60 is presented as an efficient tool for linking electro-active units giving rise to systems where both the donor and C 60 partners take up well defined volumes and orientations with respect to one another. While porphyrin is the most frequently used electron donor in artificial photosynthetic models, C 60 -based tetrathiafulvalene (TTF) or p-conjugated oligomer adducts remain interesting candidates for the preparation of photovoltaic devices. In this account, we focus on the use of the Diels-Alder cyclo-addition and its use in the synthesis of TTF-C 60 dyads, (TTF) n -C 60 polyads and C 60 -TTF-C 60 dumbbells as part of ongoing research into materials which display efficient photo-induced electron transfer. (author)

  12. Epoxy-Functionalized Porous Organic Polymers via the Diels-Alder Cycloaddition Reaction for Atmospheric Water Capture.

    Science.gov (United States)

    Byun, Yearin; Coskun, Ali

    2018-03-12

    The synthesis of highly microporous, epoxy-functionalized porous organic polymers (ep-POPs) by a one-pot, catalyst-free Diels-Alder cycloaddition polymerization is reported. The high oxygen content of ep-POPs offer efficient hydrogen-bonding sites for water molecules, thus leading to high water-uptake capacities up to 39.2-42.4 wt % under a wide temperature range of 5-45 °C, which covers the span of climatic conditions and manufacturing applications in which such materials might be used. Importantly, ep-POPs demonstrated regeneration temperatures as low as 55 °C, as well as excellent water stability, recyclability, and high specific surface areas up to 852 m 2  g -1 . © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. 7-Chloroquinolinotriazoles: synthesis by the azide-alkyne cycloaddition click chemistry, antimalarial activity, cytotoxicity and SAR studies.

    Science.gov (United States)

    Pereira, Guilherme R; Brandão, Geraldo Célio; Arantes, Lucas M; de Oliveira, Háliton A; de Paula, Renata Cristina; do Nascimento, Maria Fernanda A; dos Santos, Fábio M; da Rocha, Ramon K; Lopes, Júlio César D; de Oliveira, Alaíde Braga

    2014-02-12

    Twenty-seven 7-chloroquinolinotriazole derivatives with different substituents in the triazole moiety were synthesized via copper-catalyzed cycloaddition (CuAAC) click chemistry between 4-azido-7-chloroquinoline and several alkynes. All the synthetic compounds were evaluated for their in vitro activity against Plasmodium falciparum (W2) and cytotoxicity to Hep G2A16 cells. All the products disclosed low cytotoxicity (CC50 > 100 μM) and five of them have shown moderate antimalarial activity (IC50 from 9.6 to 40.9 μM). As chloroquine analogs it was expected that these compounds might inhibit the heme polymerization and SAR studies were performed aiming to explain their antimalarial profile. New structural variations can be designed on the basis of the results obtained. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

  14. A Straightforward Route to Enantiopure Pyrrolizidines and Indolizidines by Cycloaddition to Pyrroline N-Oxides Derived from the Chiral Pool

    Directory of Open Access Journals (Sweden)

    Alberto Brandi

    1998-12-01

    Full Text Available Enantiomerically pure, five membered cyclic nitrones, easily obtained in large amounts from protected hydroxyacids and aminoacids such as D- and L-tartaric, L-malic, and L-aspartic acids, give cycloaddition reactions with a good diastereocontrol. The adducts of L-malic and L-aspartic acids derived from addition of nitrones to dimethyl maleate and g-crotonolactone were easily converted into enantiopure pyrrolizidinones, which can be transformed into polyhydroxypyrrolidines or polyhydroxypyrrolizidines, both interesting compounds as potential glycosidase inhibitors. The method is suitable for natural products synthesis as exemplified by a straightforward and convenient access to the pyrrolizidine alkaloid necine base (–-hastanecine, as well as to indolizidine alkaloids, i.e. (+- lentiginosine.

  15. Total algorithms

    NARCIS (Netherlands)

    Tel, G.

    We define the notion of total algorithms for networks of processes. A total algorithm enforces that a "decision" is taken by a subset of the processes, and that participation of all processes is required to reach this decision. Total algorithms are an important building block in the design of

  16. Totally James

    Science.gov (United States)

    Owens, Tom

    2006-01-01

    This article presents an interview with James Howe, author of "The Misfits" and "Totally Joe". In this interview, Howe discusses tolerance, diversity and the parallels between his own life and his literature. Howe's four books in addition to "The Misfits" and "Totally Joe" and his list of recommended books with lesbian, gay, bisexual, transgender,…

  17. The Diels-Alder Cycloaddition Reaction of Substituted Hemifullerenes with 1,3-Butadiene: Effect of Electron-Donating and Electron-Withdrawing Substituents.

    Science.gov (United States)

    Mojica, Martha; Méndez, Francisco; Alonso, Julio A

    2016-02-12

    The Diels-Alder (DA) reaction provides an attractive route to increase the number of six member rings in substituted Polycyclic Aromatic Hydrocarbons (PAHs). The density functional theory (DFT) B3LYP method has been used in this work to inquire if the substitution of H over the edge of triindenetriphenylene (pristine hemifullerene 1) and pentacyclopentacorannulene (pristine hemifullerene 2), could improve the DA cycloaddition reaction with 1,3-butadiene. The substituents tested include electron-donating (NH₂, OMe, OH, Me, i-Pr) and electron-withdrawing groups (F, COOH, CF₃, CHO, CN, NO₂). The electronic, kinetic and thermodynamic parameters of the DA reactions of the substituted hemifullerenes with 1,3-butadiene have been analyzed. The most promising results were obtained for the NO₂ substituent; the activation energy barriers for reactions using this substituent were lower than the barriers for the pristine hemifullerenes. This leads us to expect that the cycloadditions to a starting fullerene fragment will be possible.

  18. Rh-Catalyzed (5+2) Cycloadditions of 3-Acyloxy-1,4-enynes and Alkynes: Computational Study of Mechanism, Reactivity, and Regioselectivity

    Science.gov (United States)

    Xu, Xiufang; Liu, Peng; Shu, Xing-zhong; Tang, Weiping; Houk, K. N.

    2013-01-01

    The mechanism of Rh-catalyzed (5+2) cycloadditions of 3-acyloxy-1,4-enyne (ACE) and alkynes is investigated using density functional theory calculations. The catalytic cycle involves 1,2-acyloxy migration, alkyne insertion, and reductive elimination to form the cycloheptatriene product. In contrast to the (5+2) cycloadditions with vinylcyclopropanes (VCP), in which alkyne inserts into a rhodium-allyl bond, alkyne insertion into a Rh–C(sp2) bond is preferred. The 1,2-acyloxy migration is found to be the rate-determining step of the catalytic cycle. The electron-rich p-dimethylaminobenzoate substrate promotes 1,2-acyloxy migration and significantly increases the reactivity. In the regioselectivity-determining alkyne insertion step, the alkyne substituent prefers to be distal to the forming C–C bond and thus distal to the OAc group in the product. PMID:23725341

  19. Chemoselective Switch in the Asymmetric Organocatalysis of 5 H -Oxazol-4-ones and N -Itaconimides: Addition-Protonation or [4+2] Cycloaddition

    KAUST Repository

    Zhu, Bo

    2015-12-09

    © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. We report a synthetic strategy for a chemoselective switch and a diastereo-divergent approach for the asymmetric reaction of 5H-oxazol-4-ones and N-itaconimides catalyzed by L-tert-leucine-derived tertiary amine-urea compounds. The reaction was modulated to harness either tandem conjugate addition-protonation or [4+2] cycloaddition as major product with excellent enantio- and diastereoselectivities. Subjecting the enantio-enriched cycloaddition products to a basic silica gel reagent yields the diastereomer vis-à-vis the product directly obtained under conditions for addition-protonation, thus opening a diastereo-divergent route for creating 1,3-tertiary-hetero-quaternary stereocenters. Quantum chemical studies further provide stereochemical analysis for the [4+2] process and a plausible mechanism for this chemoselective switch is proposed.

  20. Synthesis of Imidazopyridines via Copper-Catalyzed, Formal Aza-[3 + 2] Cycloaddition Reaction of Pyridine Derivatives with α-Diazo Oxime Ethers.

    Science.gov (United States)

    Park, Sangjune; Kim, Hyunseok; Son, Jeong-Yu; Um, Kyusik; Lee, Sooho; Baek, Yonghyeon; Seo, Boram; Lee, Phil Ho

    2017-10-06

    The Cu-catalyzed, formal aza-[3 + 2] cycloaddition reaction of pyridine derivatives with α-diazo oxime ethers in trifluoroethanol was used to synthesize imidazopyridines via the release of molecular nitrogen and elimination of alcohol. These methods enabled modular synthesis of a wide range of N-heterobicyclic compounds such as imidazopyridazines, imidazopyrimidines, and imidazopyrazines with an α-imino Cu-carbenoid generated from the α-diazo oxime ethers and copper.

  1. Facile solid-phase ruthenium assisted azide-alkyne cycloaddition (RuAAC) utilizing the Cp*RuCl(COD)-catalyst

    DEFF Research Database (Denmark)

    Engholm, Ebbe; sgz228, sgz228; Blixt, Klas Ola

    2017-01-01

    The ruthenium assisted azide-alkyne cycloaddition (RuAAC) reaction is a well-established method for the generation of 1,5- and 1,4,5-substituted 1,2,3-triazoles, which we have extended to the solid-phase synthesis of 1,2,3-triazole-peptides. The 1,2,3-triazole moieties were formed upon the reacti...

  2. Synthesis of novel isatin-type 5'-(4-Alkyl/Aryl-1H-1,2,3-triazoles) via 1,3-dipolar cycloaddition reactions

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Bianca N. M.; Silva, Barbara V.; Pinto, Angelo C., E-mail: biancanascimento@iq.ufrj.br [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Instituto de Quimica; Silva, Fernando C.; Gonzaga, Daniel T. G.; Ferreira, Vitor F. [Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil). Instituto de Quimica

    2013-02-15

    Isatin and 1H-1,2,3-triazoles are two classes of compounds with great prominence in organic synthesis and medicinal chemistry as they are heterocycle nuclei with a high reactivity allowing to obtain several compounds with important biological properties. Herein, the synthesis of novel 5'-(4-alquil/aril-1H-1,2,3-triazole)-isatin via reaction of 1,3-dipolar cycloaddition catalyzed by acetic acid is reported. (author)

  3. Solvent effect on copper-catalyzed azide-alkyne cycloaddition (CuAAC): synthesis of novel triazolyl substituted quinolines as potential anticancer agents.

    Science.gov (United States)

    Ellanki, Amarender Reddy; Islam, Aminul; Rama, Veera Swamy; Pulipati, Ranga Prasad; Rambabu, D; Krishna, G Rama; Reddy, C Malla; Mukkanti, K; Vanaja, G R; Kalle, Arunasree M; Kumar, K Shiva; Pal, Manojit

    2012-05-15

    A regioselective route to novel mono triazolyl substituted quinolines has been developed via copper-catalyzed azide-alkyne cycloaddition (CuAAC) of 2,4-diazidoquinoline with terminal alkynes in DMF. The reaction provided bis triazolyl substituted quinolines when performed in water in the presence of Et(3)N. A number of the compounds synthesized showed promising anti-proliferative properties when tested in vitro especially against breast cancer cells. Copyright © 2012 Elsevier Ltd. All rights reserved.

  4. 1,3-Dipolar Cycloaddition Reactions of 1-(4-Phenylphenacyl-1,10-phenanthrolinium N-Ylide with Activated Alkynes and Alkenes

    Directory of Open Access Journals (Sweden)

    A. Badoiu

    2005-02-01

    Full Text Available The 3 2 cycloaddition reaction of 1-(4-phenylphenacyl-1,10-phenanthrolinium ylide with activated alkynes gave pyrrolo[1,2- 4a][1,10]phenanthrolines 6a-d. The "one pot" synthesis of 6a,b,d from 4, activatedalkenes, Et3N and tetrakis-pyridine cobalt (II dichromate (TPCD is described. Thehelical chirality of pyrrolophenanthrolines 6b-d was put in evidence by NMRspectroscopy.

  5. Synthetic Studies on Bioactive Natural Polyketides: Intramolecular Nitrile Oxide-Olefin Cycloaddition Approach for Construction of a Macrolactone Skeleton of Macrosphelide B

    Directory of Open Access Journals (Sweden)

    Seung-Mann Paek

    2011-06-01

    Full Text Available Studies on the synthesis of macrosphelide B via an intramolecular nitrile oxide-olefin cycloaddition (INOC is described. In particular, an asymmetric INOC approach using phase transfer catalysts seems to be a potentially efficient and versatile procedure for the construction of the macrolactone skeleton of macrosphelide B in terms of facial selectivity. Our preliminary and unprecedented stereoselective procedure is anticipated to be usefully applied through further studies for the synthesis of the macrosphelide family.

  6. One-pot, two-step synthesis of imidazo[1,2-a]benzimidazoles via a multicomponent [4 + 1] cycloaddition reaction.

    Science.gov (United States)

    Hsiao, Ya-Shan; Narhe, Bharat D; Chang, Ying-Sheng; Sun, Chung-Ming

    2013-10-14

    A one-pot, two-step synthesis of imidazo[1,2-a]benzimidazoles has been achieved by a three-component reaction of 2-aminobenzimidazoles with an aromatic aldehyde and an isocyanide. The reaction involving condensation of 2-aminobenzimidazole with an aldehyde is run under microwave activation to generate an imine intermediate under basic conditions which then undergoes [4 + 1] cycloaddition with an isocyanide.

  7. Synthesis of novel nitroso acetal derivatives via tandem 6π-electrocyclization/ [3+2]-cycloaddition of 1-nitro-2-methyl-1,3 butadiene

    OpenAIRE

    Esra Koc

    2017-01-01

    Novel nitroso acetal derivatives (4-methyl-2,3,3a,6-tetrahydroisoxazolo[2,3-b][1,2]oxazine) were synthesized through 6π-electrocyclization/[3+2]-cycloaddition reaction of several dionophiles with 1-nitro-2-methyl-1,3-butadiene. Structures of the synthesized compounds were determined by 1H-NMR, 13C-NMR, IR and GC-MS analyses.

  8. Inverse electron-demand 1,3-dipolar cycloaddition of nitrile oxide with common nitriles leading to 3-functionalized 1,2,4-oxadiazoles.

    Science.gov (United States)

    Nishiwaki, Nagatoshi; Kobiro, Kazuya; Hirao, Shotaro; Sawayama, Jun; Saigo, Kazuhiko; Ise, Yumiko; Okajima, Yoshikazu; Ariga, Masahiro

    2011-10-07

    A carbamoyl-substituted nitrile oxide was generated upon treatment of easily available 2-methyl-4-nitro-3-isoxazolin-5(2H)-one with THF (not dried); the reaction proceeded efficiently even in the absence of any special reagents and reaction conditions. The nitrile oxide caused 1,3-dipolar cycloaddition with common aliphatic nitriles or electron-rich aromatic nitriles to afford 3-functionalized 1,2,4-oxadiazoles, which are expected to serve as precursors for the preparation of a variety of functional materials by the chemical transformation of the carbamoyl group. While conventional preparative methods for 1,2,4-oxadiazoles involve the cycloaddition of an electron-rich nitrile oxide with an electron-deficient nitrile or a nitrile activated by a Lewis acid, our method employs the complementary combination of an electron-rich nitrile and an electron-deficient nitrile oxide- the inverse electron-demand 1,3-cycloaddition. The DFT calculations using B3LYP 6-31G* supported the abovementioned inverse reactivity, and also suggested the presence of an accelerating effect by the carbamoyl group as a result of hydrogen bond formation with a dipolarophilic nitrile.

  9. Rhodium-catalyzed [5 + 2 + 1] cycloaddition of ene-vinylcyclopropanes and CO: reaction design, development, application in natural product synthesis, and inspiration for developing new reactions for synthesis of eight-membered carbocycles.

    Science.gov (United States)

    Wang, Yi; Yu, Zhi-Xiang

    2015-08-18

    Practical syntheses of natural products and their analogues with eight-membered carbocyclic skeletons are important for medicinal and biological investigations. However, methods and strategies to construct the eight-membered carbocycles are limited. Therefore, developing new methods to synthesize the eight-membered carbocycles is highly desired. In this Account, we describe our development of three rhodium-catalyzed cycloadditions for the construction of the eight-membered carbocycles, which have great potential in addressing the challenges in the synthesis of medium-sized ring systems. The first reaction described in this Account is our computationally designed rhodium-catalyzed two-component [5 + 2 + 1] cycloaddition of ene-vinylcyclopropanes (ene-VCPs) and CO for the diastereoselective construction of bi- and tricyclic cyclooctenones. The design of this reaction is based on the hypothesis that the C(sp(3))-C(sp(3)) reductive elimination of the eight-membered rhodacycle intermediate generated from the rhodium-catalyzed cyclopropane cleavage and alkene insertion, giving Wender's [5 + 2] cycloadduct, is not easy. Under CO atmosphere, CO insertion may occur rapidly, converting the eight-membered rhodacycle into a nine-membered rhodacycle, which then undergoes an easy C(sp(2))-C(sp(3)) reductive elimination process and furnishes the [5 + 2 + 1] product. This hypothesis was supported by our preliminary DFT studies and also served as inspiration for the development of two [7 + 1] cycloadditions: the [7 + 1] cycloaddition of buta-1,3-dienylcyclopropanes (BDCPs) and CO for the construction of cyclooctadienones, and the benzo/[7 + 1] cycloaddition of cyclopropyl-benzocyclobutenes (CP-BCBs) and CO to synthesize the benzocyclooctenones. The efficiency of these rhodium-catalyzed cycloadditions can be revealed by the application in natural product synthesis. Two eight-membered ring-containing natural products, (±)-asterisca-3(15),6-diene and (+)-asteriscanolide, have been

  10. Diradical reaction mechanisms in [3 + 2]-cycloadditions of hetaryl thioketones with alkyl- or trimethylsilyl-substituted diazomethanes

    Directory of Open Access Journals (Sweden)

    Grzegorz Mlostoń

    2016-04-01

    Full Text Available Reactions of dihetaryl and aryl/hetaryl thioketones with 2-diazopropane, diazoethane, and (trimethylsilyldiazomethane were studied at variable temperature. The experiments showed that reactions with 2-diazopropane carried out at –75 °C occur mainly via the initially formed, relatively stable 1,3,4-thiadiazolines as products of the [3 + 2]-cycloaddition of the diazo dipole onto the C=S bond. The latter decompose only at higher temperature (ca. −40 °C to generate thiocarbonyl S-isopropanide. In the absence of the starting thioketone, the corresponding thiiranes and/or ethene derivatives, formed from them via spontaneous desulfurization, are the main products. In contrast, reactions with diazoethane occurred predominantly via initially formed diradicals, which in cascade processes gave sterically crowded 4,4,5,5-tetrahetaryl-1,3-dithiolanes as major products. Finally, the reaction of dihetaryl thioketones with (trimethylsilyldiazomethane occur smoothly at −75 °C leading to the corresponding 4,4,5,5-tetrahetaryl-1,3-dithiolanes as the exclusive [3 + 2]-cycloadducts formed via a cascade of postulated diradicals. The presence of S or Se atoms in the hetaryl rings is of importance for stabilizing diradical intermediates. Remarkably, in no single case, the ‘head-to-head dimerization’ of aryl/hetaryl and dihetaryl substituted thiocarbonyl ylides was observed.

  11. Lateral extension of π conjugation along the bay regions of bisanthene through a diels-alder cycloaddition reaction

    KAUST Repository

    Li, Jinling; Jiao, Chongjun; Huang, Kuo-Wei; Wu, Jishan

    2011-01-01

    Diels-Alder cycloaddition reactions at the bay regions of bisanthene (1) with dienophiles such as 1,4-naphthoquinone have been investigated. The products were submitted to nucleophilic addition followed by reductive aromatization reactions to afford the laterally extended bisanthene derivatives 2 and 3. Attempted synthesis of a larger expanded bisanthene 4 revealed an unexpected hydrogenation reaction at the last reductive aromatization step. Unusual Michael addition was observed on quinone 14, which was obtained by Diels-Alder reaction between 1 and 1,4-anthraquinone. Compounds 1-3 exhibited near-infrared (NIR) absorption and emission with high-to-moderate fluorescent quantum yields. Their structures and absorption spectra were studied by density function theory and non-planar twisted structures were calculated for 2 and 3. All compounds showed amphoteric redox behavior with multiple oxidation/reduction waves. Oxidative titration with SbCl 5 gave stable radical cations, and the process was followed by UV/Vis/NIR spectroscopic measurements. Their photostability was measured and correlated to their different geometries and electronic structures. © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Lateral extension of π conjugation along the bay regions of bisanthene through a diels-alder cycloaddition reaction

    KAUST Repository

    Li, Jinling

    2011-11-14

    Diels-Alder cycloaddition reactions at the bay regions of bisanthene (1) with dienophiles such as 1,4-naphthoquinone have been investigated. The products were submitted to nucleophilic addition followed by reductive aromatization reactions to afford the laterally extended bisanthene derivatives 2 and 3. Attempted synthesis of a larger expanded bisanthene 4 revealed an unexpected hydrogenation reaction at the last reductive aromatization step. Unusual Michael addition was observed on quinone 14, which was obtained by Diels-Alder reaction between 1 and 1,4-anthraquinone. Compounds 1-3 exhibited near-infrared (NIR) absorption and emission with high-to-moderate fluorescent quantum yields. Their structures and absorption spectra were studied by density function theory and non-planar twisted structures were calculated for 2 and 3. All compounds showed amphoteric redox behavior with multiple oxidation/reduction waves. Oxidative titration with SbCl 5 gave stable radical cations, and the process was followed by UV/Vis/NIR spectroscopic measurements. Their photostability was measured and correlated to their different geometries and electronic structures. © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Total synthesis of amaminol A

    OpenAIRE

    Selkälä, Sami

    2003-01-01

    This thesis includes an extensive review of preparation of bicyclo[4.3.0]nonane derivatives. Bicyclo[4.3.0]nonanes can be prepared by several methods. The most important preparation method of bicyclo[4.3.0]nonanes is intramolecular Diels-Alder cycloaddition (IMDA). Several biologically active natural and unnatural compounds contain bicyclo[4.3.0]nonanes in their molecular framework. The synthetic efforts toward natural compounds such as pulo'upone, isopulo'upone, indanomycin, stawamycin, coch...

  14. Total Thyroidectomy

    Directory of Open Access Journals (Sweden)

    Lopez Moris E

    2016-06-01

    Full Text Available Total thyroidectomy is a surgery that removes all the thyroid tissue from the patient. The suspect of cancer in a thyroid nodule is the most frequent indication and it is presume when previous fine needle puncture is positive or a goiter has significant volume increase or symptomes. Less frequent indications are hyperthyroidism when it is refractory to treatment with Iodine 131 or it is contraindicated, and in cases of symptomatic thyroiditis. The thyroid gland has an important anatomic relation whith the inferior laryngeal nerve and the parathyroid glands, for this reason it is imperative to perform extremely meticulous dissection to recognize each one of these elements and ensure their preservation. It is also essential to maintain strict hemostasis, in order to avoid any postoperative bleeding that could lead to a suffocating neck hematoma, feared complication that represents a surgical emergency and endangers the patient’s life.It is essential to run a formal technique, without skipping steps, and maintain prudence and patience that should rule any surgical act.

  15. [3+2] Cycloaddition of propargylic alcohols and α-oxo ketene dithioacetals: synthesis of functionalized cyclopentadienes and further application in a Diels-Alder reaction.

    Science.gov (United States)

    Fang, Zhongxue; Liu, Jianquan; Liu, Qun; Bi, Xihe

    2014-07-07

    Cyclopentadienes are valuable intermediates in organic synthesis and also ubiquitous as the Cp ligands in organometallic chemistry. As part of ongoing efforts to develop novel organic reactions that employ functionalized alkynes, a [3+2] cycloaddition of propargylic alcohols and ketene dithioacetals has been developed, which leads to fully substituted 2,5-dialkylthio cyclopentadienes in good to excellent yields. In an unusual dethiolating Diels-Alder reaction, the cyclopentadienes were further reacted with maleimides to afford a family of novel fluorescent polycyclic compounds. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Theoretical Study of 1,3-Dipolar Cycloadditions Regioselectivity of Benzyl Azide with Glycosyl-O Acetylene Using Density Functional Theory (DFT

    Directory of Open Access Journals (Sweden)

    Adib Ghaleb

    2017-12-01

    Full Text Available A theoretical study of 1,3-cycloaddition has been carried out using density functional theory (DFT methods at the B3LYP/6-31G* level. The regioselectivity of the reaction have been clarified through different theoretical approaches: Case of a Two-Center Process (Domingo approach, HSAB principle (Gazquez and Mendez approach, and the activation energy calculations. The analysis of results shows that the reaction takes place along concerted asynchronous mechanism and the isomer meta is favored, in agreement with the experiment results. DOI: http://dx.doi.org/10.17807/orbital.v9i5.1017 

  17. Novel Synthesis of 1,2,3-Triazoles via 1,3-Dipolar Cycloadditions of Alkynes to Azides in Ionic Liquid

    Institute of Scientific and Technical Information of China (English)

    ZHONG,Ping(钟平); GUO,Sheng-Rong(郭圣荣)

    2004-01-01

    2-Azido-3,5-dichloropyridine and 2-azido-5-chloro-3-fluoropyridine were given by reaction of sodium azide with 2,3,5-trichloropyridine, 3,5-dichloro-2-fluoropyridine or 5-chloro-2,3-difiuoropyridine in ionic liquids.1,3-Dipolar cycloaddition of 2-azido-3,5-dichloropyridine or 2-azido-5-chloro-3-fluoropyridine to alkynes in ionic liquids afforded the corresponding 1,4,5-trisubstituted [1,2,3]-triazoles in good yields and regioselectivities.

  18. Ultrasound-promoted organocatalytic enamine–azide [3 + 2] cycloaddition reactions for the synthesis of ((arylselanylphenyl-1H-1,2,3-triazol-4-ylketones

    Directory of Open Access Journals (Sweden)

    Gabriel P. Costa

    2017-04-01

    Full Text Available The use of sonochemistry is described in the organocatalytic enamine–azide [3 + 2] cycloaddition between 1,3-diketones and aryl azidophenyl selenides. These sonochemically promoted reactions were found to be amenable to a range of 1,3-diketones or aryl azidophenyl selenides, providing an efficient access to new ((arylselanylphenyl-1H-1,2,3-triazol-4-ylketones in good to excellent yields and short reaction times. In addition, this protocol was extended to β-keto esters, β-keto amides and α-cyano ketones. Selanyltriazoyl carboxylates, carboxamides and carbonitriles were synthesized in high yields at short times of reaction under very mild reaction conditions.

  19. Synthesis of strigolactones analogues by intramolecular [2+2] cycloaddition of ketene-iminium salts to olefins and their activity on Orobanche cumana seeds.

    Science.gov (United States)

    Lachia, Mathilde; Wolf, Hanno Christian; De Mesmaeker, Alain

    2014-05-01

    Strigolactones have been the latest identified phytohormones. Among the strigolactones analogues described recently, GR-24 remains the most studied derivative which is used as standard in this field. In order to improve several properties of GR-24 for potential agronomical applications, we investigated the effect of substituents on the B and C-rings on the activity for seed germination induction. We report here the synthesis of 9 GR-24 analogues via a [2+2] intramolecular cycloaddition of ketene-iminium salts and a summary of their activity for the germination of Orobanche cumana (broomrape) seeds. Copyright © 2014 Elsevier Ltd. All rights reserved.

  20. Excess Substrate is a Spectator Ligand in a Rhodium-Catalyzed Asymmetric [2+2+2] Cycloaddition of Alkenyl Isocyanates with Tolanes

    Science.gov (United States)

    Oinen, Mark Emil; Yu, Robert T.; Rovis, Tomislav

    2009-01-01

    Excess substrate has been identified as an unintended spectator ligand affecting enantioselectivity in the [2+2+2] cycloaddition of alkenyl isocyanates with tolanes. Replacement of excess substrate with an exogenous additive affords products with consistent and higher ee’s. The increase in enantioselectivity is the result of a change in composition of a proposed rhodium(III) intermediate on the catalytic cycle. The net result is a rational probe of a short-lived rhodium(III) intermediate, and gives insight that may have applications in many rhodium catalyzed reactions. PMID:19803471

  1. Rhodium-Catalyzed Denitrogenative [3+2] Cycloaddition: Access to Functionalized Hydroindolones and the Framework of Montanine-Type Amaryllidaceae Alkaloids.

    Science.gov (United States)

    Yang, Hongjian; Hou, Shengtai; Tao, Cheng; Liu, Zhao; Wang, Chao; Cheng, Bin; Li, Yun; Zhai, Hongbin

    2017-09-18

    Rhodium-catalyzed denitrogenative [3+2] cycloaddition of 1-sulfonyl-1,2,3-triazoles with cyclic silyl dienol ethers has been developed for the synthesis of functionalized hydroindolones or their corresponding silyl ethers. The present method has been employed to construct synthetically valuable bicyclo[3.3.1]alkenone derivatives and pyrrolidine-ring-containing bicyclic indole compounds. As a further synthetic application, a stereoselective synthesis of 5,11-methanomorphanthridin-3-one, which shares a key skeleton with montanine-type Amaryllidaceae alkaloids has been achieved by using this chemistry. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. KF/Al2O3 as a Recyclable Basic Catalyst for 1,3-Dipolar Cycloaddition Reaction: Synthesis of Indolizine-1-Carbonitrile Derivatives

    Directory of Open Access Journals (Sweden)

    Abaszadeh Mehdi

    2017-07-01

    Full Text Available KF/Al2O3 as a green and efficient catalyst has been used for synthesis of indolizine-1-carbonitrile derivatives. It can be proceeded by using 1,3-dipolar cycloaddition reaction of 1-alkyl-2-chloropyridinium bromides, malononitrile and benzaldehyde in ethanol, at reflux. The great advantage of this catalyst is the ease of handling. KF/Al2O3 can be used and removed by filtration, avoiding cumbersome aqueous workups and decreasing solvent waste handling issues. High conversions, short reaction times and a cleaner reaction profiles are some of the outstanding advantages of this method.

  3. A theoretical investigation on the regioselectivity of the intramolecular hetero Diels-Alder and 1,3-dipolar cycloaddition of 2-vinyloxybenzaldehyde derivatives

    Directory of Open Access Journals (Sweden)

    Hamzehloueian Mahshid

    2014-01-01

    Full Text Available The present study reports a systematic computational analysis of the two possible pathways, fused and bridged, for an intramolecular hetero Diels-Alder (IMHDA and an intramolecular 1,3-dipolar cycloaddition (IMDCA of 2-vinyloxybenzaldehyde derivatives. The potential energy surface analysis for both reactions is in agreement with experimental observations. The activation energies associated with the two regioisomeric channels in IMHDA reaction show that the bridged product is favored, although in IMDCA, the most stable TS results the fused product. The global electronic properties of fragments within each molecule were studied to discuss the reactivity patterns and charge transfer direction in the intramolecular processes. The asynchronicity of the bond formation and aromaticity of the optimized TSs in the Diels-Alder reaction as well as cycloaddition reaction were evaluated. Finally, 1H NMR chemical shifts of the possible regioisomers have been calculated using the GIAO method which of the most stable products are in agreement with the experimental data in the both reaction.

  4. The concern of emergence of multi-station reaction pathways that might make stepwise the mechanism of the 1,3-dipolar cycloadditions of azides and alkynes

    Science.gov (United States)

    Mohtat, Bita; Siadati, Seyyed Amir; Khalilzadeh, Mohammad Ali; Zareyee, Daryoush

    2018-03-01

    After hot debates on the concerted or stepwise nature of the mechanism of the catalyst-free 1,3-dipolar cycloadditions (DC)s, nowadays, it is being believed that for the reaction of each dipole and dipolarophile, there is a possibility that the reaction mechanism becomes stepwise, intermediates emerge, and the reaction becomes non-stereospecific. Yield of even minimal amounts of unwanted side products or stereoisomers as impurities could bring many troubles like difficult purification steps. In this project, we have made attempts to study all probable reaction channels of the azide cycloadditions with two functionalized alkynes, in order to answer this question: "is there any possibility that intermediates evolve in the catalyst-free click 1,3-DC reaction of azide-alkynes?". During the calculations, several multi-station reaction pathways supporting the stepwise and concerted mechanisms were detected. Also, the born-oppenheimer molecular dynamic (BOMD) simulation was used to find trustable geometries which could be emerged during the reaction coordinate.

  5. Influence of Endo- and Exocyclic Heteroatoms on Stabilities and 1,3-Dipolar Cycloaddition Reactivities of Mesoionic Azomethine Ylides and Imines.

    Science.gov (United States)

    Champagne, Pier Alexandre; Houk, K N

    2017-10-20

    The geometries, stabilities, and 1,3-dipolar cycloaddition reactivities of 24 mesoionic azomethine ylides and imines were investigated using density functional theory calculations at the M06-2X/6-311+G-(d,p)/M06-2X/6-31G-(d) level. The computed structures highlight how the commonly used "aromatic" resonance form should be replaced by two more accurate resonance structures. Stabilities of the dipoles were assessed by various homodesmotic schemes and are consistent with these compounds being nonaromatic. The activation free energies with ethylene or acetylene range from 11.8 to 36.6 kcal/mol. Within each dipole type, the predicted cycloaddition reactivities correlate with the reaction energies and the resonance stabilization energies provided by the various substituents. Endocyclic (X) heteroatoms increase the reactivity of the 1,3-dipoles in the order of O > NH ≅ S, whereas exocyclic (Y) substituents increase it in the order of CH 2 > NH > O > S. Distortion/interaction analysis indicated that the difference in reactivity between differently substituted 1,3-dipoles is driven by distortion, whereas the difference between azomethine ylides and imines is related to lower interaction energies of imines with the dipolarophiles.

  6. [3+2] Cycloadditions of 1-halo-1-nitroethenes with (Z-C-(3,4,5-trimethoxyphenyl-N-methyl-nitrone as regio- and stereocontrolled source of novel bioactive compounds: preliminary studies

    Directory of Open Access Journals (Sweden)

    Radomir Jasiński

    2016-07-01

    Full Text Available Preliminary experiments shows, that [3+2] cycloadditions reactions proceeds with full regioselectivity and high stereoselectivity. In consequence, 3,4-trans-2-methyl-3-(3,4,5-trimethoxyphenyl-4-halo-4-nitroisoxazolidines are forming as predominantly (or sole products. Additionally, prognosis for the synthesized compounds to be potential ingredients of drugs is good.

  7. Niobium(v) chloride and imidazolium bromides as efficient dual catalyst systems for the cycloaddition of carbon dioxide and propylene oxide

    KAUST Repository

    Wilhelm, Michael E.; Anthofer, Michael H.; Reich, Robert M.; D'Elia, Valerio; Basset, Jean-Marie; Herrmann, Wolfgang A.; Cokoja, Mirza; Kü hn, Fritz

    2014-01-01

    The application of niobium(v) chloride and several imidazolium bromides as catalyst systems for the cycloaddition of propylene oxide (PO) with carbon dioxide to propylene carbonate (PC) is reported. A set of 31 different imidazolium bromides has been synthesized with varying substituents at all five imidazolium ring atoms, of which 17 have not been reported before. The impact of different substitution patterns (steric and electronic changes and solubility in PO) at the imidazolium ring on the catalytic activity was investigated. The optimisation of the catalyst structure allows for the valorisation of carbon dioxide under mild reaction conditions with high reaction rates in very good yield and selectivity for PC. This journal is © the Partner Organisations 2014.

  8. 'Clicking' on the nanoscale: 1,3-dipolar cycloaddition of terminal acetylenes on azide functionalized, nanometric surface templates with nanometer resolution

    International Nuclear Information System (INIS)

    Haensch, Claudia; Hoeppener, Stephanie; Schubert, Ulrich S

    2009-01-01

    Electro-oxidative lithography is used as a tool to create chemical nanostructures on an n-octadecyltrichlorosilane (OTS) monolayer self-assembled on silicon. The use of a bromine precursor molecule, which is exclusively assembled on these chemical templates, can be used to further functionalize the nanostructures by the site-selective generation of azide functions and performing the highly effective 1,3-dipolar cycloaddition reaction with acetylene functionalized molecules. The versatility of this reaction scheme provides the potential to integrate a large variety of functional molecules, to tailor the surface properties of the nanostructures or to anchor molecular building blocks or particles in confined, pre-defined surface areas. The results demonstrated in the present study introduce a conceivable route towards the functionalization of chemically active surface templates with high fidelity and reliability. It is demonstrated that surface features with a lateral resolution of 50 nm functionalized with propargyl alcohol can be fabricated.

  9. Etude d'une séquence allylmétallation-cycloaddition contrôlée par un groupe silyle

    OpenAIRE

    Distelmans, Anouk

    2004-01-01

    Notre thèse s'intéresse à l'étude de séquences réactionnelles permeettant la création de carbones quaternaires. Deux séquences de réactions sont envisagées : - La première s'inscrit dans le prolongement des travaux de J-M. Adam et combine une réaction d'allylmétallation asymétrique et une réaction de cycloaddition [2+2] intramoléculaire. Elle conduit à des cyclobutanones bicycliques portant un substituant méthyle en tête de pont. La réaction d'allylmétallation a tout d'abord été étud...

  10. Conversion of actual flue gas CO 2 via cycloaddition to propylene oxide catalyzed by a single-site, recyclable zirconium catalyst

    KAUST Repository

    Kelly, Michael J.

    2017-06-12

    A reusable zirconium-based catalyst for the cycloaddition of CO2 to propylene oxide (PO) was prepared by the surface organometallic chemistry (SOMC) methodology. Accordingly, well-defined amounts of the ZrCl4·(OEt2)2 precursor were grafted on the surface of silica dehydroxylated at 700°C (SiO2-700) and at 200°C (SiO2-200) in order to afford surface coordination compounds with different podality and chemical environment. The identity of the surface complexes was thoroughly investigated by FT-IR, elemental microanalysis and solid state NMR and applied as a recoverable and reusable heterogeneous catalyst for the title reaction using pure CO2 and flue gas samples from a cement factory. The observed catalytic activity for the isolated zirconium complexes is rationalized by means of systematic DFT calculations.

  11. Synthetic scope and DFT analysis of the chiral binap–gold(I complex-catalyzed 1,3-dipolar cycloaddition of azlactones with alkenes

    Directory of Open Access Journals (Sweden)

    María Martín-Rodríguez

    2013-11-01

    Full Text Available The 1,3-dipolar cycloaddition between glycine-derived azlactones with maleimides is efficiently catalyzed by the dimeric chiral complex [(Sa-Binap·AuTFA]2. The alanine-derived oxazolone only reacts with tert-butyl acrylate giving anomalous regiochemistry, which is explained and supported by Natural Resonance Theory and Nucleus Independent Chemical Shifts calculations. The origin of the high enantiodiscrimination observed with maleimides and tert-butyl acrylate is analyzed using DFT computed at M06/Lanl2dz//ONIOM(b3lyp/Lanl2dz:UFF level. Several applications of these cycloadducts in the synthesis of new proline derivatives with a 2,5-trans-arrangement and in the preparation of complex fused polycyclic molecules are described.

  12. Niobium(v) chloride and imidazolium bromides as efficient dual catalyst systems for the cycloaddition of carbon dioxide and propylene oxide

    KAUST Repository

    Wilhelm, Michael E.

    2014-02-19

    The application of niobium(v) chloride and several imidazolium bromides as catalyst systems for the cycloaddition of propylene oxide (PO) with carbon dioxide to propylene carbonate (PC) is reported. A set of 31 different imidazolium bromides has been synthesized with varying substituents at all five imidazolium ring atoms, of which 17 have not been reported before. The impact of different substitution patterns (steric and electronic changes and solubility in PO) at the imidazolium ring on the catalytic activity was investigated. The optimisation of the catalyst structure allows for the valorisation of carbon dioxide under mild reaction conditions with high reaction rates in very good yield and selectivity for PC. This journal is © the Partner Organisations 2014.

  13. Conversion of actual flue gas CO 2 via cycloaddition to propylene oxide catalyzed by a single-site, recyclable zirconium catalyst

    KAUST Repository

    Kelly, Michael J.; Barthel, Alexander; Maheu, Clement; Sodpiban, Ounjit; Dega, Frank-Blondel; Vummaleti, Sai V.C.; Abou-Hamad, Edy; Pelletier, Jeremie; Cavallo, Luigi; D'Elia, Valerio; Basset, Jean-Marie

    2017-01-01

    A reusable zirconium-based catalyst for the cycloaddition of CO2 to propylene oxide (PO) was prepared by the surface organometallic chemistry (SOMC) methodology. Accordingly, well-defined amounts of the ZrCl4·(OEt2)2 precursor were grafted on the surface of silica dehydroxylated at 700°C (SiO2-700) and at 200°C (SiO2-200) in order to afford surface coordination compounds with different podality and chemical environment. The identity of the surface complexes was thoroughly investigated by FT-IR, elemental microanalysis and solid state NMR and applied as a recoverable and reusable heterogeneous catalyst for the title reaction using pure CO2 and flue gas samples from a cement factory. The observed catalytic activity for the isolated zirconium complexes is rationalized by means of systematic DFT calculations.

  14. Highly regio- and diastereoselective, acidic clay supported intramolecular nitrile oxide-alkene cycloaddition on D-ribose derived nitriles: an efficient synthetic route to isoxazoline fused five and six membered carbocycles.

    Science.gov (United States)

    Panda, Amarendra; Das, Sulagna; Pal, Shantanu

    2014-10-29

    An efficient synthetic route to isoxazoline fused carbocycles from carbohydrate scaffolds that comprise of free hydroxyl group(s) is described with high regio- and stereoselectivity. Montmorillonite K-10/chloramine T oxidation and in situ intramolecular nitrile oxide-alkene cycloaddition (INOC) of D-ribose derived oximes have been developed for the diversity oriented synthesis of isoxazoline fused five and six membered carbocycles. Copyright © 2014 Elsevier Ltd. All rights reserved.

  15. N-methyl-3-pyrrolidines preparation by means of [3+2] dipoles cycloaddition reactions; Preparacion de N-metil-3-arilpirrolidinas mediante reacciones de cicloadicion dipolares [3+2

    Energy Technology Data Exchange (ETDEWEB)

    Negron, Guillermo [Universidad Autonoma Metropolitana-Azcapotzalco, Mexico, D.F. (Mexico); Fuentes, Aydee; Romero, Moises [Universidad Autonoma del Estado de Mexico, Toluca, Estado de Mexico (Mexico); Madrid, Gustavo; Cruz, Raymundo [Universidad Nacional Autonoma de Mexico, Mexico, D.F. (Mexico)

    1999-08-01

    The [3+2] cycloaddition reaction between azomethine ylide generated by deprotonation of trimethylamine N-oxide with LDA and various {alpha}-asarone derivatives to afford the corresponding pyrrolidines is described. [Spanish] Las reacciones de cicloadicion [3+2] entre iluros de azometino generados por accion del LDA sobre el N-oxido de trimetilamina y varios derivados de la {alpha}-asarona, permite la obtencion de las pirrolidinas correspondientes.

  16. Rh(I-catalyzed intramolecular [2 + 2 + 1] cycloaddition of allenenes: Construction of bicyclo[4.3.0]nonenones with an angular methyl group and tricyclo[6.4.0.01,5]dodecenone

    Directory of Open Access Journals (Sweden)

    Chisato Mukai

    2011-04-01

    Full Text Available The [RhCl(COdppp]2-catalyzed intramolecular carbonylative [2 + 2 + 1] cycloaddition of allenenes was developed to prepare bicyclo[4.3.0]nonenones possessing a methyl group at the ring junction, which is difficult to achieve by the Pauson–Khand reaction of the corresponding enynes. This method also provided a new procedure for the construction of the tricyclo[6.4.0.01,5]dodecenone framework in a satisfactory yield.

  17. 1,3-Dipolar cycloadditions of ethoxycarbonyl-nitrile benzylimine and synthesis of ß-amino acids. Synthesis and reactions of ethyl 2-chloro-2-ethoxyacetate and 2-chloro-2-ethoxyacetylchloride

    DEFF Research Database (Denmark)

    Bach, K.K.; El-Seedi, H.R.; Jensen, H.M.

    1994-01-01

    The principles of 1,2-cyano-hydroxylation of olefins were applied to the preparation of 1,2-cyano-amines. The dipole component of this cycloaddition was nitrile imines, which formed pyrazolines with olefins. Ring cleavage was accomplished by thermolysis of 3-carboxypyrazolines, which gave 1,2-cyano-amines...... were carried out with the allylic ester - nitrile oxide and allylic ester - nitrile imine systems....

  18. Reactivity of Single-Walled Carbon Nanotubes in the Diels-Alder Cycloaddition Reaction: Distortion-Interaction Analysis along the Reaction Pathway.

    Science.gov (United States)

    Li, Yingzi; Osuna, Sílvia; Garcia-Borràs, Marc; Qi, Xiaotian; Liu, Song; Houk, Kendall N; Lan, Yu

    2016-08-26

    Diels-Alder cycloaddition is one of the most powerful tools for the functionalization of single-walled carbon nanotubes (SWCNTs). Density functional theory at the B3-LYP level of theory has been used to investigate the reactivity of different-diameter SWCNTs (4-9,5) in Diels-Alder reactions with 1,3-butadiene; the reactivity was found to decrease with increasing SWCNT diameter. Distortion/interaction analysis along the whole reaction pathway was found to be a better way to explore the reactivity of this type of reaction. The difference in interaction energy along the reaction pathway is larger than that of the corresponding distortion energy. However, the distortion energy plots for these reactions show the same trend. Therefore, the formation of the transition state can be determined from the interaction energy. A lower interaction energy leads to an earlier transition state, which indicates a lower activation energy. The computational results also indicate that the original distortion of the SWCNTs leads to an increase in the reactivity of the SWCNTs. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Fine-Tuning Strain and Electronic Activation of Strain-Promoted 1,3-Dipolar Cycloadditions with Endocyclic Sulfamates in SNO-OCTs.

    Science.gov (United States)

    Burke, Eileen G; Gold, Brian; Hoang, Trish T; Raines, Ronald T; Schomaker, Jennifer M

    2017-06-14

    The ability to achieve predictable control over the polarization of strained cycloalkynes can influence their behavior in subsequent reactions, providing opportunities to increase both rate and chemoselectivity. A series of new heterocyclic strained cyclooctynes containing a sulfamate backbone (SNO-OCTs) were prepared under mild conditions by employing ring expansions of silylated methyleneaziridines. SNO-OCT derivative 8 outpaced even a difluorinated cyclooctyne in a 1,3-dipolar cycloaddition with benzylazide. The various orbital interactions of the propargylic and homopropargylic heteroatoms in SNO-OCT were explored both experimentally and computationally. The inclusion of these heteroatoms had a positive impact on stability and reactivity, where electronic effects could be utilized to relieve ring strain. The choice of the heteroatom combinations in various SNO-OCTs significantly affected the alkyne geometries, thus illustrating a new strategy for modulating strain via remote substituents. Additionally, this unique heteroatom activation was capable of accelerating the rate of reaction of SNO-OCT with diazoacetamide over azidoacetamide, opening the possibility of further method development in the context of chemoselective, bioorthogonal labeling.

  20. Enantioselective Rhodium-Catalyzed [2+2+2] Cycloadditions of Terminal Alkynes and Alkenyl Isocyanates: Mechanistic Insights Lead to a Unified Model that Rationalizes Product Selectivity

    Science.gov (United States)

    Dalton, Derek M.; Oberg, Kevin M.; Yu, Robert T.; Lee, Ernest E.; Perreault, Stéphane; Oinen, Mark Emil; Pease, Melissa L.; Malik, Guillaume; Rovis, Tomislav

    2009-01-01

    This manuscript describes the development and scope of the asymmetric rhodium-catalyzed [2+2+2] cycloaddition of terminal alkynes and alkenyl isocyanates leading to the formation of indolizidine and quinolizidine scaffolds. The use of phosphoramidite ligands proved crucial for avoiding competitive terminal alkyne dimerization. Both aliphatic and aromatic terminal alkynes participate well, with product selectivity a function of both the steric and electronic character of the alkyne. Manipulation of the phosphoramidite ligand leads to tuning of enantio- and product selectivity, with a complete turnover in product selectivity seen with aliphatic alkynes when moving from Taddol-based to biphenol-based phosphoramidites. Terminal and 1,1-disubstituted olefins are tolerated with nearly equal efficacy. Examination of a series of competition experiments in combination with analysis of reaction outcome shed considerable light on the operative catalytic cycle. Through a detailed study of a series of X-ray structures of rhodium(cod)chloride/phosphoramidite complexes, we have formulated a mechanistic hypothesis that rationalizes the observed product selectivity. PMID:19817441

  1. Metal-Free Poly-Cycloaddition of Activated Azide and Alkynes toward Multifunctional Polytriazoles: Aggregation-Induced Emission, Explosive Detection, Fluorescent Patterning, and Light Refraction.

    Science.gov (United States)

    Wu, Yongwei; He, Benzhao; Quan, Changyun; Zheng, Chao; Deng, Haiqin; Hu, Rongrong; Zhao, Zujin; Huang, Fei; Qin, Anjun; Tang, Ben Zhong

    2017-09-01

    The metal-free click polymerization (MFCP) of activated alkynes and azides or activated azide and alkynes have been developed into powerful techniques for the construction of polytriazoles without the obsession of metallic catalyst residues problem. However, the MFCP of activated azides and alkynes is rarely applied in preparation of functional polytriazoles. In this paper, soluble multifunctional polytriazoles (PIa and PIb) with high weight-average molecular weights (M w up to 32 000) are prepared via the developed metal-free poly-cycloaddition of activated azide and alkynes in high yields (up to 90%). The resultant PIa and PIb are thermally stable, and show aggregation-induced emission characteristics, enabling their aggregates to detect explosives with superamplification effect. Moreover, thanks to their containing aromatic rings and polar moieties, PIa and PIb exhibit high refractive indices. In addition, they can also be cross-linked upon UV irradiation to generate 2D fluorescent patterning due to their remaining azide groups and containing ester groups. Thus, these multifunctional polytriazoles are potentially applicable in the optoelectronic and sensing fields. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Site-specific bioconjugation of a murine dihydrofolate reductase enzyme by copper(I-catalyzed azide-alkyne cycloaddition with retained activity.

    Directory of Open Access Journals (Sweden)

    Sung In Lim

    Full Text Available Cu(I-catalyzed azide-alkyne cycloaddition (CuAAC is an efficient reaction linking an azido and an alkynyl group in the presence of copper catalyst. Incorporation of a non-natural amino acid (NAA containing either an azido or an alkynyl group into a protein allows site-specific bioconjugation in mild conditions via CuAAC. Despite its great potential, bioconjugation of an enzyme has been hampered by several issues including low yield, poor solubility of a ligand, and protein structural/functional perturbation by CuAAC components. In the present study, we incorporated an alkyne-bearing NAA into an enzyme, murine dihydrofolate reductase (mDHFR, in high cell density cultivation of Escherichia coli, and performed CuAAC conjugation with fluorescent azide dyes to evaluate enzyme compatibility of various CuAAC conditions comprising combination of commercially available Cu(I-chelating ligands and reductants. The condensed culture improves the protein yield 19-fold based on the same amount of non-natural amino acid, and the enzyme incubation under the optimized reaction condition did not lead to any activity loss but allowed a fast and high-yield bioconjugation. Using the established conditions, a biotin-azide spacer was efficiently conjugated to mDHFR with retained activity leading to the site-specific immobilization of the biotin-conjugated mDHFR on a streptavidin-coated plate. These results demonstrate that the combination of reactive non-natural amino acid incorporation and the optimized CuAAC can be used to bioconjugate enzymes with retained enzymatic activity.

  3. In-depth evaluation of the cycloaddition-retro-Diels-Alder reaction for in vivo targeting with [111In]-DTPA-RGD conjugates

    International Nuclear Information System (INIS)

    Laverman, Peter; Meeuwissen, Silvie A.; Berkel, Sander S. van; Oyen, Wim J.G.; Delft, Floris L. van; Rutjes, Floris P.J.T.; Boerman, Otto C.

    2009-01-01

    Introduction: The spontaneous copper-free tandem 1,3-dipolar cycloaddition-retro-Diels-Alder (tandem crDA) reaction between cyclic Arg-Gly-Asp-D-Phe-Orn(N 3 ) [c(RGDfX)] and oxanorbornadiene-DTPA (o-DTPA) or methyloxanorbornadiene-DTPA (mo-DTPA) into two DTPA-c(RGDfX) regioisomers is characterized. Since there is no information on the stability and reaction rate of the tandem crDA reaction in biological media, we set out to characterize these reaction parameters. Methods: The effects of concentration of the reactants, temperature, pH and reaction environment (serum, blood) on the kinetics of the reaction were determined using 111 In-labeled oxanorbornadiene-DTPA analogs. The affinity of the radiolabeled conjugate was determined in a solid-phase α v β 3 integrin binding assay. Furthermore, the octanol-water partition coefficient was determined and, finally, the biodistribution of the labeled compounds in mice with subcutaneous α v β 3 -expressing tumors was determined. Results: Fifty percent conversion was reached after 26 h. Kinetic experiments furthermore established that the reaction rate of the tandem crDA reaction follows temperature- and concentration-dependent second-order kinetics, but is independent of the pH of the medium. Affinity of the two [ 111 In]DTPA-cRGDfX conjugates for α v β 3 integrin is 191 nM. Biodistribution studies showed specific (α v β 3 -mediated) uptake of [ 111 In]DTPA-c(RGDfX) in the tumor and in α v β 3 -expressing tissues. Conclusion: The tandem crDA reaction using methyl-substituted oxanorbornadiene is a versatile method for a single-step ligation that proceeds independently of pH and also proceeds in serum and blood. Currently, we are further looking into enhancement of reaction kinetics and exploitation of tandem crDA in vivo.

  4. Kinetics and mechanics of photo-polymerized triazole-containing thermosetting composites via the copper(I)-catalyzed azide-alkyne cycloaddition.

    Science.gov (United States)

    Song, Han Byul; Wang, Xiance; Patton, James R; Stansbury, Jeffrey W; Bowman, Christopher N

    2017-06-01

    Several features necessary for polymer composite materials in practical applications such as dental restorative materials were investigated in photo-curable CuAAC (copper(I)-catalyzed azide-alkyne cycloaddition) thermosetting resin-based composites with varying filler loadings and compared to a conventional BisGMA/TEGDMA based composite. Tri-functional alkyne and di-functional azide monomers were synthesized for CuAAC resins and incorporated with alkyne-functionalized glass microfillers for CuAAC composites. Polymerization kinetics, in situ temperature change, and shrinkage stress were monitored simultaneously with a tensometer coupled with FTIR spectroscopy and a data-logging thermocouple. The glass transition temperature was analyzed by dynamic mechanical analysis. Flexural modulus/strength and flexural toughness were characterized in three-point bending on a universal testing machine. The photo-CuAAC polymerization of composites containing between 0 and 60wt% microfiller achieved ∼99% conversion with a dramatic reduction in the maximum heat of reaction (∼20°C decrease) for the 60wt% filled CuAAC composites as compared with the unfilled CuAAC resin. CuAAC composites with 60wt% microfiller generated more than twice lower shrinkage stress of 0.43±0.01MPa, equivalent flexural modulus of 6.1±0.7GPa, equivalent flexural strength of 107±9MPa, and more than 10 times higher energy absorption of 10±1MJm -3 when strained to 11% relative to BisGMA-based composites at equivalent filler loadings. Mechanically robust and highly tough, photo-polymerized CuAAC composites with reduced shrinkage stress and a modest reaction exotherm were generated and resulted in essentially complete conversion. Copyright © 2017 The Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  5. Ruthenium-Catalyzed Formal Dehydrative [4 + 2] Cycloaddition of Enamides and Alkynes for the Synthesis of Highly Substituted Pyridines: Reaction Development and Mechanistic Study.

    Science.gov (United States)

    Wu, Jicheng; Xu, Wenbo; Yu, Zhi-Xiang; Wang, Jian

    2015-07-29

    Reported herein is a ruthenium-catalyzed formal dehydrative [4 + 2] cycloaddition of enamides and alkynes, representing a mild and economic protocol for the construction of highly substituted pyridines. Notably, the features of broad substrate scope, high efficiency, good functional group tolerance, and excellent regioselectivities were observed for this reaction. Density functional theory (DFT) calculations and experiments have been carried out to understand the mechanism and regiochemistry. DFT calculations suggested that this formal dehydrative [4 + 2] reaction starts with a concerted metalation deprotonation of the enamide by the acetate group in the Ru catalyst, which generates a six-membered ruthenacycle intermediate. Then alkyne inserts into the Ru-C bond of the six-membered ruthenacycle, giving rise to an eight-membered ruthenacycle intermediate. The carbonyl group (which comes originally from the enamide substrate and is coordinated to the Ru center in the eight-membered ruthenacycle intermediate) then inserts into the Ru-C bond to give an intermediate, which produces the final pyridine product through further dehydration. Alkyne insertion step is a regio-determining step and prefers to have the aryl groups of the used alkynes stay away from the catalyst in order to avoid repulsion of aryl group with the enamide moiety in the six-membered ruthenacycle and to keep the conjugation between the aryl group and the triple C-C bond of the alkynes. Consequently, the aryl groups of the used alkynes are in the β-position of the final pyridines, and the present reaction has high regioselectivity.

  6. Fully recoverable rigid shape memory foam based on copper-catalyzed azide-alkyne cycloaddition (CuAAC) using a salt leaching technique.

    Science.gov (United States)

    Alzahrani, Abeer A; Saed, Mohand; Yakacki, Christopher M; Song, Han Byul; Sowan, Nancy; Walston, Joshua J; Shah, Parag K; McBride, Matthew K; Stansbury, Jeffrey W; Bowman, Christopher N

    2018-01-07

    This study is the first to employ the use of the copper-catalyzed azide-alkyne cycloaddition (CuAAC) polymerization to form a tough and stiff, porous material from a well-defined network possessing a high glass transition temperature. The effect of the network linkages formed as a product of the CuAAC reaction, i.e., the triazoles, on the mechanical behavior at high strain was evaluated by comparing the CuAAC foam to an epoxy-amine-based foam, which consisted of monomers with similar backbone structures and mechanical properties (i.e., T g of 115 °C and a rubbery modulus of 1.0 MPa for the CuAAC foam, T g of 125 °C and a rubbery modulus of 1.2 MPa for the epoxy-amine foam). When each foam was compressed uniformly to 80% strain at ambient temperature, the epoxy-amine foam was severely damaged after only reaching 70% strain in the first compression cycle with a toughness of 300 MJ/m 3 . In contrast, the CuAAC foam exhibited pronounced ductile behavior in the glassy state with three times higher toughness of 850 MJ/m 3 after the first cycle of compression to 80% strain. Additionally, when the CuAAC foam was heated above T g after each of five compression cycles to 80% strain at ambient temperature, the foam completely recovered its original shape while exhibiting a gradual decrease in mechanical performance over the multiple compression cycles. The foam demonstrated almost complete shape fixity and recovery ratios even through five successive cycles, indicative of "reversible plasticity", making it highly desirable as a glassy shape memory foams.

  7. A Theoretical Study of the Relationship between the Electrophilicity ω Index and Hammett Constant σp in [3+2] Cycloaddition Reactions of Aryl Azide/Alkyne Derivatives

    Directory of Open Access Journals (Sweden)

    Hicham Ben El Ayouchia

    2016-10-01

    Full Text Available The relationship between the electrophilicity ω index and the Hammett constant σp has been studied for the [2+3] cycloaddition reactions of a series of para-substituted phenyl azides towards para-substituted phenyl alkynes. The electrophilicity ω index—a reactivity density functional theory (DFT descriptor evaluated at the ground state of the molecules—shows a good linear relationship with the Hammett substituent constants σp. The theoretical scale of reactivity correctly explains the electrophilic activation/deactivation effects promoted by electron-withdrawing and electron-releasing substituents in both azide and alkyne components.

  8. The [2 + 2] Cycloaddition-Retroelectrocyclization and [4 + 2] Hetero-Diels-Alder Reactions of 2-(Dicyanomethylene)indan-1,3-dione with Electron-Rich Alkynes: Influence of Lewis Acids on Reactivity.

    Science.gov (United States)

    Donckele, Etienne J; Finke, Aaron D; Ruhlmann, Laurent; Boudon, Corinne; Trapp, Nils; Diederich, François

    2015-07-17

    The reaction of electrophilic 2-(dicyanomethylene)indan-1,3-dione (DCID) with substituted, electron-rich alkynes provides two classes of push-pull chromophores with interesting optoelectronic properties. The formal [2 + 2] cycloaddition-retroelectrocyclization reaction at the exocyclic double bond of DCID gives cyanobuta-1,3-dienes, and the formal [4 + 2] hetero-Diels-Alder (HDA) reaction at an enone moiety of DCID generates fused 4H-pyran heterocycles. Both products can be obtained in good yield and excellent selectivity by carefully tuning the reaction conditions; in particular, the use of Lewis acids dramatically enhances formation of the HDA adduct.

  9. Total parenteral nutrition - infants

    Science.gov (United States)

    ... medlineplus.gov/ency/article/007239.htm Total parenteral nutrition - infants To use the sharing features on this page, please enable JavaScript. Total parenteral nutrition (TPN) is a method of feeding that bypasses ...

  10. Total parenteral nutrition

    Science.gov (United States)

    ... medlineplus.gov/ency/patientinstructions/000177.htm Total parenteral nutrition To use the sharing features on this page, please enable JavaScript. Total parenteral nutrition (TPN) is a method of feeding that bypasses ...

  11. Technique of total thyroidectomy

    International Nuclear Information System (INIS)

    Rao, R.S.

    1999-01-01

    It is essential to define the various surgical procedures that are carried out for carcinoma of the thyroid gland. They are thyroid gland, subtotal lobectomy, total thyroidectomy and near total thyroidectomy

  12. Total iron binding capacity

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/article/003489.htm Total iron binding capacity To use the sharing features on this page, please enable JavaScript. Total iron binding capacity (TIBC) is a blood test to ...

  13. Total well dominated trees

    DEFF Research Database (Denmark)

    Finbow, Arthur; Frendrup, Allan; Vestergaard, Preben D.

    cardinality then G is a total well dominated graph. In this paper we study composition and decomposition of total well dominated trees. By a reversible process we prove that any total well dominated tree can both be reduced to and constructed from a family of three small trees....

  14. In-depth evaluation of the cycloaddition-retro-Diels-Alder reaction for in vivo targeting with [{sup 111}In]-DTPA-RGD conjugates

    Energy Technology Data Exchange (ETDEWEB)

    Laverman, Peter [Department of Nuclear Medicine, Radboud University Nijmegen Medical Centre, 6500 HB Nijmegen (Netherlands)], E-mail: p.laverman@nucmed.umcn.nl; Meeuwissen, Silvie A. [Department of Nuclear Medicine, Radboud University Nijmegen Medical Centre, 6500 HB Nijmegen (Netherlands); Institute for Molecules and Materials, Radboud University Nijmegen, 6500 GL Nijmegen (Netherlands); Berkel, Sander S. van [Institute for Molecules and Materials, Radboud University Nijmegen, 6500 GL Nijmegen (Netherlands); Oyen, Wim J.G. [Department of Nuclear Medicine, Radboud University Nijmegen Medical Centre, 6500 HB Nijmegen (Netherlands); Delft, Floris L. van; Rutjes, Floris P.J.T. [Institute for Molecules and Materials, Radboud University Nijmegen, 6500 GL Nijmegen (Netherlands); Boerman, Otto C. [Department of Nuclear Medicine, Radboud University Nijmegen Medical Centre, 6500 HB Nijmegen (Netherlands)

    2009-10-15

    Introduction: The spontaneous copper-free tandem 1,3-dipolar cycloaddition-retro-Diels-Alder (tandem crDA) reaction between cyclic Arg-Gly-Asp-D-Phe-Orn(N{sub 3}) [c(RGDfX)] and oxanorbornadiene-DTPA (o-DTPA) or methyloxanorbornadiene-DTPA (mo-DTPA) into two DTPA-c(RGDfX) regioisomers is characterized. Since there is no information on the stability and reaction rate of the tandem crDA reaction in biological media, we set out to characterize these reaction parameters. Methods: The effects of concentration of the reactants, temperature, pH and reaction environment (serum, blood) on the kinetics of the reaction were determined using {sup 111}In-labeled oxanorbornadiene-DTPA analogs. The affinity of the radiolabeled conjugate was determined in a solid-phase {alpha}{sub v}{beta}{sub 3} integrin binding assay. Furthermore, the octanol-water partition coefficient was determined and, finally, the biodistribution of the labeled compounds in mice with subcutaneous {alpha}{sub v}{beta}{sub 3}-expressing tumors was determined. Results: Fifty percent conversion was reached after 26 h. Kinetic experiments furthermore established that the reaction rate of the tandem crDA reaction follows temperature- and concentration-dependent second-order kinetics, but is independent of the pH of the medium. Affinity of the two [{sup 111}In]DTPA-cRGDfX conjugates for {alpha}{sub v}{beta}{sub 3} integrin is 191 nM. Biodistribution studies showed specific ({alpha}{sub v}{beta}{sub 3}-mediated) uptake of [{sup 111}In]DTPA-c(RGDfX) in the tumor and in {alpha}{sub v}{beta}{sub 3}-expressing tissues. Conclusion: The tandem crDA reaction using methyl-substituted oxanorbornadiene is a versatile method for a single-step ligation that proceeds independently of pH and also proceeds in serum and blood. Currently, we are further looking into enhancement of reaction kinetics and exploitation of tandem crDA in vivo.

  15. Total Quality Leadership

    Science.gov (United States)

    1991-01-01

    More than 750 NASA, government, contractor, and academic representatives attended the Seventh Annual NASA/Contractors Conference on Quality and Productivity. The panel presentations and Keynote speeches revolving around the theme of total quality leadership provided a solid base of understanding of the importance, benefits, and principles of total quality management (TQM). The presentations from the conference are summarized.

  16. Genoptraening efter total knaealloplastik

    DEFF Research Database (Denmark)

    Holm, Bente; Kehlet, Henrik

    2009-01-01

    The short- and long-term benefits of post-discharge physiotherapy regimens after total knee arthroplasty are debatable. A national survey including hospitals in Denmark that perform total knee arthroplasty showed a large variability in indication and regimen for post-knee arthroplasty...

  17. Laparoscopic total pancreatectomy

    Science.gov (United States)

    Wang, Xin; Li, Yongbin; Cai, Yunqiang; Liu, Xubao; Peng, Bing

    2017-01-01

    Abstract Rationale: Laparoscopic total pancreatectomy is a complicated surgical procedure and rarely been reported. This study was conducted to investigate the safety and feasibility of laparoscopic total pancreatectomy. Patients and Methods: Three patients underwent laparoscopic total pancreatectomy between May 2014 and August 2015. We reviewed their general demographic data, perioperative details, and short-term outcomes. General morbidity was assessed using Clavien–Dindo classification and delayed gastric emptying (DGE) was evaluated by International Study Group of Pancreatic Surgery (ISGPS) definition. Diagnosis and Outcomes: The indications for laparoscopic total pancreatectomy were intraductal papillary mucinous neoplasm (IPMN) (n = 2) and pancreatic neuroendocrine tumor (PNET) (n = 1). All patients underwent laparoscopic pylorus and spleen-preserving total pancreatectomy, the mean operative time was 490 minutes (range 450–540 minutes), the mean estimated blood loss was 266 mL (range 100–400 minutes); 2 patients suffered from postoperative complication. All the patients recovered uneventfully with conservative treatment and discharged with a mean hospital stay 18 days (range 8–24 days). The short-term (from 108 to 600 days) follow up demonstrated 3 patients had normal and consistent glycated hemoglobin (HbA1c) level with acceptable quality of life. Lessons: Laparoscopic total pancreatectomy is feasible and safe in selected patients and pylorus and spleen preserving technique should be considered. Further prospective randomized studies are needed to obtain a comprehensive understanding the role of laparoscopic technique in total pancreatectomy. PMID:28099344

  18. Estonian total ozone climatology

    Directory of Open Access Journals (Sweden)

    K. Eerme

    Full Text Available The climatological characteristics of total ozone over Estonia based on the Total Ozone Mapping Spectrometer (TOMS data are discussed. The mean annual cycle during 1979–2000 for the site at 58.3° N and 26.5° E is compiled. The available ground-level data interpolated before TOMS, have been used for trend detection. During the last two decades, the quasi-biennial oscillation (QBO corrected systematic decrease of total ozone from February–April was 3 ± 2.6% per decade. Before 1980, a spring decrease was not detectable. No decreasing trend was found in either the late autumn ozone minimum or in the summer total ozone. The QBO related signal in the spring total ozone has an amplitude of ± 20 DU and phase lag of 20 months. Between 1987–1992, the lagged covariance between the Singapore wind and the studied total ozone was weak. The spring (April–May and summer (June–August total ozone have the best correlation (coefficient 0.7 in the yearly cycle. The correlation between the May and August total ozone is higher than the one between the other summer months. Seasonal power spectra of the total ozone variance show preferred periods with an over 95% significance level. Since 1986, during the winter/spring, the contribution period of 32 days prevails instead of the earlier dominating 26 days. The spectral densities of the periods from 4 days to 2 weeks exhibit high interannual variability.

    Key words. Atmospheric composition and structure (middle atmosphere – composition and chemistry; volcanic effects – Meteorology and atmospheric dynamics (climatology

  19. Total photon absorption

    International Nuclear Information System (INIS)

    Carlos, P.

    1985-06-01

    The present discussion is limited to a presentation of the most recent total photonuclear absorption experiments performed with real photons at intermediate energy, and more precisely in the region of nucleon resonances. The main sources of real photons are briefly reviewed and the experimental procedures used for total photonuclear absorption cross section measurements. The main results obtained below 140 MeV photon energy as well as above 2 GeV are recalled. The experimental study of total photonuclear absorption in the nuclear resonance region (140 MeV< E<2 GeV) is still at its beginning and some results are presented

  20. [Total artificial heart].

    Science.gov (United States)

    Antretter, H; Dumfarth, J; Höfer, D

    2015-09-01

    To date the CardioWest™ total artificial heart is the only clinically available implantable biventricular mechanical replacement for irreversible cardiac failure. This article presents the indications, contraindications, implantation procedere and postoperative treatment. In addition to a overview of the applications of the total artificial heart this article gives a brief presentation of the two patients treated in our department with the CardioWest™. The clinical course, postoperative rehabilitation, device-related complications and control mechanisms are presented. The total artificial heart is a reliable implant for treating critically ill patients with irreversible cardiogenic shock. A bridge to transplantation is feasible with excellent results.

  1. Total 2004 results

    International Nuclear Information System (INIS)

    2005-02-01

    This document presents the 2004 results of Total Group: consolidated account, special items, number of shares, market environment, adjustment for amortization of Sanofi-Aventis merger-related intangibles, 4. quarter 2004 results (operating and net incomes, cash flow), upstream (results, production, reserves, recent highlights), downstream (results, refinery throughput, recent highlights), chemicals (results, recent highlights), Total's full year 2004 results (operating and net income, cash flow), 2005 sensitivities, Total SA parent company accounts and proposed dividend, adoption of IFRS accounting, summary and outlook, main operating information by segment for the 4. quarter and full year 2004: upstream (combined liquids and gas production by region, liquids production by region, gas production by region), downstream (refined product sales by region, chemicals), Total financial statements: consolidated statement of income, consolidated balance sheet (assets, liabilities and shareholder's equity), consolidated statements of cash flows, business segments information. (J.S.)

  2. Total synthesis of ciguatoxin.

    Science.gov (United States)

    Hamajima, Akinari; Isobe, Minoru

    2009-01-01

    Something fishy: Ciguatoxin (see structure) is one of the principal toxins involved in ciguatera poisoning and the target of a total synthesis involving the coupling of three segments. The key transformations in this synthesis feature acetylene-dicobalthexacarbonyl complexation.

  3. Total 2004 results

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2005-02-01

    This document presents the 2004 results of Total Group: consolidated account, special items, number of shares, market environment, adjustment for amortization of Sanofi-Aventis merger-related intangibles, 4. quarter 2004 results (operating and net incomes, cash flow), upstream (results, production, reserves, recent highlights), downstream (results, refinery throughput, recent highlights), chemicals (results, recent highlights), Total's full year 2004 results (operating and net income, cash flow), 2005 sensitivities, Total SA parent company accounts and proposed dividend, adoption of IFRS accounting, summary and outlook, main operating information by segment for the 4. quarter and full year 2004: upstream (combined liquids and gas production by region, liquids production by region, gas production by region), downstream (refined product sales by region, chemicals), Total financial statements: consolidated statement of income, consolidated balance sheet (assets, liabilities and shareholder's equity), consolidated statements of cash flows, business segments information. (J.S.)

  4. Genoptraening efter total knaealloplastik

    DEFF Research Database (Denmark)

    Holm, Bente; Kehlet, Henrik

    2009-01-01

    The short- and long-term benefits of post-discharge physiotherapy regimens after total knee arthroplasty are debatable. A national survey including hospitals in Denmark that perform total knee arthroplasty showed a large variability in indication and regimen for post-knee arthroplasty rehabilitat......The short- and long-term benefits of post-discharge physiotherapy regimens after total knee arthroplasty are debatable. A national survey including hospitals in Denmark that perform total knee arthroplasty showed a large variability in indication and regimen for post-knee arthroplasty...... rehabilitation. Since hospital stay duration has decreased considerably, the need for post-discharge physiotherapy may also have changed. Thus, the indication for and types of rehabilitation programmes need to be studied within the context of fast-track knee arthroplasty....

  5. Genoptraening efter total knaealloplastik

    DEFF Research Database (Denmark)

    Holm, Bente; Kehlet, Henrik

    2009-01-01

    The short- and long-term benefits of post-discharge physiotherapy regimens after total knee arthroplasty are debatable. A national survey including hospitals in Denmark that perform total knee arthroplasty showed a large variability in indication and regimen for post-knee arthroplasty rehabilitat......The short- and long-term benefits of post-discharge physiotherapy regimens after total knee arthroplasty are debatable. A national survey including hospitals in Denmark that perform total knee arthroplasty showed a large variability in indication and regimen for post-knee arthroplasty...... rehabilitation. Since hospital stay duration has decreased considerably, the need for post-discharge physiotherapy may also have changed. Thus, the indication for and types of rehabilitation programmes need to be studied within the context of fast-track knee arthroplasty. Udgivelsesdato: 2009-Feb-23...

  6. Supravaginal eller total hysterektomi?

    DEFF Research Database (Denmark)

    Edvardsen, L; Madsen, E M

    1994-01-01

    There has been a decline in the rate of hysterectomies in Denmark in general over the last thirteen years, together with a rise in the number of supravaginal operations over the last two years. The literature concerning the relative merits of the supravaginal and the total abdominal operation is ...... indicate a reduced frequency of orgasm after the total hysterectomy compared with the supravaginal operation. When there are technical problems peroperatively with an increased urologic risk the supravaginal operation is recommended....

  7. Total lymphoid irradiation

    International Nuclear Information System (INIS)

    Sutherland, D.E.; Ferguson, R.M.; Simmons, R.L.; Kim, T.H.; Slavin, S.; Najarian, J.S.

    1983-01-01

    Total lymphoid irradiation by itself can produce sufficient immunosuppression to prolong the survival of a variety of organ allografts in experimental animals. The degree of prolongation is dose-dependent and is limited by the toxicity that occurs with higher doses. Total lymphoid irradiation is more effective before transplantation than after, but when used after transplantation can be combined with pharmacologic immunosuppression to achieve a positive effect. In some animal models, total lymphoid irradiation induces an environment in which fully allogeneic bone marrow will engraft and induce permanent chimerism in the recipients who are then tolerant to organ allografts from the donor strain. If total lymphoid irradiation is ever to have clinical applicability on a large scale, it would seem that it would have to be under circumstances in which tolerance can be induced. However, in some animal models graft-versus-host disease occurs following bone marrow transplantation, and methods to obviate its occurrence probably will be needed if this approach is to be applied clinically. In recent years, patient and graft survival rates in renal allograft recipients treated with conventional immunosuppression have improved considerably, and thus the impetus to utilize total lymphoid irradiation for its immunosuppressive effect alone is less compelling. The future of total lymphoid irradiation probably lies in devising protocols in which maintenance immunosuppression can be eliminated, or nearly eliminated, altogether. Such protocols are effective in rodents. Whether they can be applied to clinical transplantation remains to be seen

  8. Totally optimal decision rules

    KAUST Repository

    Amin, Talha

    2017-11-22

    Optimality of decision rules (patterns) can be measured in many ways. One of these is referred to as length. Length signifies the number of terms in a decision rule and is optimally minimized. Another, coverage represents the width of a rule’s applicability and generality. As such, it is desirable to maximize coverage. A totally optimal decision rule is a decision rule that has the minimum possible length and the maximum possible coverage. This paper presents a method for determining the presence of totally optimal decision rules for “complete” decision tables (representations of total functions in which different variables can have domains of differing values). Depending on the cardinalities of the domains, we can either guarantee for each tuple of values of the function that totally optimal rules exist for each row of the table (as in the case of total Boolean functions where the cardinalities are equal to 2) or, for each row, we can find a tuple of values of the function for which totally optimal rules do not exist for this row.

  9. Totally optimal decision rules

    KAUST Repository

    Amin, Talha M.; Moshkov, Mikhail

    2017-01-01

    Optimality of decision rules (patterns) can be measured in many ways. One of these is referred to as length. Length signifies the number of terms in a decision rule and is optimally minimized. Another, coverage represents the width of a rule’s applicability and generality. As such, it is desirable to maximize coverage. A totally optimal decision rule is a decision rule that has the minimum possible length and the maximum possible coverage. This paper presents a method for determining the presence of totally optimal decision rules for “complete” decision tables (representations of total functions in which different variables can have domains of differing values). Depending on the cardinalities of the domains, we can either guarantee for each tuple of values of the function that totally optimal rules exist for each row of the table (as in the case of total Boolean functions where the cardinalities are equal to 2) or, for each row, we can find a tuple of values of the function for which totally optimal rules do not exist for this row.

  10. Total volume versus bouts

    DEFF Research Database (Denmark)

    Chinapaw, Mai; Klakk, Heidi; Møller, Niels Christian

    2018-01-01

    BACKGROUND/OBJECTIVES: Examine the prospective relationship of total volume versus bouts of sedentary behaviour (SB) and moderate-to-vigorous physical activity (MVPA) with cardiometabolic risk in children. In addition, the moderating effects of weight status and MVPA were explored. SUBJECTS....../METHODS: Longitudinal study including 454 primary school children (mean age 10.3 years). Total volume and bouts (i.e. ≥10 min consecutive minutes) of MVPA and SB were assessed by accelerometry in Nov 2009/Jan 2010 (T1) and Aug/Oct 2010 (T2). Triglycerides, total cholesterol/HDL cholesterol ratio (TC:HDLC ratio......, with or without mutual adjustments between MVPA and SB. The moderating effects of weight status and MVPA (for SB only) were examined by adding interaction terms. RESULTS: Children engaged daily in about 60 min of total MVPA and 0-15 min/week in MVPA bouts. Mean total sedentary time was around 7 h/day with over 3...

  11. Total versus subtotal hysterectomy

    DEFF Research Database (Denmark)

    Gimbel, Helga; Zobbe, Vibeke; Andersen, Anna Birthe

    2005-01-01

    The aim of this study was to compare total and subtotal abdominal hysterectomy for benign indications, with regard to urinary incontinence, postoperative complications, quality of life (SF-36), constipation, prolapse, satisfaction with sexual life, and pelvic pain at 1-year postoperative. Eighty...... women chose total and 105 women chose subtotal abdominal hysterectomy. No significant differences were found between the 2 operation methods in any of the outcome measures at 12 months. Fourteen women (15%) from the subtotal abdominal hysterectomy group experienced vaginal bleeding and three women had...

  12. Qualità totale e mobilità totale Total Quality and Total Mobility

    Directory of Open Access Journals (Sweden)

    Giuseppe Trieste

    2010-05-01

    Full Text Available FIABA ONLUS (Italian Fund for Elimination of Architectural Barriers was founded in 2000 with the aim of promoting a culture of equal opportunities and, above all, it has as its main goal to involve public and private institutions to create a really accessible and usable environment for everyone. Total accessibility, Total usability and Total mobility are key indicators to define quality of life within cities. A supportive environment that is free of architectural, cultural and psychological barriers allows everyone to live with ease and universality. In fact, people who access to goods and services in the urban context can use to their advantage time and space, so they can do their activities and can maintain relationships that are deemed significant for their social life. The main aim of urban accessibility is to raise the comfort of space for citizens, eliminating all barriers that discriminate people, and prevent from an equality of opportunity. “FIABA FUND - City of ... for the removal of architectural barriers” is an idea of FIABA that has already affected many regions of Italy as Lazio, Lombardy, Campania, Abruzzi and Calabria. It is a National project which provides for opening a bank account in the cities of referring, in which for the first time, all together, individuals and private and public institutions can make a donation to fund initiatives for the removal of architectural barriers within its own territory for a real and effective total accessibility. Last February the fund was launched in Rome with the aim of achieving a Capital without barriers and a Town European model of accessibility and usability. Urban mobility is a prerequisite to access to goods and services, and to organize activities related to daily life. FIABA promotes the concept of sustainable mobility for all, supported by the European Commission’s White Paper. We need a cultural change in management and organization of public means, which might focus on

  13. CSF total protein

    Science.gov (United States)

    CSF total protein is a test to determine the amount of protein in your spinal fluid, also called cerebrospinal fluid (CSF). ... The normal protein range varies from lab to lab, but is typically about 15 to 60 milligrams per deciliter (mg/dL) ...

  14. Total body irradiation

    International Nuclear Information System (INIS)

    Novack, D.H.; Kiley, J.P.

    1987-01-01

    The multitude of papers and conferences in recent years on the use of very large megavoltage radiation fields indicates an increased interest in total body, hemibody, and total nodal radiotherapy for various clinical situations. These include high dose total body irradiation (TBI) to destroy the bone marrow and leukemic cells and provide immunosuppression prior to a bone marrow transplant, high dose total lymphoid irradiation (TLI) prior to bone marrow transplantation in severe aplastic anemia, low dose TBI in the treatment of lymphocytic leukemias or lymphomas, and hemibody irradiation (HBI) in the treatment of advanced multiple myeloma. Although accurate provision of a specific dose and the desired degree of dose homogeneity are two of the physicist's major considerations for all radiotherapy techniques, these tasks are even more demanding for large field radiotherapy. Because most large field radiotherapy is done at an extended distance for complex patient geometries, basic dosimetry data measured at the standard distance (isocenter) must be verified or supplemented. This paper discusses some of the special dosimetric problems of large field radiotherapy, with specific examples given of the dosimetry of the TBI program for bone marrow transplant at the authors' hospital

  15. Total design of participation

    DEFF Research Database (Denmark)

    Munch, Anders V.

    2016-01-01

    The idea of design as an art made not only for the people, but also by the people is an old dream going back at least to William Morris. It is, however, reappearing vigoriously in many kinds of design activism and grows out of the visions of a Total Design of society. The ideas of participation b...

  16. Total Quality Management Simplified.

    Science.gov (United States)

    Arias, Pam

    1995-01-01

    Maintains that Total Quality Management (TQM) is one method that helps to monitor and improve the quality of child care. Lists four steps for a child-care center to design and implement its own TQM program. Suggests that quality assurance in child-care settings is an ongoing process, and that TQM programs help in providing consistent, high-quality…

  17. Total Quality Management Seminar.

    Science.gov (United States)

    Massachusetts Career Development Inst., Springfield.

    This booklet is one of six texts from a workplace literacy curriculum designed to assist learners in facing the increased demands of the workplace. The booklet contains seven sections that cover the following topics: (1) meaning of total quality management (TQM); (2) the customer; (3) the organization's culture; (4) comparison of management…

  18. Total photon absorption

    International Nuclear Information System (INIS)

    Carlos, P.

    1985-01-01

    Experimental methods using real photon beams for measurements of total photonuclear absorption cross section σ(Tot : E/sub γ/) are recalled. Most recent σ(Tot : E/sub γ/)results for complex nuclei and in the nucleon resonance region are presented

  19. Total 2004 annual report

    International Nuclear Information System (INIS)

    2004-01-01

    This annual report of the Group Total brings information and economic data on the following topics, for the year 2004: the corporate governance, the corporate social responsibility, the shareholder notebook, the management report, the activities, the upstream (exploration and production) and downstream (refining and marketing) operating, chemicals and other matters. (A.L.B.)

  20. Total Water Management - Report

    Science.gov (United States)

    There is a growing need for urban water managers to take a more holistic view of their water resource systems as population growth, urbanization, and current operations put different stresses on the environment and urban infrastructure. Total Water Management (TWM) is an approac...

  1. H-ferrierite zeolite: As an effective and reusable heterogeneous catalyst for synthesis of 1,5-benzothiazepine under solvent free condition and 1,3-dipolar cycloaddition in water

    Directory of Open Access Journals (Sweden)

    Thoraya A. Farghaly

    2017-05-01

    Full Text Available An efficient synthesis of new derivatives of 1,5-benzothiazepine has been developed by the reaction of various chalcones (1,3-diaryl-2-propenones with 2-amino-thiophenol in the presence of H-ferrierite zeolite as acidic catalyst without solvent. In addition, 1,3-dipolar cycloaddition of hydrazonoyl chlorides on CN bond of 1,5-benzothiazepines in water in the presence of Na2CO3/THAC as a base catalyst afforded 1,2,4-triazolo[3,4-d][1,5]benzothiazepines. The structure of all the newly synthesized compounds was established on the basis of spectral data (Mass, IR, 1H NMR, 13C NMR and elemental analysis.

  2. Unprecedented intramolecular [3 + 2] cycloadditions of azido-ketenimines and azido-carbodiimides. Synthesis of indolo[1,2-a]quinazolines and tetrazolo[5,1-b]quinazolines.

    Science.gov (United States)

    Alajarin, Mateo; Bonillo, Baltasar; Ortin, Maria-Mar; Orenes, Raul-Angel; Vidal, Angel

    2011-10-07

    N-(2-azidomethyl)phenyl ketenimines and N-(2-azidomethyl)phenyl-N'-alkyl(aryl) carbodiimides undergo, under mild thermal conditions, intramolecular [3 + 2] cycloaddition reactions between the azido group and either the C=C or the distal C=N double bonds of the ketenimine and carbodiimide functions respectively. The reaction products are indolo[1,2-a]quinazolines and/or indolo[2,1-b]quinazolines in the case of azido-ketenimines, and tetrazolo[5,1-b]quinazolines in the case of azido-carbodiimides. The formation of the two classes of indoloquinazolines implies the ulterior dinitrogen extrusion from the non-isolated, putative [3 + 2] cycloadducts between the azide and ketenimine functions, whereas in the case of azido-carbodiimides the initial cycloadducts, tetrazoloquinazolines, were cleanly isolated and further converted into 2-aminoquinazolines by thermally induced dinitrogen extrusion.

  3. A Polyoxovanadate-Resorcin[4]arene-Based Porous Metal-Organic Framework as an Efficient Multifunctional Catalyst for the Cycloaddition of CO2 with Epoxides and the Selective Oxidation of Sulfides.

    Science.gov (United States)

    Lu, Bing-Bing; Yang, Jin; Liu, Ying-Ying; Ma, Jian-Fang

    2017-10-02

    In this work, we report a new polyoxovanadate-resorcin[4]arene-based metal-organic framework (PMOF), [Co 2 L 0.5 V 4 O 12 ]·3DMF·5H 2 O (1), assembled with a newly functionalized wheel-like resorcin[4]arene ligand (L). 1 features an elegant porous motif and represents a rare example of PMOFs composed of both a resorcin[4]arene ligand and polyoxovanadate. Remarkably, 1 shows open V sites in the channel, which makes 1 an efficient heterogeneous Lewis acid catalyst for the cycloaddition of carbon dioxide to epoxides with high conversion and selectivity. Strikingly, 1 also exhibits high catalytic activity for the heterogeneous oxidative desulfurization of sulfides. Particularly, the heterogeneous catalyst 1 can be easily separated and reused with good catalytic activity.

  4. Efficient approach to androstene-fused arylpyrazolines as potent antiproliferative agents. Experimental and theoretical studies of substituent effects on BF(3)-catalyzed intramolecular [3 + 2] cycloadditions of olefinic phenylhydrazones.

    Science.gov (United States)

    Frank, Eva; Mucsi, Zoltán; Zupkó, István; Réthy, Borbála; Falkay, George; Schneider, Gyula; Wölfling, János

    2009-03-25

    Highly diastereoselective Lewis acid induced intramolecular 1,3-dipolar cycloadditions of alkenyl phenylhydrazones (containing various substituents on the aromatic ring) obtained from a d-secopregnene aldehyde were carried out under fairly mild conditions to furnish androst-5-ene-fused arylpyrazolines in good to excellent yields. The ability of phenylhydrazones to undergo cyclization was found to be affected significantly by the electronic features of the substituents on the aromatic moiety. The rates of the ring-closure reactions were observed to be increased by electron-donating and decreased by electron-withdrawing groups. The experimental findings on the BF(3)-catalyzed transformations were supported by calculations of the proposed mechanism at the BLYP/6-31G(d) level of theory, indicating a noteworthy dependence, mainly of the initial complexation step, and hence of the whole process, on the character of the substituent. The cycloaddition was estimated to occur via a zwitterionic intermediate rather than involving a pure concerted mechanism. The antiproliferative activities of the structurally related pyrazoline derivatives were tested in vitro on three malignant human cell lines (HeLa, MCF7, and A431): the microculture tetrazolium assay revealed that several compounds exerted marked cell growth-inhibitory effects. The highest cytotoxic activities, displayed by the p-methoxyphenylpyrazoline derivative 7d (IC(50) values: 2.01, 2.16, and 1.41 microM on HeLa, MCF7, and A341 cells, respectively), were better than those of cisplatin (IC(50) values: 12.43, 9.63, and 2.84 microM, respectively).

  5. Total 2003 Results

    International Nuclear Information System (INIS)

    2003-01-01

    This document presents the 2003 results of Total Group: consolidated account, special items, number of shares, market environment, 4. quarter 2003 results, full year 2003 results, upstream (key figures, proved reserves), downstream key figures, chemicals key figures, parent company accounts and proposed dividends, 2004 sensitivities, summary and outlook, operating information by segment for the 4. quarter and full year 2003: upstream (combined liquids and gas production by region, liquids production by region, gas production by region), downstream (refinery throughput by region, refined product sales by region, chemicals), impact of allocating contribution of Cepsa to net operating income by business segment: equity in income (loss) and affiliates and other items, Total financial statements: consolidated statement of income, consolidated balance sheet (assets, liabilities and shareholder's equity), consolidated statements of cash flows, business segments information. (J.S.)

  6. TOTAL PERFORMANCE SCORECARD

    Directory of Open Access Journals (Sweden)

    Anca ȘERBAN

    2013-06-01

    Full Text Available The purpose of this paper is to present the evolution of the Balanced Scorecard from a measurement instrument to a strategic performance management tool and to highlight the advantages of implementing the Total Performance Scorecard, especially for Human Resource Management. The study has been accomplished using the methodology of bibliographic study and various secondary sources. Implementing the classical Balanced Scorecard indicated over the years, repeatedly failure. It can be indicated that the crucial level is determined by the learning and growth perspective. It has been developed from a human perspective, which focused on staff satisfaction, innovation perspective with focus on future developments. Integrating the Total Performance Scorecard in an overall framework assures the company’s success, by keeping track of the individual goals, the company’s objectives and strategic directions. Like this, individual identity can be linked to corporate brand, individual aspirations to business goals and individual learning objectives to needed organizational capabilities.

  7. Totally parallel multilevel algorithms

    Science.gov (United States)

    Frederickson, Paul O.

    1988-01-01

    Four totally parallel algorithms for the solution of a sparse linear system have common characteristics which become quite apparent when they are implemented on a highly parallel hypercube such as the CM2. These four algorithms are Parallel Superconvergent Multigrid (PSMG) of Frederickson and McBryan, Robust Multigrid (RMG) of Hackbusch, the FFT based Spectral Algorithm, and Parallel Cyclic Reduction. In fact, all four can be formulated as particular cases of the same totally parallel multilevel algorithm, which are referred to as TPMA. In certain cases the spectral radius of TPMA is zero, and it is recognized to be a direct algorithm. In many other cases the spectral radius, although not zero, is small enough that a single iteration per timestep keeps the local error within the required tolerance.

  8. Total space in resolution

    Czech Academy of Sciences Publication Activity Database

    Bonacina, I.; Galesi, N.; Thapen, Neil

    2016-01-01

    Roč. 45, č. 5 (2016), s. 1894-1909 ISSN 0097-5397 R&D Projects: GA ČR GBP202/12/G061 EU Projects: European Commission(XE) 339691 - FEALORA Institutional support: RVO:67985840 Keywords : total space * resolution random CNFs * proof complexity Subject RIV: BA - General Mathematics Impact factor: 1.433, year: 2016 http://epubs.siam.org/doi/10.1137/15M1023269

  9. MFTF TOTAL benchmark

    International Nuclear Information System (INIS)

    Choy, J.H.

    1979-06-01

    A benchmark of the TOTAL data base management system as applied to the Mirror Fusion Test Facility (MFTF) data base was implemented and run in February and March of 1979. The benchmark was run on an Interdata 8/32 and involved the following tasks: (1) data base design, (2) data base generation, (3) data base load, and (4) develop and implement programs to simulate MFTF usage of the data base

  10. Total - annual report 2005

    International Nuclear Information System (INIS)

    2006-01-01

    This annual report presents the activities and results of TOTAL S.A., french society on oil and gas. It deals with statistics, the managers, key information on financial data and risk factors, information on the Company, unresolved Staff Comments, employees, major Shareholders, consolidated statements, markets, security, financial risks, defaults dividend arrearages and delinquencies, controls and procedures, code of ethics and financial statements. (A.L.B.)

  11. Total Absorption Spectroscopy

    International Nuclear Information System (INIS)

    Rubio, B.; Gelletly, W.

    2007-01-01

    The problem of determining the distribution of beta decay strength (B(GT)) as a function of excitation energy in the daughter nucleus is discussed. Total Absorption Spectroscopy is shown to provide a way of determining the B(GT) precisely. A brief history of such measurements and a discussion of the advantages and disadvantages of this technique, is followed by examples of two recent studies using the technique. (authors)

  12. Sobredentadura total superior implantosoportada

    Directory of Open Access Journals (Sweden)

    Luis Orlando Rodríguez García

    2010-06-01

    Full Text Available Se presenta un caso de un paciente desdentado total superior, rehabilitado en la consulta de implantología de la Clínica "Pedro Ortiz" del municipio Habana del Este en Ciudad de La Habana, Cuba, en el año 2009, mediante prótesis sobre implantes osteointegrados, técnica que se ha incorporado a la práctica estomatológica en Cuba como alternativa al tratamiento convencional en los pacientes desdentados totales. Se siguió un protocolo que comprendió una fase quirúrgica, procedimiento con o sin realización de colgajo y carga precoz o inmediata. Se presenta un paciente masculino de 56 años de edad, que acudió a la consulta multidisciplinaria, preocupado, porque se le habían elaborado tres prótesis en los últimos dos años y ninguna reunía los requisitos de retención que él necesitaba para sentirse seguro y cómodo con las mismas. El resultado final fue la satisfacción total del paciente, con el mejoramiento de la calidad estética y funcional.

  13. Total Synthesis of Hyperforin.

    Science.gov (United States)

    Ting, Chi P; Maimone, Thomas J

    2015-08-26

    A 10-step total synthesis of the polycyclic polyprenylated acylphloroglucinol (PPAP) natural product hyperforin from 2-methylcyclopent-2-en-1-one is reported. This route was enabled by a diketene annulation reaction and an oxidative ring expansion strategy designed to complement the presumed biosynthesis of this complex meroterpene. The described work enables the preparation of a highly substituted bicyclo[3.3.1]nonane-1,3,5-trione motif in only six steps and thus serves as a platform for the construction of easily synthesized, highly diverse PPAPs modifiable at every position.

  14. Total quality is people

    International Nuclear Information System (INIS)

    Vogel, C.E.

    1991-01-01

    Confronted by changing market conditions and increased global competition, in 1983 the Commercial Nuclear Fuel Division (CNFD) of Westinghouse Electric embarked on an ambitious plan to make total quality the centerpiece of its long-term business strategy. Five years later, the division's efforts in making continuous quality improvement a way of life among its more than 2,000 employees gained national recognition when it was named a charter recipient of the Malcolm Baldridge National Quality Award. What CNFD achieved during the 1980s was a cultural transformation, characterized by an empowered work force committed to a common vision. The company's quality program development strategy is described

  15. Total quality accounting

    Directory of Open Access Journals (Sweden)

    Andrijašević Maja

    2008-01-01

    Full Text Available The focus of competitive "battle" shifted from the price towards non-price instruments, above all, towards quality that became the key variable for profitability increase and achievement of better comparative position of a company. Under such conditions, management of a company, which, according to the established and certified system of total quality, strives towards achieving of a better market position, faces the problem of quality cost measurement and determination. Management, above all, cost accounting can help in solving of this problem, but the question is how much of its potential is being used for that purpose.

  16. Total_Aktion

    DEFF Research Database (Denmark)

    Søndergaard, Morten

    2008-01-01

    digitale medier er registreringen og muligheden for at opbevare og håndtere digital data uden begrænsninger. Oplevelse, registrering og bevaring knyttes sammen i en ny museal virkelighed, hvor samlingens særlige dokumentariske karakter og fokus, som er unikt for Museet for Samtidskunst, er i centrum...... at mikse deres personlige drinks. TOTAL_AKTION viser Hørbar#3, som er en videreudvikling af den første version. METASYN af Carl Emil Carlsen: Metadata er centralt for Carl Emil Carlsens projekt, der betragter museets samling som et ”univers” af værker (analoge og digitale), beskrivelser og relationer. I...

  17. Total Logistic Plant Solutions

    Directory of Open Access Journals (Sweden)

    Dusan Dorcak

    2016-02-01

    Full Text Available The Total Logistics Plant Solutions, plant logistics system - TLPS, based on the philosophy of advanced control processes enables complex coordination of business processes and flows and the management and scheduling of production in the appropriate production plans and planning periods. Main attributes of TLPS is to create a comprehensive, multi-level, enterprise logistics information system, with a certain degree of intelligence, which accepts the latest science and research results in the field of production technology and logistics. Logistic model of company understands as a system of mutually transforming flows of materials, energy, information, finance, which is realized by chain activities and operations

  18. Total Factbook 2003

    International Nuclear Information System (INIS)

    2003-01-01

    This report presents the activities and results of the Group Total-Fina-Elf for the year 2003. It brings information and economic data on the following topics: the corporate and business; the upstream activities with the reserves, the costs, standardized measure and changes of discounted future net cash flow,oil and gas acreage, drilling, liquefied natural gas, pipelines; downstream activities with refining and marketing maps, refinery, petroleum products, sales, retail gasoline outlets; chemicals with sales and operating income by sector, major applications, base chemicals and polymers, intermediates and performance polymers. (A.L.B.)

  19. Total 2004 fact book

    International Nuclear Information System (INIS)

    2004-01-01

    This report presents the activities and results of the Group Total-Fina-Elf for the year 2004. It brings information and economic data on the following topics: the corporate and business; the upstream activities with the reserves, the costs, standardized measure and changes of discounted future net cash flow,oil and gas acreage, drilling, liquefied natural gas, pipelines; downstream activities with refining and marketing maps, refinery, petroleum products, sales, retail gasoline outlets; chemicals with sales and operating income by sector, major applications, base chemicals and polymers, intermediates and performance polymers. (A.L.B.)

  20. TOTAL annual report 2003

    International Nuclear Information System (INIS)

    2004-01-01

    This 2003 annual report of the Group Total provides economical results and information of the society on the following topics: keys data, the corporate governance (Directors charter, board of directors, audit committee, nomination and remuneration committee, internal control procedures, compensation of directors and executive officers), the corporate social responsibility (environmental stewardship, the future of energy management, the safety enhancement, the human resources, ethics and local development), the investor relations, the management report, the upstream exploration and production, the downstream refining, marketing, trading and shipping, the chemicals and financial and legal information. (A.L.B.)

  1. Total knee arthroplasty

    DEFF Research Database (Denmark)

    Schrøder, Henrik M.; Petersen, Michael M.

    2016-01-01

    Total knee arthroplasty (TKA) is a successful treatment of the osteoarthritic knee, which has increased dramatically over the last 30 years. The indication is a painful osteoarthritic knee with relevant radiographic findings and failure of conservative measures like painkillers and exercise...... surgeon seems to positively influence the rate of surgical complications and implant survival. The painful TKA knee should be thoroughly evaluated, but not revised except if a relevant indication can be established. The most frequent indications for revision are: aseptic loosening, instability, infection...

  2. TOTAL user manual

    Science.gov (United States)

    Johnson, Sally C.; Boerschlein, David P.

    1994-01-01

    Semi-Markov models can be used to analyze the reliability of virtually any fault-tolerant system. However, the process of delineating all of the states and transitions in the model of a complex system can be devastatingly tedious and error-prone. Even with tools such as the Abstract Semi-Markov Specification Interface to the SURE Tool (ASSIST), the user must describe a system by specifying the rules governing the behavior of the system in order to generate the model. With the Table Oriented Translator to the ASSIST Language (TOTAL), the user can specify the components of a typical system and their attributes in the form of a table. The conditions that lead to system failure are also listed in a tabular form. The user can also abstractly specify dependencies with causes and effects. The level of information required is appropriate for system designers with little or no background in the details of reliability calculations. A menu-driven interface guides the user through the system description process, and the program updates the tables as new information is entered. The TOTAL program automatically generates an ASSIST input description to match the system description.

  3. Total process surveillance: (TOPS)

    International Nuclear Information System (INIS)

    Millar, J.H.P.

    1992-01-01

    A Total Process Surveillance system is under development which can provide, in real-time, additional process information from a limited number of raw measurement signals. This is achieved by using a robust model based observer to generate estimates of the process' internal states. The observer utilises the analytical reduncancy among a diverse range of transducers and can thus accommodate off-normal conditions which lead to transducer loss or damage. The modular hierarchical structure of the system enables the maximum amount of information to be assimilated from the available instrument signals no matter how diverse. This structure also constitutes a data reduction path thus reducing operator cognitive overload from a large number of varying, and possibly contradictory, raw plant signals. (orig.)

  4. Total and EDF invest

    International Nuclear Information System (INIS)

    Signoret, St.

    2008-01-01

    So as to prepare the future of their industrial sector,the Total company plans to invest (14 billion Euros in 2008) to increase its production capacities and strengthen in of other activities as the liquefied natural gas and the renewable energies; EDF plans to inject 35 billion Euros over three years to multiply the new projects of power plants (wind turbines, coal in Germany, gas in Great Britain and nuclear power in Flamanville). EDF wants to exploit its knowledge of leader to run more than ten E.P.R.(European pressurized water reactor) in the world before 2020, projects are in examination with China, Great Britain, South Africa and United States. (N.C.)

  5. Total quality at source

    International Nuclear Information System (INIS)

    Chiandone, A.C.

    1990-01-01

    The Total Quality at Source philosophy is based on optimizing the effectiveness of people in achieving ZERO-DEFECT results. In this paper a philosophy of what, I have come to perceive, it takes to get people to perform to the very best of their abilities and thereby achieve the best results they can, is presented. In the examples I shall describe I have played an instrumental role since it has become my belief that any job can always be done better provided that the people doing it can themselves become convinced that they can do better. Clearly there are many ideas on how to do this. The philosophy that I am presenting in this paper is based on my own experience, where I have both participated and observed it being applied; its effectiveness may be judged by the results. (author)

  6. Total ankle joint replacement.

    Science.gov (United States)

    2016-02-01

    Ankle arthritis results in a stiff and painful ankle and can be a major cause of disability. For people with end-stage ankle arthritis, arthrodesis (ankle fusion) is effective at reducing pain in the shorter term, but results in a fixed joint, and over time the loss of mobility places stress on other joints in the foot that may lead to arthritis, pain and dysfunction. Another option is to perform a total ankle joint replacement, with the aim of giving the patient a mobile and pain-free ankle. In this article we review the efficacy of this procedure, including how it compares to ankle arthrodesis, and consider the indications and complications. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

  7. Synthesis and characterization of cyclic polystyrene using copper-catalyzed alkyne-azide cycloaddition coupling - evaluation of physical properties and optimization of cyclization conditions

    Science.gov (United States)

    Elupula, Ravinder

    . Whereas, anionically prepared A-PS had much higher reliance on the molecular weight changes for its glass transition temperature. However, in thin films, c-PS films have, within error, no confinement effect. In contrast, A-PS has seen large T g reduction with confinement. Ellipsometry analysis suggests that this invariance of the Tg-confinement effect in c-PS is a result of the weak perturbation to Tg near the free surface (i.e. the polymer-air interface). These weak perturbations are the result of the high packing efficiency of cyclic PS segments. The copper-catalyzed alkyne/azide cycloaddition (CuAAC) click reaction has been used to cyclize many linear polymers with complementary azide and alkyne end groups via unimolecular heterodifunctional approach. Cyclic polymers exhibit unique and potentially useful physical properties compared to their linear analogs, hence increasing interest in techniques for preparing this class of polymers. However, a general route for producing high purity cyclic polymers remained elusive. Prior to the discovery of "click" chemistry, it was difficult to produce highly pure cyclic polymers via the ring-closure approach, requiring extensive post-cyclization purification. However, even minor amounts of linear impurities can influence the physical properties of cyclic polymers. Thermal gradient interaction chromatography (TGIC) coupled with Matrix-Assisted Laser Desorption/Ionization Time of Flight Mass Spectrometry (MALDI-ToF MS) allows the fractionation of cyclic polymer samples and produce valuable data for determining both the quantity and identity of linear impurities. This understanding further enables us to optimize cyclization conditions towards the goal of and efficient, general methodology for producing highly pure cyclic polymers. To solve the ever-growing energy needs of the world and capture the renewable energy that is generated sporadically, we need to create devices that can store high amounts of energy and discharge power at

  8. Total lymphoid irradiation

    International Nuclear Information System (INIS)

    Anon.

    1980-01-01

    An outline review notes recent work on total lymphoid irradiation (TLI) as a means of preparing patients for grafts and particularly for bone-marrow transplantation. T.L.I. has proved immunosuppressive in rats, mice, dogs, monkeys and baboons; when given before bone-marrow transplantation, engraftment took place without, or with delayed rejection or graft-versus-host disease. Work with mice has indicated that the thymus needs to be included within the irradiation field, since screening of the thymus reduced skin-graft survival from 50 to 18 days, though irradiation of the thymus alone has proved ineffective. A more lasting tolerance has been observed when T.L.I. is followed by an injection of donor bone marrow. 50% of mice treated in this way accepted allogenic skin grafts for more than 100 days, the animals proving to be stable chimeras with 50% of their peripheral blood lymphocytes being of donor origin. Experiments of a similar nature with dogs and baboons were not so successful. (U.K.)

  9. The total artificial heart.

    Science.gov (United States)

    Cook, Jason A; Shah, Keyur B; Quader, Mohammed A; Cooke, Richard H; Kasirajan, Vigneshwar; Rao, Kris K; Smallfield, Melissa C; Tchoukina, Inna; Tang, Daniel G

    2015-12-01

    The total artificial heart (TAH) is a form of mechanical circulatory support in which the patient's native ventricles and valves are explanted and replaced by a pneumatically powered artificial heart. Currently, the TAH is approved for use in end-stage biventricular heart failure as a bridge to heart transplantation. However, with an increasing global burden of cardiovascular disease and congestive heart failure, the number of patients with end-stage heart failure awaiting heart transplantation now far exceeds the number of available hearts. As a result, the use of mechanical circulatory support, including the TAH and left ventricular assist device (LVAD), is growing exponentially. The LVAD is already widely used as destination therapy, and destination therapy for the TAH is under investigation. While most patients requiring mechanical circulatory support are effectively treated with LVADs, there is a subset of patients with concurrent right ventricular failure or major structural barriers to LVAD placement in whom TAH may be more appropriate. The history, indications, surgical implantation, post device management, outcomes, complications, and future direction of the TAH are discussed in this review.

  10. Incapacidad laboral total

    Directory of Open Access Journals (Sweden)

    Orlando Díaz Tabares

    1997-04-01

    Full Text Available Se realizó un estudio longitudinal, descriptivo y retrospectivo con el objetivo de conocer el comportamiento de la incapacidad permanente para el trabajo en el municipio "San Cristóbal" durante el decenio 1982-1991, y se aplicó el método de encuesta por el que se recogieron datos que fueron extraídos del modelo oficial de peritaje médico laboral y de la entrevista con el peritado. Los resultados fueron plasmados en tablas de contingencias donde se relacionan las variables por cada año estudiado, y se aplicó la prueba estadística de chi cuadrado. El número de individuos dictaminados con incapacidad laboral total fue de 693; predominó en reportes el año 1988 con 114 casos y muy discretamente el sexo femenino sobre el masculino, el grupo etáreo de 45 a 54 años con 360 casos y la artrosis como entidad valorada por ortopedia, con análisis estadísticos significativos. No resultó estadísticamente significativo, el predominio de la hipertensión arterial sistémica entre las entidades valoradas por la especialidad de medicina interna como causas de incapacidad laboral. Fue muy significativa la variación del número de dictaminados por la comisión en cada uno de los años estudiados y que el porcentaje de ellos que se encontraban realizando trabajos que demandan esfuerzo físico de moderado a intenso al momento de aplicar la encuesta, ascendió al 64,9.A longitudinal, descriptive and retrospective study was conducted in order to know the behavior of permanent labor disability at the municipality of San Cristóbal during 1982-1991. A survey was done to collect data taken from the official model of medical inspections and from the interview with the disabled worker. The results were shown in contingency tables where the variables are related by every year studied. The chi square statistical test was applied. The number of individuals with labor disability was 693. As for reports, the year 1988 predominated with 114. There was a discreet

  11. Rh(V) -Nitrenoid as a Key Intermediate in Rh(III) -Catalyzed Heterocyclization by C-H Activation: A Computational Perspective on the Cycloaddition of Benzamide and Diazo Compounds.

    Science.gov (United States)

    Zhou, Tao; Guo, Wei; Xia, Yuanzhi

    2015-06-15

    A mechanistic study of the substituent-dependent ring formations in Rh(III) -catalyzed C-H activation/cycloaddition of benzamide and diazo compounds was carried out by using DFT calculations. The results indicated that the decomposition of the diazo is facilitated upon the formation of the five-membered rhodacycle, in which the Rh(III) center is more electrophilic. The insertion of carbenoid into Rh-C(phenyl) bond occurs readily and forms a 6-membered rhodacycle, however, the following C-N bond formation is difficult both kinetically and thermodynamically by reductive elimination from the Rh(III) species. Instead, the Rh(V) -nitrenoid intermediate could be formed by migration of the pivalate from N to Rh, which undergoes the heterocyclization much more easily and complementary ring-formations could be modulated by the nature of the substituent at the α-carbon. When a vinyl is attached, the stepwise 1,3-allylic migration occurs prior to the pivalate migration and the 8-membered ring product will be formed. On the other hand, the pivalate migration becomes more favorable for the phenyl-contained intermediate because of the difficult 1,3-allylic migration accompanied by dearomatization, thus the 5-membered ring product was formed selectively. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Reactive Energetic Plasticizers Utilizing Cu-Free Azide-Alkyne 1,3-Dipolar Cycloaddition for In-Situ Preparation of Poly(THF-co-GAP-Based Polyurethane Energetic Binders

    Directory of Open Access Journals (Sweden)

    Mingyang Ma

    2018-05-01

    Full Text Available Reactive energetic plasticizers (REPs coupled with hydroxy-telechelic poly(glycidyl azide-co-tetrahydrofuran (PGT-based energetic polyurethane (PU binders for use in solid propellants and plastic-bonded explosives (PBXs were investigated. The generation of gem-dinitro REPs along with a terminal alkyne stemmed from a series of finely designed approaches to not only satisfy common demands as conventional energetic plasticizers, but also to prevent the migration of plasticizers. The miscibility and rheological behavior of a binary mixture of PGT/REP with various REP fractions were quantitatively determined by differential scanning calorimetry (DSC and rheometer, respectively, highlighting the promising performance of REPs in the formulation process. The kinetics on the distinct reactivity of propargyl vs. 3-butynyl species of REPs towards the azide group of the PGT prepolymer in terms of Cu-free azide-alkyne 1,3-dipolar cycloaddition (1,3-DPCA was studied by monitoring 1H nuclear magnetic resonance spectroscopy and analyzing the activation energies (Ea obtained using DSC. The thermal stability of the finally cured energetic binders with the incorporation of REPs indicated that the thermal stability of the REP/PGT-based PUs was maintained independently of the REP content. The tensile strength and modulus of the PUs increased with an increase in the REP content. In addition, the energetic performance and sensitivity of REP and REP triazole species was predicted.

  13. An Active Alkali-Exchanged Faujasite Catalyst for p-Xylene Production via the One-Pot Diels-Alder Cycloaddition/Dehydration Reaction of 2,5-Dimethylfuran with Ethylene.

    Science.gov (United States)

    Rohling, Roderigh Y; Uslamin, Evgeny; Zijlstra, Bart; Tranca, Ionut C; Filot, Ivo A W; Hensen, Emiel J M; Pidko, Evgeny A

    2018-02-02

    The one-pot Diels-Alder cycloaddition (DAC)/dehydration (D) tandem reaction between 2,5-dimethylfuran and ethylene is a potent pathway toward biomass-derived p -xylene. In this work, we present a cheap and active low-silica potassium-exchanged faujasite (KY, Si/Al = 2.6) catalyst. Catalyst optimization was guided by a computational study of the DAC/D reaction mechanism over different alkali-exchanged faujasites using periodic density functional theory calculations complemented by microkinetic modeling. Two types of faujasite models were compared, i.e., a high-silica alkali-exchanged faujasite model representing isolated active cation sites and a low-silica alkali-exchanged faujasite in which the reaction involves several cations in the proximity. The mechanistic study points to a significant synergetic cooperative effect of the ensemble of cations in the faujasite supercage on the DAC/D reaction. Alignment of the reactants by their interactions with the cationic sites and stabilization of reaction intermediates contribute to the high catalytic performance. Experiments confirmed the prediction that KY is the most active catalyst among low-silica alkali-exchanged faujasites. This work is an example of how the catalytic reactivity of zeolites depends on multiple interactions between the zeolite and reagents.

  14. Comparison of Serum Concentrations of Total Cholesterol and Total ...

    African Journals Online (AJOL)

    Tuberculosis (TB) is one of the most dangerous tropical diseases that complicates HIV infection in Nigeria to date. Over two million Nigerians are known to be infected with TB and many more are at risk of the infection. Serum concentrations of total cholesterol and total lipid of 117 female TB patients attending chest clinic at ...

  15. Changes in total and differential white cell counts, total lymphocyte ...

    African Journals Online (AJOL)

    Background: Published reports on the possible changes in the various immune cell populations, especially the total lymphocyte and CD4 cell counts, during the menstrual cycle in Nigerian female subjects are relatively scarce. Aim: To determine possible changes in the total and differential white blood cell [WBC] counts, ...

  16. Total hip arthroplasty in Denmark

    DEFF Research Database (Denmark)

    Pedersen, Alma Becic; Johnsen, Søren Paaske; Overgaard, Søren

    2005-01-01

    The annual number of total hip arthroplasties (THA) has increased in Denmark over the past 15 years. There is, however, limited detailed data available on the incidence of THAs.......The annual number of total hip arthroplasties (THA) has increased in Denmark over the past 15 years. There is, however, limited detailed data available on the incidence of THAs....

  17. Congruences of totally geodesic surfaces

    International Nuclear Information System (INIS)

    Plebanski, J.F.; Rozga, K.

    1989-01-01

    A general theory of congruences of totally geodesic surfaces is presented. In particular their classification, based on the properties of induced affine connections, is provided. In the four-dimensional case canonical forms of the metric tensor admitting congruences of two-dimensional totally geodesic surfaces of rank one are given. Finally, congruences of two-dimensional extremal surfaces are studied. (author)

  18. Totality eclipses of the Sun

    CERN Document Server

    Littmann, Mark; Willcox, Ken

    2008-01-01

    A total eclipse of the Sun is the most awesome sight in the heavens. Totality: Eclipses of the Sun takes you to eclipses of the past, present, and future, and lets you see - and feel - why people travel to the ends of the Earth to observe them. - ;A total eclipse of the Sun is the most awesome sight in the heavens. Totality: Eclipses of the Sun takes you to eclipses of the past, present, and future, and lets you see - and feel - why people travel to the ends of the Earth to observe them. Totality: Eclipses of the Sun is the best guide and reference book on solar eclipses ever written. It explains: how to observe them; how to photograph and videotape them; why they occur; their history and mythology; and future eclipses - when and where to see them. Totality also tells the remarkable story of how eclipses shocked scientists, revealed the workings of the Sun, and made Einstein famous. And the book shares the experiences and advice of many veteran eclipse observers. Totality: Eclipses of the Sun is profusely ill...

  19. Total Product Life Cycle (TPLC)

    Data.gov (United States)

    U.S. Department of Health & Human Services — The Total Product Life Cycle (TPLC) database integrates premarket and postmarket data about medical devices. It includes information pulled from CDRH databases...

  20. Nutritional management after total laryngectomy

    African Journals Online (AJOL)

    28 September 2010 with a known diagnosis of cancer of the larynx. The patient, who underwent a total laryngectomy on 13 October, had a tracheostomy inserted .... status, leading to improved quality of life and better response to treatment.4.

  1. Transmandibular approach to total maxillectomy

    OpenAIRE

    Tiwari, R. M.

    2001-01-01

    Total Maxillectomy through transfacial approach has been practiced in the treatment of Cancer for more than a decade. Its role in T3 - T4 tumors extending posteriorly through gthe bony wall is questionable, since an oncological radical procedure is often not possible. Recurrences in the infratemporal fossa are common. Despite the addition of radiotherapy five year survivals have not significantly improved. Transmandibular approach to Total Maxillectomy overcomes this shortcoming by including ...

  2. Leadership and Total Quality Management

    Science.gov (United States)

    1992-04-15

    leadership and management skills yields increased productivity. This paper will focus on the skills required of senior level leaders (leaders at the...publication until it has been cleared by the appropriate mii..-, service or government agency. Leadership and Total Quality Management An Individual Study...llty Codes fAvti1 and/or DltISpecial Abstract AUTHOR: Harry D. Gatanas, LTC, USA TITLE: Leadership and Total Quality Management FORMAT- Individual

  3. Total body water and total body potassium in anorexia nervosa

    Energy Technology Data Exchange (ETDEWEB)

    Dempsey, D.T.; Crosby, L.O.; Lusk, E.; Oberlander, J.L.; Pertschuk, M.J.; Mullen, J.L.

    1984-08-01

    In the ill hospitalized patient with clinically relevant malnutrition, there is a measurable decrease in the ratio of the total body potassium to total body water (TBK/TBW) and a detectable increase in the ratio of total exchangeable sodium to total exchangeable potassium (Nae/Ke). To evaluate body composition analyses in anorexia nervosa patients with chronic uncomplicated semistarvation, TBK and TBW were measured by whole body K40 counting and deuterium oxide dilution in 10 females with stable anorexia nervosa and 10 age-matched female controls. The ratio of TBK/TBW was significantly (p less than 0.05) higher in anorexia nervosa patients than controls. The close inverse correlation found in published studies between TBK/TBW and Nae/Ke together with our results suggest that in anorexia nervosa, Nae/Ke may be low or normal. A decreased TBK/TBW is not a good indicator of malnutrition in the anorexia nervosa patient. The use of a decreased TBK/TBW ratio or an elevated Nae/Ke ratio as a definition of malnutrition may result in inappropriate nutritional management in the patient with severe nonstressed chronic semistarvation.

  4. Total body water and total body potassium in anorexia nervosa

    International Nuclear Information System (INIS)

    Dempsey, D.T.; Crosby, L.O.; Lusk, E.; Oberlander, J.L.; Pertschuk, M.J.; Mullen, J.L.

    1984-01-01

    In the ill hospitalized patient with clinically relevant malnutrition, there is a measurable decrease in the ratio of the total body potassium to total body water (TBK/TBW) and a detectable increase in the ratio of total exchangeable sodium to total exchangeable potassium (Nae/Ke). To evaluate body composition analyses in anorexia nervosa patients with chronic uncomplicated semistarvation, TBK and TBW were measured by whole body K40 counting and deuterium oxide dilution in 10 females with stable anorexia nervosa and 10 age-matched female controls. The ratio of TBK/TBW was significantly (p less than 0.05) higher in anorexia nervosa patients than controls. The close inverse correlation found in published studies between TBK/TBW and Nae/Ke together with our results suggest that in anorexia nervosa, Nae/Ke may be low or normal. A decreased TBK/TBW is not a good indicator of malnutrition in the anorexia nervosa patient. The use of a decreased TBK/TBW ratio or an elevated Nae/Ke ratio as a definition of malnutrition may result in inappropriate nutritional management in the patient with severe nonstressed chronic semistarvation

  5. Total 2004 annual report; TOTAL 2004 rapport annuel

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2004-07-01

    This annual report of the Group Total brings information and economic data on the following topics, for the year 2004: the corporate governance, the corporate social responsibility, the shareholder notebook, the management report, the activities, the upstream (exploration and production) and downstream (refining and marketing) operating, chemicals and other matters. (A.L.B.)

  6. Calidad total en el ICESI

    OpenAIRE

    González Zamora, José Hipólito

    2010-01-01

    En primer lugar deseo dar la bienvenida esta reunión al ingeniero Francisco Gensini, director ejecutivo de INCOLDA, quien ha sido fuente constante de inspiración para el trabajo relacionado con Control Total de Calidad (C.T.C.) que se ha venido desarrollando en el ICESI. El ingeniero Gensini ha logrado aglutinar alrededor de INCOLDA al grupo de seis empresas de la región, líderes en el estudio y aplicación de los principios del Control Total de Calidad , es decir Rica Rondo S.A., Banco de Oc...

  7. Sobredentadura total superior implantosoportada Superior total overdenture on implants

    Directory of Open Access Journals (Sweden)

    Luis Orlando Rodríguez García

    2010-06-01

    Full Text Available Se presenta un caso de un paciente desdentado total superior, rehabilitado en la consulta de implantología de la Clínica "Pedro Ortiz" del municipio Habana del Este en Ciudad de La Habana, Cuba, en el año 2009, mediante prótesis sobre implantes osteointegrados, técnica que se ha incorporado a la práctica estomatológica en Cuba como alternativa al tratamiento convencional en los pacientes desdentados totales. Se siguió un protocolo que comprendió una fase quirúrgica, procedimiento con o sin realización de colgajo y carga precoz o inmediata. Se presenta un paciente masculino de 56 años de edad, que acudió a la consulta multidisciplinaria, preocupado, porque se le habían elaborado tres prótesis en los últimos dos años y ninguna reunía los requisitos de retención que él necesitaba para sentirse seguro y cómodo con las mismas. El resultado final fue la satisfacción total del paciente, con el mejoramiento de la calidad estética y funcional.This is the case of a total maxilla edentulous patient seen in consultation of the "Pedro Ortíz" Clinic Implant of Habana del Este municipality in 2009 and con rehabilitation by prosthesis over osteointegration implants added to stomatology practice in Cuba as an alternative to conventional treatment in patients totally edentulous. We follow a protocol including a surgery or surgical phase, technique without or with flap creation and early or immediate load. This is a male patient aged 56 came to our multidisciplinary consultation worried because he had three prostheses in last two years and any fulfilled the requirements of retention to feel safe and comfortable with prostheses. The final result was the total satisfaction of rehabilitated patient improving its aesthetic and functional quality.

  8. Total phenolics and total flavonoids in selected Indian medicinal plants.

    Science.gov (United States)

    Sulaiman, C T; Balachandran, Indira

    2012-05-01

    Plant phenolics and flavonoids have a powerful biological activity, which outlines the necessity of their determination. The phenolics and flavonoids content of 20 medicinal plants were determined in the present investigation. The phenolic content was determined by using Folin-Ciocalteu assay. The total flavonoids were measured spectrophotometrically by using the aluminium chloride colorimetric assay. The results showed that the family Mimosaceae is the richest source of phenolics, (Acacia nilotica: 80.63 mg gallic acid equivalents, Acacia catechu 78.12 mg gallic acid equivalents, Albizia lebbeck 66.23 mg gallic acid equivalents). The highest total flavonoid content was revealed in Senna tora which belongs to the family Caesalpiniaceae. The present study also shows the ratio of flavonoids to the phenolics in each sample for their specificity.

  9. Total Synthesis of Adunctin B.

    Science.gov (United States)

    Dethe, Dattatraya H; Dherange, Balu D

    2018-03-16

    Total synthesis of (±)-adunctin B, a natural product isolated from Piper aduncum (Piperaceae), has been achieved using two different strategies, in seven and three steps. The efficient approach features highly atom economical and diastereoselective Friedel-Crafts acylation, alkylation reaction and palladium catalyzed Wacker type oxidative cyclization.

  10. Edge colouring by total labellings

    DEFF Research Database (Denmark)

    Brandt, Stephan; Rautenbach, D.; Stiebitz, M.

    2010-01-01

    We introduce the concept of an edge-colouring total k-labelling. This is a labelling of the vertices and the edges of a graph G with labels 1, 2, ..., k such that the weights of the edges define a proper edge colouring of G. Here the weight of an edge is the sum of its label and the labels of its...

  11. What is Total Quality Management?

    Science.gov (United States)

    Bryan, William A.

    1996-01-01

    Provides a general overview of Total Quality Management (TQM) and explains why there is pressure for change in higher education institutions. Defines TQM and the various themes, tools, and beliefs that make it different from other management approaches. Presents 14 principles and how they might be applied to student affairs. (RJM)

  12. A totally diverting loop colostomy.

    Science.gov (United States)

    Merrett, N. D.; Gartell, P. C.

    1993-01-01

    A technique is described where the distal limb of a loop colostomy is tied with nylon or polydioxanone. This ensures total faecal diversion and dispenses with the supporting rod, enabling early application of stoma appliances. The technique does not interfere with the traditional transverse closure of a loop colostomy. PMID:8379632

  13. A generalization of total graphs

    Indian Academy of Sciences (India)

    M Afkhami

    2018-04-12

    Apr 12, 2018 ... product of any lower triangular matrix with the transpose of any element of U belongs to U. The ... total graph of R, which is denoted by T( (R)), is a simple graph with all elements of R as vertices, and ...... [9] Badawi A, On dot-product graph of a commutative ring, Communications in Algebra 43 (2015). 43–50.

  14. Total synthesis of nepetoidin B

    Science.gov (United States)

    The total synthesis of nepetoidin B (the 2-(3,4-dihydroxyphenyl)ethenyl ester of 3-(3,4-dihydroxy¬phenyl)-2-propenoic acid) has been achieved in two steps from commercially available 1,5-bis(3,4-dimethoxyphenyl)-1,4-pentadien-3-one. Tetramethylated nepetoidin B was prepared directly by Baeyer-Villig...

  15. The "Total Immersion" Meeting Environment.

    Science.gov (United States)

    Finkel, Coleman

    1980-01-01

    The designing of intelligently planned meeting facilities can aid management communication and learning. The author examines the psychology of meeting attendance; architectural considerations (lighting, windows, color, etc.); design elements and learning modes (furniture, walls, audiovisuals, materials); and the idea of "total immersion meeting…

  16. First total synthesis of Boehmenan

    Indian Academy of Sciences (India)

    The first total synthesis of dilignan Boehmenan has been achieved. A biomimetic oxidative coupling of the ferulic acid methyl ester in the presence of silver oxide is the crucial step in the synthesis sequence, generating the dihydrobenzofuran skeleton. Hydroxyl group was protected with DHP and reducted with LiAlH4 to ...

  17. MODIFIED TECHNIQUE OF TOTAL LARYNGECTOMY

    Directory of Open Access Journals (Sweden)

    Predrag Spirić

    2010-12-01

    Full Text Available Surgical technique of total laryngectomy is well presented in many surgical textbooks. Essentially, it has remained the same since Gluck an Soerensen in 1922 described all its details. Generally, it stresses the U shape skin incision with releasing laryngeal structures and removing larynx from up to down. Further, pharyngeal reconstruction is performed with different kinds of sutures in two or more layers and is finished with skin suture and suction drainage. One of worst complications following this surgery is pharyngocutaneous fistula (PF. Modifications proposed in this this article suggests vertical skin incision with larynx removal from below upwards. In pharyngeal reconstruction we used the running locked suture in submucosal plan with „tobacco sac“ at the end on the tongue base instead of traditional T shaped suture. Suction drains were not used.The aim of study was to present the modified surgical technique of total laryingectomy and its impact on hospital stay duration and pharyngocutanous fistula formation. In this randomized study we analyzed 49 patients operated with modified surgical technique compared to 49 patient operated with traditional surgical technique of total laryngectomy. The modified technique of total laryngectomy was presented. Using modified technique we managed to decrease the PF percentage from previous 20,41% to acceptable 8,16% (p=0,0334. Also, the average hospital stay was shortened from 14,96 to 10,63 days (t =-2.9850; p=0.0358.The modified technique of total laryngectomy is safe, short and efficient surgical intervention which decreases the number of pharyngocutaneos fistulas and shortens the hospital stay.

  18. Subtotal versus total abdominal hysterectomy

    DEFF Research Database (Denmark)

    Andersen, Lea Laird; Ottesen, Bent; Alling Møller, Lars Mikael

    2015-01-01

    OBJECTIVE: The objective of the study was to compare long-term results of subtotal vs total abdominal hysterectomy for benign uterine diseases 14 years after hysterectomy, with urinary incontinence as the primary outcome measure. STUDY DESIGN: This was a long-term follow-up of a multicenter......, randomized clinical trial without blinding. Eleven gynecological departments in Denmark contributed participants to the trial. Women referred for benign uterine diseases who did not have contraindications to subtotal abdominal hysterectomy were randomized to subtotal (n = 161) vs total (n = 158) abdominal...... from discharge summaries from all public hospitals in Denmark. The results were analyzed as intention to treat and per protocol. Possible bias caused by missing data was handled by multiple imputation. The primary outcome was urinary incontinence; the secondary outcomes were pelvic organ prolapse...

  19. Institutional total energy case studies

    Energy Technology Data Exchange (ETDEWEB)

    Wulfinghoff, D.

    1979-07-01

    Profiles of three total energy systems in institutional settings are provided in this report. The plants are those of Franciscan Hospital, a 384-bed facility in Rock Island, Illinois; Franklin Foundation Hospital, a 100-bed hospital in Franklin, Louisiana; and the North American Air Defense Command Cheyenne Mountain Complex, a military installation near Colorado Springs, Colorado. The case studies include descriptions of plant components and configurations, operation and maintenance procedures, reliability, relationships to public utilities, staffing, economic efficiency, and factors contributing to success.

  20. Total synthesis of (-)- and (+)-tedanalactam

    Digital Repository Service at National Institute of Oceanography (India)

    Majik, M.S.; Parameswaran, P.S.; Tilve, S.G.

    : The Journal of Organic Chemistry, vol.74(16); 6378-6381 1 Total Synthesis of (-) and (+)-Tedanalactam Mahesh S. Majik, † Peruninakulath S. Parameswaran, ‡ and Santosh G. Tilve* ,† Department of Chemistry, Goa University, Taleigao Plateau, Goa 403..., displaying a wide range of biological activities. 1 Piperidones are key synthetic intermediates 2 for the synthesis of piperidine ring due to the presence of keto function which allows the introduction of other groups. Piperidones are also known...

  1. Intrathoracic Hernia after Total Gastrectomy

    Directory of Open Access Journals (Sweden)

    Yoshihiko Tashiro

    2016-05-01

    Full Text Available Intrathoracic hernias after total gastrectomy are rare. We report the case of a 78-year-old man who underwent total gastrectomy with antecolic Roux-Y reconstruction for residual gastric cancer. He had alcoholic liver cirrhosis and received radical laparoscopic proximal gastrectomy for gastric cancer 3 years ago. Early gastric cancer in the remnant stomach was found by routine upper gastrointestinal endoscopy. We initially performed endoscopic submucosal dissection, but the vertical margin was positive in a pathological result. We performed total gastrectomy with antecolic Roux-Y reconstruction by laparotomy. For adhesion of the esophageal hiatus, the left chest was connected with the abdominal cavity. A pleural defect was not repaired. Two days after the operation, the patient was suspected of having intrathoracic hernia by chest X-rays. Computed tomography showed that the transverse colon and Roux limb were incarcerated in the left thoracic cavity. He was diagnosed with intrathoracic hernia, and emergency reduction and repair were performed. Operative findings showed that the Roux limb and transverse colon were incarcerated in the thoracic cavity. After reduction, the orifice of the hernia was closed by suturing the crus of the diaphragm with the ligament of the jejunum and omentum. After the second operation, he experienced anastomotic leakage and left pyothorax. Anastomotic leakage was improved with conservative therapy and he was discharged 76 days after the second operation.

  2. NIF total neutron yield diagnostic

    International Nuclear Information System (INIS)

    Cooper, Gary W.; Ruiz, Carlos L.

    2001-01-01

    We have designed a total neutron yield diagnostic for the National Ignition Facility (NIF) which is based on the activation of In and Cu samples. The particular approach that we have chosen is one in which we calibrate the entire counting system and which we call the ''F factor'' method. In this method, In and/or Cu samples are exposed to known sources of DD and DT neutrons. The activated samples are then counted with an appropriate system: a high purity Ge detector for In and a NaI coincidence system for Cu. We can then calculate a calibration factor, which relates measured activity to total neutron yield. The advantage of this approach is that specific knowledge of such quantities as cross sections and detector efficiencies is not needed. Unless the actual scattering environment of the NIF can be mocked up in the calibration experiment, the F factor will have to be modified using the results of a numerical simulation of the NIF scattering environment. In this article, the calibration factor methodology will be discussed and experimental results for the calibration factors will be presented. Total NIF neutron yields of 10 9 --10 19 can be measured with this method assuming a 50 cm stand-off distance can be employed for the lower yields

  3. Total eclipses of the sun

    CERN Document Server

    Zirker, Jack B

    2014-01-01

    Eclipses have captured attention and sparked curiosity about the cosmos since the first appearance of humankind. Having been blamed for everything from natural disasters to the fall of kings, they are now invaluable tools for understanding many celestial as well as terrestrial phenomena. This clear, easy-to-understand guide explains what causes total eclipses and how they can be used in experiments to examine everything from the dust between the planets to general relativity. A new chapter has been added on the eclipse of July 11, 1991 (the great Hawaiian eclipse). Originally published in 19

  4. Reverse hybrid total hip arthroplasty

    DEFF Research Database (Denmark)

    Wangen, Helge; Havelin, Leif I.; Fenstad, Anne M

    2017-01-01

    Background and purpose - The use of a cemented cup together with an uncemented stem in total hip arthroplasty (THA) has become popular in Norway and Sweden during the last decade. The results of this prosthetic concept, reverse hybrid THA, have been sparsely described. The Nordic Arthroplasty....... Patients and methods - From the NARA, we extracted data on reverse hybrid THAs from January 1, 2000 until December 31, 2013. 38,415 such hips were studied and compared with cemented THAs. The Kaplan-Meier method and Cox regression analyses were used to estimate the prosthesis survival and the relative risk...

  5. Total knee arthroplasty in ochronosis

    Directory of Open Access Journals (Sweden)

    Vaibhav G. Patel, MBBS

    2015-09-01

    Full Text Available Alkaptonuria is disorder of tyrosine metabolism due to deficiency of homogentisic oxidase characterized by excretion of homogentisic acid in urine, deposition of oxidized homogensitate pigments in connective tissues and articular cartilages (ochronosis. The result is dark pigmentation and weakening of the tissues resulting in chronic inflammation and osteoarthritis. Management of alkaptonuric ochronic osteoarthritis is usually symptomatic and replacements have comparable outcomes to osteoarthritis in patients without ochronosis. I report a case of a patient with ochronosis of knee treated with total knee replacement and report operative pearls for surgery in this rare disorder.

  6. Total filmless digital radiology service

    International Nuclear Information System (INIS)

    Mun, S.K.; Goeringer, F.; Benson, H.; Horii, S.C.

    1989-01-01

    The completion of a comprehensive picture archiving and communication system (PACS) at Georgetown University Hospital has allowed us to identify a number of technical, administrative, personnel, and operational issues that will affect a total digital radiology service. With a hospital-wide digital imaging network system, computer simulation of communications and storage options, and economic modeling, we have developed a feasibility study and implementation strategy for the smooth transition to a nearly filmless radiology service over the next several years. This paper describes the technical and operational requirements for various database operations, workstations (used in diagnosis, review, and education), and communications. Site and installation planning, personnel training, and transition operations are discussed

  7. Qualidade total: Um novo paradigma?

    Directory of Open Access Journals (Sweden)

    Suzana da Rosa Tolfo

    1999-01-01

    Full Text Available Nos últimos anos, o movimento para a implantação da Gestão da Qualidade Total vem crescendo ao redor do mundo. Em razão disso, há uma diversidade de ações realizadas com o nome de "Qualidade Total'. Uma revisão da teoria é complexa, porque existem muitos autores que tratam da questão. Eles escolhem diferentes perspectivas de análises (teóricas e empíricas e há dificuldades em se identificar um corpo conceitual. Há uma ampla difusão de modelos, ferramentas, técnicas, mercado e consultores. Essa popularidade, muitas vezes, faz com que determinadas organizações adotem essa forma de gestão do trabalho sem o conhecimento necessário das implicações que um modelo dessa ordem representa; especialmente no caso brasileiro, suscetível a proposições importadas. O presente artigo propõe um exame daquilo que os fundadores têm articulado sobre TQM, as principais críticas nesta direção e a avaliação de como vem sendo aplicadono nosso país.

  8. Testing EDM of Total Stations

    Directory of Open Access Journals (Sweden)

    Cirbus Ján

    2001-03-01

    Full Text Available The paper is devoted to testing electrooptical distance measuring devices (EDM built in total stations, than can be used for various tasks in the contemporary geodetic works. A rich market offer and availability of these universal measuring systems with satisfying distance range, excellent accuracy and other parameters, make total stations as dominant terrestrial geodetic instruments.For succesfully applying these instruments, above all for relliable distance measurements, the stability of the modulation frequency is the most important pre-condition. In the article, therefore, there are given some methods to verify the modulation frequency stability. In addition, some ways for determining the EDM distance constant and periodical corrections of the phase measuring unit are introduced for 4 types of EDM : LEICA 1700L, TOPCON GTS6A, TOPCON GTS2, C.ZEISS ELTA50. It were also investigated their possibilities for precise distance survey. Values of the determined constants and periodical corrections are presented in Tab. 2.Based on the investigation results of the 4 EDM types and using the values m obtained for different distances S, equations of the a posteriori standard deviations in form : m = (a+b.S were derived too.

  9. Total Value of Phosphorus Recovery.

    Science.gov (United States)

    Mayer, Brooke K; Baker, Lawrence A; Boyer, Treavor H; Drechsel, Pay; Gifford, Mac; Hanjra, Munir A; Parameswaran, Prathap; Stoltzfus, Jared; Westerhoff, Paul; Rittmann, Bruce E

    2016-07-05

    Phosphorus (P) is a critical, geographically concentrated, nonrenewable resource necessary to support global food production. In excess (e.g., due to runoff or wastewater discharges), P is also a primary cause of eutrophication. To reconcile the simultaneous shortage and overabundance of P, lost P flows must be recovered and reused, alongside improvements in P-use efficiency. While this motivation is increasingly being recognized, little P recovery is practiced today, as recovered P generally cannot compete with the relatively low cost of mined P. Therefore, P is often captured to prevent its release into the environment without beneficial recovery and reuse. However, additional incentives for P recovery emerge when accounting for the total value of P recovery. This article provides a comprehensive overview of the range of benefits of recovering P from waste streams, i.e., the total value of recovering P. This approach accounts for P products, as well as other assets that are associated with P and can be recovered in parallel, such as energy, nitrogen, metals and minerals, and water. Additionally, P recovery provides valuable services to society and the environment by protecting and improving environmental quality, enhancing efficiency of waste treatment facilities, and improving food security and social equity. The needs to make P recovery a reality are also discussed, including business models, bottlenecks, and policy and education strategies.

  10. Potential Chemical Systems for Intramolecular Cycloaddition Cures

    Science.gov (United States)

    1979-05-01

    allowed electrocyclic photochemical ring closure of stilbene to dihydrophenanthrene is well known (Reference 12). The presence of an oxidant , e.g...CH (c) R 3 0 00 > 0 I I (42) The keto-diynes 36 follow a uniform reaction pathway with chlorotris- ( triphenylphosphine )rhodium[I] to yield the...Irradiation of 36b similarly gives 49. The mechanism proposed for the photochemical reaction involves an initial formation of the reactive cyclobutadiene by

  11. Total employment effect of biofuels

    International Nuclear Information System (INIS)

    Stridsberg, S.

    1998-08-01

    The study examined the total employment effect of both direct production of biofuel and energy conversion to heat and electricity, as well as the indirect employment effect arising from investments and other activities in conjunction with the production organization. A secondary effect depending on the increased capital flow is also included in the final result. The scenarios are based on two periods, 1993-2005 and 2005-2020. In the present study, the different fuels and the different applications have been analyzed individually with regard to direct and indirect employment within each separate sector. The greatest employment effect in the production chain is shown for logging residues with 290 full-time jobs/TWh, whereas other biofuels range between 80 and 280 full-time jobs/TWh. In the processing chain, the corresponding range is 200-300 full-time jobs per each additional TWh. Additionally and finally, there are secondary effects that give a total of 650 full-time jobs/TWh. Together with the predicted increase, this suggests that unprocessed fuel will provide an additional 16 000 annual full-time jobs, and that fuel processing will contribute with a further 5 000 full-time jobs. The energy production from the fuels will provide an additional 13 000 full-time jobs. The total figure of 34 000 annual full-time jobs must then be reduced by about 4000 on account of lost jobs, mainly in the oil sector and to some extent in imports of biofuel. In addition, the anticipated increase in capital turnover that occurs within the biofuel sector, will increase full-time jobs up to year 2020. Finally, a discussion is given of the accomplishment of the programmes anticipated by the scenario, where it is noted that processing of biofuel to wafers, pellets or powder places major demands on access to raw material of good quality and that agrarian fuels must be given priority if they are to enter the system sufficiently fast. Straw is already a resource but is still not accepted by

  12. Conversion total hip arthroplasty: Primary or revision total hip arthroplasty

    Science.gov (United States)

    Schwarzkopf, Ran; Baghoolizadeh, Mahta

    2015-01-01

    Total hip arthroplasty (THA) is an increasingly common procedure among elderly individuals. Although conversion THA is currently bundled in a diagnosis related group (DRG) with primary THA, there is a lack of literature supporting this classification and it has yet to be identified whether conversion THA better resembles primary or revision THA. This editorial analyzed the intraoperative and postoperative factors and functional outcomes following conversion THA, primary THA, and revision THA to understand whether the characteristics of conversion THA resemble one procedure or the other, or are possibly somewhere in between. The analysis revealed that conversion THA requires more resources both intraoperatively and postoperatively than primary THA. Furthermore, patients undergoing conversion THA present with poorer functional outcomes in the long run. Patients undergoing conversion THA better resemble revision THA patients than primary THA patients. As such, patients undergoing conversion THA should not be likened to patients undergoing primary THA when determining risk stratification and reimbursement rates. Conversion THA procedures should be planned accordingly with proper anticipation of the greater needs both in the operating room, and for in-patient and follow-up care. We suggest that conversion THA be reclassified in the same DRG with revision THA as opposed to primary THA as a step towards better allocation of healthcare resources for conversion hip arthroplasties. PMID:26601055

  13. Instability after total hip arthroplasty

    Science.gov (United States)

    Werner, Brian C; Brown, Thomas E

    2012-01-01

    Instability following total hip arthroplasty (THA) is an unfortunately frequent and serious problem that requires thorough evaluation and preoperative planning before surgical intervention. Prevention through optimal index surgery is of great importance, as the management of an unstable THA is challenging even for an experienced joints surgeon. However, even after well-planned surgery, a significant incidence of recurrent instability still exists. Non-operative management is often successful if the components are well-fixed and correctly positioned in the absence of neurocognitive disorders. If conservative management fails, surgical options include revision of malpositioned components; exchange of modular components such as the femoral head and acetabular liner; bipolar arthroplasty; tripolar arthroplasty; use of a larger femoral head; use of a constrained liner; soft tissue reinforcement and advancement of the greater trochanter. PMID:22919568

  14. A total safety management model

    International Nuclear Information System (INIS)

    Obadia, I.J.; Vidal, M.C.R.; Melo, P.F.F.F.

    2002-01-01

    In nuclear organizations, quality and safety are inextricably linked. Therefore, the search for excellence means reaching excellence in nuclear safety. The International Atomic Energy Agency, IAEA, developed, after the Chernobyl accident, the organizational approach for improving nuclear safety based on the safety culture, which requires a framework necessary to provide modifications in personnel attitudes and behaviors in situations related to safety. This work presents a Total Safety Management Model, based on the Model of Excellence of the Brazilian Quality Award and on the safety culture approach, which represents an alternative to this framework. The Model is currently under validation at the Nuclear Engineering Institute, in Rio de Janeiro, Brazil, and the results of its initial safety culture self assessment are also presented and discussed. (author)

  15. Demand: a total nuclear disarmament

    International Nuclear Information System (INIS)

    Hessel, Stephane; Jacquard, Albert

    2012-01-01

    This bibliographical note presents a book, in which the authors make a plea for a total nuclear disarmament. They think that humanity cannot be found in competition, but in emulation, and examine how we can get rid of the nuclear bomb. They discuss the background of nuclear energy, state that nuclear weapons have always been useless and extremely dangerous, consider arms race as crazy and as a crime against humanity, recall that nuclear weapons already made numerous victims (Hiroshima, Nagasaki, nuclear tests), that they are a sword of Damocles over 7 billions human beings, that nuclear winter would be an apocalypse, that the Non Proliferation Treaty is a decoy. They discuss the political role of nuclear weapons, and outline that the only solution is their abolition. They discuss what has already been done and what is still to be done, and formulate a strategy for the future

  16. Total synthesis of mycalamide A.

    Science.gov (United States)

    Sohn, Jeong-Hun; Waizumi, Nobuaki; Zhong, H Marlon; Rawal, Viresh H

    2005-05-25

    This communication describes a concise and efficient total synthesis of mycalamide A by the convergent coupling of pederic acid unit with the mycalamine unit. The left-half, (+)-7-benzoylpederic acid, was synthesized from (2R,3R)-3-methylpent-4-en-2-ol in seven steps and 34.6% overall yield through a route that features a one-step Pd(II)-catalyzed tandem Wacker/Heck cyclization reaction to prepare the tetrahydropyran ring system. The right-half, the mycalamine unit, was synthesized in 21 steps and 10.5% overall yield from diethyl d-tartrate. Effective, stereoselective methods were developed for the assembly of the two parts to yield either mycalamide A or C(10)-epi-mycalamide A.

  17. Total quality management implementation guidelines

    Energy Technology Data Exchange (ETDEWEB)

    1993-12-01

    These Guidelines were designed by the Energy Quality Council to help managers and supervisors in the Department of Energy Complex bring Total Quality Management to their organizations. Because the Department is composed of a rich mixture of diverse organizations, each with its own distinctive culture and quality history, these Guidelines are intended to be adapted by users to meet the particular needs of their organizations. For example, for organizations that are well along on their quality journeys and may already have achieved quality results, these Guidelines will provide a consistent methodology and terminology reference to foster their alignment with the overall Energy quality initiative. For organizations that are just beginning their quality journeys, these Guidelines will serve as a startup manual on quality principles applied in the Energy context.

  18. Towards the total synthesis of Stawamycin. Synthesis of C11-C21 fragment

    Directory of Open Access Journals (Sweden)

    Dias Luiz C.

    2001-01-01

    Full Text Available The carbocyclic (C11-C21 fragment of Stawamycin has been prepared by a sequence involving 11 steps (10% overall yield from methyl (R-(--3-hydroxy-2-methylpropionate. Key steps are Pd-catalyzed Stille coupling reaction between a vinyl iodide and a vinylstannane followed by an intramolecular Diels-Alder cycloaddition reaction to afford the desired adduct as the major isomer together with three other possible adducts in 78% overall yield.

  19. Total quality management program planning

    Energy Technology Data Exchange (ETDEWEB)

    Thornton, P.T.; Spence, K.

    1994-05-01

    As government funding grows scarce, competition between the national laboratories is increasing dramatically. In this era of tougher competition, there is no for resistance to change. There must instead be a uniform commitment to improving the overall quality of our products (research and technology) and an increased focus on our customers` needs. There has been an ongoing effort to bring the principles of total quality management (TQM) to all Energy Systems employees to help them better prepare for future changes while responding to the pressures on federal budgets. The need exists for instituting a vigorous program of education and training to an understanding of the techniques needed to improve and initiate a change in organizational culture. The TQM facilitator is responsible for educating the work force on the benefits of self-managed work teams, designing a program of instruction for implementation, and thus getting TQM off the ground at the worker and first-line supervisory levels so that the benefits can flow back up. This program plan presents a conceptual model for TQM in the form of a hot air balloon. In this model, there are numerous factors which can individually and collectively impede the progress of TQM within the division and the Laboratory. When these factors are addressed and corrected, the benefits of TQM become more visible. As this occurs, it is hoped that workers and management alike will grasp the ``total quality`` concept as an acceptable agent for change and continual improvement. TQM can then rise to the occasion and take its rightful place as an integral and valid step in the Laboratory`s formula for survival.

  20. Instability following total knee arthroplasty.

    Science.gov (United States)

    Rodriguez-Merchan, E Carlos

    2011-10-01

    Background Knee prosthesis instability (KPI) is a frequent cause of failure of total knee arthroplasty. Moreover, the degree of constraint required to achieve immediate and long-term stability in total knee arthroplasty (TKA) is frequently debated. Questions This review aims to define the problem, analyze risk factors, and review strategies for prevention and treatment of KPI. Methods A PubMed (MEDLINE) search of the years 2000 to 2010 was performed using two key words: TKA and instability. One hundred and sixty-five initial articles were identified. The most important (17) articles as judged by the author were selected for this review. The main criteria for selection were that the articles addressed and provided solutions to the diagnosis and treatment of KPI. Results Patient-related risk factors predisposing to post-operative instability include deformity requiring a large surgical correction and aggressive ligament release, general or regional neuromuscular pathology, and hip or foot deformities. KPI can be prevented in most cases with appropriate selection of implants and good surgical technique. When ligament instability is anticipated post-operatively, the need for implants with a greater degree of constraint should be anticipated. In patients without significant varus or valgus malalignment and without significant flexion contracture, the posterior cruciate ligament (PCL) can be retained. However, the PCL should be sacrificed when deformity exists particularly in patients with rheumatoid arthritis, previous patellectomy, previous high tibial osteotomy or distal femoral osteotomy, and posttraumatic osteoarthritis with disruption of the PCL. In most cases, KPI requires revision surgery. Successful outcomes can only be obtained if the cause of KPI is identified and addressed. Conclusions Instability following TKA is a common cause of the need for revision. Typically, knees with deformity, rheumatoid arthritis, previous patellectomy or high tibial osteotomy, and

  1. Total Petroleum Hydrocarbons (TPH): ToxFAQs

    Science.gov (United States)

    ... a state: This map displays locations where Total Petroleum Hydrocarbons (TPH) is known to be present. On ... I get more information? ToxFAQs TM for Total Petroleum Hydrocarbons (TPH) ( Hidrocarburos Totales de Petróleo (TPH) ) August ...

  2. Global Drought Total Economic Loss Risk Deciles

    Data.gov (United States)

    National Aeronautics and Space Administration — Global Drought Total Economic Loss Risk Deciles is a 2.5 minute grid of global drought total economic loss risks. A process of spatially allocating Gross Domestic...

  3. Chinese National Strategy of Total War

    National Research Council Canada - National Science Library

    Good, Michael J

    2008-01-01

    ... concept of total warfare. This research seeks to determine if China is currently engaged in a total war with the United States across nontraditional forms of conflict including economic, political, information, financial...

  4. Totally optimal decision trees for Boolean functions

    KAUST Repository

    Chikalov, Igor; Hussain, Shahid; Moshkov, Mikhail

    2016-01-01

    We study decision trees which are totally optimal relative to different sets of complexity parameters for Boolean functions. A totally optimal tree is an optimal tree relative to each parameter from the set simultaneously. We consider the parameters

  5. Asymmetric total synthesis of cladosporin and isocladosporin.

    Science.gov (United States)

    Zheng, Huaiji; Zhao, Changgui; Fang, Bowen; Jing, Peng; Yang, Juan; Xie, Xingang; She, Xuegong

    2012-07-06

    The first asymmetric total syntheses of cladosporin and isocladosporin were accomplished in 8 steps with 8% overall yield and 10 steps with 26% overall yield, respectively. The relative configuration of isocladosporin was determined via this total synthesis.

  6. Global Landslide Total Economic Loss Risk Deciles

    Data.gov (United States)

    National Aeronautics and Space Administration — Global Landslide Total Economic Loss Risk Deciles is a 2.5 minute grid of global landslide total economic loss risks. A process of spatially allocating Gross...

  7. TUW at the First Total Recall Track

    Science.gov (United States)

    2015-11-20

    TUW AT THE FIRST TOTAL RECALL TRACK MIHAI LUPU Abstract. For the first participation in the TREC Total Recall track, we set out to try some basic...significantly and consistently outperformed it. 1. Introduction As the organizers point out, the focus of the Total Recall Track is to evaluate methods to...TUW AT THE FIRST TOTAL RECALL TRACK 3 The only change we made was at a higher level. The Sofia ML library provides 5 more ML algorithms. The following

  8. Defense meteorological satellite measurements of total ozone

    International Nuclear Information System (INIS)

    Lovill, J.E.; Ellis, J.S.; Luther, F.M.; Sullivan, R.J.; Weichel, R.L.

    1992-01-01

    A multichannel filter radiometer (MFR) on Defense Meteorological Satellites (DMS) that measured total ozone on a global-scale from March 1977 - February 1980 is described. The total ozone data measured by the MFR were compared with total ozone data taken by surfaced-based Dobson spectrophotometers. When comparisons were made for five months, the Dobson spectrophotometer measured 2-5% more total ozone than the MFR. Comparisons between the Dobson spectrophotometer and the MFR showed a reduced RMS difference as the comparisons were made at closer proximity. A Northern Hemisphere total ozone distribution obtained from MFR data is presented

  9. Towards the total synthesis of stawamycin. Synthesis of C11-C21 fragment.

    OpenAIRE

    Dias, LC; Jardim, LSA; Ferreira, AA; Soarez, HU

    2001-01-01

    The carbocyclic (C11-C21) fragment of Stawamycin has been prepared by a sequence involving 11 steps (10% overall yield) from methyl (R)-(-)-3-hydroxy-2-methylpropionate. Key steps are Pd-catalyzed Stille coupling reaction between a vinyl iodide and a vinylstannane followed by an intramolecular Diels-Alder cycloaddition reaction to afford the desired adduct as the major isomer together with three other possible adducts in 78% overall yield. A porção carbocíclica (C11-C21) da Estavamicina fo...

  10. Total Productive Maintenance at Paccar INC

    Directory of Open Access Journals (Sweden)

    Ştefan Farkas

    2010-06-01

    Full Text Available This paper reports the application of total productive maintenance method at Paccar Inc. truck’s plant in Victoria, Australia. The total productive maintenance method and total productive maintenance house are presented. The global equipment effectiveness is computed and exemplified. The production structure and organising maintenance are presented. Resultas of the variation of global equipment effectiveness and autonomous maintenance in a two weeks period of time are reported.

  11. Total Productive Maintenance at Paccar INC

    OpenAIRE

    Ştefan Farkas

    2010-01-01

    This paper reports the application of total productive maintenance method at Paccar Inc. truck’s plant in Victoria, Australia. The total productive maintenance method and total productive maintenance house are presented. The global equipment effectiveness is computed and exemplified. The production structure and organising maintenance are presented. Resultas of the variation of global equipment effectiveness and autonomous maintenance in a two weeks period of time are reported.

  12. Total pollution effect of urban surface runoff.

    Science.gov (United States)

    Luo, Hongbing; Luo, Lin; Huang, Gu; Liu, Ping; Li, Jingxian; Hu, Sheng; Wang, Fuxiang; Xu, Rui; Huang, Xiaoxue

    2009-01-01

    For pollution research with regard to urban surface runoff, most sampling strategies to date have focused on differences in land usage. With single land-use sampling, total surface runoff pollution effect cannot be evaluated unless every land usage spot is monitored. Through a new sampling strategy known as mixed stormwater sampling for a street community at discharge outlet adjacent to river, this study assessed the total urban surface runoff pollution effect caused by a variety of land uses and the pollutants washed off from the rain pipe system in the Futian River watershed in Shenzhen City of China. The water quality monitoring indices were COD (chemical oxygen demand), TSS (total suspend solid), TP (total phosphorus), TN (total nitrogen) and BOD (biochemical oxygen demand). The sums of total pollution loads discharged into the river for the four indices of COD, TSS, TN, and TP over all seven rainfall events were very different. The mathematical model for simulating total pollution loads was established from discharge outlet mixed stormwater sampling of total pollution loads on the basis of four parameters: rainfall intensity, total land area, impervious land area, and pervious land area. In order to treat surface runoff pollution, the values of MFF30 (mass first flush ratio) and FF30 (first 30% of runoff volume) can be considered as split-flow control criteria to obtain more effective and economical design of structural BMPs (best management practices) facilities.

  13. Operational resource theory of total quantum coherence

    Science.gov (United States)

    Yang, Si-ren; Yu, Chang-shui

    2018-01-01

    Quantum coherence is an essential feature of quantum mechanics and is an important physical resource in quantum information. Recently, the resource theory of quantum coherence has been established parallel with that of entanglement. In the resource theory, a resource can be well defined if given three ingredients: the free states, the resource, the (restricted) free operations. In this paper, we study the resource theory of coherence in a different light, that is, we consider the total coherence defined by the basis-free coherence maximized among all potential basis. We define the distillable total coherence and the total coherence cost and in both the asymptotic regime and the single-copy regime show the reversible transformation between a state with certain total coherence and the state with the unit reference total coherence. Extensively, we demonstrate that the total coherence can also be completely converted to the total correlation with the equal amount by the free operations. We also provide the alternative understanding of the total coherence, respectively, based on the entanglement and the total correlation in a different way.

  14. Total quality management in American industry.

    Science.gov (United States)

    Widtfeldt, A K; Widtfeldt, J R

    1992-07-01

    The definition of total quality management is conformance to customer requirements and specifications, fitness for use, buyer satisfaction, and value at an affordable price. The three individuals who have developed the total quality management concepts in the United States are W.E. Deming, J.M. Juran, and Philip Crosby. The universal principles of total quality management are (a) a customer focus, (b) management commitment, (c) training, (d) process capability and control, and (e) measurement through quality improvement tools. Results from the National Demonstration Project on Quality Improvement in Health Care showed the principles of total quality management could be applied to healthcare.

  15. A note on totally normal spaces

    International Nuclear Information System (INIS)

    Zougdani, H.K.

    1990-10-01

    In this note we give the necessary and sufficient condition for a topological space X such that the product space X x Y is totally normal for any (non discrete) metric space Y, and we show that a totally normal p-space need not be a perfectly normal in general, which makes Theorem 2 doubtful. (author). 6 refs

  16. Total cardiovascular disease risk assessment: a review.

    LENUS (Irish Health Repository)

    Cooney, Marie Therese

    2011-09-01

    The high risk strategy for the prevention of cardiovascular disease (CVD) requires an assessment of an individual\\'s total CVD risk so that the most intensive risk factor management can be directed towards those at highest risk. Here we review developments in the assessment and estimation of total CVD risk.

  17. Total cross section of highly excited strings

    International Nuclear Information System (INIS)

    Lizzi, F.; Senda, I.

    1990-01-01

    The unpolarized total cross section for the joining of two highly excited strings is calculated. The calculation is performed by taking the average overall states in the given excitation levels of the initial strings. We find that the total cross section grows with the energy and momentum of the initial states. (author). 8 refs, 1 fig

  18. Simultaneous and staged bilateral total hip arthroplasty

    DEFF Research Database (Denmark)

    Lindberg-Larsen, Martin; Joergensen, Christoffer Calov; Husted, Henrik

    2013-01-01

    Bilateral total hip arthroplasty (BTHA) and bilateral simultaneous total hip arthroplasty (BSTHA) are done increasingly. Previous studies evaluating outcomes after bilateral procedures have found different results. The aim of this study was to investigate length of hospital stay (LOS), 30 days...

  19. Total internal reflection effect on gyrotropic interface

    Science.gov (United States)

    Glushchenko, Alexander G.; Glushchenko, Eugene P.; Zhukov, Sergey V.

    2018-02-01

    This article considers the physical features of total internal reflection at gyrotropic and isotropic interfaces for two cases: electrical gyrotropy (plasma) and magnetic gyrotropy (ferrite). It is shown that the plasma magnetization may lead to the formation of the total internal reflection effect, which does not occur in isotropic plasma. The threshold values of the magnetic field, which are necessary for the total internal reflection effect, are determined. The total internal reflection effect on a ferrite-dielectric interface for waves emanating from different angles is observed in various frequency ranges and magnetization fields. The study points out the possibility of changing the total internal reflection angle value in large limits due to a change in the external magnetic field magnitude. The calculation results of the total internal reflection angle dependence on the external magnetic field magnitude are presented. The formulas are elaborated for calculating the total internal reflection angles of different interfaces for gyrotropic and isotropic media. The generalized formulas are defined for calculating the Doppler effect in the gyrotropic media. The study demonstrates how the velocity of the media interface affects the limiting angle of total internal refection.

  20. Records Management in Organization and Total Quality

    Directory of Open Access Journals (Sweden)

    Fahrettin Özdemirci

    1999-06-01

    Full Text Available In this article the relationship between total quality management and records managemen t are examined. It has also been indicated that the records mana­gement has vita'ly important part for realizing the total quality management approach.

  1. Vibrational enhancement of total breakup cross sections

    International Nuclear Information System (INIS)

    Haftel, M.I.; Lim, T.K.

    1984-01-01

    This paper considers the role of multi-two-body bound states, namely vibrational excitations, on total three-body breakup cross-sections. Total cross-sections are usually easy to measure, and they play a fundamental role in chemical kinetics. (orig.)

  2. A Total Factor Productivity Toolbox for MATLAB

    NARCIS (Netherlands)

    B.M. Balk (Bert); J. Barbero (Javier); J.L. Zofío (José)

    2018-01-01

    textabstractTotal Factor Productivity Toolbox is a new package for MATLAB that includes functions to calculate the main Total Factor Productivity (TFP) indices and their decompositions, based on Shephard’s distance functions and using Data Envelopment Analysis (DEA) programming techniques. The

  3. Timing the total reflection of light

    International Nuclear Information System (INIS)

    Chauvat, Dominique; Bonnet, Christophe; Dunseath, Kevin; Emile, Olivier; Le Floch, Albert

    2005-01-01

    We have identified for the first time the absolute delay at total reflection, envisioned by Newton. We show that there are in fact two divergent Wigner delays, depending on the polarisation of the incident light. These measurements give a new insight on the passage from total reflection to refraction

  4. Sexuality after total vs. subtotal hysterectomy

    DEFF Research Database (Denmark)

    Zobbe, Vibeke Bahn; Gimbel, Helga Margrethe Elisabeth; Andersen, Birthe Margrethe

    2004-01-01

    The effect of hysterectomy on sexuality is not fully elucidated and until recently total and subtotal hysterectomies have only been compared in observational studies.......The effect of hysterectomy on sexuality is not fully elucidated and until recently total and subtotal hysterectomies have only been compared in observational studies....

  5. The total energy policy in Flanders

    International Nuclear Information System (INIS)

    Bouma, J.W.J.

    1994-01-01

    The policy of the Flemish region (Belgium) with regard to the total energy principle are presented. An overview of the main policy instruments to support energy saving and environmental-friendly investments as well as the development of new technologies is given. The total energy policy of the Flanders Region forms part of the general Flemish (energy) policy. (A.S.)

  6. Airway Complications of Total Artificial Heart.

    Science.gov (United States)

    Pathak, Vikas; Donovan, Colin; Malhotra, Rajiv

    2017-02-01

    The total artificial heart is the mechanical device which is used as a bridge to the heart transplant in patients with biventricular failure. Due to the mechanical nature of the device, patients receiving total artificial heart (TAH) require to be on anticoagulation therapy. Hemorrhage and coagulopathy are few of the known complications of TAH.

  7. Total Quality Management in Education. Second Edition.

    Science.gov (United States)

    Sallis, Edward

    Quality is at the top of most agendas, and improving quality is probably the most important task facing any institution. In addition, quality is difficult to define or measure. This book, the second edition of "Total Quality Management in Education," introduces the key concepts of Total Quality Management (TQM) and demonstrates how they…

  8. The Total Quality Movement in Education.

    Science.gov (United States)

    Leuenberger, John A.; Whitaker, Sheldon V., Jr.

    The total quality movement began as a result of the desire of W. Edwards Deming, an American statistician, to permit the economic system to maintain its edge in a growing global market. The 14 points Deming listed as essential to "total quality management" have recently been adapted to the field of education. The success of the total…

  9. Creating the Total Quality Effective School.

    Science.gov (United States)

    Lezotte, Lawrence W.

    This book shows how Deming's Total Quality Management (TQM) theory for organizational management can be integrated with the effective-schools literature. Part 1 compares the 14 principles of TQM with the tenets of effective-schools research. The second part develops a blueprint for creating the total quality effective school. The conceptual…

  10. Totally optimal decision trees for Boolean functions

    KAUST Repository

    Chikalov, Igor

    2016-07-28

    We study decision trees which are totally optimal relative to different sets of complexity parameters for Boolean functions. A totally optimal tree is an optimal tree relative to each parameter from the set simultaneously. We consider the parameters characterizing both time (in the worst- and average-case) and space complexity of decision trees, i.e., depth, total path length (average depth), and number of nodes. We have created tools based on extensions of dynamic programming to study totally optimal trees. These tools are applicable to both exact and approximate decision trees, and allow us to make multi-stage optimization of decision trees relative to different parameters and to count the number of optimal trees. Based on the experimental results we have formulated the following hypotheses (and subsequently proved): for almost all Boolean functions there exist totally optimal decision trees (i) relative to the depth and number of nodes, and (ii) relative to the depth and average depth.

  11. Total's LNG activities from Algeria to Yemen

    International Nuclear Information System (INIS)

    Vedrenne, J.P.

    1997-01-01

    In March 1995, further to an international tender, Total was awarded the leadership of the first LNG project in Yemen. On January 1997 Total announced the extension of the share-holding of the Yemen LNG Co. to include the companies with interests in the Marib area (Hunt-Exxon-Yukong). The Marib area will supply the gas to the future liquefaction plant. The ratification of these agreements confirms the role of Total as lead shareholder with 36% in the share-holding structure and guarantees gas supply from the Marib licence, operated by Hunt-Exxon. (author)

  12. Total dominator chromatic number of a graph

    Directory of Open Access Journals (Sweden)

    Adel P. Kazemi

    2015-06-01

    Full Text Available Given a graph $G$, the total dominator coloring problem seeks a proper coloring of $G$ with the additional property that every vertex in the graph is adjacent to all vertices of a color class. We seek to minimize the number of color classes. We initiate to study this problem on several classes of graphs, as well as finding general bounds and characterizations. We also compare the total dominator chromatic number of a graph with the chromatic number and the total domination number of it.

  13. Total neutron cross section of lead

    International Nuclear Information System (INIS)

    Kanda, K.; Aizawa, O.

    1976-01-01

    The total thermal-neutron cross section of natural lead under various physical conditions was measured by the transmission method. It became clear that the total cross section at room temperature previously reported is lower than the present data. The total cross section at 400, 500, and 600 0 C, above the melting point of lead, 327 0 C, was also measured, and the changes in the cross section as a function of temperature were examined, especially near and below the melting point. The data obtained for the randomly oriented polycrystalline state at room temperature were in reasonable agreement with the theoretical values calculated by the THRUSH and UNCLE-TOM codes

  14. The total plasmatic estriol on normal gestation

    International Nuclear Information System (INIS)

    Thiesen, A.L.

    1980-01-01

    The total plasmatic estriol in normal pregnants was determinated by radioimmunological method using estriol labelled with sup(125)I. The obtained results presented similar results in comparison with methods using sup(19)C and sup(3)H. (author)

  15. TOTAL REWARDS MODEL IN ROMANIAN COMPANIES

    Directory of Open Access Journals (Sweden)

    Elena-Sabina HODOR

    2014-04-01

    Full Text Available Total Rewards Management is a subject of major importance for companies, because, by using models for this, firms can achieve their objectives of high performance. In order to analyse a validated total rewards model in Romanian Accounting and Consulting Companies, it is used The WorldatWork Total Rewards Model, which depict what contributes to applicant attraction and employee motivation and retention. Thus, the methodology of the previous survey is adjusted to the local context. The conclusions for the methodological aspects illustrate that the present research involves three strategic steps in order to achieve the objectives presented: the analysis of organizational environment of the companies from the sample, checking if Total Rewards Model proposed in the previous research is applicable for the same romanian companies from the previous survey, the analysing of the differences between results, and, if necessary, the adaptation of the model for Romania.

  16. Pulmonary nodules secondary to total parenteral alimentation

    International Nuclear Information System (INIS)

    Landry, B.A.; Melhem, R.E.

    1989-01-01

    A seven-year-old male, who had a retroperitoneal alveolar rhabdomyosarcoma and was on total parenteral alimentation (TPN) developed muliple pulmonary nodules, indistinguishable from metastases. These proved to be multiple lipid emboli on open biopsy. (orig.)

  17. Definition of total bootstrap current in tokamaks

    International Nuclear Information System (INIS)

    Ross, D.W.

    1995-01-01

    Alternative definitions of the total bootstrap current are compared. An analogous comparison is given for the ohmic and auxiliary currents. It is argued that different definitions than those usually employed lead to simpler analyses of tokamak operating scenarios

  18. The First Total Synthesis of Isoliquiritin

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    A first total synthesis of isoliquiritin was accomplished starting from p-hydroxy- benzaldehyde and 2,4-dihydroxyacetylphenone. The key step is condensation reaction. In synthetic process need not protect the hydroxy group of reacting substance.

  19. Can You Depend Totally on Computers?

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 3; Issue 2. Can You Depend Totally on Computers? Computer Security, Availability and Correctness. H N Mahabala. General Article Volume 3 Issue 2 February 1998 pp 35-44 ...

  20. NESDIS Blended Total Precipitable Water (TPW) Products

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The blended Total Precipitable Water (TPW) product is derived from multiple sensors/satellites. The Percentage of TPW normal (PCT), or TPW anomaly, shows the...

  1. Establishing a total information management program

    International Nuclear Information System (INIS)

    Hegstrom, K.L.; Fisher, J.

    1982-01-01

    A total information management program manages documents for easy access and identifies data elements commonly found in all documents. The program thus links disparate documents by identifying information they share in common

  2. Safety Precautions for Total Release Foggers

    Science.gov (United States)

    Total release foggers, also known as bug bombs, are pesticide products containing aerosol propellants that release their contents at once to fumigate an area. They can pose a hazard if used incorrectly. Find safety information and videos on this page.

  3. Medicaid Financial Management Data – National Totals

    Data.gov (United States)

    U.S. Department of Health & Human Services — This dataset reports summary state-by-state total expenditures by program for the Medicaid Program, Medicaid Administration and CHIP programs. These state...

  4. The 1995 total solar eclipse: an overview.

    Science.gov (United States)

    Singh, J.

    A number of experiments were conducted during the total solar eclipse of October 24, 1995. First time efforts were made to photograph the solar corona using IAF jet aircrafts and transport planes ad hot air balloons.

  5. US-Total Electron Content Product (USTEC)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The US Total Electron Content (US-TEC) product is designed to specify TEC over the Continental US (CONUS) in near real-time. The product uses a Kalman Filter data...

  6. Total Analysis System for Ship Structural Strength

    OpenAIRE

    Takuya, Yoneya; Hiroyuki, Kobayashi; Abdul M., Rahim; Yoshimichi, Sasaki; Masaki, Irisawa; Technical Investigation and Information Department, Research Center; Technical Investigation and Information Department, Research Center; Singapore Office; Technical Investigation and Information Department, Research Center; Technical Investigation and Information Department, Research Center

    2001-01-01

    This paper outlines a total analysis system for ship hull structures, which integrates a wide variety of analysis functions to realise practical applications of rational methods for assessing ship structural strength. It is based on direct calculation of wave-induced loads as well as three-dimensional structural analysis of an entire-ship or hold structure. Three major analysis functions of the total system are ship motion and wave load analysis, ship structural analysis and statistical analy...

  7. Total Quality Service and the Business College

    OpenAIRE

    James Perotti

    1995-01-01

    Moving a business college to commit to a total quality service approach is much more difficult than the literature suggests. The commitment to customer satisfaction is the essential focus of total quality service. It is unlikely to occur in business colleges. While small incremental change is readily possible, the values and culture of the faculty and administration prevent the requisite acceptance by the faculty of students as their customers, and acceptance of the faculty as customers of th...

  8. A strategic zone for Total's future

    International Nuclear Information System (INIS)

    Legros, E.J.

    1997-01-01

    In 1997, the Total company investments in the Middle East reached 1.2 billions of French Francs. This region is considered as a major growth zone by the French group. This paper summarizes the Total's participations in oil and gas activities and partnerships of Middle East countries (Abu Dhabi, Dubai, Oman, Qatar, Yemen): exploration, production, development, contracts, permits, technical assistance etc.. (J.S.)

  9. Studies towards a total synthesis of tagetitoxin

    OpenAIRE

    Mahoney, Brian

    2017-01-01

    Tagetitoxin was first isolated over thirty five years ago and a total synthesis has not been achieved to date. A vast amount of research has been carried out on the biological activity of tagetitoxin with hundreds of literature reports. However, very few papers have been published regarding the synthesis and within this thesis we will explore a number of synthetic pathways some towards tagetitoxin. The first chapter reviews previous developments regarding the total synthesis of...

  10. Expressions for the Total Yaw Angle

    Science.gov (United States)

    2016-09-01

    1. Introduction 1 2. Mathematical Notation 1 3. Total Yaw Expression Derivations 2 3.1 First Derivation 2 3.2 Second Derivation 4 3.3 Other...4 iv Approved for public release; distribution is unlimited. 1. Introduction The total yaw angle, γt , of a ballistic projectile is... elevation angles from spherical coordinates.∗ We again place point A at the end point of V. Now imagine a plane parallel to the y-z plane that includes

  11. Total energy system in the future

    International Nuclear Information System (INIS)

    Hijikata, K.

    1994-01-01

    The possibility of improving the thermal efficiency of energy systems from an exergy point of view is discussed. In total energy systems, we should employ multi-pass recycling consisting of thermal and chemical energies. The recycling system is supported by electrical energy, which is provided by a renewable energy source or by excess commercial electric power. This total energy system should be considered not only in one country, but all around the globe. (author). 6 figs., 4 tabs., 8 refs

  12. Cataract incidence after total-body irradiation

    International Nuclear Information System (INIS)

    Zierhut, D.; Lohr, F.; Schraube, P.; Huber, P.; Haas, R.; Hunstein, W.; Wannenmacher, M.

    1997-01-01

    Purpose: Aim of this retrospective study was to evaluate cataract incidence in a homogeneous group of patients after total-body irradiation followed by autologous bone marrow transplantation or peripheral blood stem cell transplantation. Method and Materials: Between 11/1982 and 6/1994 in total 260 patients received in our hospital total-body irradiation for treatment of haematological malignancy. In 1996-96 patients out of these 260 patients were still alive. 85 from these still living patients (52 men, 33 women) answered evaluable on a questionnaire and could be examined ophthalmologically. Median age of these patients was 38,5 years (15 - 59 years) at time of total-body irradiation. Radiotherapy was applied as hyperfractionated total-body irradiation with a median dose of 14,4 Gy in 12 fractions over 4 days. Minimum time between fractions was 4 hours, photons with a energy of 23 MeV were used, and the dose rate was 7 - 18 cGy/min. Results: Median follow-up is now 5,8 years (1,7 - 13 years). Cataract occurred in (28(85)) patients after a median time of 47 months (1 - 104 months). In 6 out of these 28 patients who developed a cataract, surgery of the cataract was performed. Whole-brain irradiation prior to total-body irradiation was more often in the group of patients developing a cataract (14,3%) vs. 10,7% in the group of patients without cataract. Conclusion: Cataract is a common side effect of total-body irradiation. Cataract incidence found in our patients is comparable to results of other centres using a fractionated regimen for total-body irradiation. The hyperfractionated regimen used in our hospital does obviously not result in a even lower cataract incidence. In contrast to acute and late toxicity in other organ/organsystems, hyperfractionation of total-body irradiation does not further reduce toxicity for the eye-lens. Dose rate may have more influence on cataract incidence

  13. A high performance totally ordered multicast protocol

    Science.gov (United States)

    Montgomery, Todd; Whetten, Brian; Kaplan, Simon

    1995-01-01

    This paper presents the Reliable Multicast Protocol (RMP). RMP provides a totally ordered, reliable, atomic multicast service on top of an unreliable multicast datagram service such as IP Multicasting. RMP is fully and symmetrically distributed so that no site bears un undue portion of the communication load. RMP provides a wide range of guarantees, from unreliable delivery to totally ordered delivery, to K-resilient, majority resilient, and totally resilient atomic delivery. These QoS guarantees are selectable on a per packet basis. RMP provides many communication options, including virtual synchrony, a publisher/subscriber model of message delivery, an implicit naming service, mutually exclusive handlers for messages, and mutually exclusive locks. It has commonly been held that a large performance penalty must be paid in order to implement total ordering -- RMP discounts this. On SparcStation 10's on a 1250 KB/sec Ethernet, RMP provides totally ordered packet delivery to one destination at 842 KB/sec throughput and with 3.1 ms packet latency. The performance stays roughly constant independent of the number of destinations. For two or more destinations on a LAN, RMP provides higher throughput than any protocol that does not use multicast or broadcast.

  14. Total lymphoid irradiation of intractable rheumatoid arthritis

    International Nuclear Information System (INIS)

    Herbst, M.; Fritz, H.; Sauer, R.

    1986-01-01

    Eleven patients with intractable rheumatoid arthritis were treated with fractionated total lymphoid irradiation, (total dose 20 Gy). Lasting improvement in clinical symptoms was found in four patients during treatment and the remaining patients experienced similar benefit within 2 months of irradiation. There was marked reduction in exacerbations and number of joints involved. Morning stiffness, joint swelling and tenderness decreased. Complications included severe fatigue during treatment and acute bacterial arthritis in multiple joints in one patient. Four patients have since died, one of renal failure, another of cardiogenic shock following surgery 3 and 24 months after total lymphoid irradiation. Both had generalised amyloidosis. The third patient developed joint empyema and died of toxic cardiac failure. The fourth died 3 months after resection of a Kaposi's sarcoma complicated by wound infection which responded to treatment. Immunologically, total lymphoid irradiation resulted in suppression of the absolute lymphocyte count and reduction in T-helper cells, the number of T-suppressor cells remaining unchanged. These data provide evidence of T-cell involvement in the pathogenesis of rheumatoid arthritis. Total lymphoid irradiation can induce sustained improvement in clinical disease activity, but severe, possibly fatal, side-effects cannot be ignored. (author)

  15. Total lymphoid irradiation of intractable rheumatoid arthritis

    Energy Technology Data Exchange (ETDEWEB)

    Herbst, M.; Fritz, H.; Sauer, R.

    1986-12-01

    Eleven patients with intractable rheumatoid arthritis were treated with fractionated total lymphoid irradiation, (total dose 20 Gy). Lasting improvement in clinical symptoms was found in four patients during treatment and the remaining patients experienced similar benefit within 2 months of irradiation. There was marked reduction in exacerbations and number of joints involved. Morning stiffness, joint swelling and tenderness decreased. Complications included severe fatigue during treatment and acute bacterial arthritis in multiple joints in one patient. Four patients have since died, one of renal failure, another of cardiogenic shock following surgery 3 and 24 months after total lymphoid irradiation. Both had generalised amyloidosis. The third patient developed joint empyema and died of toxic cardiac failure. The fourth died 3 months after resection of a Kaposi's sarcoma complicated by wound infection which responded to treatment. Immunologically, total lymphoid irradiation resulted in suppression of the absolute lymphocyte count and reduction in T-helper cells, the number of T-suppressor cells remaining unchanged. These data provide evidence of T-cell involvement in the pathogenesis of rheumatoid arthritis. Total lymphoid irradiation can induce sustained improvement in clinical disease activity, but severe, possibly fatal, side-effects cannot be ignored.

  16. Use of the total motile sperm count to predict total fertilization failure in in vitro fertilization

    NARCIS (Netherlands)

    Repping, Sjoerd; van Weert, Janne-Meije; Mol, Ben W. J.; de Vries, Jan W. A.; van der Veen, Fulco

    2002-01-01

    Objective: To evaluate the capacity of baseline characteristics and total motile sperm count (TMC) to predict total fertilization failure (TIFF) in patients undergoing IVF. Design: Retrospective cohort study. Setting: University hospital. Patient(s): Eight hundred ninety-two couples with a total of

  17. Chambolle's Projection Algorithm for Total Variation Denoising

    Directory of Open Access Journals (Sweden)

    Joan Duran

    2013-12-01

    Full Text Available Denoising is the problem of removing the inherent noise from an image. The standard noise model is additive white Gaussian noise, where the observed image f is related to the underlying true image u by the degradation model f=u+n, and n is supposed to be at each pixel independently and identically distributed as a zero-mean Gaussian random variable. Since this is an ill-posed problem, Rudin, Osher and Fatemi introduced the total variation as a regularizing term. It has proved to be quite efficient for regularizing images without smoothing the boundaries of the objects. This paper focuses on the simple description of the theory and on the implementation of Chambolle's projection algorithm for minimizing the total variation of a grayscale image. Furthermore, we adapt the algorithm to the vectorial total variation for color images. The implementation is described in detail and its parameters are analyzed and varied to come up with a reliable implementation.

  18. A method for total body irradiation

    International Nuclear Information System (INIS)

    Yasukochi, Hiroshi; Higashi, Shizuka; Okuhata, Yoshitaka; Lee, Keiichi; Ishioka, Kuniaki; Murakami, Koji; Nagai, Jun; Kuniyasu, Yoshio

    1988-01-01

    In these two years, we have treated four infant patients of acute leukemia by Cobalt-60 total body irradiation and bone marrow transplantation. During total body irradiation, thermoluminescence dosimeters were attached to the skin of patients. For four patients, nine dosimetries were performed. Reliability of this method was examined by phantom experiment. Every irradiation for the patient per fraction was 2.4 Gy, that is, 60 cGy for each four positions, right decubitus A-P and PA directions and left decubitus A-P and PA directions under aseptic circumstances. Radiation dose was uniform by this technique for each patient, and average determined dose for surface of the patients was between 87 % and 106 % compared with the air dose of the center of aseptic space (wagon). As the result, we suggest that this method is suitable for the total body irradiation of acute leukemia of infant. (author)

  19. Total reflection X-ray fluorescence analysis

    International Nuclear Information System (INIS)

    Michaelis, W.; Prange, A.

    1987-01-01

    In the past few years, total reflection X-ray flourescence analysis (TXRF) has found an increasing number of assignments and applications. Experience of trace element analysis using TXRF and examples of applications are already widespread. Therefore, users of TXRF had the opportunity of an intensive exchange of their experience at the 1st workshop on total reflection X-ray fluorescence analysis which took place on May 27th and 28th 1986 at the GKSS Research Centre at Geesthacht. In a series of lectures and discussions dealing with the analytical principle itself, sample preparation techniques and applications as well as comuter programs for spectrum evaluation, the present state of development and the range of applications were outlined. 3 studies out of a total of 14 were included separately in the INIS and ENERGY databases. With 61 figs., 12 tabs [de

  20. Assay development status report for total cyanide

    International Nuclear Information System (INIS)

    Simpson, B.C.; Jones, T.E.; Pool, K.H.

    1993-02-01

    A validated cyanide assay that is applicable to a variety of tank waste matrices is necessary to resolve certain waste tank safety issues and for purposes of overall waste characterization. The target for this effort is an assay with an applicable range of greater than 1,000 ppM (0.10 wt%) total cyanide and a confidence level greater than 80%. Figure 1 illustrates the operating regime of the proposed cyanide assay method. The Assay Development Status Report for Total Cyanide will summarize the past experience with cyanide analyses on-tank waste matrices and will rate the status of the analytical methods used to assay total cyanide (CN - ion) in the tank waste matrices as acceptable or unacceptable. This paper will also briefly describe the current efforts for improving analytical resolution of the assays and the attempts at speciation

  1. Total quality management in orthodontic practice.

    Science.gov (United States)

    Atta, A E

    1999-12-01

    Quality is the buzz word for the new Millennium. Patients demand it, and we must serve it. Yet one must identify it. Quality is not imaging or public relations; it is a business process. This short article presents quality as a balance of three critical notions: core clinical competence, perceived values that our patients seek and want, and the cost of quality. Customer satisfaction is a variable that must be identified for each practice. In my practice, patients perceive quality as communication and time, be it treatment or waiting time. Time is a value and cost that must be managed effectively. Total quality management is a business function; it involves diagnosis, design, implementation, and measurement of the process, the people, and the service. Kazien is a function that reduces value services, eliminates waste, and manages time and cost in the process. Total quality management is a total commitment for continuous improvement.

  2. Heterotopic bone formation following total shoulder arthroplasty

    DEFF Research Database (Denmark)

    Kjaersgaard-Andersen, P.; Frich, Lars Henrik; Sjøbjerg, J.O.

    1989-01-01

    The incidence and location of heterotopic bone formation following total shoulder arthroplasty were evaluated in 58 Neer Mark-II total shoulder replacements. One year after surgery, 45% had developed some ectopic ossification. In six shoulders (10%) the ossifications roentgenographically bridged...... the glenohumeral and/or the glenoacromial space. There was no correlation between shoulder pain and the development of ossification. Shoulders with grade III heterotopic bone formation had a limited range of active elevation compared with shoulders without or with only a milder lesion. Men and patients...... with osteoarthritis of the shoulder joint were significantly disposed to the development of heterotopic bone. Heterotopic bone formation following total shoulder arthroplasty is frequent, but disabling heterotopic ossifications seem to be rare....

  3. Severe Heterotopic Ossification following Total Knee Replacement

    Directory of Open Access Journals (Sweden)

    Alexander L. Dodds

    2014-01-01

    Full Text Available Although the incidence of minor heterotopic ossification is probably higher than what is usually expected, severe heterotopic ossification (HO is an extremely rare event following total knee replacement surgery. We present the case of a 66-year-old woman who initially had achieved an excellent range of motion following bilateral uncemented rotating platform total knee replacement, before presenting with pain and loss of range of motion at 2 months after surgery. Severe HO was diagnosed on X-rays. Treatment consisted of nonoperative measures only, including physiotherapy with hydrotherapy and anti-inflammatories. She eventually regained her range of motion when seen at 8 months after operation. This case illustrates that nonoperative treatment without the use of radiotherapy or surgery can be used to safely resolve stiffness caused by HO after total knee replacement.

  4. Mixed total screening for sulfur isotope

    International Nuclear Information System (INIS)

    Cui Bin; Zhao Lei; Zhan Zhaoyang; He Zhijun

    2003-01-01

    The research on modern economic geology indicates that most ore deposits formed with characters of multi-origin, multi-stage and multi-genesis. Quantificational research of Sulfur isotope origin is a difficult problem that puzzles Geochemists all along. So the formation process of an ore deposit can be taken as the mix or the superposition of multi totals, which can be described by the mathematics model of mixed total screening. In the study of mid-down Yangtze River and Dongpo ore field in Hunan province, the authors successfully applied the mathematics model of mixed total screening, quantificationally resolved the problem of Sulfur isotope origin and mineralizing matter origin, and found out the mineralizing mechanism. This is very valuable. (authors)

  5. Correlations between corneal and total wavefront aberrations

    Science.gov (United States)

    Mrochen, Michael; Jankov, Mirko; Bueeler, Michael; Seiler, Theo

    2002-06-01

    Purpose: Corneal topography data expressed as corneal aberrations are frequently used to report corneal laser surgery results. However, the optical image quality at the retina depends on all optical elements of the eye such as the human lens. Thus, the aim of this study was to investigate the correlations between the corneal and total wavefront aberrations and to discuss the importance of corneal aberrations for representing corneal laser surgery results. Methods: Thirty three eyes of 22 myopic subjects were measured with a corneal topography system and a Tschernig-type wavefront analyzer after the pupils were dilated to at least 6 mm in diameter. All measurements were centered with respect to the line of sight. Corneal and total wavefront aberrations were calculated up to the 6th Zernike order in the same reference plane. Results: Statistically significant correlations (p the corneal and total wavefront aberrations were found for the astigmatism (C3,C5) and all 3rd Zernike order coefficients such as coma (C7,C8). No statistically significant correlations were found for all 4th to 6th order Zernike coefficients except for the 5th order horizontal coma C18 (p equals 0.003). On average, all Zernike coefficients for the corneal aberrations were found to be larger compared to Zernike coefficients for the total wavefront aberrations. Conclusions: Corneal aberrations are only of limited use for representing the optical quality of the human eye after corneal laser surgery. This is due to the lack of correlation between corneal and total wavefront aberrations in most of the higher order aberrations. Besides this, the data present in this study yield towards an aberration balancing between corneal aberrations and the optical elements within the eye that reduces the aberration from the cornea by a certain degree. Consequently, ideal customized ablations have to take both, corneal and total wavefront aberrations, into consideration.

  6. Imaging Total Stations - Modular and Integrated Concepts

    Science.gov (United States)

    Hauth, Stefan; Schlüter, Martin

    2010-05-01

    Keywords: 3D-Metrology, Engineering Geodesy, Digital Image Processing Initialized in 2009, the Institute for Spatial Information and Surveying Technology i3mainz, Mainz University of Applied Sciences, forces research towards modular concepts for imaging total stations. On the one hand, this research is driven by the successful setup of high precision imaging motor theodolites in the near past, on the other hand it is pushed by the actual introduction of integrated imaging total stations to the positioning market by the manufacturers Topcon and Trimble. Modular concepts for imaging total stations are manufacturer independent to a large extent and consist of a particular combination of accessory hardware, software and algorithmic procedures. The hardware part consists mainly of an interchangeable eyepiece adapter offering opportunities for digital imaging and motorized focus control. An easy assembly and disassembly in the field is possible allowing the user to switch between the classical and the imaging use of a robotic total station. The software part primarily has to ensure hardware control, but several level of algorithmic support might be added and have to be distinguished. Algorithmic procedures allow to reach several levels of calibration concerning the geometry of the external digital camera and the total station. We deliver insight in our recent developments and quality characteristics. Both the modular and the integrated approach seem to have its individual strengths and weaknesses. Therefore we expect that both approaches might point at different target applications. Our aim is a better understanding of appropriate applications for robotic imaging total stations. First results are presented. Stefan Hauth, Martin Schlüter i3mainz - Institut für Raumbezogene Informations- und Messtechnik FH Mainz University of Applied Sciences Lucy-Hillebrand-Straße 2, 55128 Mainz, Germany

  7. Failure of aseptic revision total knee arthroplasties.

    Science.gov (United States)

    Leta, Tesfaye H; Lygre, Stein Håkon L; Skredderstuen, Arne; Hallan, Geir; Furnes, Ove

    2015-02-01

    In Norway, the proportion of revision knee arthroplasties increased from 6.9% in 1994 to 8.5% in 2011. However, there is limited information on the epidemiology and causes of subsequent failure of revision knee arthroplasty. We therefore studied survival rate and determined the modes of failure of aseptic revision total knee arthroplasties. This study was based on 1,016 aseptic revision total knee arthroplasties reported to the Norwegian Arthroplasty Register between 1994 and 2011. Revisions done for infections were not included. Kaplan-Meier and Cox regression analyses were used to assess the survival rate and the relative risk of re-revision with all causes of re-revision as endpoint. 145 knees failed after revision total knee arthroplasty. Deep infection was the most frequent cause of re-revision (28%), followed by instability (26%), loose tibial component (17%), and pain (10%). The cumulative survival rate for revision total knee arthroplasties was 85% at 5 years, 78% at 10 years, and 71% at 15 years. Revision total knee arthroplasties with exchange of the femoral or tibial component exclusively had a higher risk of re-revision (RR = 1.7) than those with exchange of the whole prosthesis. The risk of re-revision was higher for men (RR = 2.0) and for patients aged less than 60 years (RR = 1.6). In terms of implant survival, revision of the whole implant was better than revision of 1 component only. Young age and male sex were risk factors for re-revision. Deep infection was the most frequent cause of failure of revision of aseptic total knee arthroplasties.

  8. Radiological evaluation of failed total hip replacement

    International Nuclear Information System (INIS)

    Raspa, V.; Aldrovandi, S.; Pompei, G.

    1988-01-01

    The retrospective study of 50 operated cases of cemented total hip replacement and a review of the literature enabled the authors to define the radiological features of the above-mentioned condition. These features include one or more of the following signs: calcar reabsorption, lacunar erosions, modified relatioships between the prosthesis components, sepsis and loosening, periarticular calcifications dislocation and fracture of prosthesis components. Careful evaluation of these radiological features is extremely important for both an early diagnosis of failed total hip replacement and the choice of an adequate surgical treatment

  9. ANALYSIS AND ACCOUNTING OF TOTAL CASH FLOW

    Directory of Open Access Journals (Sweden)

    MELANIA ELENA MICULEAC

    2012-01-01

    Full Text Available In order to reach the objective of supplying some relevant information regarding the liquidity inflows and outflows during a financial exercise, the total cash flow analysis must include the analysis of result cashable from operation, of payments and receipts related to the investment and of financing decisions of the last exercise, as well as the analysis of treasury variation (of cash items. The management of total cash flows ensures the correlation of current liquidness flows as consequence of receipts with the payments ’flows, in order to provide payment continuity of mature obligations.

  10. Employee benefits in a total rewards framework.

    Science.gov (United States)

    Kwon, Jane; Hein, Pam

    2013-01-01

    Benefits represent one of the largest investments a company makes in its talent. However, our tendency can be to design, deliver and communicate benefits programs independently, without fully considering how those programs fit within a bigger picture of total rewards. Sure, we need to manage and execute individual benefit programs--but not at the expense of getting a real return on our more significant investment in talent. This article provides employers with perspectives on the value of managing benefits within the broader framework of total rewards, why it works and, most importantly, how to make it work.

  11. TOTAL 2003 activities report in brief

    International Nuclear Information System (INIS)

    2004-01-01

    This activities report presents the activities of the petroleum industry Group Total for the year 2003. The following topics are detailed: the corporate social responsibility with the environment stewardship, the energy future management, the safety enhancing, the human resources and the ethics and local development; the shareholder information with the Total share and the share-holding structure; the activities with informations on the Group, the main events, the upstream exploration and production,, the downstream refining, marketing, trading and shipping, the chemicals with overview 2003, base chemical and polymers, performance and specialities. (A.L.B.)

  12. Total shoulder replacement in rheumatoid arthritis

    DEFF Research Database (Denmark)

    Sneppen, O; Fruensgaard, S; Johannsen, Hans Viggo

    1996-01-01

    A prospective study of 62 Neer mark II total shoulder arthroplasties performed during the period from 1981 to 1990 on 51 patients with rheumatoid arthritis was undertaken to evaluate factors associated with component loosening and proximal humeral migration. Thirty-two (51%) showed proximal......, range of movement, abduction force, or function. The risk of clinical asymptomatic loosening is a relatively late complication that is eventually followed by pronounced bone destruction related to the loose component. Long-term radiographic control of total shoulders with rheumatoid arthritis...... is recommended. Hemiarthroplasty with a cemented humeral prosthesis may be a better treatment in the end stage of rheumatoid arthritis of the shoulder....

  13. Development of kits for total PSA monitoring

    International Nuclear Information System (INIS)

    Suprarop, P.

    1999-01-01

    The development of kits for Total PSA assay has shown promising results. All essential components of the assay were prepared with reproducibility and used to optimize the assay. By choosing two steps method, we could avoid the hook effect and obtain satisfactory Q.C. parameters of the standard curve i.e. blank = 0.8%, maximum binding = 65%. If reference material for calibration of the standard is agree upon, the validation could then be carried out with total confidence. Our final goal is to reduce the step of incubation to just one step with no interference from hook effect

  14. TOTAL FINA ELF. Annual report 2002

    International Nuclear Information System (INIS)

    2003-01-01

    This document is the annual report 2002 of Total-Fina-Elf society, great company on the hydrocarbons market. According to the company objective (set the standard not only with the financial performance, but also with stringent requirements in terms of social and environmental responsibility), it presents the Chairman message, the corporate governance, the social and environmental responsibility, the future of energy, the human resources policy, the investor relations, the overview of Total-Fina-Elf fiscal year with financial information and 2002 industrial events. (A.L.B.)

  15. Determination of total solutes in synfuel wastewaters

    Energy Technology Data Exchange (ETDEWEB)

    Wallace, J.R.; Bonomo, F.S.

    1984-03-01

    Efforts to investigate both lyophilization and the measurement of colligative properties as an indication of total solute content are described. The objective of the work described is to develop a method for measuring total dissolved material in retort wastewaters which is simple and rugged enough to be performed in a field laboratory in support of pollution control tests. The analysis should also be rapid enough to provide timely and pertinent data to the pollution control plant operator. To be of most value, the technique developed also should be applicable to other synfuel wastewaters, most of which contain similar major components as oil shale retort waters. 4 references, 1 table.

  16. Management of hypocalcemia following total thyroidectomy

    International Nuclear Information System (INIS)

    Pahuja, D.N.; Patwardhan, U.N.; Samuel, A.M.

    1999-01-01

    A retrospective analysis of calcemic status of 500 randomly selected patients, who underwent total thyroidectomy (TTx) for differentiated thyroid carcinoma (DTC) was studied. These patients were followed up from a minimum of 2-3 years, to a maximum of 15-20 years, and calcemic status was ascertained at varying times following their surgery and radioiodine ( 131 ) therapy

  17. Predicting thyroxine requirements following total thyroidectomy.

    Science.gov (United States)

    Mistry, Dipan; Atkin, Stephen; Atkinson, Helen; Gunasekaran, Sinnappa; Sylvester, Deborah; Rigby, Alan S; England, R James

    2011-03-01

    Optimal thyroxine replacement following total thyroidectomy is critical to avoid symptoms of hypothyroidism. The aim of this study was to determine the best formula to determine the initiated replacement dose of levothyroxine immediately following total thyroidectomy. Prospective study. All patients were initiated on 100 μg levothyroxine and titrated to within the reference range for TSH and free T4. Correlations to height, weight, age, lean body mass (LBM), body surface area (BSA) and body mass index (BMI) were calculated. One hundred consecutive adult patients underwent total thyroidectomy for non-malignant disease. Comparison between three methods of levothyroxine dose prediction, aiming for a levothyroxine dose correct to within 25 μg of actual dose required. Correlations were seen between levothyroxine dose and patient age (r=-0.346, Pregression equation was calculated (predicted levothyroxine dose=[0·943 × bodyweight] + [-1.165 × age] + 125.8), simplified to (levothyroxine dose= bodyweight - age + 125) pragmatically. Initiating patients empirically on 100 μg post-operatively showed that 40% of patients achieved target within 25 μg of their required dose; this increased to 59% when using a weight-only dose calculation (1.6 μg/kg) and to 72% using the simplified regression equation. A simple calculated regression equation gives a more accurate prediction of initiated levothyroxine dose following total thyroidectomy, reducing the need for outpatient attendance for dose titration. © 2011 Blackwell Publishing Ltd.

  18. Total Quality Management in Libraries. ERIC Digest.

    Science.gov (United States)

    Masters, Denise G.

    Total Quality Management (TQM) is "a system of continuous improvement employing participative management and centered on the needs of customers." Key components of TQM are employee involvement and training, problem-solving teams, statistical methods, long-term goals and thinking, and recognition that the system, not people, produces…

  19. Total spectral distributions from Hawking radiation

    Energy Technology Data Exchange (ETDEWEB)

    Broda, Boguslaw [University of Lodz, Department of Theoretical Physics, Faculty of Physics and Applied Informatics, Lodz (Poland)

    2017-11-15

    Taking into account the time dependence of the Hawking temperature and finite evaporation time of the black hole, the total spectral distributions of the radiant energy and of the number of particles have been explicitly calculated and compared to their temporary (initial) blackbody counterparts (spectral exitances). (orig.)

  20. Accumulation pattern of total nonstructural carbohydrate in ...

    African Journals Online (AJOL)

    Umukoro

    1977-09-09

    Sep 9, 1977 ... 1Instituto Nacional de Tecnología Agropecuaria (INTA), EEA Famaillá, Argentina. 2Department of Plant Sciences, University of California Davis, CA, USA. Accepted 17 October, 2012. The pattern of total nonstructural carbohydrate (TNC) accumulation in strawberry (Fragaria ananassa. Duch.) nursery ...

  1. Concepts of total quality management in radiology

    International Nuclear Information System (INIS)

    Pratik Kumar

    2003-01-01

    Quality is one of the touch-stones to determine the competitive advantage for a service, product or company. Total Quality Management has a large ambit, which encompasses not only the quality of images and services producing these images, but also the customers satisfaction. In health care patients satisfaction is divided into three parts: patient quality, professional quality and management quality

  2. Total pressing Indonesian gas development, exports

    International Nuclear Information System (INIS)

    Anon.

    1994-01-01

    Total is on track to become Indonesia's leading gas exporter by the turn of the century. Total's aggressive development of its Mahakam Delta acreage in East Kalimantan is intended to keep pace with growing liquefied natural gas demand, mainly from Japan but also increasingly from South Korea and Taiwan. A frantic scramble is under way among natural gas suppliers in the Pacific Rim region, particularly those with current LNG export facilities, to accommodate projections of soaring natural gas demand in the region. Accordingly, Total's Indonesian gas production goal is the centerpiece of a larger strategy to become a major player in the Far East Asia gas scene. Its goals also fall in line with Indonesia's. Facing flat or declining oil production while domestic oil demand continues to soar along with a rapidly growing economy, Indonesia is heeding some studies that project the country could become a net oil importer by the turn of the century. The paper describes Total's Far East strategy, the Mahakam acreage which it operates, the shift to gas development, added discoveries, future development, project spending levels, and LNG export capacity

  3. Adapting Total Quality Management (TQM) to Government.

    Science.gov (United States)

    Swiss, James E.

    1992-01-01

    Total quality management will not work well in government agencies because of stress on products, not services; on well-defined consumer groups; on inputs/processes, not results; and on preoccupation with quality. An effective revised version emphasizes client feedback, performance monitoring, continuous improvement, and worker participation. (SK)

  4. Production Function Geometry with "Knightian" Total Product

    Science.gov (United States)

    Truett, Dale B.; Truett, Lila J.

    2007-01-01

    Authors of principles and price theory textbooks generally illustrate short-run production using a total product curve that displays first increasing and then diminishing marginal returns to employment of the variable input(s). Although it seems reasonable that a temporary range of increasing returns to variable inputs will likely occur as…

  5. Total hip reconstruction in acetabular dysplasia.

    NARCIS (Netherlands)

    Schller, H.M.; Dalstra, M.; Huiskes, R.; Marti, R.K.

    1993-01-01

    In acetabular dysplasia, fixation of the acetabular component of a cemented total hip prosthesis may be insecure and superolateral bone grafts are often used to augment the acetabular roof. We used finite element analysis to study the mechanical importance of the lateral acetabular roof and found

  6. Total Quality Management in Libraries: A Sourcebook.

    Science.gov (United States)

    O'Neil, Rosanna M., Comp.

    Total Quality Management (TQM) brings together the best aspects of organizational excellence by driving out fear, offering customer-driven products and services, doing it right the first time by eliminating error, and maintaining inventory control without waste. Libraries are service organizations which are constantly trying to improve service.…

  7. The Total Synthesis of Cephalosporin C

    Indian Academy of Sciences (India)

    IAS Admin

    The Total Synthesis of Cephalosporin C. Edited by Setty Mallikarjuna Babu and Subramania Ranganathan. Keywords. Cephalosporin C. The Nobel Prize in Chemistry for 1965 has been awarded for contributions to the art of chemical synthesis. It gives me much pleasure to record here my gratification with the citation, ...

  8. Total Body Opacification 'Technique Neonatal Adrenal Haemorrhage

    African Journals Online (AJOL)

    1971-12-11

    Dec 11, 1971 ... A case is reported illustrating the possible usefulness of total body opacification in the diagnosis of neonatal adrenal haemorrhage. To derive maximum benefit from this principle, the routine use of an early film coupled with high dosage is urged whenever an intravenous pyelogram is performed for ...

  9. [Contents of total flavonoids in Rhizoma Arisaematis].

    Science.gov (United States)

    Du, S S; Lin, H Y; Zhou, Y X; Wei, L X

    2001-06-01

    Comparing the contents of total flavonoides of Rhizoma Arisaematis, which collected in different time, regions, different varieties and processed. Determining the contents by ultraviolet spectro-photometry. The contents were found in the following sequence: 1. the end of July, the begin of July, August, September; 2. Beijing, Shanxi, Sichuan, Anhui; 3. Arisaema erubenscens, A. heterophyllum, A. amurense; 4. unprocessed product, processed product.

  10. Total cross section results for deuterium electrodisintegration

    International Nuclear Information System (INIS)

    Skopik, D.M.; Murphy, J.J. II; Shin, Y.M.

    1976-01-01

    Theoretical total cross sections for deuterium electrodisintegration are presented as a function of incident electron energy. The cross section has been calculated using virtual photon theory with Partovi's photodisintegration calculation for E/subx/ > 10 MeV and effective range theory for E/subx/ 2 H(e, n) reaction in Tokamak reactors

  11. Total hip arthroplasty for giant cell tumour.

    Directory of Open Access Journals (Sweden)

    Kulkarni S

    1996-07-01

    Full Text Available A 32 month follow up of an uncommon case of a Giant Cell Tumour affecting the proximal end of femur is presented. Following a wide excision, the hip was reconstructed using Charnley type of low friction total hip arthroplasty. At a 32 month review, there was no recurrence and the function was good.

  12. Coordinating Council. Ninth Meeting: Total Quality Management

    Science.gov (United States)

    1992-01-01

    This report summarizes the 9th meeting of the STI Coordinating Council. The council listened to the speakers' understanding of Total Quality Management (TQM) principles and heard stories of successful applications of these principles. Definitions of quality stated were focused on customer satisfaction. Reports presented by the speakers are also included.

  13. Revitalizing Space Operations through Total Quality Management

    Science.gov (United States)

    Baylis, William T.

    1995-01-01

    The purpose of this paper is to show the reader what total quality management (TQM) is and how to apply TQM in the space systems and management arena. TQM is easily understood, can be implemented in any type of business organization, and works.

  14. Application of Total Quality Management in Education

    Science.gov (United States)

    Farooq, M. S.; Akhtar, M. S.; Ullah, S. Zia; Memon, R. A.

    2007-01-01

    The purpose of the paper is to analyzing thoughts of the modern management paradigm "Total Quality Management" (TQM), and its application in the field of education. The basic theme of TQM is participatory approach to address the question(s) of quality in business aswell as in the field of education. Reviewing fresh literature from the internet …

  15. Diagnosing Total Quality Management. Part I

    NARCIS (Netherlands)

    Bossink, B.A.G.; Gieskes, J.F.B.; Pas, T.N.M.

    1992-01-01

    From extensive literature research a total quality management (TQM) model is developed. This model describes the basic elements of the concept of TQM. It also provides the way in which the basic elements can be made operational in practice. Based on this model a quality-diagnostical instrument is

  16. Diagnosing Total Quality Management - part 2

    NARCIS (Netherlands)

    Bossink, B.A.G.; Gieskes, J.F.B.; Pas, T.N.M.

    1993-01-01

    From extensive literature research a total quality management (TQM) model is developed. This model describes the basic elements of the concept of TQM. It also provides the way in which the basic elements can be made operational in practice. Based on this model a quality-diagnostical instrument is

  17. Accumulation pattern of total nonstructural carbohydrate in ...

    African Journals Online (AJOL)

    The pattern of total nonstructural carbohydrate (TNC) accumulation in strawberry (Fragaria ananassa Duch.) nursery runner plants, cv. eCamarosaf, was determined for three growing seasons. Plant growth and fruit production patterns were also evaluated. The experiments were carried out on plants propagated in high ...

  18. Total Synthesis of balanol, Part 2

    DEFF Research Database (Denmark)

    Tanner, David Ackland; Kelly, Nicholas; Tedenborg, Lars

    1997-01-01

    A convergent enantioselective total synthesis of the natural product (-)-balanol (1) is described. In addition to benzophenone fragment 8, key intermediates are chiral bicyclic aziridine 3 and the corresponding epoxide 4, both of which undergo highly regio- and stereoselective nucleophilic ring...

  19. Total synthesis of insect antifeedant drimane sesquiterpenes

    NARCIS (Netherlands)

    Jansen, B.J.M.

    1993-01-01

    The investigations described in this thesis deal with the total synthesis of sesquiterpenes of the drimane family, named for their widespread occurrence in the stem bark of South American Drimys species. These compounds contain the bicyclofarnesol nucleus

  20. Feasibility study of transanal total mesorectal excision

    NARCIS (Netherlands)

    Velthuis, S.; Boezem, P.B. van den; Peet, D.L. van der; Cuesta, M.A.; Sietses, C.

    2013-01-01

    BACKGROUND: Laparoscopic resection of colorectal cancers is a safe alternative to open surgery. The conversion rate to open surgery remains fairly constant but is associated with increased morbidity. A new approach to the surgical excision of rectal cancer is transanal total mesorectal excision

  1. TOTAL HIP REPLACEMENTS AT KIKUYU HOSPITAL, KENYA

    African Journals Online (AJOL)

    equipments, few trained personnel and the high cost of implants. It is mainly in the ..... function more affected than the sensory a day after. There was a foot drop. .... 60: Issue 2, 217-. 220. 13. NIH Consensus Development Panel on Total Hip.

  2. Total Survey Error for Longitudinal Surveys

    NARCIS (Netherlands)

    Lynn, Peter; Lugtig, P.J.

    2016-01-01

    This article describes the application of the total survey error paradigm to longitudinal surveys. Several aspects of survey error, and of the interactions between different types of error, are distinct in the longitudinal survey context. Furthermore, error trade-off decisions in survey design and

  3. Food safety and total quality management

    NARCIS (Netherlands)

    Barendsz, A.W.

    1998-01-01

    Food safety is a growing global concern not only because of its continuing importance for public health but also because of its impact on international trade. The application of total quality management (TQM) provides the best possible care by continuously improving products and services to meet or

  4. Total pancreatic lipomatosis with malabsorption syndrome

    Directory of Open Access Journals (Sweden)

    Rama Anand

    2011-01-01

    Full Text Available Total fat replacement of the pancreas is rare. Focal fatty replacement is the most common degenerative lesion of pancreas. Focal fatty deposits have no major clinical significance; however, extreme fat replacement is of pathologic significance, as it is associated with marked reduction in exocrine function of pancreas, resulting in malabsorption due to pancreatic enzyme insufficiency.

  5. Brutally Unfair Tactics Totally OK Now

    DEFF Research Database (Denmark)

    Wilson, Douglas

    2011-01-01

    In this paper, I use a party game that I co-designed, Brutally Unfair Tactics Totally OK Now (B.U.T.T.O.N.), as a case study to suggest some alternative possibilities for the design of digitally-mediated play and games. Specifically, I argue that that intentionally “broken” or otherwise incomplet...

  6. Total energy calculations and bonding at interfaces

    International Nuclear Information System (INIS)

    Louie, S.G.

    1984-08-01

    Some of the concepts and theoretical techniques employed in recent ab initio studies of the electronic and structural properties of surfaces and interfaces are discussed. Results of total energy calculations for the 2 x 1 reconstructed diamond (111) surface and for stacking faults in Si are reviewed. 30 refs., 8 figs

  7. Trying and the Arguments from Total Failure

    DEFF Research Database (Denmark)

    Grünbaum, Thor

    2008-01-01

    New Volitionalism is a name for certain widespread conception of the nature of intentional action. Some of the standard arguments for New Volitionalism, the so-called arguments from total failure, have even acquired the status of basic assumptions for many other kinds of philosophers. It is there...

  8. A formal model for total quality management

    NARCIS (Netherlands)

    S.C. van der Made-Potuijt; H.B. Bertsch (Boudewijn); L.P.J. Groenewegen

    1996-01-01

    textabstractTotal Quality Management (TQM) is a systematic approach to managing a company. TQM is systematic in the sense that it is uses facts through observation, analysis and measurable goals. There are theoretical descriptions of this management concept, but there is no formal model of it. A

  9. Multicultural Leadership, Sustainable Total School Environment

    Science.gov (United States)

    Yeung, See-Wai Alison; Lee, Yeung; Yue, K. W. Ryan

    2006-01-01

    Banks (2002) stated that to implement multicultural education successfully, we must think of the school as a social system. Therefore, if educational equity and excellence are to be provided to all students, a systemic Total School Environment [Banks (2001) "Cultural diversity and education: Foundations curriculum and teaching, 4th ed." Allyn and…

  10. Recurrent hemarthrosis after total knee arthroplasty

    NARCIS (Netherlands)

    Rukavina, A.; Kerkhoffs, G.M.M.J.; Schneider, P.; Kuster, M.S.

    2010-01-01

    This report describes a case of spontaneous recurrent hemarthrosis of the knee that presented 4 weeks after total knee arthroplasty. Femoral arteriography showed a false aneurysm of a branch of the inferior lateral geniculate artery. Therapeutic embolization of the arterial branch was performed

  11. An approach to total quality assurance

    International Nuclear Information System (INIS)

    Archer, L.G.

    1976-01-01

    Total Quality Assurance must be based on amalgamating three quality functions: effective quality control, competent inspection, and regularly audited Quality Assurance programmes. In applying these functions the fuel supplier must regard each of his sub-contractors as part of his own works and ensure a common policy of motivated Quality Assurance throughout his own works and those of his suppliers. (author)

  12. On total noncommutativity in quantum mechanics

    Science.gov (United States)

    Lahti, Pekka J.; Ylinen, Kari

    1987-11-01

    It is shown within the Hilbert space formulation of quantum mechanics that the total noncommutativity of any two physical quantities is necessary for their satisfying the uncertainty relation or for their being complementary. The importance of these results is illustrated with the canonically conjugate position and momentum of a free particle and of a particle closed in a box.

  13. Flavonoid, hesperidine, total phenolic contents and antioxidant ...

    African Journals Online (AJOL)

    Additionally, the antioxidant activities were also determined by ferric reducing antioxidant power (FRAP) and 1,1-diphenyl-2-picryl hydrazyl (DPPH) radical scavenging activity. C. hystrix had the highest flavonoid and total phenolic contents while C. aurantifolia had the highest hesperidine content. The antioxidant activity of ...

  14. Total dissolved carbohydrate in Mahi river estuary

    Digital Repository Service at National Institute of Oceanography (India)

    Bhosle, N.B.; Rokade, M.A.; Zingde, M.D.

    Total dissolved carbohydrate varied from 4.37-15 mg l-1 and 3.71-15.95 mg l-1 in the surface and bottom samples respectively. Highest concentration of carbohydrate was observed at station 1 which decreased downward upto Station 6 which showed...

  15. Total Evidence, Uncertainty and A Priori Beliefs

    NARCIS (Netherlands)

    Bewersdorf, Benjamin; Felline, Laura; Ledda, Antonio; Paoli, Francesco; Rossanese, Emanuele

    2016-01-01

    Defining the rational belief state of an agent in terms of her initial or a priori belief state as well as her total evidence can help to address a number of important philosophical problems. In this paper, I discuss how this strategy can be applied to cases in which evidence is uncertain. I argue

  16. Total and the Algerian shale gas

    International Nuclear Information System (INIS)

    Chapelle, Sophie; Petitjean, Olivier; Maurin, Wilfried; Balvet, Jacqueline; Combes, Maxime; Geze, Francois; Hamouchene, Hamza; Hidouci, Ghazi; Malti, Hocine; Renaud, Juliette; Simon, Antoine; Titouche, Fateh

    2015-01-01

    This publication proposes a rather detailed and discussed overview of the movement of mobilisation of Algerian people (notably those living in the Sahara) against projects of exploration and exploitation of shale gases in Algeria by the Total group. The authors also recall and comment the long and heavy history of hydrocarbon management in Algeria, the role of international firms and of western interests (notably French interests) in this country, and the position of Total regarding the stake related to shale gases. The authors outline problems created by shale gas exploitation regarding water consumption and waste waters. They also notice that the safety of wells is at the centre of the protest. Problems raised by hydraulic fracturing are reviewed: seismic activity, chemical pollution, air pollution and greenhouse gases, landscape destruction. The attitude of the Algerian government is commented. Then, the authors try to identify and describe the action of Total in the Algerian shale gas sector, discuss the possible French influence, and outline the presence of Total all over the world in this sector

  17. LAMBDA p total cross-section measurement

    CERN Multimedia

    CERN PhotoLab

    1970-01-01

    A view of the apparatus used for the LAMBDA p total cross-section measurement at the time of its installation. The hyperons decaying into a proton and a pion in the conical tank in front were detected in the magnet spectrometer in the upper half of the picture. A novel detection technique using exclusively multiwire proportional chambers was employed.

  18. Extracorporeal total artificial heart as bailout surgery.

    Science.gov (United States)

    Perrodin, Stéphanie F; Muller, Olivier; Gronchi, Fabrizio; Liaudet, Lucas; Hullin, Roger; Kirsch, Matthias

    2017-03-01

    We report the use of a total extracorporeal heart for uncontrolled bleeding following a proximal left anterior descending artery perforation, using two centrifugal ventricular assist devices after heart explantation. The literature describing similar techniques and patient outcomes for this "bailout" technique are reviewed. © 2017 Wiley Periodicals, Inc.

  19. Benchmarking, Total Quality Management, and Libraries.

    Science.gov (United States)

    Shaughnessy, Thomas W.

    1993-01-01

    Discussion of the use of Total Quality Management (TQM) in higher education and academic libraries focuses on the identification, collection, and use of reliable data. Methods for measuring quality, including benchmarking, are described; performance measures are considered; and benchmarking techniques are examined. (11 references) (MES)

  20. Salinity: Electrical conductivity and total dissolved solids

    Science.gov (United States)

    The measurement of soil salinity is a quantification of the total salts present in the liquid portion of the soil. Soil salinity is important in agriculture because salinity reduces crop yields by reducing the osmotic potential making it more difficult for the plant to extract water, by causing spe...

  1. Total Quality Management: Implications for Educational Assessment.

    Science.gov (United States)

    Rankin, Stuart C.

    1992-01-01

    Deming's "System of Profound Knowledge" is even more fundamental than his 14-principle system transformation guide and is based on 4 elements: systems theory, statistical variation, a theory of knowledge, and psychology. Management should revamp total system processes so that quality of product is continually improved. Implications for…

  2. Total Quality Management. ERIC Digest, Number 73.

    Science.gov (United States)

    Weaver, Tyler

    The Japanese success story has made W. Edwards Deming's Total Quality Management (TQM) theory increasingly popular among American managers, from car manufacturers to educational leaders. TQM is based on two tenets: the primacy of customer satisfaction and the necessity of tapping nontraditional sources (especially employee ideas) to institute…

  3. Staff Development and Total Quality Management.

    Science.gov (United States)

    Norris, Gerald L.; Norris, Joye H.

    Professional development is an emerging view of faculty development that places teachers in charge of their own professional growth. The emergence of Total Quality Management (TQM) provides a vehicle for designing professional development to meet the needs of individuals and the organizations that employ them. The eight tenets of Deming's theory…

  4. Curriculum Transformation through Total Quality Management.

    Science.gov (United States)

    Edwards, Barbara; Algozzine, Bob

    1995-01-01

    Describes a massive cultural transformation project at two Charlotte, North Carolina, elementary schools that used Deming's total quality management principles to restructure curricula according to Boyer's eight commonalities of learning. Shows how the FADE (focus, analyze, develop, and execute) model was used to develop a well-coordinated,…

  5. Total Quality Management in Higher Education.

    Science.gov (United States)

    Sherr, Lawrence A.; Lozier, G. Gredgory

    1991-01-01

    Total Quality Management, based on theories of W. Edward Deming and others, is a style of management using continuous process improvement characterized by mission and customer focus, a systematic approach to operations, vigorous development of human resources, long-term thinking, and a commitment to ensuring quality. The values espoused by this…

  6. Inestabilidad de la Artroplastia Total de Cadera

    OpenAIRE

    Ezquerra Herrando, Laura; Albareda Albareda, Jorge; Seral García, Belén

    2014-01-01

    INTRODUCCIÓN La artroplastia total de cadera (ATC) es un procedimiento muy frecuente en los Servicios de Cirugía Ortopédica y Traumatología, y aunque su efectividad es muy elevada, no está exenta de complicaciones como son el aflojamiento aséptico, luxaciones, infección y fracturas periprotésicas. A pesar de los avances en las técnicas y modelos protésicos, la luxación sigue siendo la segunda complicación más frecuente después del aflojamiento aséptico en las artroplastias totales de cadera. ...

  7. A Modern Approach to Total Wellbeing

    Science.gov (United States)

    Hadzic, Maja; Chen, Meifania; Brouwer, Rick; Dillon, Tharam

    The events of the last decades have impacted our lives and our health significantly. We expected that the technology boom will improve our lives. While this may be true in a specific context, generally speaking our societies are suffering from moral decays, terrorism fears, wars, financial crisis and unpredictable acts of nature that are increasing in frequency and in intensity. The complex nature of the world we live is impacting our health and wellbeing considerably. Our health is not only determined by our physical health but is the end product of the interplay of the physical, mental, emotional, financial, relational and spiritual events of a lifetime. In this paper we develop a framework that will help us define and measure total wellbeing of individuals in our volatile societies. This framework will help us better understand the complex nature of total wellbeing and develop effective prevention and intervention strategies.

  8. Quality Indicators for the Total Testing Process.

    Science.gov (United States)

    Plebani, Mario; Sciacovelli, Laura; Aita, Ada

    2017-03-01

    ISO 15189:2012 requires the use of quality indicators (QIs) to monitor and evaluate all steps of the total testing process, but several difficulties dissuade laboratories from effective and continuous use of QIs in routine practice. An International Federation of Clinical Chemistry and Laboratory Medicine working group addressed this problem and implemented a project to develop a model of QIs to be used in clinical laboratories worldwide to monitor and evaluate all steps of the total testing process, and decrease error rates and improve patient services in laboratory testing. All laboratories are invited, at no cost, to enroll in the project and contribute to harmonized management at the international level. Copyright © 2016 Elsevier Inc. All rights reserved.

  9. Total gastrectomy for non-neoplastic diseases

    DEFF Research Database (Denmark)

    Bjorn, Niels; Ainsworth, Alan Patrick; Mortensen, Michael Bau

    2017-01-01

    Background: The aim of this study was to describe patients who had total gastrectomy for non-neoplastic diseases within a well-defined geographical area. Material and Methods: Retrospective study of patients who had gastrectomy for a non-neoplastic disease at the Department of Surgery, Odense...... University Hospital from 1 January 2005 to 31 December 2014. Results: A total of 268 gastrectomies were performed with the 10-year period. Of these, ten (4%) were done for non-neoplastic diseases. Two were men and eight women with a median age of 51 years (range 31 to 96 years). Six had emergency surgery...... of 10 and 2 of 10, respectively. Histology of the resected specimens showed: Oedema, inflammation and/or necrosis (n=6), Menetrier's disease (n=2) and perforation (n=2). Conclusions: Gastrectomy for non-neoplastic diseases accounts for less than 5% of all gastrectomies. The majority of these cases...

  10. Atomic resonances above the total ionization energy

    International Nuclear Information System (INIS)

    Doolen, G.

    1975-01-01

    A rigorous result obtained using the theory associated with dilatation analytic potentials is that by performing a complex coordinate rotation, r/subj/ → r/subj/e/subi//sup theta/, on a Hamiltonian whose potential involves only pairwise Coulombic interactions, one can show that when theta = π/2, no complex eigenvalues (resonances) appear whose energies have a real part greater than the total ionization energy of the atomic system. This appears to conflict with experimental results of Walton, Peart, and Dolder, who find resonance behavior above the total ionization energy of the H -- system and also the theoretical stabilization results of Taylor and Thomas for the same system. A possible resolution of this apparent conflict is discussed and a calculation to check its validity is proposed

  11. Total: overview of the 2002 financial year

    International Nuclear Information System (INIS)

    Anon.

    2003-01-01

    In a globally less favourable environment than 2001, Total company (the former 'TotalFinaElf') succeeded in limiting the decay of its results thanks to the increase of its hydrocarbons production which reached the record level of 10% and to the implementation of its synergy and productivity programs. The three activity sectors of the group are: the upstream (exploration, production of hydrocarbons, gas electric power and other energies), the downstream (refining, distribution of petroleum products, special products, trading and shipping of crudes and products), and the chemistry (basic chemistry and big polymers, intermediate and performance polymers, special products). This article details the 2002 results of the group for the three sectors: upstream (exploration and development, reserves, production, natural gas sales), gas and electric power integration (Europe, Americas, Asia), electric power and cogeneration. (J.S.)

  12. Asymptotic Behaviour of Total Generalised Variation

    KAUST Repository

    Papafitsoros, Konstantinos; Valkonen, Tuomo

    2015-01-01

    © Springer International Publishing Switzerland 2015. The recently introduced second order total generalised variation functional TGV2 β,α has been a successful regulariser for image processing purposes. Its definition involves two positive parameters α and β whose values determine the amount and the quality of the regularisation. In this paper we report on the behaviour of TGV2 β,α in the cases where the parameters α, β as well as their ratio β/α becomes very large or very small. Among others, we prove that for sufficiently symmetric two dimensional data and large ratio β/α, TGV2 β,α regularisation coincides with total variation (TV) regularization

  13. Total quality management of cobalt-60 sources

    International Nuclear Information System (INIS)

    Malkoske, G.R.

    1999-01-01

    Total Quality Management of Cobalt-60 sources by a supplier requires a life cycle approach to source management. This covers various aspects, including design, manufacturing, installation, field inspection, source surveillance and return of cobalt-60 sources at the end of their useful life. The Total Quality Management approach demonstrates a strong industry commitment to the beneficial use of gamma technology for industrial irradiation applications in both developed nations and in those nations who are developing their infrastructure and techniques for the beneficial use of this technology. MDS Nordion continues to demonstrate its support and commitment to the industry by developing and implementing state-of-the-art standards for the safe use of cobalt-60 sources

  14. Total variation-based neutron computed tomography

    Science.gov (United States)

    Barnard, Richard C.; Bilheux, Hassina; Toops, Todd; Nafziger, Eric; Finney, Charles; Splitter, Derek; Archibald, Rick

    2018-05-01

    We perform the neutron computed tomography reconstruction problem via an inverse problem formulation with a total variation penalty. In the case of highly under-resolved angular measurements, the total variation penalty suppresses high-frequency artifacts which appear in filtered back projections. In order to efficiently compute solutions for this problem, we implement a variation of the split Bregman algorithm; due to the error-forgetting nature of the algorithm, the computational cost of updating can be significantly reduced via very inexact approximate linear solvers. We present the effectiveness of the algorithm in the significantly low-angular sampling case using synthetic test problems as well as data obtained from a high flux neutron source. The algorithm removes artifacts and can even roughly capture small features when an extremely low number of angles are used.

  15. Increasing productivity through Total Reuse Management (TRM)

    Science.gov (United States)

    Schuler, M. P.

    1991-01-01

    Total Reuse Management (TRM) is a new concept currently being promoted by the NASA Langley Software Engineering and Ada Lab (SEAL). It uses concepts similar to those promoted in Total Quality Management (TQM). Both technical and management personnel are continually encouraged to think in terms of reuse. Reuse is not something that is aimed for after a product is completed, but rather it is built into the product from inception through development. Lowering software development costs, reducing risk, and increasing code reliability are the more prominent goals of TRM. Procedures and methods used to adopt and apply TRM are described. Reuse is frequently thought of as only being applicable to code. However, reuse can apply to all products and all phases of the software life cycle. These products include management and quality assurance plans, designs, and testing procedures. Specific examples of successfully reused products are given and future goals are discussed.

  16. An unusual case of total ophthalmoplegia

    Directory of Open Access Journals (Sweden)

    Chowdhury Ravindra

    2009-01-01

    Full Text Available An eight-year-old male child presented with drooping of the left eyelid with a history of penetrating injury of hard palate by an iron spoon seven days ago, which had already been removed by the neurosurgeon as the computed tomography scan revealed a spoon in the left posterior ethmoid and sphenoid bone penetrating into the middle cranial fossa. On examination, visual acuity was 20/20 in each eye and left eye showed total ophthalmoplegia. Oral cavity revealed a hole in the left lateral part of the hard palate. We managed the case with tapering dose of systemic prednisolone. The total ophthalmoplegia was markedly improved in one month. Cases of foreign bodies in the orbit with intracranial extension are not unusual, but the path this foreign body traveled through the hard palate without affecting the optic nerve, internal carotid artery or cavernous sinus makes an interesting variation.

  17. Implantation of total body irradiation in radiotherapy

    International Nuclear Information System (INIS)

    Habitzreuter, Angela Beatriz

    2010-01-01

    Before implementing a treatment technique, the characteristics of the beam under irradiation conditions must be well acknowledged and studied. Each one of the parameters used to calculate the dose has to be measured and validated before its utilization in clinical practice. This is particularly necessary when dealing with special techniques. In this work, all necessary parameters and measurements are described for the total body irradiation implementation in facilities designed for conventional treatments that make use of unconventional geometries to generate desired enlarged field sizes. Furthermore, this work presents commissioning data of this modality at Hospital das Clinicas of Sao Paulo using comparison of three detectors types for measurements of entrance dose during total body irradiation treatment. (author)

  18. Overview of Total Group financial year

    International Nuclear Information System (INIS)

    Anon.

    2003-01-01

    In 2004, the combination of very high crude oil prices with a strong rise of refining margins, and in the second half of 2004 of the start off again of the rise of petrochemical margins, has led Total Group to reach a record level of 9.04 billion euros for its net adjusted result, which represents a 23% rise with respect to 2003, and this despite a fall of the Dollar exchange rate. Total has also carried on its downstream strategy of natural gas production. This strategy aims at facilitating and optimizing the access to its present day and future productions and reserves, not only to traditional markets but also to markets opened to world competition. (J.S.)

  19. Total quality management in hotel industry

    OpenAIRE

    Mitreva, Elizabeta; Saneva, Dusica; Miteva, Natasa

    2017-01-01

    Total quality management (TQM) is a systematic management approach aiming at continuous increase of the value offered to consumers through improvement of service quality. In hotel industry, success is achieved through service quality, which stands as a key factor for sustainability in the twenty-first century. Nowadays, quality is the basic factor for survival on the market, better competition, and greater profitability. TQM is a process that starts and ends with the consumer. The aim of this...

  20. Total Quality Management. A Selected Bibliography

    Science.gov (United States)

    1994-03-01

    and Publow, Mark. "Understanding and Managing Authority Relationships : Guidelines for Supervisors and Sub- ordinates." QUALITY PROGRESS, Vol. 25...NEXT OPERATION AS CUSTOMER (NOAC): HOW TO IMPROVE QUALITY, COST AND CYCLE TIME IN SERVICE OPERATIONS. New York: American Management Association, 1991...Keith. HORIZONTAL MANAGEMENT : BEYOND TOTAL CUSTOMER SATISFACTION. New York: Lexington Books, 1991. 211pp. (HD66 D45 1991) Donnelly, James H., Jr. CLOSE

  1. Changing trends in total knee replacement

    OpenAIRE

    Goudie, Ewan; Robinson, Cal; Walmsley, Phil; Brenkel, Ivan

    2017-01-01

    Introduction:  This study evaluates a possible change in the demographics and surgical practice observed in a large cohort of patients undergoing total knee replacement (TKR). Patients and methods:  We performed a retrospective analysis of a prospectively collected data on two groups of consecutive patients undergoing primary TKR. Group one consisted of patients who underwent surgery between 1994 and 1998. Group two consisted of patients who had surgery between 2009 and 2012. Results:  The me...

  2. Total Quality Management (TQM): Group Dynamics Workshop

    Science.gov (United States)

    1990-05-15

    take for these changes to penetrate most OSD agencies. - The unique organizational culture, structure, and functioning of OSD (i.e., a gigantic size...Performing (group problem solving; Performing diagnosing and solving quality problems and sele2cting and implementing solutions). Total Quality Management...Stage, the quality improvement group diagnoses the quality problem/opportunity, gathers the right kind of quantitative data, and formulates, selects, and

  3. Total dissociation cross section of halo nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Formanek, J. [Karlova Univ., Prague (Czech Republic). Fakulta Matematicko-Fyzikalni; Lombard, R.J. [Paris-11 Univ., 91 - Orsay (France). Inst. de Physique Nucleaire

    1996-10-01

    Calculations of the total dissociation cross section is performed in the impact parameter representation. The case of {sup 11}Be and {sup 11}Li loosing one and two neutron(s), respectively, by collision on a {sup 12}C target, which remains in its ground state are discussed. The results are found to depend essentially on the rms radius of the halo wave function. (author). 12 refs.

  4. The First Total Synthesis of Dragmacidin D

    OpenAIRE

    Garg, Neil K.; Sarpong, Richmond; Stoltz, Brian M.

    2002-01-01

    The first total synthesis of the biologically significant bis-indole alkaloid dragmacidin D (5) has been achieved. Thermal and electronic modulation provides the key for a series of palladium-catalyzed Suzuki cross-coupling reactions that furnished the core structure of the complex guanidine- and aminoimidazole-containing dragmacidins. Following this crucial sequence, a succession of meticulously controlled final events was developed leading to the completion of the natural product.

  5. Counterterrorism and cybersecurity total information awareness

    CERN Document Server

    Lee, Newton

    2013-01-01

    Provides a broad survey of the United States' counterterrorism history, the use of artificial intelligence in data mining, social media and privacy, cyber attacks and prevention, and longstanding issues of war and peace Closely examines how Total Information Awareness, a governmental data mining project focused on scanning public and private data, plays an integral role in cybersecurity Analyzes recent cyberattacks across the globe orchestrated by 'hacktivist' groups, such as Anonymous

  6. Heisenberg rise of total cross sections

    International Nuclear Information System (INIS)

    Ezhela, V.V.; Yushchenko, O.P.

    1988-01-01

    It is shown that on the basis of the original idea of Heisenberg on the quasiclassical picture of extended particle interactions one can construct a satisfactory description of the total cross sections, elastic cross sections, elastic diffractive slopes and mean charged multiplicities in the cm energy range from 5 to 900 GeV, and produce reasonable extrapolations up to several tens of TeV. 14 refs.; 7 figs.; 2 tabs

  7. Total elbow arthroplasty: a radiographic outcome study

    Energy Technology Data Exchange (ETDEWEB)

    Bai, Xue Susan [University of Washington, Department of Radiology, Box 357115, Seattle, WA (United States); Petscavage-Thomas, Jonelle M. [Penn State Hershey Medical Center, Department of Radiology, Hershey, PA (United States); Ha, Alice S. [University of Washington, Department of Radiology, Box 354755, Seattle, WA (United States)

    2016-06-15

    Total elbow arthroplasty (TEA) is becoming a popular alternative to arthrodesis for patients with end-stage elbow arthrosis and comminuted distal humeral fractures. Prior outcome studies have primarily focused on surgical findings. Our purpose is to determine the radiographic outcome of TEA and to correlate with clinical symptoms such as pain. This is an IRB-approved retrospective review from 2005 to 2015 of all patients with semiconstrained TEA. All available elbow radiographs and clinical data were reviewed. Data analysis included descriptive statistics and Kaplan-Meier survival curves for radiographic and clinical survival. A total of 104 total elbow arthroplasties in 102 patients were reviewed; 75 % were in women and the mean patient age was 63.1 years. Mean radiographic follow-up was 826 days with average of four radiographs per patient. Seventy TEAs (67 %) developed radiographic complications, including heterotopic ossification (48 %), perihardware lucency (27 %), periprosthetic fracture (23 %), hardware subluxation/dislocation (7 %), polyethylene wear (3 %), and hardware fracture/dislodgement (3 %); 56 patients (55 %) developed symptoms of elbow pain or instability and 30 patients (30 %) underwent at least one reoperation. In patients with radiographic complications, 66 % developed elbow pain, compared to 19 % of patients with no radiologic complications (p = 0.001). Of the patients with radiographic complications, 39 % had at least one additional surgery compared to 0 % of patients without radiographic complications (p = 0.056). Radiographic complications are common in patients after total elbow arthroplasty. There is a strong positive association between post-operative radiographic findings and clinical outcome. Knowledge of common postoperative radiographic findings is important for the practicing radiologist. (orig.)

  8. NASA total quality management 1990 accomplishments report

    Science.gov (United States)

    1991-01-01

    NASA's efforts in Total Quality Management are based on continuous improvement and serve as a foundation for NASA's present and future endeavors. Given here are numerous examples of quality strategies that have proven effective and efficient in a time when cost reduction is critical. These accomplishment benefit our Agency and help to achieve our primary goal, keeping American in the forefront of the aerospace industry.

  9. Apparatus for measuring total flow in pipes

    International Nuclear Information System (INIS)

    Matthews, H.

    1986-01-01

    To obtain a sample representative of the total flow in a pipe over a given period a Pitot tube is located in the pipe and connected to a collector outside the pipe. The collector is pressurised to a pressure substantially equal to the static head of the flow in the pipe via a line. Liquid is discharged from a collector to a container which is vented to atmosphere. (author)

  10. Total evaporation in thermal ionization mass spectrometry

    International Nuclear Information System (INIS)

    Callis, E.L.; Cappis, J.H.

    1996-01-01

    Experiments were conducted to assess the effects of impurities on the total evaporation method for mass spectrometric measurement of the isotope ratio of uranium. Standard samples were spiked with Na, Ca, Fe, Zr and Ba. The results indicated that only Fe, and possible Na, displayed any interference, and then only at high concentrations. One problem limiting the accuracy of the method is the determination of the relative efficiency of the collectors in the multicollector system. 3 refs., 1 tab

  11. Total fact-book 2000-2005

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2005-07-01

    TOTAL S.A., a French society incorporated in France on March 28, 1924, together with its subsidiaries and affiliates, is the fourth largest publicly-traded integrated oil and gas company in the world. This document provides statistical data and information on the corporate (highlights, statements), upstream (production, costs,main producing fields, drilling), upstream maps, downstream (refining, distillation, retail gasoline outlets) and chemicals (sales, specialities). (A.L.B.)

  12. Total fact-book 2000-2005

    International Nuclear Information System (INIS)

    2005-01-01

    TOTAL S.A., a French society incorporated in France on March 28, 1924, together with its subsidiaries and affiliates, is the fourth largest publicly-traded integrated oil and gas company in the world. This document provides statistical data and information on the corporate (highlights, statements), upstream (production, costs,main producing fields, drilling), upstream maps, downstream (refining, distillation, retail gasoline outlets) and chemicals (sales, specialities). (A.L.B.)

  13. Calidad total: fuente de ventaja competitiva

    OpenAIRE

    Tarí, Juan-José

    2000-01-01

    El objeto de este trabajo es analizar la dirección de la calidad estudiando sus pilares básicos como son, la planificación, organización y control por un lado y los aspectos humanos por otro, centrándonos en sus dos elementos clave para desarrollar la calidad total: el liderazgo y la involucración de todos los empleados.

  14. Total synthesis of (+)-antroquinonol and (+)-antroquinonol D.

    Science.gov (United States)

    Sulake, Rohidas S; Chen, Chinpiao

    2015-03-06

    The first total synthesis of (+)-antroquinonol and (+)-antroquinonol D, two structurally unique quinonols with a sesquiterpene side chain, is described. The route features an iridium-catalyzed olefin isomerization-Claisen rearrangement reaction (ICR), lactonization, and Grubbs olefin metathesis. The requisite α,β-unsaturation was achieved via the selenylation/oxidation protocol and elimination of β-methoxy group to provide two natural products from a common intermediate.

  15. Multi sensor reanalysis of total ozone

    Directory of Open Access Journals (Sweden)

    R. J. van der A

    2010-11-01

    Full Text Available A single coherent total ozone dataset, called the Multi Sensor Reanalysis (MSR, has been created from all available ozone column data measured by polar orbiting satellites in the near-ultraviolet Huggins band in the last thirty years. Fourteen total ozone satellite retrieval datasets from the instruments TOMS (on the satellites Nimbus-7 and Earth Probe, SBUV (Nimbus-7, NOAA-9, NOAA-11 and NOAA-16, GOME (ERS-2, SCIAMACHY (Envisat, OMI (EOS-Aura, and GOME-2 (Metop-A have been used in the MSR. As first step a bias correction scheme is applied to all satellite observations, based on independent ground-based total ozone data from the World Ozone and Ultraviolet Data Center. The correction is a function of solar zenith angle, viewing angle, time (trend, and effective ozone temperature. As second step data assimilation was applied to create a global dataset of total ozone analyses. The data assimilation method is a sub-optimal implementation of the Kalman filter technique, and is based on a chemical transport model driven by ECMWF meteorological fields. The chemical transport model provides a detailed description of (stratospheric transport and uses parameterisations for gas-phase and ozone hole chemistry. The MSR dataset results from a 30-year data assimilation run with the 14 corrected satellite datasets as input, and is available on a grid of 1× 1 1/2° with a sample frequency of 6 h for the complete time period (1978–2008. The Observation-minus-Analysis (OmA statistics show that the bias of the MSR analyses is less than 1% with an RMS standard deviation of about 2% as compared to the corrected satellite observations used.

  16. TOTAL QUALITY MANAGEMENT AND CONTEMPORARY HOTEL INDUSTRY

    OpenAIRE

    Ivica Batinić

    2013-01-01

    Strong competition in the market has caused the development of a new management approach known as Total Quality Management (TQM). Due to importance that quality plays in achieving competitive advantage, the hotel industry started to apply TQM. During the introduction of these systems, hotel companies may use different approaches to suit their own buseiness requirements. In doing so, 'TQM standards' can be used, or various international standards and models of business ...

  17. Climate Change and Tropical Total Lightning

    Science.gov (United States)

    Albrecht, R.; Petersen, W.; Buechler, D.; Goodman, S.; Blakeslee, R.; Christian, H.

    2009-01-01

    While global warming is regarded as a fact by many in the scientific community, its future impact remains a challenge to be determined and measured. The International Panel on Climate Change (IPCC) assessment report (IPCC, 2007) shows inconclusive answers on global rainfall trends and general agreement on a future drier climate with increased global warming. The relationship between temperature, humidity and convection is not linear and is strongly dependent on regional scale features, such as topography and land cover. Furthermore, the relationship between convective lightning production (thunderstorms) and temperature is even more complicated, being subjected to the cloud dynamics and microphysics. Total lightning (intracloud and cloud-to-ground) monitoring is a relatively new field of observation. Global and tropical total lightning began to be more extensively measured by satellites in the mid 90s. In this scope, the Lightning Imaging Sensor (LIS) onboard of the Tropical Rainfall Measurement Mission (TRMM) has been operational for over 11 years. Here we address total lightning trends observed by LIS from 1998 to 2008 in different temporal (annual and seasonal) and spatial (large and regional) scales. The observed 11-year trends are then associate to different predicted/hypothesized climate change scenarios.

  18. Total generating costs: coal and nuclear plants

    International Nuclear Information System (INIS)

    1979-02-01

    The study was confined to single and multi-unit coal- and nuclear-fueled electric-generating stations. The stations are composed of 1200-MWe PWRs; 1200-MWe BWRs; 800-and 1200-MWe High-Sulfur Coal units, and 800- and 1200-MWe Low-Sulfur Coal units. The total generating cost estimates were developed for commercial operation dates of 1985 and 1990; for 5 and 8% escalation rates, for 10 and 12% discount rates; and, for capacity factors of 50, 60, 70, and 80%. The report describes the methodology for obtaining annualized capital costs, levelized coal and nuclear fuel costs, levelized operation and maintenance costs, and the resulting total generating costs for each type of station. The costs are applicable to a hypothetical Middletwon site in the Northeastern United States. Plant descriptions with general design parameters are included. The report also reprints for convenience, summaries of capital cost by account type developed in the previous commercial electric-power cost studies. Appropriate references are given for additional detailed information. Sufficient detail is given to allow the reader to develop total generating costs for other cases or conditions

  19. Total Variation Depth for Functional Data

    KAUST Repository

    Huang, Huang

    2016-11-15

    There has been extensive work on data depth-based methods for robust multivariate data analysis. Recent developments have moved to infinite-dimensional objects such as functional data. In this work, we propose a new notion of depth, the total variation depth, for functional data. As a measure of depth, its properties are studied theoretically, and the associated outlier detection performance is investigated through simulations. Compared to magnitude outliers, shape outliers are often masked among the rest of samples and harder to identify. We show that the proposed total variation depth has many desirable features and is well suited for outlier detection. In particular, we propose to decompose the total variation depth into two components that are associated with shape and magnitude outlyingness, respectively. This decomposition allows us to develop an effective procedure for outlier detection and useful visualization tools, while naturally accounting for the correlation in functional data. Finally, the proposed methodology is demonstrated using real datasets of curves, images, and video frames.

  20. Total quality in spent fuel pool reracking

    International Nuclear Information System (INIS)

    Cranston, J.S.; Bradbury, R.B.; Cacciapouti, R.J.

    1993-01-01

    The nuclear utility environment is one of strict cost control under prescriptive regulations and increasing public scrutiny. This paper presents the results of A Total Quality approach, by a dedicated team, that addresses the need for increased on-site spent fuel storage in this environment. Innovations to spent fuel pool reracking, driven by utilities' specific technical needs and shrinking budgets, have resulted in both product improvements and lower prices. A Total Quality approach to the entire turnkey project is taken, thereby creating synergism and process efficiency in each of the major phases of the project: design and analysis, licensing, fabrication, installation and disposal. Specific technical advances and the proven quality of the team members minimizes risk to the utility and its shareholders and provides a complete, cost effective service. Proper evaluation of spent fuel storage methods and vendors requires a full understanding of currently available customer driven initiatives that reduce cost while improving quality. In all phases of a spent fuel reracking project, from new rack design and analysis through old rack disposal, the integration of diverse experts, at all levels and throughout all phases of a reracking project, better serves utility needs. This Total Quality environment in conjunction with many technical improvements results in a higher quality product at a lower cost

  1. Liver failure in total artificial heart therapy.

    Science.gov (United States)

    Dimitriou, Alexandros Merkourios; Dapunt, Otto; Knez, Igor; Wasler, Andrae; Oberwalder, Peter; Koerfer, Reiner; Tenderich, Gero; Spiliopoulos, Sotirios

    2016-07-01

    Congestive hepatopathy (CH) and acute liver failure (ALF) are common among biventricular heart failure patients. We sought to evaluate the impact of total artificial heart (TAH) therapy on hepatic function and associated clinical outcomes. A total of 31 patients received a Syncardia Total Artificial Heart. Preoperatively 17 patients exhibited normal liver function or mild hepatic derangements that were clinically insignificant and did not qualify as acute or chronic liver failure, 5 patients exhibited ALF and 9 various hepatic derangements owing to CH. Liver associated mortality and postoperative course of liver values were prospectively documented and retrospectively analyzed. Liver associated mortality in normal liver function, ALF and CH cases was 0%, 20% (P=0.03) and 44.4% (P=0.0008) respectively. 1/17 (5.8%) patients with a normal liver function developed an ALF, 4/5 (80%) patients with an ALF experienced a markedly improvement of hepatic function and 6/9 (66.6%) patients with CH a significant deterioration. TAH therapy results in recovery of hepatic function in ALF cases. Patients with CH prior to surgery form a high risk group with increased liver associated mortality.

  2. The error in total error reduction.

    Science.gov (United States)

    Witnauer, James E; Urcelay, Gonzalo P; Miller, Ralph R

    2014-02-01

    Most models of human and animal learning assume that learning is proportional to the discrepancy between a delivered outcome and the outcome predicted by all cues present during that trial (i.e., total error across a stimulus compound). This total error reduction (TER) view has been implemented in connectionist and artificial neural network models to describe the conditions under which weights between units change. Electrophysiological work has revealed that the activity of dopamine neurons is correlated with the total error signal in models of reward learning. Similar neural mechanisms presumably support fear conditioning, human contingency learning, and other types of learning. Using a computational modeling approach, we compared several TER models of associative learning to an alternative model that rejects the TER assumption in favor of local error reduction (LER), which assumes that learning about each cue is proportional to the discrepancy between the delivered outcome and the outcome predicted by that specific cue on that trial. The LER model provided a better fit to the reviewed data than the TER models. Given the superiority of the LER model with the present data sets, acceptance of TER should be tempered. Copyright © 2013 Elsevier Inc. All rights reserved.

  3. Total neutron cross section for 181Ta

    Directory of Open Access Journals (Sweden)

    Schilling K.-D.

    2010-10-01

    Full Text Available The neutron time of flight facility nELBE, produces fast neutrons in the energy range from 0.1 MeV to 10 MeV by impinging a pulsed relativistic electron beam on a liquid lead circuit [1]. The short beam pulses (∼10 ps and a small radiator volume give an energy resolution better than 1% at 1 MeV using a short flight path of about 6 m, for neutron TOF measurements. The present neutron source provides 2 ⋅ 104  n/cm2s at the target position using an electron charge of 77 pC and 100 kHz pulse repetition rate. This neutron intensity enables to measure neutron total cross section with a 2%–5% statistical uncertainty within a few days. In February 2008, neutron radiator, plastic detector [2] and data acquisition system were tested by measurements of the neutron total cross section for 181Ta and 27Al. Measurement of 181Ta was chosen because lack of high quality data in an anergy region below 700 keV. The total neutron cross – section for 27Al was measured as a control target, since there exists data for 27Al with high resolution and low statistical error [3].

  4. Total body irradiation: current indications; L`irradiation corporelle totale: les indications actuelles

    Energy Technology Data Exchange (ETDEWEB)

    Giraud, P.; Danhier, S.; Dubray, B.; Cosset, J.M. [Institut Curie, 75 - Paris (France)

    1998-05-01

    The choice of dose and fractionation for total body irradiation is made difficult by the large number of considerations to be taken into account. The outcome of bone marrow transplantation after total body irradiation can be understood in terms of tumor cell killing, engraftment, and normal tissue damage, each of these endpoints being influenced by irradiation-, disease-, transplant-, and patient- related factors. Interpretation of clinical data is further hampered by the overwhelming influence of logistic constraints, the small numbers of randomized studies, and the concomitant variations in total dose and fraction size or dose rate. So far, three cautious conclusions can be drawn in order to tentatively adapt the total body irradiation schedule to clinically-relevant situations. Firstly, the organs at risk for normal tissue damage (lung, liver, lens, kidney) are protected by delivering small doses per fraction at low dose rate. This suggests that, when toxicity is at stake (e.g. in children), fractionated irradiation should be preferred, provided that inter-fraction intervals are long enough. Secondly, fractionated irradiation should be avoided in case of T-cell depleted transplant, given the high risk of graft rejection in this setting. An alternative would be to increase total (or fractional) dose of fractionated total body irradiation, but this approach is likely to induce more normal tissue toxicity. Thirdly, clinical data have shown higher relapse rates in chronic myeloid leukemia after fractionated or low dose rate total body irradiation, suggesting that fractionated irradiation should not be recommended, unless total (or fractional) dose is increased. Total body irradiation-containing regimens, primarily cyclophosphamide / total body irradiation, are either equivalent to or better than the chemotherapy-only regimens, primarily busulfan / cyclophosphamide. Busulfan / cyclophosphamide certainly represents a reasonable alternative, especially in patients who

  5. Fluorogenic membrane overlays to enumerate total coliforms, Escherichia coli, and total Vibrionaceae in shellfish and seawater

    Science.gov (United States)

    Three assays were developed to enumerate total coliforms, Escherichia coli, and total Vibrionaceae in shellfish and other foods and in seawater and other environmental samples. Assays involve membrane overlays of overnight colonies on non-selective agar plates to detect ß-glucuronidase and lysyl am...

  6. Total Radiosynthesis: Thinking outside "the box".

    Science.gov (United States)

    Liang, Steven H; Vasdev, Neil

    2015-09-01

    The logic of total synthesis transformed a stagnant state of medicinal and synthetic organic chemistry when there was a paucity of methods and reagents to synthesize drug molecules and/or natural products. Molecular imaging by positron emission tomography (PET) is now experiencing a renaissance in the way radiopharmaceuticals for molecular imaging are synthesized, however, a paradigm shift is desperately needed in the discovery pipeline to accelerate in vivo imaging studies. A significant challenge in radiochemistry is the limited choice of labeled reagents (or building blocks) available for the synthesis of novel radiopharmaceuticals with the most commonly used short-lived radionuclides carbon-11 ( 11 C; half-life ~20 minutes) and fluorine-18 ( 18 F; half-life ~2 hours). In fact, most drugs cannot be labeled with 11 C or 18 F due to a lack of efficient and diverse radiosynthetic methods. In general, routine radiopharmaceutical production relies on the incorporation of the isotope at the last or penultimate step of synthesis, ideally within one half-life of the radionuclide, to maximize radiochemical yields and specific activities thereby reducing losses due to radioactive decay. Reliance on radiochemistry conducted within the constraints of an automated synthesis unit ("box") has stifled the exploration of multi-step reactions with short-lived radionuclides. Radiopharmaceutical synthesis can be transformed by considering logic of total synthesis to develop novel approaches for 11 C- and 18 F-radiolabeling complex molecules via retrosynthetic analysis and multi-step reactions. As a result of such exploration, new methods, reagents and radiopharmaceuticals for in vivo imaging studies are discovered. A new avenue to develop radiotracers that were previously unattainable due to the lack of efficient radiosynthetic methods is necessary to work towards our ultimate, albeit impossible goal - the concept we term total radiosynthesis - to radiolabel virtually any molecule

  7. Total urogenital sinus mobilization for ambiguous genitalia.

    Science.gov (United States)

    Jesus, Vinicius Menezes; Buriti, Francisco; Lessa, Rodrigo; Toralles, Maria Betânia; Oliveira, Luciana Barros; Barroso, Ubirajara

    2018-04-01

    Genital ambiguity is a very common phenomenon in disorders of sex development (DSD). According to the Chicago Consensus 2006, feminizing genitoplasty, when indicated, should be performed in the most virilized cases (Prader III to V). Advances in the knowledge of genital anatomy in DSD have enabled the development and improvement of various surgical techniques. Mobilization of the urogenital sinus (MUS), first described by Peña, has become incorporated by most surgeons. However, the proximity of the urethral sphincter prompts concern over urinary incontinence, especially for full mobilization of the urogenital sinus. To retrospectively evaluate the short-term surgical results of feminizing genitoplasty with total mobilization of the urogenital sinus in patients with DSD. Review of medical records of all patients undergoing feminizing genitoplasty with mobilization of the urogenital sinus. We evaluated the rates of complications from surgery and of urinary incontinence, as well as cosmetic results, according to the opinion of the surgeon and the family. A total of 8 patients were included in the study. The mean age at surgery was 51months. Congenital adrenal hyperplasia (CAH) was diagnosed in six patients, and gonadal dysgenesis in the other two. The vagina was separated from the urethra, with suitable distance in all cases. No patient had urinary incontinence after surgery. The mean follow-up of patients was. 20months (3-56months). In all cases, surgeons recorded being satisfied with the aesthetic result of post-surgical genitalia. The family was recorded as satisfied with the aesthetic result of the genitalia after surgery. In every case, there was no need for a second surgical procedure. The total mobilization of the urogenital sinus is a feasible and safe technique. The technique permits good cosmetic results, and urinary incontinence is absent. Therapeutic study. Level III. Copyright © 2017 Elsevier Inc. All rights reserved.

  8. Assessment of total efficiency in adiabatic engines

    Science.gov (United States)

    Mitianiec, W.

    2016-09-01

    The paper presents influence of ceramic coating in all surfaces of the combustion chamber of SI four-stroke engine on working parameters mainly on heat balance and total efficiency. Three cases of engine were considered: standard without ceramic coating, fully adiabatic combustion chamber and engine with different thickness of ceramic coating. Consideration of adiabatic or semi-adiabatic engine was connected with mathematical modelling of heat transfer from the cylinder gas to the cooling medium. This model takes into account changeable convection coefficient based on the experimental formulas of Woschni, heat conductivity of multi-layer walls and also small effect of radiation in SI engines. The simulation model was elaborated with full heat transfer to the cooling medium and unsteady gas flow in the engine intake and exhaust systems. The computer program taking into account 0D model of engine processes in the cylinder and 1D model of gas flow was elaborated for determination of many basic engine thermodynamic parameters for Suzuki DR-Z400S 400 cc SI engine. The paper presents calculation results of influence of the ceramic coating thickness on indicated pressure, specific fuel consumption, cooling and exhaust heat losses. Next it were presented comparisons of effective power, heat losses in the cooling and exhaust systems, total efficiency in function of engine rotational speed and also comparison of temperature inside the cylinder for standard, semi-adiabatic and full adiabatic engine. On the basis of the achieved results it was found higher total efficiency of adiabatic engines at 2500 rpm from 27% for standard engine to 37% for full adiabatic engine.

  9. Mesh Excision: Is Total Mesh Excision Necessary?

    Science.gov (United States)

    Wolff, Gillian F; Winters, J Christian; Krlin, Ryan M

    2016-04-01

    Nearly 29% of women will undergo a secondary, repeat operation for pelvic organ prolapse (POP) symptom recurrence following a primary repair, as reported by Abbott et al. (Am J Obstet Gynecol 210:163.e1-163.e1, 2014). In efforts to decrease the rates of failure, graft materials have been utilized to augment transvaginal repairs. Following the success of using polypropylene mesh (PPM) for stress urinary incontinence (SUI), the use of PPM in the transvaginal repair of POP increased. However, in recent years, significant concerns have been raised about the safety of PPM mesh. Complications, some specific to mesh, such as exposures, erosion, dyspareunia, and pelvic pain, have been reported with increased frequency. In the current literature, there is not substantive evidence to suggest that PPM has intrinsic properties that warrant total mesh removal in the absence of complications. There are a number of complications that can occur after transvaginal mesh placement that do warrant surgical intervention after failure of conservative therapy. In aggregate, there are no high-quality controlled studies that clearly demonstrate that total mesh removal is consistently more likely to achieve pain reduction. In the cases of obstruction and erosion, it seems clear that definitive removal of the offending mesh is associated with resolution of symptoms in the majority of cases and reasonable practice. There are a number of complications that can occur with removal of mesh, and patients should be informed of this as they formulate a choice of treatment. We will review these considerations as we examine the clinical question of whether total versus partial removal of mesh is necessary for the resolution of complications following transvaginal mesh placement.

  10. Total internal reflection tomography of small objects

    International Nuclear Information System (INIS)

    Chen Xudong

    2008-01-01

    The multiple signal classification (MUSIC) imaging method is applied to determine the locations of a collection of small anisotropic spherical scatterers in the framework of the total internal reflection tomography. Multiple scattering between scatterers is considered and the inverse scattering problem is nonlinear, which, however, is solved by the proposed fast analytical approach where no associated forward problem is iteratively evaluated. The paper also discusses the role of the polarization of incidence waves, the incidence angle, the separation of scatterers from the surface of the substrate, and the level of noise on the resolution of imaging.

  11. Qβ measurements with a total absorption detector

    International Nuclear Information System (INIS)

    Shibata, Michihiro; Kawade, Kiyoshi; Shindou, Terumasa; Kojima, Yasuaki; Taniguchi, Akihiro; Kawase, Yoichi; Ichikawa, Shin-ichi

    2003-01-01

    For Q β determination, we have developed a newly total absorption detector that can detect almost all radiation from the radioactive nuclei. The detector is composed of large volume and low background twin BGO scintillation detectors. The estimated efficiency is more than two orders of magnitude larger than those of Ge or Si detectors. The Q β s of some fission products of 235 U were successfully measured using an on-line mass separator for the first time (KUR-ISOL). We have proposed the possibility of determination Q β up to about 10 MeV using the detector without the knowledge of the decay scheme. (author)

  12. Nuclear war would cause total destruction

    International Nuclear Information System (INIS)

    Caldicott, H.

    1985-01-01

    In this paper, the author urges everyone to become better informed about the nuclear hazard humanity faces and challenges the reader to take action to ensure human survival on Earth. The author explains what would happen in the event of a nuclear war. Population centers would be smashed flat. Firestorms would rage over millions of acres. People near the center of the blast would die immediately. Those who survived would reenter a totally devastated world, lacking the life-support systems on which the human species depends. Epidemics would be rampant. Only if we abolish nuclear weapons and permanently halt the nuclear power industry can we hope to survive

  13. Total down to work for Chtokman's gas

    International Nuclear Information System (INIS)

    Labeyre, J.

    2008-01-01

    In the framework of the exploitation contract signed with Gazprom, Total group, partner of the project with StatoilHydro, has started the feasibility study for the huge Chtokman gas field in Russia (Barents sea). A definitive investment decision should be given within less a year. The pre-project phase started in summer 2008 but nothing has been decided yet. Russia has two big projects in competition: Chtokman and Kharasavey in Yamal province. Considering the extreme climate conditions and the technical challenges, Russia will need the experience of foreign partners. (J.S.)

  14. Total quality management (TQM) in diagnostic radiology

    International Nuclear Information System (INIS)

    Rehani, M.M.

    1995-01-01

    The branch of quality assurance is now taking a new direction towards total quality management (TQM). Being of industrial origin, the concepts and terminologies in TQM are alien to medical and paramedical professionals. However, the impetus it has already made in other areas of health sciences makes medical physicists left out when diagnostic radiology does not encompass TQM. The purpose of this paper is to introduce the terms used in TQM and some aspects of its application to diagnostic radiology. (author). 12 refs., 1 tab

  15. Total ankle arthroplasty: An imaging overview

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Da Rae; Choi, Yun Sun; Chun, Ka Young; Jung, Yoon Young; Kim, Jin Su; Young, Ki Won [Eulji Hospital, Eulji University, Seoul (Korea, Republic of); Potter, Hollis G.; Li, Angela E. [Dept. of Radiology and Imaging, Hospital for Special Surgery, New York (United States)

    2016-06-15

    With advances in implant technology, total ankle arthroplasty (TAA) has become an increasingly popular alternative to arthrodesis for the management of end-stage ankle arthritis. However, reports in the literature do not focus on the imaging features of TAA. Through a literature review, we demonstrate basic design features of the current ankle arthroplasty system, and the normal and abnormal postoperative imaging features associated with such devices. Pre- and postoperative evaluations of ankle arthroplasty mainly include radiography; in addition, computed tomography and magnetic resonance imaging provide further characterization of imaging abnormalities. Familiarization with multimodal imaging features of frequent procedural complications at various postoperative intervals is important in radiological practice.

  16. PENDEKATAN TOTAL QUALITY MANAGEMENT PRODUK BROILER TOLAKAN

    Directory of Open Access Journals (Sweden)

    Zeetpy Maisana

    2012-11-01

    Full Text Available ABSTRACTThe purpose of this study was to analyze rejected product in slaughterhouse division using total quality management approach. The secondary data were collected from the company archives and judgmental sampling was used to collect primary data from six experienced respondents. The analysis method used was total quality management, include stratification, Pareto diagrams, control charts, fishbone diagrams, and quality function deployment. The findings of this study showed that the use of line production system by the slaughterhouse to produce the product; where products’ redness/bruises, size uniformity, bloodless feature, incorrect delivery, delivery delay, and damaged package were the cause of product rejection. The strategies ordered based on the priority to improve the management quality are: tools repair and replacement, creating quality based projects, build an information system between the production lines, training and seminar. The managerial implications of the study suggested the slaughterhouse to replace or repair the plucker, scalder and automatic weighing machine. It also suggested the slaughterhouse to tighten the span of control in the chilling room to maintain product freshness.Keywords: rejected product analysis, TQM, QFD, chicken slaughterhouse, carcassABSTRAKPenelitian ini bertujuan menganalisis produk tolakan pada rumah potong ayam melalui pendekatan total quality management. Pengumpulan data sekunder penelitian diperoleh dari arsip perusahaan dan judgemental sampling digunakan terhadap enam responden ahli untuk memperoleh data primer penelitian. Metode analisis data yang digunakan total quality management, meliputi stratifikasi, diagram pareto, peta kendali, diagram tulang ikan, dan quality function deployment.  Hasil penelitian menunjukkan penggunaan sistem lini produksi pada proses produksi di perusahaan, dimana memar pada produk, keseragaman ukuran, kesegaran produk, pengiriman tidak sesuai pesanan

  17. THE TOTAL SOLAR IRRADIANCE CLIMATE DATA RECORD

    Energy Technology Data Exchange (ETDEWEB)

    Dewitte, Steven; Nevens, Stijn [Royal Meteorological Institute of Belgium, Ringlaan 3, B-1180 Brussels (Belgium)

    2016-10-10

    We present the composite measurements of total solar irradiance (TSI) as measured by an ensemble of space instruments. The measurements of the individual instruments are put on a common absolute scale, and their quality is assessed by intercomparison. The composite time series is the average of all available measurements. From 1984 April to the present the TSI shows a variation in phase with the 11 yr solar cycle and no significant changes of the quiet-Sun level in between the three covered solar minima.

  18. Hyperon magnetic moments and total cross sections

    International Nuclear Information System (INIS)

    Lipkin, H.J.

    1982-06-01

    The new data on both total cross sections and magnetic moments are simply described by beginning with the additive quark model in an SU(3) limit where all quarks behave like strange quarks and breaking both additivity and SU(3) simultaneously with an additional non-additive mechanism which affects only nonstrange quark contributions. The suggestion that strange quarks behave more simply than nonstrange may provide clues to underlying structure or dynamics. Small discrepancies in the moments are analyzed and shown to provide serious difficulties for most models if they are statistically significant. (author)

  19. Asymmetric Total Synthesis of Ieodomycin B

    Directory of Open Access Journals (Sweden)

    Shuangjie Lin

    2017-01-01

    Full Text Available Ieodomycin B, which shows in vitro antimicrobial activity, was isolated from a marine Bacillus species. A novel asymmetric total synthetic approach to ieodomycin B using commercially available geraniol was achieved. The approach involves the generation of 1,3-trans-dihydroxyl at C-3 and C-5 positions via a Crimmins-modified Evans aldol reaction and a chelation-controlled Mukaiyama aldol reaction of a p-methoxybenzyl-protected aldehyde, as well as the generation of a lactone ring in a deprotection–lactonization one-pot reaction.

  20. Contemporary pain management in total knee arthroplasty.

    Science.gov (United States)

    Khanasuk, Yutthana; Ngarmukos, Srihatach

    2012-10-01

    Pain management has become a very important part of postoperative care for total knee arthroplasty patients. Contemporary pain control has evolved from high-dose opioid in the past to state-of-the-art multimodal regimens. These include multiple non-opioid medication such as NSAIDs, COX-2 inhibitors, and gabapentinoid, and novel anesthetic techniques such as preemptive analgesia and ultrasound-guided peripheral nerve blocks. Another method which is gaining popularity is intraarticular injection of anesthetic cocktail during surgery. Pre-op education can also help patients cope with their pain better.