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Sample records for adamanzanes-bicyclic tetraamines syntheses

  1. Bowl adamanzanes-bicyclic tetraamines: syntheses and crystal structures of complexes with cobalt(III) and chelating coordinated oxo-anions

    Broge, Louise; Søtofte, Inger; Jensen, Kristian;

    2007-01-01

    Seven cobalt(III) complexes of the macrobicyclic tetraamine ligand [2(4).3(1)]adamanzane ([2(4).3(1)]adz) are reported along with the crystal structure of six of these complexes. The solid state and solution structures are discussed, and a detailed assignment of the NMR spectra of the sulfato com...

  2. 40 CFR 721.10003 - Manganese heterocyclic tetraamine complex (generic).

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Manganese heterocyclic tetraamine... Specific Chemical Substances § 721.10003 Manganese heterocyclic tetraamine complex (generic). (a) Chemical... as manganese heterocyclic tetraamine complex (PMNs P-98-625/626/627/628/629 and P-00-614/617)...

  3. In vitro and in vivo evaluation of polymethylene tetraamine derivatives as NMDA receptor channel blockers.

    Saiki, Ryotaro; Yoshizawa, Yuki; Minarini, Anna; Milelli, Andrea; Marchetti, Chiara; Tumiatti, Vincenzo; Toida, Toshihiko; Kashiwagi, Keiko; Igarashi, Kazuei

    2013-07-01

    The biological activities of six symmetrically substituted 2-methoxy-benzyl polymethylene tetraamines (1-4) and diphenylethyl polymethylene tetraamines (5 and 6) as N-methyl-D-aspartate (NMDA) receptor channel blockers, were evaluated in vitro and in vivo. Although all compounds exhibited stronger channel block activities in comparison to memantine in Xenopus oocytes voltage clamped at -70 mV, only compound 2 (0.4 mg/kg intravenous injection) decreased the size of brain infarction in a photochemically induced thrombosis model mice at the same extent of memantine (10mg/kg intravenous injection). Other compounds (1, 3, 4, 5 and 6) did not decrease the size of brain infarction significantly due to the limited injection doses. The present study suggests that compound 2 could represent a valuable lead compound to design low toxicity polyamines for clinical use against stroke. PMID:23692871

  4. Vascular Response of Ruthenium Tetraamines in Aortic Ring from Normotensive Rats

    Ana Gabriela Conceição-Vertamatti

    2015-03-01

    Full Text Available Background: Ruthenium (Ru tetraamines are being increasingly used as nitric oxide (NO carriers. In this context, pharmacological studies have become highly relevant to better understand the mechanism of action involved. Objective: To evaluate the vascular response of the tetraamines trans-[RuII(NH34(Py(NO]3+, trans-[RuII(Cl(NO (cyclan](PF62, and trans-[RuII(NH34(4-acPy(NO]3+. Methods: Aortic rings were contracted with noradrenaline (10−6 M. After voltage stabilization, a single concentration (10−6 M of the compounds was added to the assay medium. The responses were recorded during 120 min. Vascular integrity was assessed functionally using acetylcholine at 10−6 M and sodium nitroprusside at 10−6 M as well as by histological examination. Results: Histological analysis confirmed the presence or absence of endothelial cells in those tissues. All tetraamine complexes altered the contractile response induced by norepinephrine, resulting in increased tone followed by relaxation. In rings with endothelium, the inhibition of endothelial NO caused a reduction of the contractile effect caused by pyridine NO. No significant responses were observed in rings with endothelium after treatment with cyclan NO. In contrast, in rings without endothelium, the inhibition of guanylate cyclase significantly reduced the contractile response caused by the pyridine NO and cyclan NO complexes, and both complexes caused a relaxing effect. Conclusion: The results indicate that the vascular effect of the evaluated complexes involved a decrease in the vascular tone induced by norepinephrine (10−6 M at the end of the incubation period in aortic rings with and without endothelium, indicating the slow release of NO from these complexes and suggesting that the ligands promoted chemical stability to the molecule. Moreover, we demonstrated that the association of Ru with NO is more stable when the ligands pyridine and cyclan are used in the formulation of the compound.

  5. Vascular Response of Ruthenium Tetraamines in Aortic Ring from Normotensive Rats

    Conceição-Vertamatti, Ana Gabriela; Ramos, Luiz Alberto Ferreira [Universidade Estadual de Campinas (UNICAMP), São Paulo, SP (Brazil); Calandreli, Ivy; Chiba, Aline Nunes [Universidade de São Paulo (USP), Campus Ribeirão Preto, São Paulo, SP (Brazil); Franco, Douglas Wagner [Universidade de São Paulo (USP), Campus São Carlos, São Paulo, SP (Brazil); Tfouni, Elia [Universidade de São Paulo (USP), Campus Ribeirão Preto, São Paulo, SP (Brazil); Grassi-Kassisse, Dora Maria, E-mail: doramgk@unicamp.br [Universidade Estadual de Campinas (UNICAMP), São Paulo, SP (Brazil)

    2015-03-15

    Ruthenium (Ru) tetraamines are being increasingly used as nitric oxide (NO) carriers. In this context, pharmacological studies have become highly relevant to better understand the mechanism of action involved. To evaluate the vascular response of the tetraamines trans-[Ru{sup II}(NH{sub 3}){sub 4}(Py)(NO)]{sup 3+}, trans-[Ru{sup II}(Cl)(NO) (cyclan)](PF{sub 6}){sub 2}, and trans-[Ru{sup II}(NH{sub 3}){sub 4}(4-acPy)(NO)]{sup 3+}. Aortic rings were contracted with noradrenaline (10{sup −6} M). After voltage stabilization, a single concentration (10{sup −6} M) of the compounds was added to the assay medium. The responses were recorded during 120 min. Vascular integrity was assessed functionally using acetylcholine at 10{sup −6} M and sodium nitroprusside at 10{sup −6} M as well as by histological examination. Histological analysis confirmed the presence or absence of endothelial cells in those tissues. All tetraamine complexes altered the contractile response induced by norepinephrine, resulting in increased tone followed by relaxation. In rings with endothelium, the inhibition of endothelial NO caused a reduction of the contractile effect caused by pyridine NO. No significant responses were observed in rings with endothelium after treatment with cyclan NO. In contrast, in rings without endothelium, the inhibition of guanylate cyclase significantly reduced the contractile response caused by the pyridine NO and cyclan NO complexes, and both complexes caused a relaxing effect. The results indicate that the vascular effect of the evaluated complexes involved a decrease in the vascular tone induced by norepinephrine (10{sup −6} M) at the end of the incubation period in aortic rings with and without endothelium, indicating the slow release of NO from these complexes and suggesting that the ligands promoted chemical stability to the molecule. Moreover, we demonstrated that the association of Ru with NO is more stable when the ligands pyridine and cyclan are used

  6. Carbon-13 nuclear magnetic resonance studies of trans-diacido(tetraamine)cobalt(III)

    Brubaker, G.R.; Johnson, D.W.

    1982-06-01

    Carbon-13 nuclear magnetic resonance spectra of a series of trans-diacido(1,10-diamino-4,7-diazadecane)cobalt(III) complexes (trans-Co(3,2,3-tet)X/sub 2/, X = Br/sup -/, Cl/sup -/, N/sub 3//sup -/, NO/sub 2//sup -/, OAc) and trans-diacido(1,9-diamino-3,7-diazononane)cobalt(III) complexes (trans-Co(2,3,2-tet)X/sub 2/, X = Cl/sup -/, GlyH, /sup -/OAc, NH/sub 3/, NO/sub 2//sup -/) will be discussed. The /sup 13/C chemical shift is found to be linearly dependent on the ligand field strength (estimated from the electronic spectrum) of the axial ligands (X). The shielding of selected carbon atoms within the tetraamine ligand, which has been attributed to the central metal ion, increases with increasing axial ligand field strength.

  7. Carbon 13 nuclear magnetic resonance spectroscopy of cobalt(III) complexes with flexible tetraamine ligands

    Brubaker, G.R.; Johnson, D.W.

    1983-10-01

    Carbon 13 NMR was found to be an extremely sensitive probe of the stereochemistry of this series of diamagnetic ''Werner'' complexes. Our interpretation is based upon two parameters, the donation of electron density to the metal and the steric perturbation required for coordination. The different symmetry of the complexes often permits determination of stereochemistry from the electronic spectrum. In addition, other methods including vibrational spectroscopy and proton NMR, have been used with some success to determine stereochemistry. These methods suffer, however, from a lack of sensitivity, especially in complexes with unsymmetrical ligands. In the course of continuing study of the stereochemistry of six coordinate transition metal complexes, we have investigated a large variety of cobalt(III) complexes with various tetraamine ligands.

  8. Tc-99m labeled triethelene tetraamine polysterene resin gastric emptying studies in bulimia patients

    Shih Weijen; Castellanos, F.X.; Domstad, P.A.; DeLand, F.H.; Humphries, L.; Digenis, G.A.

    1987-07-01

    To evaluate gastric emptying in patients with bulimia, 20 patients (all women, ranging in age from 12 to 49 years) with upper gastrointestinal symptoms ingested 150-200 ..mu..Ci/sup 99m/ Tc-triethelene tetraamine polysterene resin in cereal and had scintigraphy in the supine position. Data were accumulated at 5 min intervals to determine the gastric emptying time (GET). The results showed that the gastric emptying time was prolonged in 12 patients and decreased in 8. All 12 patients with prolonged emptying time were given 10 mg metoclopramide intravenously; 9 of these had a good response and 3 had no response. Although all patients had subjective symptoms of gastric dysfunction, the results indicate that about 60% had delayed and 40% had rapid gastric emptying. The findings of two extremes of gastric emptying time remain to be explained, however, this enables (Albibi and McCullum 1983) objective documentation of gastric emptying as this technique (American Psychiatric Association 1980) can separate those patients with rapid GET from those with prolonged GET, who might benefit from metoclopramide.

  9. Tc-99m labeled triethelene tetraamine polysterene resin gastric emptying studies in bulimia patients

    To evaluate gastric emptying in patients with bulimia, 20 patients (all women, ranging in age from 12 to 49 years) with upper gastrointestinal symptoms ingested 150-200 μCi99m Tc-triethelene tetraamine polysterene resin in cereal and had scintigraphy in the supine position. Data were accumulated at 5 min intervals to determine the gastric emptying time (GET). The results showed that the gastric emptying time was prolonged in 12 patients and decreased in 8. All 12 patients with prolonged emptying time were given 10 mg metoclopramide intravenously; 9 of these had a good response and 3 had no response. Although all patients had subjective symptoms of gastric dysfunction, the results indicate that about 60% had delayed and 40% had rapid gastric emptying. The findings of two extremes of gastric emptying time remain to be explained, however, this enables (Albibi and McCullum 1983) objective documentation of gastric emptying as this technique (American Psychiatric Association 1980) can separate those patients with rapid GET from those with prolonged GET, who might benefit from metoclopramide. (orig.)

  10. Direct Asymmetric Michael Additions of Ketones to Nitroolefins and Chalcones Catalyzed by a Chiral C2-Symmetric Pyrrolidine-based Tetraamine

    马世俊; 吴璐璐; 刘明; 王永梅

    2012-01-01

    C2-Symmetric pyrrolidine-based tetraamine, available from commercially starting materials, showed good cata- lytic activity for asymmetric Michael additions of ketones to nitroalkenes especially to chalcones. The reactions proceeded to give the corresponding products in good yields and in a highly selective manner.

  11. Catalytic Hydrolysis of Phosphate Diester with Metal Complexesof Macrocyclic Tetraamine in Comicellar Solution

    XIANG Qing-Xiang; YU Xiao-Qi; YOU Jing-Song; YAN Qian-Shun; XIE Ru-Gang

    2001-01-01

    Four novel pyridine or benzene ring-containing pendant macrocyclic dioxotetraanines 2,6-dioxo-1,4,7,10-tetraazacy-clododeane ligands have been synthesized.Their metal com-plexes have been investigated as catalysts for the hydrolysis of bis(p-nitrophenyl) phosphate (BNPP) in aqueous comicellar solution.The results indicate that the hydrophobic interaction between substrate and metal complex, the nature of transition metal ion, and the micellar microenvironment are important factors for the hydrolysis, of BNPP.Large rate enhancement (up to over two-three orders magnitude) employing 5 hasbeen observed.

  12. Coal conversion processes. Quarterly report, March 13, 1984-June 12, 1984. [N-cyclohexyl-2-pyrrolidones and triethylene-tetraamine absorbents

    Cobb, J.T. Jr.; Biloen, P.; Holder, G.D.; Klinzing, G.E.; Tierney, J.W.

    1984-08-01

    Experimental work is continuing on four separate projects related to coal conversion processes. The direct digital control of exothermic multiphase reactions is being studied in an experimental adiabatic flow reactor. A paper based on earlier results has been submitted for publication. The effect of step changes of important process variables on reactor performance has been determined. Various absorbents for SO/sub 2/ and NO/sub x/ are being studied. Further data on the absorption of SO/sub 2/ and NO/sub x/ by a solution of N-cyclohexyl-2-pyrrolidone (CHP) have been obtained. Data on the absorption of NO in triethylene-tetraamine has also been obtained. Characterization of liquid membranes formed experimentally have been performed; the FeCl/sub 2//CHP system will be examined first. Isotopic switching is being used to study the way in which promoters affect supported metal catalysts. Non-statistical distributions of /sup 13/C in Fischer-Tropsch products have been observed experimentally. A model for the ingrowth of /sup 13/C in ethane has been developed. A program for the study of the extraction of coal and oil shale using supercritical fluids is being carried out. The effect of stirrer speed, density and reaction time on the amount of toluene solubles and tetrahydrofuran solubles produced by supercritical extraction of Bruceton coal with toluene. 2 references, 11 figures, 6 tables.

  13. Properties of the tetraethynylborate anion as a ligand in reactions with tetraamine complexes of nickel(II)

    Shevchenko, Yu.N.; Esaulenko, A.N.; Porai-Koshits, M.A.; Svitsyn, R.A.; Kukina, G.A.

    1987-05-01

    New tetra- and hexaamine complex compounds of nickel(II) with mono-, bi-, and tetradentate linear or cyclic amines of the aliphatic series containing both outer-sphere tetraethynylborate anions and (B(C identical with CH)/sub 4/)/sup -/ anions which are coordinated to the metal ion have been synthesized. The possibility of the coordination of ligands having strong acceptor properties in the axial positions of square-planar complexes of nickel(II) has been demonstrated. The dative transfer of electron density from a nickel(II) 3d/sub xz, 3d/sub yz/, or 3d/sub z/sup 2// orbital occupied by an electron pair to vacant acceptor orbitals of the axial ligands, for example, the antibonding ..pi.. orbitals of the C identical with C bonds of the tetraethynylborate anion is allowed in this case.

  14. Green syntheses, v.1

    Tundo, Pietro

    2014-01-01

    Introduction to the Green Syntheses SeriesPietro Tundo and John AndraosApplication of Material Efficiency Metrics to Assess Reaction Greenness-Illustrative Case Studies from Organic SynthesesJohn AndraosReaction 1: Synthesis of 3-Benzyl-5-Methyleneoxazolidin-2-one from N-Benzylprop-2-yn-1-Amine and CO2Qing-Wen Song and Liang-Nian HeReaction 2: Synthesis of the 5-Membered Cyclic Carbonates from Epoxides and CO2Qing-Wen Song, Liang-Nian HePart I: Green Methods for the Epoxidation of

  15. Wisdom, Intelligence & Creativity Synthesized

    Sternberg, Robert J.

    2009-01-01

    How is it that smart administrators who want to do a good job often find themselves in situations that degenerate into confrontation and, ultimately, termination? In this article, the author discusses why in terms of a model of leadership--which he refers to it as WICS, an acronym for wisdom, intelligence and creativity synthesized. He describes…

  16. Research synthese Geweld verslagen

    Knaap, L. van der; Bogaerts, S.

    2006-01-01

    Dit is een kort overzicht van de belangrijkste bevindingen uit het onderzoeksrappport 'Geweld verslagen?' waarin verslag wordt gedaan van een synthese van 48 studies naar de effecten van preventie van geweld in het publieke en semi-publieke domein. Het volledige rapport is te vinden via het vak 'Links' aan de rechterkant. Deze uitgave is verschenen in de nieuwe reeks Fact sheet (nr. 2006-23).

  17. Programmable electronic synthesized capacitance

    Kleinberg, Leonard L. (Inventor)

    1987-01-01

    A predetermined and variable synthesized capacitance which may be incorporated into the resonant portion of an electronic oscillator for the purpose of tuning the oscillator comprises a programmable operational amplifier circuit. The operational amplifier circuit has its output connected to its inverting input, in a follower configuration, by a network which is low impedance at the operational frequency of the circuit. The output of the operational amplifier is also connected to the noninverting input by a capacitor. The noninverting input appears as a synthesized capacitance which may be varied with a variation in gain-bandwidth product of the operational amplifier circuit. The gain-bandwidth product may, in turn, be varied with a variation in input set current with a digital to analog converter whose output is varied with a command word. The output impedance of the circuit may also be varied by the output set current. This circuit may provide very small ranges in oscillator frequency with relatively large control voltages unaffected by noise.

  18. SYNTH: A spectrum synthesizer

    A computer code has been written at the Pacific Northwest Laboratory (PNL) to synthesize the results of typical gamma ray spectroscopy experiments. The code, dubbed SYNTH, allows a user to specify physical characteristics of a gamma ray source, the quantity of the nuclides producing the radiation, the source-to-detector distance and the presence of absorbers, the type and size of the detector, and the electronic set up used to gather the data. In the process of specifying the parameters needed to synthesize a spectrum, several interesting intermediate results are produced, including a photopeak transmission function versus energy, a detector efficiency curve, and a weighted list of gamma and x rays produced from a set of nuclides. All of these intermediate results are available for graphical inspection and for printing. SYNTH runs on personal computers. It is menu driven and can be customized to user specifications. SYNTH contains robust support for coaxial germanium detectors and some support for sodium iodide detectors. SYNTH is not a finished product. A number of additional developments are planned. However, the existing code has been compared carefully to spectra obtained from National Institute for Standards and Technology (NIST) certified standards with very favorable results. Examples of the use of SYNTH and several spectral results are presented

  19. SYNTH: A spectrum synthesizer

    A computer code has been written at the Pacific Northwest Laboratory (PNL) to synthesize the results of typical gamma-ray spectroscopy experiments. The code, dubbed SYNTH, allows a use r to specify physical characteristics of a gamma-ray source, the quantity of the nuclides producing the radiation, the source-to-detector distance and the type and thickness of absorbers, the size and composition of the detector (Ge or NaI), and the electronic set up used to gather the data. In the process of specifying the parameters needed to synthesize a spectrum, several interesting intermediate results are produced, including a photopeak transmission function vs energy, a detector efficiency curve, and a weighted list of gamma and x rays produced from a set of nuclides. All of these intermediate results are available for graphical inspection and for printing. SYNTH runs on personal computers. It is menu driven and can be customized to user specifications. SYNTH contains robust support for coaxial germanium detectors and some support for sodium iodide detectors. SYNTH is not a finished product. A number of additional developments are planned. However, the existing code has been compared carefully to spectra obtained from National Institute for Standards and Technology (NIST) certified standards with very favorable results. Examples of the use of SYNTH and several spectral results will be presented

  20. SYNTH. A spectrum synthesizer

    A computer code has been written at the Pacific Northwest Laboratory (PNL) to synthesize the results of typical gamma-ray spectroscopy experiments. The code, dubbed SYNTH, allows users to specify physical characteristics of a gamma-ray source the quantity of the nuclides producing the radiation, the source-to-detector distance, the type and thickness of absorbers, the size and composition of the detector (Ge or Nal), and the electronic set up used to gather the data. In the process of specifying the parameters needed to synthesize a spectrum, several interesting intermediate results are produced, including a photopeak transmission function vs. energy, a detector efficiency curve, and a weighted list of gamma and x rays produced from a set of nuclides. All of these intermediate results are available for graphical inspection and for printing. SYNTH runs on personal computers, is menu driven and can be customized to user specifications. SYNTH contains robust support for coaxial germanium detectors and some support for sodium iodide detectors. SYNTH is not a finished product. A number of additional developments are planned. However, the existing code has been carefully compared to spectra obtained from National Institute for Standards and Technology (NIST) certified standards with very favorable results. (author) 5 refs.; 8 figs

  1. Light-Induced Copper(II) Coordination by a Bicyclic Tetraaza Chelator through a Ligand-to-Metal Charge-Transfer Reaction

    Holm-Jørgensen, Jacob Rørdam; Jensen, Mikael; Bjerrum, Morten J.

    2011-01-01

    To enable utilization of the broad potential of copper isotopes in nuclear medicine, rapid and robust chelation of the copper is required. Bowl adamanzanes (bicyclic tetraaza ligands) can form kinetically stable copper complexes, but they are usually formed at low rates unless high pH values and...

  2. Solvent resistant microfluidic DNA synthesizer.

    Huang, Yanyi; Castrataro, Piero; Lee, Cheng-Chung; Quake, Stephen R

    2007-01-01

    We fabricated a microfluidic DNA synthesizer out of perfluoropolyether (PFPE), an elastomer with excellent chemical compatibility which makes it possible to perform organic chemical reactions, and synthesized 20-mer oligonucleotides on chip. PMID:17180201

  3. Doclet To Synthesize UML

    Barry, Matthew R.; Osborne, Richard N.

    2005-01-01

    The RoseDoclet computer program extends the capability of Java doclet software to automatically synthesize Unified Modeling Language (UML) content from Java language source code. [Doclets are Java-language programs that use the doclet application programming interface (API) to specify the content and format of the output of Javadoc. Javadoc is a program, originally designed to generate API documentation from Java source code, now also useful as an extensible engine for processing Java source code.] RoseDoclet takes advantage of Javadoc comments and tags already in the source code to produce a UML model of that code. RoseDoclet applies the doclet API to create a doclet passed to Javadoc. The Javadoc engine applies the doclet to the source code, emitting the output format specified by the doclet. RoseDoclet emits a Rose model file and populates it with fully documented packages, classes, methods, variables, and class diagrams identified in the source code. The way in which UML models are generated can be controlled by use of new Javadoc comment tags that RoseDoclet provides. The advantage of using RoseDoclet is that Javadoc documentation becomes leveraged for two purposes: documenting the as-built API and keeping the design documentation up to date.

  4. Synthesizing Exoplanet Demographics

    Clanton, Christian

    2016-01-01

    The discovery of thousands of exoplanets has revealed a large diversity of systems, the majority of which look nothing like our own. On the theoretical side, we are able to make ab initio calculations that make predictions about the properties of exoplanets. However, in order to link these predictions with observations, we must construct a statistical census of exoplanet demographics over as broad a range of parameters as possible. Current constraints on exoplanet demographics are typically constructed using the results of individual surveys using a single detection technique, and thus are incomplete. The only way to derive a statistically-complete census that samples a wide region of exoplanet parameter space is to synthesize the results from surveys employing all of the different discovery methods at our disposal. I present the first studies to demonstrate that this is actually possible, and describe a (mostly) de-biased exoplanet census that is constructed from the synthesis of results from microlensing, radial velocity, and direct imaging surveys. I will also discuss future work that will include the results of transit surveys (in particular, Kepler discoveries) to complete the census of exoplanets in our Galaxy, and describe the application of this census to develop the most comprehensive, observationally-constrained models of planet formation and evolution that have been derived to date.

  5. Fully automated parallel oligonucleotide synthesizer

    Lebl, M.; Burger, Ch.; Ellman, B.; Heiner, D.; Ibrahim, G.; Jones, A.; Nibbe, M.; Thompson, J.; Mudra, Petr; Pokorný, Vít; Poncar, Pavel; Ženíšek, Karel

    2001-01-01

    Roč. 66, č. 8 (2001), s. 1299-1314. ISSN 0010-0765 Institutional research plan: CEZ:AV0Z4055905 Keywords : automated oligonucleotide synthesizer Subject RIV: CC - Organic Chemistry Impact factor: 0.778, year: 2001

  6. RAMESES publication standards: realist syntheses

    Wong Geoff

    2013-01-01

    Full Text Available Abstract Background There is growing interest in realist synthesis as an alternative systematic review method. This approach offers the potential to expand the knowledge base in policy-relevant areas - for example, by explaining the success, failure or mixed fortunes of complex interventions. No previous publication standards exist for reporting realist syntheses. This standard was developed as part of the RAMESES (Realist And MEta-narrative Evidence Syntheses: Evolving Standards project. The project's aim is to produce preliminary publication standards for realist systematic reviews. Methods We (a collated and summarized existing literature on the principles of good practice in realist syntheses; (b considered the extent to which these principles had been followed by published syntheses, thereby identifying how rigor may be lost and how existing methods could be improved; (c used a three-round online Delphi method with an interdisciplinary panel of national and international experts in evidence synthesis, realist research, policy and/or publishing to produce and iteratively refine a draft set of methodological steps and publication standards; (d provided real-time support to ongoing realist syntheses and the open-access RAMESES online discussion list so as to capture problems and questions as they arose; and (e synthesized expert input, evidence syntheses and real-time problem analysis into a definitive set of standards. Results We identified 35 published realist syntheses, provided real-time support to 9 on-going syntheses and captured questions raised in the RAMESES discussion list. Through analysis and discussion within the project team, we summarized the published literature and common questions and challenges into briefing materials for the Delphi panel, comprising 37 members. Within three rounds this panel had reached consensus on 19 key publication standards, with an overall response rate of 91%. Conclusion This project used multiple

  7. Stabilization of transition-metal complexes in high oxidation states by macrocyclic tertiary amines. Electrochemical generation and spectroscopic properties of novel dihalogeno and pseudohalogeno tetraamine complexes of ruthenium(IV)

    Che, C.M.; Wong, K.Y.; Poon, C.K.

    1986-05-21

    1,4,8,12-Tetramethyl-1,4,8,12-tetraazacyclopentadecane (15-TMC) was synthesized by the reaction of 1,4,8,12-tetraazacyclopentadecane with formaldehyde. Reactions of K/sub 2/(RuCl/sub 5/H/sub 2/O) with 15-TMC and 16-TMC (16-TMC = 1,5,9,13-tetramethyl-1,5,9,13-tetraazacyclohexadecane) in ethanol yielded trans-(RuLCl/sub 2/)Cl (L = 15-TMC and 16-TMC, respectively) in high yields. The syntheses of trans-(RuLBr/sub 2/)ClO/sub 4/ (L = (TMEA)/sub 2/ (TMEA = N,N,N',N'-tetramethyl-1,2-ethanediamine), 14-TMC (1,4,8,11-tetramethyl-1,4,8,11-tetraazacyclotetradecane), and 15-TMC), trans-(Ru(TMEA)/sub 2/(NCS)/sub 2/)NCS, and trans-(Ru(14-TMC)(CH/sub 3/CN)/sub 2/)(ClO/sub 4/)/sub 2/ are also described. The electrochemistry of trans-(RuLX/sub 2/)/sup +/ (L = (TMEA)/sub 2/, 14-TMC, 15-TMC, and 16-TMC; X = Cl, Br, and NCO) in acetonitrile were examined. Controlled-potential electrolyses of trans-(RuLX/sub 2/)/sup +/ at 1.30 V vs. the ferrocene couple generated some novel trans-(Ru/sup IV/LX/sub 2/)/sup 2 +/ complexes. The ligand-to-metal charge-transfer transitions in the UV-vis spectra of trans-(Ru/sup IV/(TMEA)/sub 2/X/sub 2/)/sup 2 +/ have been identified at 410 (X = Cl) and 570 nm (X = Br), which are considerably red-shifted with respect to their Ru(III) counterparts.

  8. Synthese und Eigenschaften von Kohlenstoffnitriden

    Horvath-Bordon, Elisabeta

    2004-01-01

    In der hier vorliegenden Arbeit über die „Synthese und Eigenschaften von Kohlenstoffnitriden“ wird im ersten Teil über die Synthese, die Strukturaufklärung, thermische Stabilität und die optischen Eigenschaften von Tri-s-triazin Derivaten (Cyamelurate, Melonate, Melem usw.) berichtet. Weil sich molekulare und polymere Tri-s-triazin Derivaten relativ einfach in reiner Form darstellen lassen, wurden sie als Precursoren zur Herstellung von harten Kohlenstoffnitriden ausgewählt. Im zweiten Teil w...

  9. Method of synthesizing pyrite nanocrystals

    Wadia, Cyrus; Wu, Yue

    2013-04-23

    A method of synthesizing pyrite nanocrystals is disclosed which in one embodiment includes forming a solution of iron (III) diethyl dithiophosphate and tetra-alkyl-ammonium halide in water. The solution is heated under pressure. Pyrite nanocrystal particles are then recovered from the solution.

  10. Template-synthesized opal hydrogels

    LI Jun; JI Lijun; RONG Jianhua; YANG Zhenzhong

    2003-01-01

    Opal hydrogels could be synthesized with polymer inverse opal template. A pH responsive opal N-iso- propylacrylamide/acrylic acid copolymerized hydrogel was prepared as an example. The ordered structure and response to pH were investigated. Through the sol-gel process of tetrabutyl titanate, opal titania was obtained with the opal hydrogel template.

  11. X-Band PLL Synthesizer

    P. Kutin

    2006-04-01

    Full Text Available This paper deals with design and realization of a PLL synthesizer for the microwave X−band. The synthesizer is intended for use as a local oscillator in a K−band downconverter. The design goal was to achieve very low phase noise and spurious free signal with a sufficient power level. For that purpose a low phase noise MMIC VCO was used in phase locked loop. The PLL works at half the output frequency, therefore there is a frequency doubler at the output of the PLL. The output signal from the frequency doubler is filtered by a band-pass filter and finally amplified by a single stage amplifier.

  12. Catalytic method for synthesizing hydrocarbons

    Sapienza, Richard S.; Sansone, Michael J.; Slegeir, William A. R.

    1984-01-01

    A method for synthesizing hydrocarbons from carbon monoxide and hydrogen by contacting said gases with a slurry of a catalyst composed of palladium or platinum and cobalt supported on a solid phase is disclosed. The catalyst is prepared by heating a heterogeneous component of the palladium or platinum deposited on the solid support in a solution of cobalt carbonyl or precursors thereof. The catalyst exhibits excellent activity, stability in air, and produces highly desirable product fractions even with dilute gaseous reactants.

  13. Method of synthesizing tungsten nanoparticles

    Thoma, Steven G; Anderson, Travis M

    2013-02-12

    A method to synthesize tungsten nanoparticles has been developed that enables synthesis of nanometer-scale, monodisperse particles that can be stabilized only by tetrahydrofuran. The method can be used at room temperature, is scalable, and the product concentrated by standard means. Since no additives or stabilizing surfactants are required, this method is particularly well suited for producing tungsten nanoparticles for dispersion in polymers. If complete dispersion is achieved due to the size of the nanoparticles, then the optical properties of the polymer can be largely maintained.

  14. Synthesized Optimization of Triangular Mesh

    HU Wenqiang; YANG Wenyu

    2006-01-01

    Triangular mesh is often used to describe geometric object as computed model in digital manufacture, thus the mesh model with both uniform triangular shape and excellent geometric shape is expected. But in fact, the optimization of triangular shape often is contrary with that of geometric shape. In this paper, one synthesized optimizing algorithm is presented through subdividing triangles to achieve the trade-off solution between the geometric and triangular shape optimization of mesh model. The result mesh with uniform triangular shape and excellent topology are obtained.

  15. Synthese de champs sonores adaptative

    Gauthier, Philippe-Aubert

    La reproduction de champs acoustiques est une approche physique au probleme technologique de la spatialisation sonore. Cette these concerne l'aspect physique de la reproduction de champs acoustiques. L'objectif principal est l'amelioration de la reproduction de champs acoustiques par "synthese de champs acoustiques" ("Wave Field Synthesis", WFS), une approche connue, basee sur des hypotheses de champ libre, a l'aide du controle actif par l'ajout de capteurs de l'erreur de reproduction et d'une boucle fermee. Un premier chapitre technique (chapitre 4) expose les resultats d'appreciation objective de la WFS par simulations et mesures experimentales. L'effet indesirable de la salle de reproduction sur les qualites objectives de la WFS fut illustre. Une premiere question de recherche fut ensuite abordee (chapitre 5), a savoir s'il est possible de reproduire des champs progressifs en salle dans un paradigme physique de controle actif: cette possibilite fut prouvee. L'approche technique privilegiee, "synthese de champs adaptative" ("Adaptive Wave Field Synthesis" [AWFS]), fut definie, puis simulee (chapitre 6). Cette approche d'AWFS comporte une originalite en controle actif et en reproduction de champs acoustiques: la fonction cout quadratique representant la minimisation des erreurs de reproduction inclut une regularisation de Tikhonov avec solution a priori qui vient de la WFS. L'etude de l'AWFS a l'aide de la decomposition en valeurs singulieres (chapitre 7) a permis de comprendre les mecanismes propres a l'AWFS. C'est la deuxieme principale originalite de la these. L'algorithme FXLMS (LMS et reference filtree) est modifie pour l'AWFS (chapitre 8). Le decouplage du systeme par decomposition en valeurs singulieres est illustre dans le domaine du traitement de signal et l'AWFS basee sur le controle independant des modes de rayonnement est simulee (chapitre 8). Ce qui constitue la troisieme originalite principale de cette these. Ces simulations du traitement de signal

  16. FUNCTIONAL POLYHYDROXYALKANOATES SYNTHESIZED BY MICROORGANISMS

    Guo-qiang Chen; Qiong Wu; Kai Zhao; Peter H.Yu

    2000-01-01

    Many bacteria have been found to synthesize a family of polyesters termed polyhydroxyalkanoate, abbreviated as PHA. Some interesting physical properties of PHAs such as piezoelectricity, non-linear optical activity, biocompatibility and biodegradability offer promising applications in areas such as degradable packaging, tissue engineering and drug delivery.Over 90 PHAs with various structure variations have been reported and the number is still increasing. The mechanical property of PHAs changes from brittle to flexible to elastic, depending on the side-chainlength of PHA. Many attempts have been made to produce PHAs as biodegradable plastics using various microorganisms obtained from screening natural environments, genetic engineering and mutation. Due to the high production cost, PHAs still can not compete with the nondegradable plastics, such as polyethylene and polypropylene. Various processes have been developed using low cost raw materials for fermentation and an inorganic extraction process for PHA purification. However, a super PHA production strain may play the most critical role for any large-scale PHA production. Our recent study showed that PHA synthesis is a common phenomenon among bacteria inhabiting various locations, especially oil-contaminated soils. This is very important for finding a suitable bacterial strain for PHA production. In fact, PHA production strains capable of rapid growth and rapid PHA synthesis on cheap molasses substrate have been found on molasses contaminated soils. A combination of novel properties and lower cost will allow easier commercialization of PHA for many applications.

  17. Composites comprising biologically-synthesized nanomaterials

    Curran, Seamus; Dias, Sampath; Blau, Werner; Wang, Jun; Oremland, Ronald S; Baesman, Shaun

    2013-04-30

    The present disclosure describes composite materials containing a polymer material and a nanoscale material dispersed in the polymer material. The nanoscale materials may be biologically synthesized, such as tellurium nanorods synthesized by Bacillus selenitireducens. Composite materials of the present disclosure may have optical limiting properties and find use in optical limiting devices.

  18. Syntheses and Functional Properties of Phthalocyanines

    Keiichi Sakamoto

    2009-08-01

    Full Text Available Metal phthalocyanine tetrasulfonic acids, metal phthalocyanine octacarboxylic acids, metal octakis(hexyloxymethylphthalocyanines, and metal anthraquinocyanines have been synthesized. Then, zinc bis(1,4-didecylbenzo-bis(3,4-pyridoporphyrazines, the cyclotetramerization products of a 1:1 mixture of 3,6-didecylphthalonitrile and 3,4-dicyanopyridine, were synthesized. Futher, subphthalocyanine and its derivatives, with substituents such as thiobutyl and thiophenyl moieties were synthesized. Electrochemical measurements were performed on the abovementioned phthalocyanine derivatives and analogues in order to examine their electron transfer abilities and electrochemical reaction mechanisms in an organic solvent. Moreover, 1,4,8,11,15,18,22,25-octakis(thiophenylmethyl phthalocyanes were synthesized. The Q-bands of the latter compounds appeared in the near-infrared region. Furthermore, non-colored transparent films in the visible region can be produced.

  19. Progress in synthesizing functional nano materials

    2006-01-01

    @@ With the consistent investment, the research team directed by Prof. Yadong Li of Chemistry Department of Tsinghua University achieved new progress in synthesizing nano materials with specific functions. The research team led by Prof.

  20. Freestanding doped silicon nanocrystals synthesized by plasma

    Freestanding silicon nanocrystals (Si NCs) have recently gained great popularity largely due to their easily accessible surface and flexible incorporation into device structures. In the past decade plasmas have been increasingly employed to synthesize freestanding Si NCs. As freestanding Si NCs move closer to applications in a variety of fields such as electronics, thermoelectrics and lithium-ion batteries, doping becomes more imperative. Such a context explains the current great interest in plasma-synthesized doped freestanding Si NCs. In this work we review the synthesis of freestanding doped Si NCs by plasma. Doping-induced structural, electronic, optical and oxidation properties of Si NCs are discussed. We also review the applications of plasma-synthesized doped freestanding Si NCs that have been demonstrated so far. The development of freestanding doped Si NCs synthesized by plasma in the future is envisioned. (review article)

  1. Raman assisted lightwave synthesized frequency sweeper

    Pedersen, Anders Tegtmeier; Rottwitt, Karsten

    2010-01-01

    We present a Lightwave Synthesized Frequency Sweeper comprising a Raman amplifier for loss compensation. The generated pulse train contains 123 pulses and has a flat signal level as well as a low noise level.......We present a Lightwave Synthesized Frequency Sweeper comprising a Raman amplifier for loss compensation. The generated pulse train contains 123 pulses and has a flat signal level as well as a low noise level....

  2. Radiolytic syntheses of nanoparticles in supramolecular assemblies.

    Chen, Qingde; Shen, Xinghai; Gao, Hongcheng

    2010-08-11

    Ionizing radiation is a powerful method in the syntheses of nanoparticles (NPs). The application of ionizing radiation in supramolecular assemblies can afford us more unique conditions to control the composition and morphology of the NPs. So far, most work focused on water-in-oil (W/O) microemulsions or reversed micelles. In this supramolecular organization, it has been proved that the effects of many conditions on the yield of e(aq)(-) play a key role, remarkably different from the mechanism in routine chemical method. Besides, some supramolecular assemblies of cyclodextrins and ionic liquids have been used in the syntheses of NPs by ionizing radiation, and many novel and interesting phenomena appeared. This review is intended to underline the three significant aspects of the radiolytic syntheses of NPs in supramolecular assemblies. PMID:20653087

  3. Total Syntheses of Periconiasins A-E.

    Tian, Chong; Lei, Xiaoqiang; Wang, Yuanhao; Dong, Zhen; Liu, Gang; Tang, Yefeng

    2016-06-01

    The first and collective total syntheses of periconiasins A-E, a group of naturally occurring cytochalasans, were achieved by a series of rationally designed or bioinspired transformations. Salient features of the syntheses include a tandem aldol condensation/Grob fragmentation to assemble the linear polyketide-amino acid hybrid precursor, a Diels-Alder macrocylization to construct the 9/6/5 tricyclic core of periconiasins A-C, and a transannular carbonyl-ene reaction to forge the polycyclic framework of periconiasins D and E. PMID:27121397

  4. High pressure syntheses of carbonates. 8

    The ternary carbonates TlLn(CO3)2 with Ln = La to Lu and Y are synthesized at 3500C by dehydration of the carbonates TlLn(CO3)2xxH2O or at 5000C by reaction of Tl2CO3 and Ln2(C2O4)3xyH2O under 3000 bar CO2. X-ray and IR investigations show the existence of five different structures. The compound Tl5La(CO3)4 is synthesized and X-ray and IR investigations were performed. (author)

  5. Method and apparatus for synthesizing filamentary structures

    Height, Murray J.; Howard, Jack B.; Vandersande, John B.

    2008-02-26

    Method and apparatus for producing filamentary structures. The structures include single-walled nanotubes. The method includes combusting hydrocarbon fuel and oxygen to establish a non-sooting flame and providing an unsupported catalyst to synthesize the filamentary structure in a post-flame region of the flame. Residence time is selected to favor filamentary structure growth.

  6. Synthesizing Chaotic Maps with Prescribed Invariant Densities

    Rogers, Alan; Shorten, Robert; Heffernan, Daniel M.

    2004-01-01

    The Inverse Frobenius-Perron problem (IFPP) concerns the creation of discrete chaotic mappings with arbitrary invariant densities. In this note, we present a new and elegant solution to the IFPP, based on positive matrix theory. Our method allows chaotic maps with arbitrary piecewise-constant invariant densities, and with arbitrary mixing properties, to be synthesized.

  7. Highly Efficient Syntheses of Hyaluronic Acid Oligosaccharides

    Huang, Lijun; Huang, Xuefei

    2007-01-01

    Highly efficient syntheses of hyaluronic acid oligosaccharides have been accomplished through the pre-activation based iterative one-pot strategy. A series of oligosaccharides ranging from di- to hexasaccharides were rapidly assembled using only near stoichiometric amounts of the building blocks without aglycon adjustment or purifications of intermediate oligosaccharides. Deprote...

  8. SYNTHESES AND PROPERTIES OF SOME ORGANOSILANE POLYMERS

    ZHANG Xinghua; Robert West

    1984-01-01

    Some organosilane polymers with high molecular weights have been synthesized by cocondensation of organosilicon dihalide monomers with sodium metal in toluene. These polymers are both soluble in common solvents and meltable at lower temperatures, and can be molded, cast into films or drawn into fibers. Exposure of the solid polymers to ultraviolet light leads to degradation or crosslinking.

  9. A Novel Method to Synthesize Polyorganozircosilazane

    2002-01-01

    A new kind of polyorganozircosilazane as Si/Zr/C/N-based ceramic precursor was synthesized from the condensation reaction of hexamethylcyclotrisilazane lithium salts (D3NLi) and zirconium tetrachloride (ZrCl4). In the presence of N, N, N′, N′-tetramethyl ethylene diamine (TMEDA), polyorganozircosilazane was obtained in high yield.

  10. Syntheses of Arnottin I and Arnottin II

    Moschitto, Matthew J.; Anthony, David R.; Lewis, Chad A.

    2015-01-01

    Short total syntheses of arnottin I and II were accomplished in 5 and 6 steps, respectively. A sesamol-benzyne cycloaddition with a 3-furyl-benzoate followed by regiospecific lactonization provided rapid, large-scale access to the core of arnottin I. Saponification of arnottin I and hypervalent iodide mediated spirocyclization provided an efficient and direct preparation of racemic arnottin II.

  11. Synthesizing Waves from Animated Height Fields

    Nielsen, Michael Bang; Söderström, Andreas; Bridson, Robert

    2013-01-01

    Computer animated ocean waves for feature films are typically carefully choreographed to match the vision of the director and to support the telling of the story. The rough shape of these waves is established in the previsualization (previs) stage, where artists use a variety of modeling tools...... with fast feedback to obtain the desired look. This poses a challenge to the effects artists who must subsequently match the locked-down look of the previs waves with high-quality simulated or synthesized waves, adding the detail necessary for the final shot. We propose a set of automated techniques...... for synthesizing Fourier-based ocean waves that match a previs input, allowing artists to quickly enhance the input wave animation with additional higher-frequency detail that moves consistently with the coarse waves, tweak the wave shapes to flatten troughs and sharpen peaks if desired (as is characteristic...

  12. Synthese von cyclischen Disacchariden durch intramolekulare Glycosylierung

    Claude, Patrick

    2005-01-01

    Organic chemists have always confronted the difficult task of synthesizing carbohydrates of with regio- and sterospecific specific glycosydic linkages, some of them frequently found in nature, with exert significant biological activities. To overcome this hurdle, they introduced an ingenuous synthetic method called "Intramolecular Glycosylation". Intramolecular glycosylation is the reaction between a glycosyl donor and acceptor that are both linked to a tether. The tether can be a tempora...

  13. Mechanismen der Laserablation zur Synthese nanoskopischer Kolloide

    Schaumberg, Christian Alexander

    2016-01-01

    Die Synthese kolloidaler Nanopartikel ist daher eines der wichtigsten Forschungsthemen der letzten Jahre. Die gepulste Laserablation in Flüssigkeiten stellt eine Alternative zu den nasschemischen Synthesewegen dar. Merkmale der gepulsten Laserablation in Flüssigkeiten ist der geringe experimentelle Aufwand, die Vielseitigkeit und die Möglichkeit stabilisatorfreie kolloidale Nanopartikel herzustellen. Eine Weiterentwicklung ist die Verwendung von Pulversuspensionen als Ausgangsmaterial. Dies f...

  14. High pressure syntheses of carbonates. 6

    The ternary carbonates NaLn(CO3)2 with Ln = La to Lu and Y are synthesized by dehydration of NaLn(CO3)2.xH2O or by reaction of Na2CO3 with Ln2(C2O4)3.xH2O under 3000 bar CO2 and 350 - 500 0C. Two structures are found, characterized by IR and X-ray investigations and by thermal decomposition. (author)

  15. Predictions of synthesizing element 119 and 120

    2011-01-01

    The evaporation residue cross sections of synthesizing superheavy nuclei Z=119, 120 are calculated by different sets of master equations with different dynamical variables. Two methods basically predicted similar results that the Ca induced hot fusion can 48 produce element 119 easier than produce 120, and the evaporation residue cross sections for 119 are detectable by current advanced techniques, while the evaporation residue cross sections are below 0.1 pb for producing element 120.

  16. Spurious in PLL-DDS frequency synthesizers

    Kroupa, Věnceslav František; Štursa, Jarmil

    2002-01-01

    Roč. 2, č. 1 (2002), s. 48-51. ISSN 1335-8243. [Digital Signal Processing and Multimedia Communications DSP-MCOM 2001 /5./. Košice, 27.11.2001-29.11.2001] R&D Projects: GA ČR GA102/00/0958 Institutional research plan: CEZ:AV0Z2067918 Keywords : frequency synthesizers * phase locked loops * direct digital synthesis Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering

  17. Shock Syntheses of Novel Nitrides and Biomolecules

    Sekine, Toshimori

    2013-06-01

    High-pressure spinel nitride of Si3N4 was discovered more than 10 years ago. Since then there have been many studies on the spinel nitrides and related materials including oxynitrides. We have developed shock synthesis method to investigate their structural, mechanical, chemical, physical, and optical properties. At the same time we tried to synthesize carbon nitrides from the organic substances. And later we extended to shock synthesis of ammonia through the Haber-Bosch reaction under shock in order to apply geochemical subjects related to the origin of life. The simplest amino acid of glycine, as well as animes (up to propylamine) and carboxylic acids (up to pentanoic acid), has been synthesized successfully in aqueous solutions through meteoritic impact reactions. Recently we are trying to make more complex biomolecules for implications of biomolecule formation for the origin of life through meteorite impacts on early Earth's ocean. These results of shock syntheses may imply significant contributions to materials science and Earth and planetary sciences. This research is collaborated with National Institute for Materials Science and Tohoku University.

  18. Magnesioferrite synthesized from magnesian-magnetites

    Marcelo Hidemassa Anami

    2014-02-01

    Full Text Available Magnesioferrite is an important mineral due to its use in different scientific fields and by the fact that the soil through the action of weathering, can be a source of nutrients essential for plant development by the fact that in the soil. Its use in pure form or associated with other minerals is only possible through the synthesis in laboratory conditions. This study aimed to synthesize magnesioferrite and hematite from magnesian-magnetite by a co-precipitation procedure. The methodology used is an adaptation of the method of synthesis of pure magnetite, partially replacing the soluble salts of iron with soluble magnesium salts in the proportion of 30.0 mol% of Fe for Mg. The characterization of the synthetic minerals used x-rays diffraction, total chemical analysis and mass specific magnetic susceptibility. The results showed that besides the magnesian-magnetite an unprecedented muskoxita was synthesized, which upon annealing was converted to magnesioferrite and hematite and in the proportion of 93.1% and 6.9% respectively. The isomorphous substitution of Fe for Mg enhanced the thermal stability of the ferrimagnetic mineral synthesized.

  19. Syntheses and studies of acetylenic polymers

    Yiwei, Ding

    1994-03-03

    Based on new diiodo aryl compounds a series of novel soluble polymers, poly(2,5-dialkoxy-1,4-phenyleneethynylene)s (PPE polymers) were synthesized using palladium-catalysis. The molecular weights (MW) range from 8,000 to 40,000. Properties such as absorption, fluorescence, and conductivity were studied. A PPE polymer with butoxy side chain exhibits a weak electrical conductivity ({sigma} = 10{sup {minus}3} S/cm) after doping with AsF{sub 5}. Absorption spectra in THF solution at room temperature (RT) show a maximum at 440 nm. However, absorption spectra of PPE polymers in the film state at (RT) show a maximum at 480 nm. PPE polymer-based light emitting diode (LED) devices have been prepared; greenish light from these LED devices can be observed. Poly(ethynylene-p-arylene-ethynylene-silylene)s were synthesized through the same palladium-catalyzed polymerization; MWs are between 6,000 and 82,000. Absorption and fluorescence were studied. Some of these polymers exhibit thermotropic liquid crystalline properties. In addition, nonlinear optical properties were briefly examined. Poly(silylene-ethynylene) homopolymers as well as alternating copolymers were synthesized through a novel palladium-catalyzed polymerization; MWs range from 56 {times} 10{sup 3} to 5.3 {times} 10{sup 3}. Thermal stability of these was also investigated; char yields range from 56 to 83%. One of these polymers exhibits thermotropic liquid crystalline properties.

  20. Synthese stereoskopischer Sequenzen aus 2-dimensionalen Videoaufnahmen

    Knorr, Sebastian

    2008-01-01

    Die rasante Entwicklung der 3D-Technologie führt derzeit zu einer verstärkten Nachfrage nach 3D-Spielen, 3D-Filmen, 3D-Präsentationen und interaktiven 3D-Inhalten. Von der Motiviation getrieben, alte Filme als Neuauflage in 3D zu erleben, beschäftigt sich die vorliegende Dissertation mit der automatischen Konvertierung von Videosequenzen von 2D in stereoskopisch 3D. Zur Umsetzung dieses Ziels wird ein neues Verfahren zur realistischen Synthese stereoskopischer Ansichten (RSVS) aus monokularen...

  1. Biocompatibility of poly allylamine synthesized by plasma

    A study of the electric and hydrophilic properties of poly allylamine (PAI) synthesized by plasma whose structure contains N-H, C-H, C-O and O-H bonds is presented, that promote the biocompatibility with the human body. To study the PAI hydrolytic affinity, solutions of salt concentration similar to those of the human body were used. The results indicate that the solutions modify the charge balance in the surfaces reducing the hydrophobicity in the poly allylamine whose contact angle oscillates among 10 and 16 degrees and the liquid-solid surface tension between 4 and 8 dina/cm. (Author)

  2. Biogenic synthesized nanoparticles and their applications

    Singh, Abhijeet; Sharma, Madan Mohan

    2016-05-01

    In the present scenario, there are growing concerns over the potential impacts of bioengineered nanoparticles in the health sector. However, our understanding of how bioengineered nanoparticles may affect organisms within natural ecosystems, lags far behind our rapidly increasing ability to engineer novel nanoparticles. To date, research on the biological impacts of bioengineered nanoparticles has primarily consisted of controlled lab studies of model organisms with single species in culture media. Here, we described a cost effective and environment friendly technique for green synthesis of silver nanoparticles. Silver nanoparticles were successfully synthesized from 1 mM AgNO3 via a green synthesis process using leaf extract as reducing as well as capping agent. Nanoparticles were characterized with the help of UV-vis absorption spectroscopy, X-ray diffraction and TEM analysis which revealed the size of nanoparticles of 30-40 nm size. Further the nanoparticles synthesized by green route are found highly toxic against pathogenic bacteria and plant pathogenic fungi viz. Escherichia coli, Pseudomonas syringae and Sclerotiniasclerotiorum. The most important outcome of this work will be the development of value-added products and protection of human health from pathogens viz., bacteria, virus, fungi etc.

  3. Enantioselective catalytic syntheses of alpha-branched chiral amines

    Brase, S.; Baumann, T.; Dahmen, S.;

    2007-01-01

    Chiral amines play a pivotal role in fine chemical and natural product syntheses and the design of novel materials.......Chiral amines play a pivotal role in fine chemical and natural product syntheses and the design of novel materials....

  4. PZT Powders Synthesized by Hydrothermal Method

    ZHU Kong-Jun, ZHU Ren-Qiang, DONG Na-Na, GU Hong-Hui, QIU Jin-Hao, JI Hong-Li

    2012-05-01

    Full Text Available Lead zirconate titanate (PZT) powders with single―phase, cubic morphology and average size of 1 μm were synthesized using hydrothermal methods. Effects of KOH concentration, hydrothermal treatment time and Pb excess were investigated. The results show that KOH concentration has an important influence on the solid solubility of Pb ion in A―site of PZT perovskite structure. The concentration of Pb2+ vacancies increased with the increase of OH― concentration. However, this kind of deficiency could be compensated by adding more Pb ions in the raw materials, and more Pb ions were needed to add with higher alkaline concentration in the starting solution. But excessive compensation of Pb ions would result in the appearance of the second phase.

  5. Structure of the enzymatically synthesized fructan inulin

    Construction, purification and characterization of a fusion protein of maltose-binding protein of Escherichia coli and the fructosyltransferase of Streptococcus mutans is described. With the purified protein, in vitro synthesis of inulin was performed. The obtained polysaccharide was characterized by high-performance size-exclusion chromatography (HPSEC) and static light scattering (SLS) in dilute aqueous and dimethyl sulfoxide solution. For all samples very high molecular weights between 60x106 and 90x106 g/mol and a remarkable small polydispersity index of 1.1 have been determined. Small root-mean-square radii of gyration point to a compact conformation in dilute solution. No difference between native and enzymatically synthesized inulin was observed by X-ray powder diffraction and thermoanalysis of solid samples. (Copyright (c) 1998 Elsevier Science B.V., Amsterdam. All rights reserved.)

  6. Method and apparatus for synthesizing hydrocarbons

    Colmenares, C.A.; Somorjai, G.A.; Maj, J.J.

    1983-06-21

    A method and apparatus for synthesizing a mixture of hydrocarbons having five carbons or less is disclosed. An equal molar ratio of CO and H/sub 2/ gases is caused to pass through a ThO/sub 2/ catalyst having a surface area of about 80 to 125 m/sup 2//g. The catalyst further includes Na present as a substitutional cation in an amount of about 5 to 10 atom %. At a temperature of about 340 to 360/sup 0/C, and at pressures of about 20 to 50 atm, CH/sub 3/OH is produced in an amount of about 90 wt % of the total hydrocarbon mixture, and comprised 1 mole % of the effluent gas.

  7. Methods for synthesizing metal oxide nanowires

    Sunkara, Mahendra Kumar; Kumar, Vivekanand; Kim, Jeong H.; Clark, Ezra Lee

    2016-08-09

    A method of synthesizing a metal oxide nanowire includes the steps of: combining an amount of a transition metal or a transition metal oxide with an amount of an alkali metal compound to produce a mixture; activating a plasma discharge reactor to create a plasma discharge; exposing the mixture to the plasma discharge for a first predetermined time period such that transition metal oxide nanowires are formed; contacting the transition metal oxide nanowires with an acid solution such that an alkali metal ion is exchanged for a hydrogen ion on each of the transition metal oxide nanowires; and exposing the transition metal oxide nanowires to the plasma discharge for a second predetermined time period to thermally anneal the transition metal oxide nanowires. Transition metal oxide nanowires produced using the synthesis methods described herein are also provided.

  8. High pressure syntheses of carbonates. 4

    The ternary carbonates LiLn(CO3)2 with Ln = La to Lu and Y are synthesized from mixtures of Li2CO3 and Ln2(C2O4)3 . xH2O under 2000 bar CO2 and 500 0C. Two monoclinic types are found. They are characterized by IR and X-ray investigation and thermal decomposition. With the pressure of 200 bar and 550 0C one gets oxide-carbonates LiLnOCO3 with Ln = Sm to Lu and Y. All substances are of the same monoclinic type. Again they are characterized by IR and X-ray investigations and by thermal decomposition. The influence of the CO2 pressure and of the temperature on the formation of either LiLn(CO3)2 or LiLnOCO3 is investigated. (author)

  9. National Gas Survey. Synthesized gaseous hydrocarbon fuels

    None

    1978-06-01

    The supply-Technical Advisory Task Force-Synthesized Gaseous Hydrocarbon Fuels considered coal, hydrocarbon liquids, oil shales, tar sands, and bioconvertible materials as potential feedstocks for gaseous fuels. Current status of process technology for each feedstock was reviewed, economic evaluations including sensitivity analysis were made, and constraints for establishment of a synthesized gaseous hydrocarbon fuels industry considered. Process technology is presently available to manufacture gaseous hydrocarbon fuels from each of the feedstocks. In 1975 there were eleven liquid feedstock SNG plants in the United States having a capacity of 1.1 billion SCFD. There can be no contribution of SNG before 1982 from plants using feedstocks other than liquids because there are no plants in operation or under construction as of 1977. Costs for SNG are higher than current regulated prices for U.S. natural gas. Because of large reserves, coal is a prime feedstock candidate although there are major constraints in the area of coal leases, mining and water permits, and others. Commercial technology is available and several new gasification processes are under development. Oil shale is also a feedstock in large supply and commercial process technology is available. There are siting and permit constraints, and water availability may limit the ultimate size of an oil shale processing industry. Under projected conditions, bioconvertible materials are not expected to support the production of large quantities of pipeline quality gas during the next decade. Production of low or medium Btu gas from municipal solid wastes can be expected to be developed in urban areas in conjunction with savings in disposal costs. In the economic evaluations presented, the most significant factor for liquid feedstock plants is the anticipated cost of feedstock and fuel. The economic viability of plants using other feedstocks is primarily dependent upon capital requirements.

  10. Porous oxides synthesized by the combustion method

    The result of this work, seeks to be a contribution for the treatment of radioactive wastes, with base to the sorption properties that present those porous oxides, synthesized by a method that allows to increase the sorption capacity. The main objective of the present investigation has been the modification of the structural characteristics of the oxides of Fe, Mg and Zn to increase its capacity of sorption of 60 Co in particular. It was studied the effect of the synthesis method by combustion in the inorganic oxides; the obtained solids were characterized using the following techniques: X-ray diffraction (XRD), scanning electron microscopy (SEM), semiquantitative elementary analysis by Dispersive energy spectroscopy (EDS) and determination of surface area by the Brunauner-Emmett-Teller method (BET). Also was carried out batch type experiments for the sorption of Co2+, with the purpose of studying the sorption capacity of each one of the prepared oxides. In accordance with that previously exposed, the working plan that was carried out in this investigation is summarized in the following stages: 1. Preparation of inorganic oxides by two different methods, studying the effect of the temperature in the synthesis process. 2. Characterization of the inorganic oxides by XRD, by means of which those were chosen the solids with better properties. 3. Characterization of the inorganic oxides by SEM and EDS where it was studied the morphology of the synthesized materials and the semiquantitative elemental composition. 4. Realization of a sorption experiment type Batch with non radioactive Co2+ to simulate the sorption of 60 Co and determination of the sorption capacity by means of neutron activation of the non radioactive cobalt. 5. Determination of the surface area by the (BET) technique of the inorganic oxides with better sorption properties. (Author)

  11. 一种新型不对称三足四胺席夫碱锌(Ⅱ)配合物的合成、结构及杀菌性能研究%Synthesis,Crystal Structure and Biocidal Study of a New Schiff-base Zn (Ⅱ) Complex Derived from Asymmetrical Tripodal Tetraamine

    高健; 陈军; 许兴友; 李树安; 杨绪杰; 陆路德; 汪信

    2004-01-01

    A new tripodal complex [ZnL](ClO4)2 (C26H31Cl2N7O8Zn) was synthesized by Schiff base condensation of 2-aminoethyl-bi (3-aminopropyl)amine with 2-pyridinecarbaldehyde in the presence of Zn2+ and characterized by Xray diffraction and ES mass spectral analysis. It crystallized in the Monoclinic system, space group P21/c with a=1.088 5(4) nm, b=1.614 6(6) nm, c=1.783 0(5) nm,β=94.405(2)°. Z=4, R1=0.092 9, wR2=0.175 8. Zn atom rendered six-coordinate in a trigonal antiprism geometry. The complex was valued for its antimicrobial activity against bacterial strands using the agar diffusion method. It was found to be active against the four test bacterial organisms.

  12. Localization of ANP-synthesizing cells in rat stomach

    Chun-Hui Li; Li-Hui Pan; Chun-Yu Li; Chang-Lin Zhu; Wen-Xie Xu

    2006-01-01

    AIM: To study the morphological positive expression of antrial natriuretic peptide (ANP)-synthesizing cells and ultrastructural localization and the relationship between ANP-synthesizing cells and microvessel density in the stomach of rats and to analyze the distribution of the three histologically distinct regions of ANP-synthesizing cells.METHODS: Using immunohistochemical techniques, we studied positive expression of ANP-synthesizing cells in rat stomach. A postembedding immunogold microscopy technique was used for ultrastructural localization of ANP-synthesizing cells. Microvessel density in the rat stomach was estimated using tannic acid-ferric chloride (TAFC) method staining. Distribution of ANP-synthesizing cells were studied in different regions of rat stomach histochemically.RESULTS: Positive expression of ANP-synthesizing cells were localized in the gastric mucosa of rats. Localization of ANP-synthesizing cells identified them to be enterochrochromaffin cells (EC) by using a postembedding immunogold electron microscopy technique. EC cells were in the basal third of the cardiac mucosa region.ANP-synthesizing cells existed in different regions of rat stomach and its density was largest in the gastric cardiac region, and the distribution order of ANP-synthesizing cells in density was cardiac region, pyloric region and fundic region in mucosa layer. We have also found a close relationship between ANP-synthesizing cells and microvessel density in gastric mucosa of rats using TAFC staining.CONCLUSION: ANP-synthesizing cells are expressed in the gastric mucosa. EC synthesize ANP. There is a close relationship between ANP-synthesizing cells and microvessel density in gastric mucosa of rats.The distribution density of ANP-synthesizing cells is largest in the gastric cardiac region.

  13. Chemical syntheses of inulin and levan structures.

    Oscarson, Stefan; Sehgelmeble, Fernando W

    2002-11-29

    A fructofuranosyl thiglycoside donor, ethyl 6-O-acetyl-3-O-benzyl-1,4-O-(1,1,3,3-tetraisopropyldisiloxane-1,3-diyl)-2-thio-beta-D-fructofuranoside (11), designed to yield stereospecifically beta-linkages and also to allow subsequent elongation in the 6- and/or 1-positions, was prepared and used in syntheses of levan and inulin structures. DMTST-promoted glycosylation between 11 (1.3 mol equiv) and methyl beta-D-fructofuranoside 6-OH and 1-OH acceptors (3 and 6) gave stereospecifically the protected methyl levanobioside 12 and inulinobioside 17 in excellent yields (80 and 86%), respectively. Protecting group manipulations on these afforded new disaccharide 6'-OH and 1'-OH acceptors (13 and 19), which were coupled again with donor 11 (1.0 mol equiv) to yield methyl levanotrioside 14 and inulinotrioside 20 in high yields, 65 and 67%, respectively. These were transformed into new acceptors and also fully deprotected to afford the methyl glycosides of levanotriose and inulinotriose, all structures that have earlier not been accessible by chemical synthesis. PMID:12444625

  14. Syntheses of surfactants from oleochemical epoxides

    Warwel Siegfried

    2001-01-01

    Full Text Available Sugar-based surfactants were obtained in good yields (up to 100% under mild conditions (70°C, methanol or mixtures of methanol and water by ring-opening of terminal epoxides with aminopolyols, derived from glucose. Reaction of N-methyl glucamine with epoxides from even-numbered C4-C18 alpha-olefins or from terminal unsaturated fatty acid methyl esters leads to linear products, while corresponding reactions with N-dodecyl glucamine or glucamine yield surfactants with different Y-structures. Products obtained by conversion of omega-epoxy fatty acid methyl esters were saponificated with NaOH or hydrolyzed enzymatically to sodium salts or free acids respectively, which are amphoteric surfactants. Studies of the surfactants at different pH-values demonstrate different surface active properties in aqueous solutions. Critical micelle concentrations (c.m.c. in a range between 2 and 500mg/l and surface tensions of 25-40mN/m were measured for several of the synthesized sugar-based surfactants. The ring-opening products are rather poor foamers, whereas some of the corresponding hydrobromides show good foaming properties.

  15. Legionella bozemanae synthesizes phosphatidylcholine from exogenous choline.

    Palusinska-Szysz, Marta; Janczarek, Monika; Kalitynski, Rafal; Dawidowicz, Andrzej L; Russa, Ryszard

    2011-02-20

    The phospholipid class and fatty acid composition of Legionella bozemanae were determined using thin-layer chromatography, gas-liquid chromatography, and matrix-assisted laser desorption ionization-time of flight mass spectrometry. Phosphatidylcholine, phosphatidylethanolamine, and diphosphatidylglycerol were the predominant phospholipids, while phosphatidyl-N-monomethylethanolamine, phosphatidylglycerol, and phosphatidyl-N,N-dimethylethanolamine were present at low concentrations. With the use of the LC/MS technique, PC16:0/15:0, PC17:/15:0, and PE16:1/15:0 were shown to be the dominant phospholipid constituents, which may be taxonomically significant. Two independent phosphatidylcholine synthesis pathways (the three-step methylation and the one-step CDP-choline pathway) were present and functional in L. bozemanae. In the genome of L. bozemanae, genes encoding two potential phosphatidylcholine forming enzymes, phospholipid N-methyl transferase (PmtA) and phosphatidylcholine synthase (Pcs), homologous to L. longbeachae, L. drancourtii, and L. pneumophila pmtA and pcs genes were identified. Genes pmtA and pcs from L. bozemanae were sequenced and analyzed on nucleotide and amino acid levels. Bacteria grown on an artificial medium with labelled choline synthesized phosphatidylcholine predominantly via the phosphatidylcholine synthase pathway, which indicates that L. bozemanae phosphatidylcholine, similarly as in other bacteria associated with eukaryotes, is an important determinant of host-microbe interactions. PMID:20338739

  16. Multistep sintering to synthesize fast lithium garnets

    Xu, Biyi; Duan, Huanan; Xia, Wenhao; Guo, Yiping; Kang, Hongmei; Li, Hua; Liu, Hezhou

    2016-01-01

    A multistep sintering schedule is developed to synthesize Li7La3Zr2O12 (LLZO) doped with 0.2 mol% Al3+. The effect of sintering steps on phase, relative density and ionic conductivity of Al-doped LLZO has been evaluated using powder X-Ray diffraction (XRD), scanning electron microscopy (SEM), 27Al magic spinning nuclear magnetic resonance (NMR) spectroscopy and electrochemical impedance spectroscopy (EIS). The results show that by holding the sample at 900 °C for 6 h, the mixture of tetragonal and cubic garnet phases are obtained; by continuously holding at 1100 °C for 6 h, the tetragonal phase completely transforms into cubic phase; by holding at 1200 °C, the relative density increases without decomposition of the cubic phase. The Al-LLZO pellets after multistep sintering exhibit cubic phase, relative density of 94.25% and ionic conductivity of 4.5 × 10-4 S cm-1 at room temperature. Based on the observation, a sintering model is proposed and discussed.

  17. Mechanochemically Driven Syntheses of Boride Nanomaterials

    Blair, Richard G.

    Solid state metathesis reactions have proven to be a viable route to the production of unfunctionalized nanomaterials. However, current implementations of this approach are limited to self-propagating reactions. We have been investigating mechanically driven metathesis reactions. The use of high-energy ball mills allows control of crystallite sizes without the use of a capping group. Reinforcement materials with crystallite sizes on the order of 5-30 nm can be produced in such a manner. Borides are of particular interest due to their strength, high melting point, and electrical conductivity. The ultimate goal of this work is to prepare oxide and capping group-free nanoparticles suitable for incorporation in thermoelectric, polymer, and ceramic composites. Ultimately this work will facilitate the production of improved thermoelectric materials that will provide robust, deployable, power generation modules to supplement or replace fuel cell, Stirling, and battery-derived power sources. It will also result in scalable, bulk syntheses of tough, refractory, conductive nanomaterials for polymer composites with improved electrical properties, ceramic composites with enhanced fracture toughness, and composites with enhanced neutron reflectance and/or absorbance.

  18. Recent progress at the Petawatt Field Synthesizer

    Skrobol, Christoph; Major, Zsuzsanna; Krausz, Ferenc; Karsch, Stefan [Max-Planck-Institut fuer Quantenoptik, Garching (Germany); Department fuer Physik, Ludwig-Maximilians-Universitaet Muenchen, Garching (Germany); Klingebiel, Sandro; Wandt, Christoph; Ahmad, Izhar; Siebold, Mathias; Trushin, Sergei A. [Max-Planck-Institut fuer Quantenoptik, Garching (Germany)

    2010-07-01

    The Petawatt Field Synthesizer (PFS) aims at delivering wave-form controlled, few-cycle laser pulses with petawatt-scale peak power. The PFS design is based on a modified scheme of optical parametric chirped pulse amplification (OPCPA), where short pulses (of the order of 1 ps) are used for both pumping and seeding. The broadband seed pulses (700-1400 nm) are amplified in a series of DKDP crystals, pumped by 515 nm pulses with a total energy of 15-20 J at a repetition rate of 10 Hz. The chirped pulse amplifier chain of the pump laser uses diode pumping and Yb:YAG as the gain material in order to support the 1 ps pulse duration. To ensure a high level of synchronization between pump and seed pulses (< 100 fs), both are derived from a common frontend and are thereby inherently optically synchronized. However, along the large optical path difference between the seed and the pump chain additional temporal jitter can be accumulated, which is detrimental to the short-pulse OPCPA scheme. After an introduction to the PFS system, we report on our recent progress in identifying and eliminating the sources of timing jitter in preparation for the OPCPA stages.

  19. Recent progress at the Petawatt Field Synthesizer

    The Petawatt Field Synthesizer (PFS) aims at delivering wave-form controlled, few-cycle laser pulses with petawatt-scale peak power. The PFS design is based on a modified scheme of optical parametric chirped pulse amplification (OPCPA), where short pulses (of the order of 1 ps) are used for both pumping and seeding. The broadband seed pulses (700-1400 nm) are amplified in a series of DKDP crystals, pumped by 515 nm pulses with a total energy of 15-20 J at a repetition rate of 10 Hz. The chirped pulse amplifier chain of the pump laser uses diode pumping and Yb:YAG as the gain material in order to support the 1 ps pulse duration. To ensure a high level of synchronization between pump and seed pulses (< 100 fs), both are derived from a common frontend and are thereby inherently optically synchronized. However, along the large optical path difference between the seed and the pump chain additional temporal jitter can be accumulated, which is detrimental to the short-pulse OPCPA scheme. After an introduction to the PFS system, we report on our recent progress in identifying and eliminating the sources of timing jitter in preparation for the OPCPA stages.

  20. Computational Models to Synthesize Human Walking

    Lei Ren; David Howard; Laurence Kenney

    2006-01-01

    The synthesis of human walking is of great interest in biomechanics and biomimetic engineering due to its predictive capabilities and potential applications in clinical biomechanics, rehabilitation engineering and biomimetic robotics. In this paper,the various methods that have been used to synthesize humanwalking are reviewed from an engineering viewpoint. This involves a wide spectrum of approaches, from simple passive walking theories to large-scale computational models integrating the nervous, muscular and skeletal systems. These methods are roughly categorized under four headings: models inspired by the concept of a CPG (Central Pattern Generator), methods based on the principles of control engineering, predictive gait simulation using optimisation, and models inspired by passive walking theory. The shortcomings and advantages of these methods are examined, and future directions are discussed in the context of providing insights into the neural control objectives driving gait and improving the stability of the predicted gaits. Future advancements are likely to be motivated by improved understanding of neural control strategies and the subtle complexities of the musculoskeletal system during human locomotion. It is only a matter of time before predictive gait models become a practical and valuable tool in clinical diagnosis, rehabilitation engineering and robotics.

  1. Study of photoconductor polymers synthesized by plasma

    In this work the photoconductivity in poly thiophene (PTh), poly pyrrole (PPy) and doped poly pyrrole with iodine (PPy/I) is studied, whose structures depend of the intensity of the electric field applied during the synthesis by plasma. The conjugated organic polymers possess double alternated bonds in its chemical structure that its allow the one movement of π electrons through the polymeric chains. The plasma is produced by means of splendor discharges to 13.5 MHz, resistive coupling, at one pressure that oscillates in the interval from 2 to 3x10-1 mbar, 180 min and powers of 10, 24, 40, 60, 80 and 100 W. Its were used heteroaromatic polymers like PTh and PPy/I, due to their potential applications in optoelectronics. The influence of the iodine is evaluated as dopant in PPy and it is compared with their similar one without doping in the light absorption/emission processes. The polymers synthesized by plasma can ramify or to intersect due to the energy applied during the synthesis. However, if the polymer intersects, the aromaticity can continue through the polymeric chains. The absorptions obtained by infrared spectroscopy, suggest that the polymer conserves the aromatic structure of the monomer fundamentally with substitutions that indicate inter crossing and partial fragmentation. The structure of most of the polymers spreads to be amorphous because they don't possess any classification. However, the PPy/I and PTh synthesized by this technique present crystalline segments whose intensity diminishes with the power of the discharge. In PTh, the average crystallinity diminishes from 19.8% to 9.9%, and in PPy/I of 15.9% to 13.3% in the interval of 10 to 100 W of power. In this work, however, its were crystalline arrangements in all the studied powers. The classification of the polymeric structure favors the formation of trajectories of transfer of electric loads among the chains, that which influences in the global electric conductivity of the material. In UV

  2. Syntheses of dopa glycosides using glucosidases.

    Sivakumar, Ramaiah; Ponrasu, Thangavel; Divakar, Soundar

    2009-02-01

    Syntheses of L: -dopa 1a glucoside 10a,b and DL: -dopa 1b glycosides 10-18 with D: -glucose 2, D: -galactose 3, D: -mannose 4, D: -fructose 5, D: -arabinose 6, lactose 7, D: -sorbitol 8 and D: -mannitol 9 were carried out using amyloglucosidase from Rhizopus mold, beta-glucosidase isolated from sweet almond and immobilized beta-glucosidase. Invariably, L: -dopa and DL: -dopa gave low to good yields of glycosides 10-18 at 12-49% range and only mono glycosylated products were detected through glycosylation/arylation at the third or fourth OH positions of L: -dopa 1a and DL: -dopa 1b. Amyloglucosidase showed selectivity with D: -mannose 4 to give 4-O-C1beta and D: -sorbitol 8 to give 4-O-C6-O-arylated product. beta-Glucosidase exhibited selectivity with D: -mannose 4 to give 4-O-C1beta and lactose 7 to give 4-O-C1beta product. Immobilized beta-glucosidase did not show any selectivity. Antioxidant and angiotensin converting enzyme inhibition (ACE) activities of the glycosides were evaluated glycosides, out of which L: -3-hydroxy-4-O-(beta-D: -galactopyranosyl-(1'-->4)beta-D: -glucopyranosyl) phenylalanine 16 at 0.9 +/- 0.05 mM and DL: -3-hydroxy-4-O-(beta-D: -glucopyranosyl) phenylalanine 11b,c at 0.98 +/- 0.05 mM showed the best IC(50) values for antioxidant activity and DL: -3-hydroxy-4-O-(6-D: -sorbitol)phenylalanine 17 at 0.56 +/- 0.03 mM, L: -dopa-D: -glucoside 10a,b at 1.1 +/- 0.06 mM and DL: -3-hydroxy-4-O-(D: -glucopyranosyl)phenylalanine 11a-d at 1.2 +/- 0.06 mM exhibited the best IC(50) values for ACE inhibition. PMID:18712474

  3. Syntheses and electronic structures of decamethylmetallocenes

    The synthesis of decamethylmanganocene [(eta-C5(CH3)5)2Mn or (Me5Cp)2Mn)] is described. Magnetic susceptibility and electron paramagnetic resonance (EPR) studies show that (Me5Cp)2Mn is a low-spin, 17-electron compound with an orbitally degenerate, 2E/sub 2g/ [e/sub 2g/3 a/sub 1g/2] ground state. An x-ray crystallographic study of (Me5Cp)2Mn shows that it is a monomeric, D/sub 5d/ decamethylmetallocene with metal to ring carbon distances that are about 0.3 A shorter than those determined for high-spin manganocenes. The syntheses of new (Me5Cp)2M (M = Mg,V,Cr,Co, and Ni) and [(Me5Cp)2M]PF6 (M = Cr,Co, and Ni) compounds are described. In addition, a preparative route to a novel, dicationic decamethylmetallocene, [(Me5Cp)2Ni](PF6)2 is reported. Infrared, nuclear magnetic resonance, magnetic susceptibility, and/or x-ray crystallographic studies indicate that all the above compounds are D/sub 5d/ or D/sub 5h/ decamethylmetallocenes with low-spin electronic configurations. Cyclic voltammetry studies verify the reversibility and the one-electron nature of the (Me5Cp)2M → [(Me5Cp)2M]+ (M = Cr,Mn,Fe,Co,Ni), [(Me5Cp)2Mn]- → (Me5Cp)2Mn and [(Me5Cp)2Ni]+ → [Me5Cp)2Ni]2+ redox reactions. These studies reveal that the neutral decamethylmetallocenes are much more easily oxidized than their metallocene counterparts. This result attests to the electron-donating properties of the ten substituent methyl groups. Proton and carbon-13 NMR data are reported for the diamagnetic Mg(II), Mn(I), Fe(II), Co(III), and Ni(IV) decamethylmetallocenes and for [(Me5Cp)2V(CO)2]+. The uv-visible absorption spectra of the 15-, 18- and 20- electron decamethylmetallocenes are also reported

  4. Syntheses and electronic structures of decamethylmetallocenes

    Robbins, J.L.

    1981-04-01

    The synthesis of decamethylmanganocene ((eta-C/sub 5/(CH/sub 3/)/sub 5/)/sub 2/Mn or (Me/sub 5/Cp)/sub 2/Mn)) is described. Magnetic susceptibility and electron paramagnetic resonance (EPR) studies show that (Me/sub 5/Cp)/sub 2/Mn is a low-spin, 17-electron compound with an orbitally degenerate, /sup 2/E/sub 2g/ (e/sub 2g//sup 3/ a/sub 1g//sup 2/) ground state. An x-ray crystallographic study of (Me/sub 5/Cp)/sub 2/Mn shows that it is a monomeric, D/sub 5d/ decamethylmetallocene with metal to ring carbon distances that are about 0.3 A shorter than those determined for high-spin manganocenes. The syntheses of new (Me/sub 5/Cp)/sub 2/M (M = Mg,V,Cr,Co, and Ni) and ((Me/sub 5/Cp)/sub 2/M)PF/sub 6/ (M = Cr,Co, and Ni) compounds are described. In addition, a preparative route to a novel, dicationic decamethylmetallocene, ((Me/sub 5/Cp)/sub 2/Ni)(PF/sub 6/)/sub 2/ is reported. Infrared, nuclear magnetic resonance, magnetic susceptibility, and/or x-ray crystallographic studies indicate that all the above compounds are D/sub 5d/ or D/sub 5h/ decamethylmetallocenes with low-spin electronic configurations. Cyclic voltammetry studies verify the reversibility and the one-electron nature of the (Me/sub 5/Cp)/sub 2/M ..-->.. ((Me/sub 5/Cp)/sub 2/M)/sup +/ (M = Cr,Mn,Fe,Co,Ni), ((Me/sub 5/Cp)/sub 2/Mn)/sup -/ ..-->.. (Me/sub 5/Cp)/sub 2/Mn and ((Me/sub 5/Cp)/sub 2/Ni)/sup +/ ..-->.. (Me/sub 5/Cp)/sub 2/Ni)/sup 2 +/ redox reactions. These studies reveal that the neutral decamethylmetallocenes are much more easily oxidized than their metallocene counterparts. This result attests to the electron-donating properties of the ten substituent methyl groups. Proton and carbon-13 NMR data are reported for the diamagnetic Mg(II), Mn(I), Fe(II), Co(III), and Ni(IV) decamethylmetallocenes and for ((Me/sub 5/Cp)/sub 2/V(CO)/sub 2/)/sup +/. The uv-visible absorption spectra of the 15-, 18- and 20- electron decamethylmetallocenes are also reported.

  5. Synthesizing Smart Polymeric and Composite Materials

    Gong, Chaokun

    ,1-phenylene)bismaleimide (MDPB). It showed the same healing ability as 2MEP4F while all starting materials are cheaper and commercially available. To further improve the mechanical strength of the PFA-MDPB healable polymer, epoxy as a strengthening component was mixed with PFA-MDPB healable polymer. The PFA, MDPB and epoxy composite polymers were further reinforced by carbon fiber as done with 2MEP4F matrix and the final composites were proved to have higher short beam shear strength than 2MEP4F while exhibiting a similar healing efficiency. Healable polymer MDPB (a two maleimide groups monomer) -- FGEEDR (a four furan groups monomer) was also designed and synthesized for transparent healable polymer. The MDPB-FGEEDR healable polymer was composited with silver nanowires (AgNWs) to afford healable transparent composite conductor. Razer blade cuts in the composite conductor could heal upon heating to recover the mechanical strength and electrical conductivity of the composite. The healing could be repeated for multiple times on the same cut location. The healing process was as fast as 3 minutes for conductivity to recover 97% of the original value. For electroactive polymer polypyrrole, the fast volume change upon electrical field change due to electrochemical oxidization or reduction was studied for actuation targeting toward a robotic application. The flexibility of polypyrrole was improved via copolymerization with pyrrole derivatives. Actuator devices are fabricated that more suitable for implantable medical device application than pyrrole homopolymer. The change of dipole re-orientation and thus dielectric constant of ferroelectric polymers and ceramics upon electrical field may be exploited for electrocaloric effect (ECE) and solid state refrigeration. For ferroelectric ceramics, we synthesized a series of Ba1-xSrxTiO3 nanoparticles with diameter ranging from 8-12 nm and characterized their dielectric and ferroelectric properties through hysteresis measurement. It was

  6. Syntheses of (±-Romucosine and (±-Cathafiline

    Surachai Nimgirawath

    2006-11-01

    Full Text Available The structures previously assigned to (--romucosine and (+-cathafiline, N-(methoxycarbonyl aporphine alkaloids from Rollina mucosa (Annonaceae and Cassytha filiformis (Lauraceae respectively, have been confirmed by total syntheses of the racemic substances. The key step of the syntheses involved formation of ring C of the aporphines by a radical-initiated cyclisation.

  7. Low noise frequency synthesizer of a centimeter range wave

    I. S. Tsvelikh

    2007-06-01

    Full Text Available A highly stable, low noise 10.7 GHz frequency synthesizer for radio-relay link transceiver is presented. The basic elements of synthesizer are electrically tuned 5.35 GHz dielectric ring oscillator and transistor frequency doubler.

  8. Assessment voice synthesizers for reading in digital books

    Sérvulo Fernandes da Silva Neto

    2013-07-01

    Full Text Available The digital accessibility shows ways to information access in digital media that assist people with different types of disabilities to a better interaction with the computer independent of its limitations. Of these tools are composed by voice synthesizers, that supposedly simplifying their access to any recorded knowledge through digital technologies. However such tools have emerged originally in countries foreign language. Which brings us to the following research problem: the voice synthesizers are appropriate for reading digital books in the Portuguese language? The objective of this study was to analyze and classify different software tools voice synthesizers in combination with software digital book readers to support accessibility to e-books in Portuguese. Through literature review were identified applications software voice synthesizers, composing the sample analyzed in this work. We used a simplified version of the method of Multiple Criteria Decision Support - MMDA, to assess these. In the research 12 were considered readers of e-books and 11 software voice synthesizer, tested with six formats of e-books (E-pub, PDF, HTML, DOC, TXT, and Mobi. In accordance with the results, the software Virtual Vision achieved the highest score. Relative to formats, it was found that the PDF has measured a better score when summed the results of the three synthesizers. In the studied universe contacted that many synthesizers simply cannot be used because they did not support the Portuguese language.

  9. A terminal molybdenum arsenide complex synthesized from yellow arsenic.

    Curley, John J; Piro, Nicholas A; Cummins, Christopher C

    2009-10-19

    A terminal molybdenum arsenide complex is synthesized in one step from the reactive As(4) molecule. The properties of this complex with its arsenic atom ligand are discussed in relation to the analogous nitride and phosphide complexes. PMID:19764796

  10. Renewable nanocomposite polymer foams synthesized from Pickering emulsion templates

    Blaker, J.J.; Lee, K-Y; Li, X; Menner, A.; Bismarck, A.

    2009-01-01

    Fully renewable macroporous thermosetting and UV-cured cellulose nanocomposites have been synthesized from medium and high internal phase water-in-acrylated soybean oil emulsions stabilized solely by hydrophobized bacterial cellulose nano-fibrils.

  11. GaN Nanowires Synthesized by Electroless Etching Method

    Najar, Adel

    2012-01-01

    Ultra-long Gallium Nitride Nanowires is synthesized via metal-electroless etching method. The morphologies and optical properties of GaN NWs show a single crystal GaN with hexagonal Wurtzite structure and high luminescence properties.

  12. Proteins synthesized in tobacco mosaic virus infected protoplasts

    The author deals with research on the multiplication of tobacco mosaic virus (TMV) in leaf cell protoplasts. An attempt is made to answer three questions: (1) Which proteins are synthesized in TMV infected protoplasts as a result of TMV multiplication. (2) Which of the synthesized proteins are made under the direction of the TMV genome and, if any, which of the proteins are host specific. (3) In which functions are these proteins involved. (Auth.)

  13. Antimicrobial activity of silver nanoparticles synthesized via green chemistry

    KAVAZ DOGA; LAMIDO SURAYYA MUHAMMAD; UMAR HUZAIFA

    2015-01-01

    Silver nanoparticles (AgNPs) synthesis is among the new areas of nanotechnological research and it’s a bit cost effective, pollution free and environmental friendly compared to other metals used to synthesized nanoparticles. The synthesized nanoparticle was characterized using Atomic Force Microscope (AFM), FTIR, EDX, UV-Vis, Zeta Sizer and anti-microbial activity studies was also carried out. These techniques of identification were for morphological, particle size and concentration of NPs fo...

  14. Synthese und Charakterisierung aromatischer periodisch mesoporöser Organosilicas

    Morell, Jürgen

    2008-01-01

    Die zugrunde liegende Arbeit befasst sich mit der Synthese und Charakterisierung aromatischer periodisch mesoporöser Organosilicas. Neben der Untersuchung des Bildungsmechanismus Biphenyl-verbrückter PMO-Materialien durch in situ-SAXS-Messungen wurden eine Reihe Thiophen-verbrückter PMOs unter Verwendung verschiedener Tenside als Strukturdirektoren synthetisiert. Es konnten so 2D-hexagonale sowie kubische Produkte erhalten werden. Des Weiteren konnte die Synthese von bifunktionellen PMO-Mat...

  15. Thermotoga lettingae Can Salvage Cobinamide To Synthesize Vitamin B12

    Butzin, Nicholas C.; Secinaro, Michael A.; Swithers, Kristen S.; Gogarten, J Peter; Noll, Kenneth M.

    2013-01-01

    We recently reported that the Thermotogales acquired the ability to synthesize vitamin B12 by acquisition of genes from two distantly related lineages, Archaea and Firmicutes (K. S. Swithers et al., Genome Biol. Evol. 4:730–739, 2012). Ancestral state reconstruction suggested that the cobinamide salvage gene cluster was present in the Thermotogales' most recent common ancestor. We also predicted that Thermotoga lettingae could not synthesize B12 de novo but could use the cobinamide salvage...

  16. Rhythmic Patterns and Literary Genres in Synthesized Speech

    Delais-Roussarie, Elisabeth; Lolive, Damien; Yoo, Hiyon; Guennec, David

    2016-01-01

    International audience In this paper, the rhythmic patterns observed in natural and synthesized speech are compared for three literary forms (rhymes, poems, and fairy tales). The aim of the comparison is to evaluate how rhythm could be improved in synthesized speech, which could allow adapting it to specific styles or genres.The study is based on the analysis of a corpus of six rhymes, four poems and two extracts from fairy tales. All texts were recorded by three speakers and were generate...

  17. Mechanism of the industrial enterprises marketing communication synthesized effect formation

    Ya.O. Tymokhina

    2014-09-01

    Full Text Available The aim of the article. The main purpose of the article is to propose mechanism of the industrial enterprises marketing communication (MC synthesized effect formation. An indispensable component of MC mechanism synthesized effect of industrial enterprise is the legislation that governs use of synthesized marketing communications and obtaines synthesized effect from using them. It can be divided into three groups: legislation that regulates entrepreneurial activities, legislation governing communication activities, legislation governing innovation activities. Legislation of Ukraine regulating communication activities needs to be clarified in regulation of using the latest MC tools, features of their combination, rules of their using and order of action in violation case of applicable law. The results of the analysis. Any economic activity of enterprises governed by principles that are divided into general and specific by the level of coverage. The proposed set of formation principles of synthesized effect are principles of systematic using that focus on the result and periodicity which refer to general. Within the principle of periodicity it should consider principles that characterize each level of management that are such principles as using synthesis, using synergy and complexity. Functions of synthesized effect that are subject to general principles of economic analysis are: searching, score, analysis and accounting. Essence of specific features of MC synthesized effect consists the following positions: planning function, integration function, communicative function, synthesis implementation function. Mechanism formation MC synthesized effect of industrial enterprise is a set of systems that are used in process of its creation by management levels that reflects subject-object relationship between these systems. Input elements system form factors of external and internal environment, information about which enterprise collects through market

  18. Biphenyl-3,3′,4,4′-tetraamine

    Hui-Fen Qian

    2010-05-01

    Full Text Available The title compound, C12H14N4, has a crystallographically imposed centre of symmetry. Intermolecular N—H...N hydrogen bonds between amino groups link adjacent molecules into a three-dimensional network where ten-membered hydrogen-bonded rings are observed.

  19. Chemical and biological properties of a cationic Tc-tetraamine complex

    Blaeuenstein, P.; Pfeiffer, G.; Schubiger, P.A. (Eidgenoessisches Inst. fuer Reaktorforschung, Wuerenlingen (Switzerland)); Anderegg, G.; Zollinger, K. (Eidgenoessische Technische Hochschule, Zurich (Switzerland). Inst. of Organic Chemistry); May, K. (Eidgenoessische Technische Hochschule, Zurich (Switzerland). Lab. fuer Radiochemie); Proso, Z.; Ianovici, E.; Lerch, P. (Ecole Polytechnique Federale, Lausanne (Switzerland). Lab. d' Electrochimie et de Radiochimie)

    1985-04-01

    The complex of /sup 99/Tc with the ligand 1,4,8,11-tetraazaundecane (2,3,2-tet) was prepared and was compared with the similar /sup 99/Tc complexes with ethylenediamine and 1,4,8,11-tetraazacyclotetradecane. The results are all consistent with the formula (TcO/sub 2/(2,3,2-tet))/sup +/. The biological behavior was tested with sup(99m)Tc in Wistar rats. A fast clearance via the kidneys was found, and no accumulation in any other organ was observed.

  20. A low-power CMOS frequency synthesizer for GPS receivers

    A low-power frequency synthesizer for GPS/Galileo L1/E1 band receivers implemented in a 0.18 μm CMOS process is introduced. By adding clock-controlled transistors at latch outputs to reduce the time constant at sensing time, the working frequency of the high-speed source-coupled logic prescaler supplying quadrature local oscillator signals has been increased, compared with traditional prescalers. Measurement results show that this synthesizer achieves an in-band phase noise of -87 dBc/Hz at 15 kHz offset, with spurs less than -65 dBc. The whole synthesizer consumes 6 mA in the case of a 1.8 V supply, and its core area is 0.6 mm2. (semiconductor integrated circuits)

  1. FRACTIONAL-N FREQUENCY SYNTHESIZER DESIGN FOR RFAPPLICATIONS

    MUDASSAR I. Y. MEER

    2011-11-01

    Full Text Available In this work, design of Fractional-N Frequency Synthesizer using PLL has been investigated. The simulation is done in 0.18 μm CMOS technology with CADENCE tools using UMC foundry models. The different parts of synthesizer discussed in detail. Three different phase detector architectures are implemented. High speed TSPC DFF has designed to divide the frequency of GHz range. The prescalar is modified to have a delay of 80 ps only.For VCO, a multi layer inductor is used to save the area. The phase noise can be further reduced with a ΔΣ modulator in feedback loop. The designed frequency synthesizer targets RF applications like DVB-SH, WLAN,802.11, bluetooth, cordless phones and remote control.

  2. Monodisperse Silver Nanoparticles Synthesized by a Microwave-Assisted Method

    ZHU Shao-Peng; TANG Shao-Chun; MENG Xiang-Kang

    2009-01-01

    Silver nanoparticles with an average size of about 2Onto are synthesized in a colloidal solution with the aid of microwave irradiation. Neither additional reductant nor stabilizer is required in this microwave-assisted method.The color of the colloidal solution is found to be dark green, different from the characteristic yellow of silver colloidal solutions. The silver nanoparticles in the colloidal solution have a narrow size distribution and large yield quantity. UV-visible absorption spectroscopy analysis reveals that the as-synthesized monodisperse silver nanoparticles have exceptional optical properties. Raman spectroscopy measurements demonstrate that these silver nanoparticles exhibit a notable surface-enhanced Raman scattering ability.

  3. Zinc Oxide Nano crystals Synthesized by Quenching Technique

    This paper reports an attempt to synthesize non toxic zinc oxide (ZnO) nano crystals using a simple quenching technique. The hot zinc oxide powder was quenched in hexane solution to obtain ZnO nano crystals. As the result, diameter size of the synthesized ZnO is 200 nm. It was also exhibited a good crystalline with wurtzite phase. The nano crystals properties of ZnO were revealed from good absorbance and green luminescence under UV exposure. This may be related with oxygen vacancy ionization during the annealing process. (author)

  4. Chemical phase analysis of seed mediated synthesized anisotropic silver nanoparticles

    Bharti, Amardeep; Singh, Suman; Singla, M. L.; Goyal, Navdeep

    2015-08-01

    Noble-metal nanoparticles are of great interest because of its broad applications almost in every stream (i.e. biology, chemistry and engineering) due to their unique size/shape dependant properties. In this paper, chemical phase of seed mediated synthesized anisotropic silver nanoparticle (AgNPs) has been investigated via fourier transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA). These nanaoparticles were synthesized by seed-growth method controlled by urea and dextrose results to highly stable 12-20 nm particle size revealed by zeta potential and transmission electron microscopy (TEM).

  5. Chemical phase analysis of seed mediated synthesized anisotropic silver nanoparticles

    Noble-metal nanoparticles are of great interest because of its broad applications almost in every stream (i.e. biology, chemistry and engineering) due to their unique size/shape dependant properties. In this paper, chemical phase of seed mediated synthesized anisotropic silver nanoparticle (AgNPs) has been investigated via fourier transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA). These nanaoparticles were synthesized by seed-growth method controlled by urea and dextrose results to highly stable 12-20 nm particle size revealed by zeta potential and transmission electron microscopy (TEM)

  6. Copper nanoparticles synthesized in polymers by ion implantation

    Popok, Vladimir; Nuzhdin, Vladimir; Valeev, Valerij; Stepanov, Andrei

    2015-01-01

    Polymethylmethacrylate (PMMA) and polyimide (PI) samples are implanted by 40 keV Cu+ ions with high fluences in order to synthesize copper nanoparticles in shallow polymer layers. The produced metal/polymer nanocomposites are studied using atomic force and scanning electron microscopies as well as...... optical transmission spectroscopy. It is found that copper nanoparticles nucleation and growth are strongly fluence dependent as well as they are affected by the polymer properties, in particular, by radiation stability yielding different nanostructures for the implanted PI and PMMA. Shallow synthesized...

  7. Indenyl-Ruthenium-Thioaldehyd-Komplexe : Synthese, Struktur und Additionsreaktionen

    Fischer, Frank

    2006-01-01

    Neue Indenyl-Ruthenium-Thioaldehyd-Komplexe wurden in einer fünfstufigen Synthese ausgehend von Ruthenium-(III)-chlorid erhalten. Die Thioaldehyd-Komplexe und alle Zwischenprodukte wurden NMR-spektroskopisch sowie kristallographisch untersucht und charakterisiert. Die neuartigen Verbindungen wurden auf ihre Reaktivität in Hetero-Diels-Alder-Reaktionen und nucleophilen Additionen hin untersucht.

  8. Some Remarks on Asymmetric Syntheses from Recent Studies

    Baba, Naomichi

    1990-01-01

    Some asymmetric syntheses were presented here and discussed briefly including NADH model reactions, phase transfer-catalyzed asymmetric epoxidation, enantiotopic group-selective hydrolysis of a malonic anhydride with alkoxide anion, intramolecular acid-catalyzed lactonizations, catalytic asymmetric Diels-Alder synthesis, asymmetric aldol condensation, chiral homoallyl alcohol synthesis, asymmetric addition of diethylzinc to aldehyde, kinetic resolution of racemic hydroperoxides and binaphthol...

  9. A frequency tracking synthesizer for beam diagnostic systems

    In low and medium energy synchrotrons the beam revolution frequency changes by a large factor during the acceleration process. High production rates require that these machines cycle rapidly. In attempting to diagnose instabilities which develop during the acceleration process it is useful to be able to select some frequency segment between revolution harmonics for viewing. Most types of test equipment operating in the frequency domain, such as spectrum analyzers and network analyzers, are not suited to making direct measurements on such rapidly sweeping signals. Ideally, one would want to set the frequency frame of reference to the spot in the accelerating revolution harmonic domain where the measurements are to be made. A scheme using a direct digital synthesizer (DDS) was developed to provide this moving reference frame. This paper describes a synthesizer scheme combining digital and analog synthesizer techniques to allow tracking of signals during acceleration. Virtually any ratio of synthesizer to beam revolution frequency may be generated by this scheme. Details of hardware and measurement results are presented

  10. Method for synthesizing peptides with saccharide linked enzyme polymer conjugates

    Callstrom, M.R.; Bednarski, M.D.; Gruber, P.R.

    1997-06-17

    A method is disclosed for synthesizing peptides using water soluble enzyme polymer conjugates. The method comprises catalyzing the peptide synthesis with enzyme which has been covalently bonded to a polymer through at least three linkers which linkers have three or more hydroxyl groups. The enzyme is conjugated at lysines or arginines. 19 figs.

  11. Design und Synthese maßgeschneiderter funktioneller Rylenfarbstoffe

    Schnitzler, T.

    2011-01-01

    Die vorgelegte Dissertation beschäftigt sich mit der Darstellung und Untersuchung von funktionellen Farbstoffen auf der Basis von Rylendiimiden. Diese Substanzklasse zeichnet sich durch gute Funktionalisierbarkeit, hohe chemische und photochemische Stabilität sowie durch hohe Fluoreszenzquantenausbeuten und Extinktionskoeffizienten aus. Rylendiimide spielen eine bedeutsame Rolle in den modernen Materialwissenschaften. Ein Schwerpunkt der Arbeit liegt auf der Synthese und Untersuchung von neue...

  12. Parametric Audio Based Decoder and Music Synthesizer for Mobile Applications

    Oomen, A.W.J.; Szczerba, M.Z.; Therssen, D.

    2011-01-01

    This paper reviews parametric audio coders and discusses novel technologies introduced in a low-complexity, low-power consumption audiodecoder and music synthesizer platform developed by the authors. Thedecoder uses parametric coding scheme based on the MPEG-4 Parametric Audio standard. In order to

  13. Antibacterial activity of silver nanoparticles synthesized from serine

    Jayaprakash, N. [Catalysis and Nanomaterials Research Laboratory, Department of Chemistry, Loyola College, Chennai 600 034 (India); SRM Valliammai Engineering College, Department of Chemistry, Chennai 603 203 (India); Judith Vijaya, J., E-mail: jjvijayaloyola@yahoo.co.in [Catalysis and Nanomaterials Research Laboratory, Department of Chemistry, Loyola College, Chennai 600 034 (India); John Kennedy, L. [Materials Division, School of Advanced Sciences, VIT University, Chennai Campus, Chennai 600 048 (India); Priadharsini, K.; Palani, P. [Department of Center for Advanced Study in Botany, University of Madras, Guindy Campus, Chennai 600 025 (India)

    2015-04-01

    Silver nanoparticles (Ag NPs) were synthesized by a simple microwave irradiation method using polyvinyl pyrrolidone (PVP) as a capping agent and serine as a reducing agent. UV–Visible spectra were used to confirm the formation of Ag NPs by observing the surface plasmon resonance (SPR) band at 443 nm. The emission spectrum of Ag NPs showed an emission band at 484 nm. In the presence of microwave radiation, serine acts as a reducing agent, which was confirmed by Fourier transformed infrared (FT-IR) spectrum. High-resolution transmission electron microscopy (HR-TEM) and high-resolution scanning electron microscopy (HR-SEM) were used to investigate the morphology of the synthesized sample. These images showed the sphere-like morphology. The elemental composition of the sample was determined by the energy dispersive X-ray analysis (EDX). Selected area electron diffraction (SAED) was used to find the crystalline nature of the Ag NPs. The electrochemical behavior of the synthesized Ag NPs was analyzed by the cyclic voltammetry (CV). Antibacterial experiments showed that the prepared Ag NPs showed relatively similar antibacterial activities, when compared with AgNO{sub 3} against Gram-positive and Gram-negative bacteria. - Highlights: • Microwave irradiation method is used to synthesize silver nanoparticles. • Highly stable silver nanoparticles are produced from serine. • A detailed study of antibacterial activities is discussed. • Formation mechanism of silver microspheres has been proposed.

  14. Irradiation study of PNNL synthesized glass-ceramics

    Kossoy-simakov, Anna-eden [Los Alamos National Laboratory; Tang, Ming [Los Alamos National Laboratory; Valdez, James A [Los Alamos National Laboratory; Usov, Igor O [Los Alamos National Laboratory; Sickafus, Kurt E [Los Alamos National Laboratory

    2011-01-18

    Two types of glass-ceramic were investigated: (1) for immobilization of Ln, alkali, and alkaline earths (GC4); and (2) same as above + high (7%) molybdenum content (Mo7) multiphase specimens. The purpose was to study the radiation stability of PNNL synthesized glass-ceramics and changes in microstructure/phase composition.

  15. Synthesizing the Effect of Building Condition Quality on Academic Performance

    Gunter, Tracey; Shao, Jing

    2016-01-01

    Since the late 1970s, researchers have examined the relationship between school building condition and student performance. Though many literature reviews have claimed that a relationship exists, no meta-analysis has quantitatively examined this literature. The purpose of this review was to synthesize the existing literature on the relationship…

  16. CEO-Phase Stabilized Few-Cycle Field Synthesizer

    Rausch, Stefan; Binhammer, Thomas; Harth, Anne; Kärtner, Franz X.; Morgner, Uwe

    We present an optical field synthesizer consisting of a CEO-phase stabilized octavespanning Ti:sapphire laser oscillator and prism-based pulse shaper allowing for full control of the electric field on a sub-femtosecond time-scale.

  17. A Model of Educational Leadership: Wisdom, Intelligence, and Creativity, Synthesized

    Sternberg, Robert J.

    2005-01-01

    This article presents a model of educational leadership--WICS--that encompasses "wisdom", "intelligence" and "creativity", "synthesized". The article opens with a general discussion of issues in models of leadership. Then it discusses the role of creativity in leadership, dividing the discussion into academic and practical aspects. Next it deals…

  18. Synthesizing a Life: An Interview with Carl Djerassi

    Cardellini, Liberato

    2011-01-01

    In this interview, Carl Djerassi recalls his first years, from his pleasant childhood, to how he escaped the Nazi persecutions, to his college education in America. He remembers how with his research group he won the race for synthesis of cortisone, and how they then synthesized norethindrone, the active ingredient in oral contraceptives. Djerassi…

  19. Branched nanostructures and method of synthesizing the same

    Fonseca, Luis F. (Inventor); Resto, Oscar (Inventor); Sola, Francisco (Inventor)

    2009-01-01

    A branched nanostructure is synthesized. A porous material, with pores having a diameter of approximately 1 .mu.m or less, is placed in a vacuum. It is irradiated with an electron beam. This causes a trunk to grow from the porous material and further causes branches to grow from the trunk.

  20. Syntheses of Some Organic Fluorescent Dyes for Security Tickers

    LI Jun-fen; BAI Guan; LIN Pei-hua; TIAN Mei-lin; DONG Chuan; LI Du-xin

    2004-01-01

    Five organic fluorescence dyes were synthesized by two- or three-step reactions. These synthetic methods have an advantage of the simple processes, low costs and high yields. The compositions of the five compounds are characterized by IR, 1H NMR, elemental analyses and fluorescence spectroscopies. The quantum yields of fluorescence were measured.

  1. ARSENIC REMOVAL USING SOL-GEL SYNTHESIZED TITANIUM DIOXIDE NANOPARTICLES

    In this study, the effectiveness of TiO2 nanoparticles in arsenic adsorption was examined. TiO2 particles (LS) were synthesized via sol-gel techniques and characterized for their crystallinity, surface area and pore volume. Batch adsorption studies were perf...

  2. Radiolitically Synthesized Hybrid Nanosystems for Bio-Nano-Technologies

    In this report a review of the main results and the studies carried out under the scope of the IAEA CRP project: Nanoscale Radiation Engineering of Advanced Materials for Potential Biomedical Application is presented. In particular two topics are discussed: radiation synthesizing of Ag nanoparticles in hydrogels for potential biomedical application and decoration of carbon nanotubes with Ag clusters by gamma irradiation. (author)

  3. Plasma-Liquid Interaction: a New Way to Synthesize Nanomaterials

    Chen, Qiang; Li, Yongfeng; Zhang, Xianhui; Yang, Size

    2014-01-01

    In this review, we have summarized the recent advances and present conditions of the nanomaterials synthesis from the plasma-liquid interactions. A theoretical analysis for the nanomaterials synthesis process is presented by analyzing the experimental data. Besides the theoretical analysis, the practical applications in several nanomaterials syntheses of the the plasma-liquid interactions are also presented.

  4. Kinetics of Enzyme Biodegradation of New Synthesized Copolymers

    Rosa Mateva

    2005-04-01

    Full Text Available Block copolymers of the poly-(hexanlactam-co-block-poly-(?-valerolactone from ABA-type were synthesized via anionic polymerization of hexanlactam (HL with the sodium salt of hexanlactam (Na-HL as an initiator and polymeric activator (PAC. PAC, on the base of poly-?-valerolactone (PVL, was used as a soft central block. Synthetic PVL is very attractive biomaterial - nontoxic, biocompatibility and biodegradable polyester[5-8]. Modification of HL with PVL, renders these system biodegradable[1]. Isolated copolymers were characterized by various spectroscopic techniques. The effect of the chemical and physical structure of the synthesized block copolymers on the biodegradation was investigated. Biodegradation of block copolyester amides was studied by means of lipase and involves the enzymatic hydrolysis of ester groups in PVL.

  5. Is Synthesizing MRI Contrast Useful for Inter-modality Analysis?

    Iglesias, Juan Eugenio; Konukoglu, Ender; Zikic, Darko;

    2013-01-01

    Availability of multi-modal magnetic resonance imaging (MRI) databases opens up the opportunity to synthesize different MRI contrasts without actually acquiring the images. In theory such synthetic images have the potential to reduce the amount of acquisitions to perform certain analyses. However......, to what extent they can substitute real acquisitions in the respective analyses is an open question. In this study, we used a synthesis method based on patch matching to test whether synthetic images can be useful in segmentation and inter-modality cross-subject registration of brain MRI. Thirty......-nine T1 scans with 36 manually labeled structures of interest were used in the registration and segmentation of eight proton density (PD) scans, for which ground truth T1 data were also available. The results show that synthesized T1 contrast can considerably enhance the quality of non...

  6. Doped semiconductor nanoparticles synthesized in gas-phase plasmas

    Crystalline nanoparticles (NPs) of semiconductor materials have been attracting huge research interest due to their potential use in future applications like photovoltaics and bioimaging. The important role that intentional impurity doping plays in semiconductor technology has ignited a great deal of research effort aiming at synthesizing semiconductor NPs doped with foreign impurities and at understanding their physical and chemical properties. In this respect, plasma-grown semiconductor NPs doped in situ during synthesis have been key in studies of doped NPs. This article presents a review of the advances in understanding the properties of doped semiconductor NPs synthesized by means of plasma methods and the role played by these NPs for our current understanding of doped NPs and the general behavior of doping in nanoscale materials. (review article)

  7. Cerium uptake by zeolite A synthesized from natural clinoptilolite tuffs

    Natural clinoptilolite tuffs from the Semnan region in Iran was used for the synthesis of zeolite A. The tuffs and synthesized zeolites were characterized by XRD and XRF. The sorption behavior of the synthesized zeolite toward cerium was studied. Using the Lagergren's equation, the absorption constant was calculated. The measured distribution coefficient values (Kd) indicated that cerium uptake is higher in lower initial concentrations, higher temperature and higher pH values. Thermodynamic parameters of the exchange were calculated through construction of ion-exchange isotherms at three temperatures of 298, 323 and 343 K. The dynamic absorption of cerium was also studied by passing the solution through a column in the presence and absence of sodium ions. (author)

  8. Properties of zeolite a synthesized by natural bentonite

    Synthetic zeolite was prepared by using of natural bentonite from Kampo area and the application of detergent builder was investigated. The optimum synthetic condition was SiO2/Al2O3 = 2, Na2O/Al2O3 = 1, H2O/Al2O3 30 at 90 deg C for 3 hr and it was found by XRD analysis that the zeolite synthesized under this condition was type A. When the zeolite A synthesized under the optimum condition was contacted with 40 deg Dh CaCl2 solution at 30 deg C for 15 min, the cation exchange capacity was 264.9 mg CaO/g-zeolite. And the whiteness of the sample was 89% and the mean particle size was 9.95μm. (author)

  9. Interaction Studies between Newly Synthesized Photosensitive Polymer and Ionic Liquids

    In Tae Kim

    2015-01-01

    Full Text Available In this information age, different kinds of photosensitive materials have been used in the manufacture of information storage devices. But these photosensitive materials have the bane of low diffraction efficiency. In order to solve this problem, we have synthesized a novel photosensitive polymer from epoxy-based azopolymers (with three types of azochromophores. Furthermore, we have studied the interaction between this newly synthesized azopolymer and ionic liquids (ILs. For this purpose, we have used the ammonium and imidazolium families of ILs, such as diethylammonium dihydrogen phosphate (DEAP, tributylammonium methyl sulfate (TBMS, triethylammonium 4-aminotoluene-3-sulfonic acid (TASA, and 1-methylimidazolium chloride ([Mim]Cl. To investigate the molecular interaction between azopolymer and ILs, we have used the following spectroscopic methods of analysis: UV-visible spectroscopy, photoluminescence (PL spectroscopy, Fourier transformed infrared spectroscopy (FT-IR, and confocal Raman spectroscopy. In this study, we have developed new photosensitive materials by combining polymer with ILs.

  10. Fatty acid composition of oil synthesized by Aspergillus nidulans.

    Sharma, N D; Mathur, J M; Saxena, B S; Sen, K

    1981-01-01

    The filamentous fungus Aspergillus nidulans Eidam strain 300 was found to be capable of synthesizing 24.9% oil or remarkably low free fatty acidity, in a chemically defined medium with 34% glucose as sole carbon source. although the total content of oil synthesized was less, utilization of the carbon source is better as shown by the high (8.4) fat coefficient. The major component fatty acids of the oil were palmitic, stearic, oleic and linoleic and are influenced by the source of carbon. Palmitoleic acid is present in traces, confirming thereby the general observation that high oil formers produce oil of low hexadecenoic acid content. The relatively high stearic acid content of the oil distinguishes it from those of other microorganisms and resembles the oil produced by certain tropical plants, such as Madhuca latifolia. PMID:7026394

  11. Antibacterial and catalytic activities of green synthesized silver nanoparticles

    Bindhu, M. R.; Umadevi, M.

    2015-01-01

    The aqueous beetroot extract was used as reducing agent for silver nanoparticles synthesis. The synthesized nanoparticles were characterized using UV-visible spectroscopy, X-ray diffraction (XRD) and transmission electron microscopy (TEM). The surface plasmon resonance peak of synthesized nanoparticles was observed at 438 nm. As the concentration of beetroot extract increases, absorption spectra shows blue shift with decreasing particle size. The prepared silver nanoparticles were well dispersed, spherical in shape with the average particle size of 15 nm. The prepared silver nanoparticles are effective in inhibiting the growth of both gram positive and gram negative bacteria. The prepared silver nanoparticles reveal faster catalytic activity. This natural method for synthesis of silver nanoparticles offers a valuable contribution in the area of green synthesis and nanotechnology avoiding the presence of hazardous and toxic solvents and waste.

  12. Method of synthesizing silica nanofibers using sound waves

    Sharma, Jaswinder K.; Datskos, Panos G.

    2015-09-15

    A method for synthesizing silica nanofibers using sound waves is provided. The method includes providing a solution of polyvinyl pyrrolidone, adding sodium citrate and ammonium hydroxide to form a first mixture, adding a silica-based compound to the solution to form a second mixture, and sonicating the second mixture to synthesize a plurality of silica nanofibers having an average cross-sectional diameter of less than 70 nm and having a length on the order of at least several hundred microns. The method can be performed without heating or electrospinning, and instead includes less energy intensive strategies that can be scaled up to an industrial scale. The resulting nanofibers can achieve a decreased mean diameter over conventional fibers. The decreased diameter generally increases the tensile strength of the silica nanofibers, as defects and contaminations decrease with the decreasing diameter.

  13. Design of optocoupler for synthesizing four color spectra

    Liu, Zechun; Ge, Aiming; Tao, Xinran; Yang, Shengqi; Wang, Tianyi

    2016-07-01

    LEDs with the advantage of high luminous efficacy and long life time show the potential of replacing traditional luminaire. Most commercial white LED light sources use blue or ultraviolet chip coated with emitting phosphor, but the sensitivity and instability of such phosphors has become a big issue. The typical RGB-LED by using individual chips has the problem of spatial separation and insufficient spectral overlap which leads to low CRI. This study suggests a novel and high-efficiency design of fiber optical optocoupler to synthesize four colors emitted by separate LEDs to provide the ideal light sources by adjusting the individual LEDs separately. By choosing different colored light to be synthesized, this optocoupler can be used as light sources which can be highly controlled to offer the best lighting conditions. Compared with other widely used commercial LED sources, this new design of light sources can be used in special experiments which require multi-spectral light.

  14. Syntheses of amidoxime polyethylene resin for selective Uranium (VI) adsorption

    Kim, Jong Seung; Lee, Soo Yeon; Kim, Sang Hoon [Korea University, Seoul (Korea, Republic of)

    2010-05-15

    Uranium is a major element in the management of spent nuclear fuel (SF) or radioactive wastes, and selective separation of U has been one of research targets. For the separation of U from fission products (FP) in a SF, usually, a solvent extraction or an ion exchange technology has been usually used in an acid medium. In the case of ion exchange method, anion exchanger has been used. However, recently, some absorbents containing amidoxime functional group selective for the U have been designed and synthesized. Therefore, new adsorbent capable of selective sensing U over FP in a carbonate solution are now highly demanded. So, in this study, total synthesis of the polymer-amidoxime derivatives, divinylbenzene-amidoxime (DVB-AO) and polyethylene amidoxime (PE-AO) have been developed and the desired final products were successfully synthesized

  15. Syntheses of amidoxime polyethylene resin for selective Uranium (VI) adsorption

    Uranium is a major element in the management of spent nuclear fuel (SF) or radioactive wastes, and selective separation of U has been one of research targets. For the separation of U from fission products (FP) in a SF, usually, a solvent extraction or an ion exchange technology has been usually used in an acid medium. In the case of ion exchange method, anion exchanger has been used. However, recently, some absorbents containing amidoxime functional group selective for the U have been designed and synthesized. Therefore, new adsorbent capable of selective sensing U over FP in a carbonate solution are now highly demanded. So, in this study, total synthesis of the polymer-amidoxime derivatives, divinylbenzene-amidoxime (DVB-AO) and polyethylene amidoxime (PE-AO) have been developed and the desired final products were successfully synthesized

  16. Practical enantiospecific syntheses of lysobisphosphatidic acid and its analogues.

    Jiang, Guowei; Xu, Yong; Prestwich, Glenn D

    2006-02-01

    We describe a versatile, efficient, and practical method for the preparation of enantiomerically pure lysobisphosphatidic acid (LBPA), bisether analogues, and phosphorothioate analogues of LBPA from solketal. Phosphorylation of a protected sn-2-O-oleoyl glycerol with 2-cyanoethyl bis(N,N-diisopropylamino)phosphite, followed by oxidation and deprotection, generated the enantiomers of 2,2'-LBPA. The corresponding phosphorothioate analogues were obtained by oxidation with sulfur. The (R,R) and (S,S) enantiomers of both LBPA and phosphorothioate LBPA were synthesized from (S)- and (R)-solketal, respectively. The ether analogue of (S,S)-lysobisphosphatidic acid (LBPA) and its enantiomer were synthesized from the same enantiomer (S)-solketal by simply changing the sequence of deprotection steps. PMID:16438504

  17. Kinetics of Enzyme Biodegradation of New Synthesized Copolymers

    Rosa Mateva; Natalia Toncheva; Lubov Yotova

    2005-01-01

    Block copolymers of the poly-(hexanlactam)-co-block-poly-(?-valerolactone) from ABA-type were synthesized via anionic polymerization of hexanlactam (HL) with the sodium salt of hexanlactam (Na-HL) as an initiator and polymeric activator (PAC). PAC, on the base of poly-?-valerolactone (PVL), was used as a soft central block. Synthetic PVL is very attractive biomaterial - nontoxic, biocompatibility and biodegradable polyester[5-8]. Modification of HL with PVL, renders these system biodegradable...

  18. Annual reports in inorganic and general syntheses 1972

    Niedenzu, Kurt

    1973-01-01

    Annual Reports in Inorganic and General Syntheses-1972 presents an organized annual summary of synthetic developments in inorganic chemistry and its related areas. The book discusses alkali and alkaline earth elements, alloys, silver, gold, zinc, cadmium, mercury, boron, aluminum, gallium, indium, thallium, yttrium, scandium, lanthanides, actinides, titanium, zirconium, hafnium, Group V and VI transition elements, manganese, technetium, rhenium, iron, cobalt, nickel, ruthenium, osmium, rhodium, and iridium. The text also describes the chemistry of palladium, platinum, silicon, germanium, tin,

  19. Annual reports in inorganic and general syntheses 1974

    Niedenzu, Kurt

    1975-01-01

    Annual Reports in Inorganic and General Syntheses-1974 presents an organized annual summary of synthetic developments in inorganic chemistry and its related areas. The book discusses the chemistry of simple and complex metal hydrides of main groups I, II, and III, boron, aluminium, gallium, indium, thallium, silicon, germanium, tin, lead, phosphorus, arsenic, antimony, bismuth, chalcogens, halogens, and pseudohalogens. The text also describes the chemistry of scandium, yttrium, lanthanides, actinides, titanium, zirconium, hafnium, vanadium, niobium, tantalum, chromium, molybdenum, tungsten, ma

  20. Synthesizing Sierpinski Antenna by Genetic Algorithm and Swarm Optimization

    Z. Raida; Vidal, B. M.

    2008-01-01

    The paper discusses the synthesis of the Sierpinski antenna operating at three prescribed frequencies: 0.9 GHz, 1.8 GHz (both GSM) and 2.4 GHz (Bluetooth). In order to synthesize the antenna, a genetic algorithm and a particle swarm optimization were used. The numerical model of the antenna was developed in Zeland IE3D, optimization scripts were programmed in MATLAB. Results of both the optimization methods are compared and experimentally verified.

  1. Mesoporous zeolite and zeotype single crystals synthesized in fluoride media

    Egeblad, Kresten; Kustova, Marina; Klitgaard, Søren Kegnæs;

    2007-01-01

    materials were all prepared by hydrothermal crystallization of gels adsorbed on carbon matrices which were subsequently removed by combustion. The procedures presented here resulted in mesoporous zeolite and zeotypes materials with MFI, MEL, BEA, AFI and CHA framework structures. All samples were...... opposed to mesoporous single crystals. For the zeotype materials it was found that highly crystalline mesoporous materials of AFI and CHA structure types could be synthesized using a newly developed procedure. (c) 2006 Elsevier Inc. All rights reserved....

  2. Bioinspired Collective Syntheses of Iboga-Type Indole Alkaloids.

    Zhao, Gaoyuan; Xie, Xingang; Sun, Haiyu; Yuan, Ziyun; Zhong, Zhuliang; Tang, Shouchu; She, Xuegong

    2016-05-20

    We present the application of a bioinspired collective synthesis strategy in the total syntheses of seven iboga-type indole alkaloids: (±)-tabertinggine, (±)-ibogamine, (±)-ibogaine, (±)-ibogaine hydroxyindolenine, (±)-3-oxoibogaine hydroxyindolenine, (±)-iboluteine, and (±)-ervaoffines D. In particular, tabertinggine and its congeners serve as iboga precursors for the subsequent biomimetic transformations into other iboga-type alkaloids. PMID:27160167

  3. New synthesizing feature parameter of wear particles image

    2001-01-01

    This paper outlines the application of wavelet analysis method to computering wear par-ticles image processing and introduces the concept of grain parameter for wear particle imagebased on statistical feature parameters. The feature of wear particles image can be obtained fromthe wavelet decomposition and the statistics analysis. Test results showed that grain parametercan be used as a synthesizing feature parameter for wear particle image.

  4. Economical parallel oligonucleotide and peptide synthesizer - PET OLIGATOR

    Lebl, M.; Pistek, Ch.; Hachmann, J.; Mudra, Petr; Pešek, Václav; Pokorný, Vít; Poncar, Pavel; Ženíšek, Karel

    2007-01-01

    Roč. 13, 1/2 (2007), s. 367-375. ISSN 1573-3149 Grant ostatní: NIH SBIR(US) R43 GM61511-01; NIH SBIR(US) R43 GM58981-01 Institutional research plan: CEZ:AV0Z40550506 Keywords : automated synthesizer * centrifugation * parallel synthesis Subject RIV: CC - Organic Chemistry Impact factor: 0.971, year: 2007

  5. Bis(indolyl)methane alkaloids: Isolation, bioactivity, and syntheses

    Praveen, P.; Parameswaran, P.S.; Majik, M.S.

    Author version: Synthesis - Stuttgart, vol.47; 2015; 1827-1837 Bisindolyl Methane Alkaloids: Isolation, Bioactivity and Syntheses P. J. Praveen,a,b P. S. Parameswaran*b, M. S. Majik*c aCSIR-National Institute of Oceanography, Bioorganic Chemistry... Laboratory, Dona Paula Goa- India; bCSIR-National Institute of Oceanography Regional centre, Kochi, India, Email:param@nio.org; cDepartment of Chemistry, Goa University, Goa 403 206, India, Email:majikms@gmail.com Abstract Bis...

  6. EPR Beams and Photon Number Detector: Toward Synthesizing Optical Nonlinearity

    Sasaki, M; Wakui, K.; Mizuno, J.; Fujiwara, M.; Akiba, M

    2006-01-01

    We present the two kinds of experimental results. One is a continuous variable dense coding experiment, and the other is a photon number detector with high linearity response, the so called charge integration photon detector (CIPD). They can be combined together to be a potential tool for implementing the cubic phase gate which is an important gate element to synthesize the measurement induced nonlinearity for photonic quantum information processing.

  7. A novel way to synthesize Pb nanotapes in liquid ammonia

    Lei Sun; Meng Lei Zhang; Xiao Jun Tao; Yan Bao Zhao

    2011-01-01

    Lead nanotapes were synthesized in liquid ammonia solvent in the presence of sodium metal at low temperature. The process was template free. Transmission electron microscopy (TEM) observations and X-ray diffraction (XRD) characterizations revealed that the as-prepared Pb nanotapes have average diameters in the range of 40-50 nm, and lengths up to several hundred nanometers, and exhibit cubic crystal structures.

  8. Applications of Magnetosomes Synthesized by Magnetotactic Bacteria in Medicine

    EdouardAlphandéry

    2014-01-01

    Magnetotactic bacteria belong to a group of bacteria that synthesize iron oxide nanoparticles covered by biological material that are called magnetosomes. These bacteria use the magnetosomes as a compass to navigate in the direction of the earth’s magnetic field. This compass helps the bacteria to find the optimum conditions for their growth and survival. Here, we review several medical applications of magnetotactic bacteria and magnetosomes, such as those in magnetic resonance imaging (MRI),...

  9. Monodispersive CoPt Nanoparticles Synthesized Using Chemical Reduction Method

    SHEN Cheng-Min; HUI Chao; YANG Tian-Zhong; XIAO Cong-Wen; CHEN Shu-Tang; DING Hao; GAO Hong-Jun

    2008-01-01

    @@ Monodispersive CoPt nanoparticles in sizes of about 2.2 nm are synthesized by superhydride reduction of CoCl2 and PtCl2 in diphenyl ether. The as-prepared nanoparticles show a chemically disordered A1 structure and are superparamagnetic. Thermal annealing transforms the A1 structure into chemically ordered L1o structure and the particles are ferromagnetic at room temperature.

  10. Chemie metastabiler Anionen : Synthese und Charakterisierung neuer Auride und Ozonide

    Nuß, Hannelore

    2007-01-01

    Die vorliegende Arbeit beschreibt die Synthese und Charakterisierung neuer Ozonid- und Auridverbindungen, sowie Verbindungen des Quadratatdianions. Fünf neue Ozonidverbindungen wurden ausgehend von den Alkalimetallozoniden KO_3, RbO_3 und CsO_3 durch Umsetzung mit verschiedenen Kronenetherliganden in flüssigem Ammoniak hergestellt. Das Verhältnis zwischen Ligandendurchmesser und Kationenradius bestimmt dabei die Art der Komplexierung des Metallzentrums und damit auch die Packung der Kompl...

  11. Transport properties of chemically synthesized polypyrrole thin films

    Bufon, C. C. Bof; Heinzel, T.

    2007-01-01

    The electronic transport in polypyrrole thin films synthesized chemically from the vapor phase is studied as a function of temperature as well as of electric and magnetic fields. We find distinct differences in comparison to the behavior of both polypyrrole films prepared by electrochemical growth as well as of the bulk films obtained from conventional chemical synthesis. For small electric fields F, a transition from Efros-Shklovskii variable range hopping to Arrhenius activated transport is...

  12. A green chemistry approach for synthesizing biocompatible gold nanoparticles

    Gurunathan, Sangiliyandi; Han, JaeWoong; Park, Jung Hyun; Kim, Jin-Hoi

    2014-01-01

    Gold nanoparticles (AuNPs) are a fascinating class of nanomaterial that can be used for a wide range of biomedical applications, including bio-imaging, lateral flow assays, environmental detection and purification, data storage, drug delivery, biomarkers, catalysis, chemical sensors, and DNA detection. Biological synthesis of nanoparticles appears to be simple, cost-effective, non-toxic, and easy to use for controlling size, shape, and stability, which is unlike the chemically synthesized nan...

  13. Core-modified octaphyrins: Syntheses and anion-binding properties

    Rajneesh Misra; Venkataramanarao G Anand; Harapriya Rath; Tavarekere K Chandrashekar

    2005-03-01

    In this paper, a brief review of the syntheses, characterization and anion-binding properties of core-modified octaphyrins is presented. It has been shown that the core-modified octaphyrins exhibit aromaticity both in solution and in solid state, confirming the validity of the (4 + 2) Huckel rule for larger -electron systems. Solid-state binding characteristics of TFA anions of two core-modified octaphyrins are also described.

  14. Blue Luminescence of CdS Nanowires Synthesized by Sulfurization

    GAO Tao; MENG Guo-Wen; WANG Tai-Hong

    2004-01-01

    @@ Polycrystalline CdS nanowires have been synthesized by sulfurizing metal Cd nanowires deposited electrochemically within the nanochannels of porous anodic alumina (PAA) templates. Photoluminescence (PL) investigation shows that the CdS nanowires have an intensive and broad PL emission band peaked around 435nm. The investigation results suggest that localized defects and excess S atoms existing in the CdS nanowires are responsible for this blue luminescence.

  15. Annual reports in inorganic and general syntheses 1973

    Niedenzu, Kurt

    1974-01-01

    Annual Reports in Inorganic and General Syntheses-1973 presents an organized annual summary of synthetic developments in inorganic chemistry and its related areas. The book covers the synthetic aspects and structural or mechanistic features of elements, including the main group hydrides, alkali and alkaline earth elements, boron, aluminium, gallium, indium, thallium, silicon, germanium, tin, and lead, nitrogen, phosphorus, arsenic, antimony, bismuth, chalcogens, halogens and pseudohalogens, and noble gases. The text also discusses the synthetic aspects and structural or mechanistic features of

  16. Dendritische Polythioetherliganden zur Synthese von Goldnanopartikel-Oligonucleotid-Monokonjugaten

    Mönninghoff, Sven

    2009-01-01

    Basierend auf der Entwicklung des Rubigoldes als thermostabilem Marker für Biomoleküle wurden in dieser Arbeit Polythioether-Liganden zur Synthese von monofunktionalen Cluster-Oligonucleotid-Konjugaten (COK) entwickelt. Zum Aufbau der Liganden wurden 2,4,6-substituierte Phenole als zentrales Strukturmotiv eingesetzt. Durch Konjugation der Ligandensysteme an Oligonucleotide wurden Ligand-Oligonucleotid-Konjugate (LOK) hergestellt, die durch Reduktion von Au (III)-Ionen in Anwesenhe...

  17. A Novel Synthesizing Genetic Logic Circuit: Frequency Multiplier.

    Chuang, Chia-Hua; Lin, Chun-Liang

    2014-01-01

    This paper presents a novel synthesizing genetic logic circuit design based on an existing synthetic genetic oscillator, which provides a function of frequency multiplier to synthesize a clock signal whose frequency is a multiple of that of the genetic oscillator. In the renowned literature, the synthetic genetic oscillator, known as a repressilator, has been successfully built in Escherichia coli to generate a periodic oscillating phenomenon through three repressive genes repress each other in a chain. On the basis of this fact, our proposed genetic frequency multiplier circuit utilizes genetic Buffers in series with a waveform-shaping circuit to reshape the genetic oscillation signal into a crisp logic clock signal. By regulating different threshold levels in the Buffer, the time length of logic high/low levels in a fundamental sinusoidal wave can be engineered to pulse-width-modulated (PWM) signals with various duty cycles. Integrating some of genetic logic XOR gates and PWM signals from the output of the Buffers, a genetic frequency multiplier circuit can be created and the clock signal with the integer-fold of frequency of the genetic oscillator is generated. The synthesized signal can be used in triggering the downstream digital genetic logic circuits. Simulation results show the applicability of the proposed idea. PMID:26356341

  18. Synthesizing Behavioral Model of Event-Based Requirements

    Seyyed M. Babamir

    2008-01-01

    Full Text Available Problem Statement: in the software engineering field, satisfaction of user's requirements by software has been a matter of concern. Therefore, monitoring software behavior against user's high-level requirements has already received a considerable and significant attention. However, the gap between low-level software behavior and high-level requirements has put an obstacle in the way of monitoring. Approach: to overcome the obstacle, we presented a method to synthesize a behavioral model of the event-based requirements in three steps: (1 eliciting event-based requirements; (2 specifying the requirements in event-based formulae and (3 mapping the formulae into a behavioral model. Results: to show effectiveness of the method, it was applied to requirements of a safety critical system, called Railroad Crossing Control (RCC one and a behavioral model was synthesized. The model was used to synthesize monitor of the RCC system. The monitor is responsible for surveillance of software behavior for preventing the collision between the train and some car at the junction of rail and road.Conclusions: we proposed a systematic method started from users' requirements elicitation and concluded with its behavioral specification. Focus of the method was on event-based real-time requirements which were stated by scenarios in a sequence of real-time interactions.

  19. A simple method for synthesizing and producing guitar sounds

    Torres, Jesús A.; Rendón, Pablo L.

    2013-05-01

    An uncomplicated model is proposed to describe the transverse force exerted by a plucked string on a guitar bridge. This model incorporates the effect of internal damping, lending the synthesized sound a transient quality that makes it more realistic than sound produced without taking damping into account. The synthesized signals are then compared to actual measurements for both free and palm-muted vibrations, and show agreement in both cases. These synthesized signals can also be used to play MIDI files through a guitar acting as a modified loudspeaker cone, driving the instrument mechanically. The sound thus obtained is realistic and provides an interesting classroom exercise for an undergraduate audience. The main set-up is also affordable as a laboratory activity and for public demonstrations, and has the advantage of being simple to implement and flexible enough to allow different kinds of modification. It is, in fact, reliable enough to use as a tool for the comparison of different guitars driven in the same manner.

  20. Bacteriocins synthesized by Bacillus thuringiensis: generalities and potential applications

    Salazar-Marroquín, Elma Laura; Galán-Wong, Luis J.; Moreno-Medina, Víctor Ricardo; Reyes-López, Miguel Ángel; Pereyra-Alférez, Benito

    2016-01-01

    The members of the Bacillus thuringiensis group, commonly known as Bt, produce a huge number of metabolites, which show biocidal and antagonistic activity. B. thuringiensis is widely known for synthesizing Cry, Vip and Cyt proteins, active against insects and other parasporins with biocidal activity against certain types of cancerous cells. Nevertheless, B. thuringiensis also synthesizes compounds with antimicrobial activity, especially bacteriocins. Some B. thuringiensis bacteriocins resemble lantibiotics and other small linear peptides (class IIa) from the lactic acid bacteria bacteriocins classification system. Although many bacteriocins produced by Bt have been reported, there is no proper classification for them. In this work, we have grouped these based on molecular weight and functionality. Bacteriocins are small peptides synthesized by bacteria, presenting inhibitory activity against Gram-positive and Gram-negative bacteria and to a lesser extent against fungi. These molecules represent a good study model in the search for microbial control alternatives. Lactic acid bacteria produces a huge number of these types of molecules with great potential. Nonetheless, members of the Bacillus, cereus group, especially B. thuringiensis, emerge as an attractive alternative for obtaining bacteriocins showing novel activities. This review describes the potential applications of B. thuringiensis bacteriocins in the control of foodborne pathogens, environment and medical area. PMID:27340340

  1. Soft-Template-Synthesized Mesoporous Carbon for Oral Drug Delivery

    Saha, Dipendu [ORNL; Warren, Kaitlyn E [ORNL; Naskar, Amit K [ORNL

    2014-01-01

    Template-synthesized mesoporous carbons were successfully used in in vitro investigations of controlled delivery of three model drugs, captopril, furosemide, and ranitidine hydrochloride. Captopril and furosemide exhibited desorption kinetics over 30 40 h, and ranitidine HCl had a complete release time of 5 10 h. As evident from the slow release kinetics, we contend that our mesoporous carbon is an improved drug-delivery medium compared to state-of-the-art porous silica-based substrates. The mesoporous carbons, synthesized from phloroglucinol and lignin, a synthetic and a sustainable precursor, respectively, exhibit BET surface area of 200 400 m2 g-1 and pore volume of 0.2 0.6 cm3 g-1. The phloroglucinol-based carbon has narrower pore widths and higher pore volume than the lignin-derived counterpart and maintains a longer release time. Numerical modeling of the release kinetics data reveals that the diffusivities of all the drugs from lignin-based carbon media are of equivalent magnitude (10-22 to 10-24 m2 s-1). However, a tailored reduction of pore width in the sorbent reduces the diffusivity of smaller drug molecules (captopril) by an order of magnitude. Thus, engineered pore morphology in our synthesized carbon sorbent, along with its potential to tailor the chemistry of its interaction with sorbet, can be exploited for optimal delivery system of a preferred drug within its therapeutic level and below the level of toxicity.

  2. Nanoformulation and antimicrobial evaluation of newly synthesized thiouracil derivatives.

    Fadda, Ahmed A; Bayoumy, Nesma M; El-Sherbiny, Ibrahim M

    2016-07-01

    The present work reports the synthesis of a new series of pyridopyrimidine derivatives. The newly synthesized compounds were characterized by various analytical and spectral techniques. In addition, their antimicrobial activity was evaluated as well as modeling studies were performed to investigate their ability to recognize and bind to the biotin carboxylase (BC)-active site. The results showed a broad spectrum antibacterial and antifungal profile of the synthesized derivatives. Docking results demonstrated that all members of this class of new derivatives were able to recognize the active site of Escherichia coli BC and form different types of bonding interactions with key active site amino acid residues. Besides the compounds with promising antimicrobial activity in addition to 6-aminothiouracil, as control, were incorporated into polycaprolactone nanoparticles to improve their water solubility, permeability through physiological barriers and consequently enhanced therapeutic efficacy. The compounds-loaded nanoparticles were prepared using single emulsion-solvent evaporation technique, and their diameters were found to be in the range 136 ± 30 to 213 ± 28 nm. Transmission electron microscopy (TEM) showed a spherical and dense morphology of the nanoparticles. The results also showed high entrapment efficiency of the synthesized bioactive compounds in the nanoparticles (85 ± 5% to 91 ± 2%) with a desirable in vitro biodegradation and release profiles. PMID:26559404

  3. Design & Implementation of High Switching & Low Phase Noise Frequency Synthesizer

    Ali M. N. Hassan

    2006-01-01

    Full Text Available This research describes the design & implementation of frequency synthesizer using single loop Phase lock loop with the following specifications: Frequency range (1.5 – 2.75 GHz,Step size (1 MHz, Switching time 36.4 µs, & phase noise @10 kHz = -92dBc & spurious -100 dBc The development in I.C. technology provide the simplicity in the design of frequency synthesizer because it implements the phase frequency detector(PFD , prescalar & reference divider in single chip. Therefore our system consists of a single chip contains (low phase noise PFD, charge pump, prescalar & reference divider, voltage controlled oscillator , loop filter & reference oscillator. The single chip is used to provide the following properties :•Low power consumptionSmall size, light weight.Flexibility in selecting crystal oscillator frequencies to fit into the system frequency planning.•High reliability.The application of this synthesizer in frequency hopping systems, satellite communications & radar because it has high switching speed ,low phase noise & low spurious level.

  4. Substitution of conventional high-temperature syntheses of inorganic compounds by near-room-temperature syntheses in ionic liquids

    Groh, Matthias Friedrich

    2013-01-01

    The high-temperature syntheses of the low-valent halogenides P2I4, Te2Br, α-Te4I4, Te4(Al2Cl7)2, Te4(Bi6Cl20), Te8(Bi4Cl14),Bi8(AlCl4)2, Bi6Cl7,and Bi6Br7, as well as of WSCl4 andWOCl4 have been replaced by resource-efficient low-temperature syntheses in room temperature ionic liquids (RTILs). The simple one-pot syntheses generally do not require elaborate equipment such as twozone furnaces or evacuated silica ampoules. Compared to the published conventional approaches, reduction of reaction time (up to 80%) and temperature (up to 500 K) and, simultaneously, an increase in yield were achieved. In the majority of cases, the solid products were phase-pure. X-Ray diffraction on single crystals (redetermination of 11 crystal structures) has demonstrated that the quality of the crystals from RTILs is comparable to that of products obtained by chemical transport reactions. © 2013 Verlag der Zeitschrift für Naturforschung, Tübingen.

  5. A NEW METHOD TO SYNTHESIZE THE CATIONIC GRAFT STARCH

    Lin Li; Bingyue Liu; Yafeng Cao

    2004-01-01

    The cationic graft copolymer was synthesized by reversed phase emulsion copolymerization of starch with diallydimethyl ammoniumlchlorid (DADMAC)and acrylamide (AM). The copolymerization was carried out using (NH4)2S2O8-NH2CONH2 redox as initiator and selecting Span-20 as emulsifier. The effects of emulsifier content in oil phase, volume ratio of oil to water, initiator concentration and mole ratio of DADMAC to AM on the graft copolymerization were discussed. The optimum condition of synthetics was found with the orthogonal test method.

  6. Comparative sinterability of combustion synthesized and commercial titanium carbides

    The influence of various parameters on the sinterability of combustion synthesized titanium carbide was investigaged. Titanium carbide powders, prepared by the combustion synthesis process, were sintered in the temperature range 1150 to 16000C. Incomplete combustion and high oxygen contents were found to be the cause of reduced shrinkage during sintering of the combustion syntheized powders when compared to the shrinkage of commercial TiC. Free carbon was shown to inhibit shrinkage. The activation energy for sintering was found to depend on stoichiometry (C/Ti). With decreasing C/Ti, the rate of sintering increased. 29 references, 16 figures, 13 tables

  7. Reduktive Synthese zu neuartigen cyclischen und acyclischen Borverbindungen

    Claes, Christina

    2016-01-01

    Ein Teil der hier vorliegenden Arbeit beschäftigte sich mit der Synthese und Charakterisierung neuer Boran-Addukte. Dabei wurden neben den NHCs IMe und IMeMe die Phosphane PEt3 und PMe3 als stabilisierende Lewisbasen eingesetzt. Neben dem Liganden wurde auch der borgebundene organische Rest variiert (Phenyl und n-Butyl), um deren Einfluss auf die Eigenschaften der Addukte zu untersuchen. Die NHC-stabilisierten Monoborane IMe∙B(nBu)Cl2 (99) und IMeMe∙B(Ph)Cl2 (100) konnten in guten Ausbeuten i...

  8. Proposal of an Algorithm to Synthesize Music Suitable for Dance

    Morioka, Hirofumi; Nakatani, Mie; Nishida, Shogo

    This paper proposes an algorithm for synthesizing music suitable for emotions in moving pictures. Our goal is to support multi-media content creation; web page design, animation films and so on. Here we adopt a human dance as a moving picture to examine the availability of our method. Because we think the dance image has high affinity with music. This algorithm is composed of three modules. The first is the module for computing emotions from an input dance image, the second is for computing emotions from music in the database and the last is for selecting music suitable for input dance via an interface of emotion.

  9. Algorithms for Synthesizing Priorities in Component-based Systems

    Cheng, Chih-Hong; Chen, Yu-Fang; Yan, Rongjie; Jobstmann, Barbara; Ruess, Harald; Buckl, Christian; Knoll, Alois

    2011-01-01

    We present algorithms to synthesize component-based systems that are safe and deadlock-free using priorities, which define stateless-precedence between enabled actions. Our core method combines the concept of fault-localization (using safety-game) and fault-repair (using SAT for conflict resolution). For complex systems, we propose three complementary methods as preprocessing steps for priority synthesis, namely (a) data abstraction to reduce component complexities, (b) alphabet abstraction and #-deadlock to ignore components, and (c) automated assumption learning for compositional priority synthesis.

  10. Syntheses of DL-threo-Thiamphenicol via Green Oxidation

    2006-01-01

    Four methyl aryl thioethers related to thiamphenicol syntheses and methyl phenyl sulfide were cleanly oxidized into methyl sulfones in high to excellent yields via catalytic green oxidation with aqueous hydrogen peroxide in combination with sodium tungstate. When the same reactions were similarly performed in the absence of the catalyst, the corresponding sulfoxides could be obtained. This viable synthetic approach for the synthesis of DL-threo-thiamphenicol is a simple procedure, which has an economic advantage in view of its application for the large-scale synthesis because it can be carried out under mild conditions.

  11. Syntheses and characterizations of three acid-base supramolecular complexes

    Three acid-base compounds with supramolecular architectures, namely, (1,2-H2bdc)(dmt) (1), (trans-1,4-H2ccdc)0.5(phdat) (2) and (1,3-H2bdc)(phdat) (3) (1,2-H2bdc = 1,2-benzenedicarboxylic acid, trans-1, 4-H2ccdc = trans-1, 4-cyclohexanedicarboxylic acid, 1,3-H2bdc = 1,3-benzenedicarboxylic acid, dmt = 2,4-diamino-6-methyl-s-triazine, phdat = 2,4-diamino-6-phenyl-s-triazine) have been synthesized and characterized by IR spectra, elemental analyses, single-crystal X-ray diffractions and TGA. (author)

  12. Bio-inspired routes for synthesizing efficient nanoscale platinum electrocatalysts

    Cha, Jennifer N. [Univ. of California, San Diego, CA (United States); Wang, Joseph [Univ. of California, San Diego, CA (United States)

    2014-08-31

    The overall objective of the proposed research is to use fundamental advances in bionanotechnology to design powerful platinum nanocrystal electrocatalysts for fuel cell applications. The new economically-viable, environmentally-friendly, bottom-up biochemical synthetic strategy will produce platinum nanocrystals with tailored size, shape and crystal orientation, hence leading to a maximum electrochemical reactivity. There are five specific aims to the proposed bio-inspired strategy for synthesizing efficient electrocatalytic platinum nanocrystals: (1) isolate peptides that both selectively bind particular crystal faces of platinum and promote the nucleation and growth of particular nanocrystal morphologies, (2) pattern nanoscale 2-dimensional arrays of platinum nucleating peptides from DNA scaffolds, (3) investigate the combined use of substrate patterned peptides and soluble peptides on nanocrystal morphology and growth (4) synthesize platinum crystals on planar and large-area carbon electrode supports, and (5) perform detailed characterization of the electrocatalytic behavior as a function of catalyst size, shape and morphology. Project Description and Impact: This bio-inspired collaborative research effort will address key challenges in designing powerful electrocatalysts for fuel cell applications by employing nucleic acid scaffolds in combination with peptides to perform specific, environmentally-friendly, simultaneous bottom-up biochemical synthesis and patterned assembly of highly uniform and efficient platinum nanocrystal catalysts. Bulk synthesis of nanoparticles usually produces a range of sizes, accessible catalytic sites, crystal morphologies, and orientations, all of which lead to inconsistent catalytic activities. In contrast, biological systems routinely demonstrate exquisite control over inorganic syntheses at neutral pH and ambient temperature and pressures. Because the orientation and arrangement of the templating biomolecules can be precisely

  13. Antibacterial screening of silver nanoparticles synthesized by marine micro algae

    D Devina Merin; S Prakash; B Valentine Bhimba

    2010-01-01

    Objective:To explore the biosynthesis of silver nanoparticles synthesized by marine microalgae. Methods: Marine microalgae was collected from Central Marine Fisheries Research Institute (CMFRI, tuticorin) and cultured in the lab. Silver nanoparticles synthesis were observed in normal and microwave irradiated microalgae and screened against human pathogens for the presence of antimicrobials.Results: The presence of silver nanoparticle was confirmed by UV-Visible spectroscopy at420 nm by the presence of plasmon peak. Further confirmation was done by scanning electron microscope(SEM).Conclusions: These results not only provide a base for further research but are useful for drug development in the present and future.

  14. Practical Large Scale Syntheses of New Drug Candidates

    Hui-Yin Li

    2001-01-01

    @@ This presentation will be focus on Practical large scale syntheses of lead compounds and drug candidates from three major therapeutic areas from DuPont Pharmaceuticals Research Laboratory: 1). DMP777-a selective, non-toxic, orally active human elastase inhibitor; 2). DMP754-a potent glycoprotein IIb/IIIa antagonist; 3). R-Wafarin-the pure enantiomeric form of wafarin. The key technology used for preparation these drug candidates is asymmetric hydrogenation under very mild reaction conditions, which produced very high quality final products at large scale (>99% de, >99 A% and >99 wt%). Some practical and GMP aspects of process development will be also discussed.

  15. Practical Large Scale Syntheses of New Drug Candidates

    Hui-Yin; Li

    2001-01-01

    This presentation will be focus on Practical large scale syntheses of lead compounds and drug candidates from three major therapeutic areas from DuPont Pharmaceuticals Research Laboratory: 1). DMP777-a selective, non-toxic, orally active human elastase inhibitor; 2). DMP754-a potent glycoprotein IIb/IIIa antagonist; 3). R-Wafarin-the pure enantiomeric form of wafarin. The key technology used for preparation these drug candidates is asymmetric hydrogenation under very mild reaction conditions, which produced very high quality final products at large scale (>99% de, >99 A% and >99 wt%). Some practical and GMP aspects of process development will be also discussed.……

  16. Integrated digital superconducting logic circuits for the quantum synthesizer. Report

    This report presents the results, which were reached in the framework of the BMBF cooperative plan ''Quantum Synthesizer'' in the partial plan ''Integrated Digital Superconducting Logic Circuits''. As essential goal of the plan a novel instrument on the base of quantum-coherent superconducting circuits should be developed. which allows to generate praxis-relevant wave forms with quantum accuracy, the quantum synthesizer. The main topics of development of the reported partial plan lied at the one hand in the development of integrated, digital, superconducting circuit in rapid-single-flux (RSFQ) quantum logics for the pattern generator of the quantum synthesizer, at the other hand in the further development of the fabrication technology for the aiming of high circuit complexity. In order to fulfil these requirements at the PTB a new design system was implemented, based on the software of Cadence. Together with the required RSFQ extensions for the design of digital superconducting circuits was a platform generated, on which the reachable circuit complexity is exclusively limited by the technology parameters of the available fabrication technology: Physical simulations are with PSCAN up to a complexity of more than 1000 circuit elements possible; furthermore VHDL allows the verification of arbitrarily large circuit architectures. In accordance for this the production line at the PTB was brought to a level, which allows in Nb/Al-AlxOy/Nb SIS technology implementation the fabrication of highly integrable RSFQ circuit architectures. The developed and fabricated basic circuits of the pattern generator have proved correct functionality and reliability in the measuring operation. Thereby for the circular RSFQ shift registers a key role as local memories in the construction of the pattern generator is devolved upon. The registers were realized with the aimed bit lengths up to 128 bit and with reachable signal-processing speeds of above 10 GHz. At the interface RSFQ

  17. Nanostructured superhydrophobic films synthesized by electrodeposition of fluorinated polyindoles

    Gabriela Ramos Chagas; Thierry Darmanin; Frédéric Guittard

    2015-01-01

    Materials with bioinspired superhydrophobic properties are highly desirable for many potential applications. Here, nine novel monomers derived from indole are synthesized to obtain these properties by electropolymerization. These monomers differ by the length (C4F9, C6F13 and C8F17) and the position (4-, 5- and 6-position of indole) of the perfluorinated substituent. Polymeric films were obtained with C4F9 and C6F13 chains and differences in the surface morphology depend especially on the sub...

  18. Photopolymerization of C60 crystal synthesized from organic solution

    We have been developing a novel process to synthesize C60 polymers as superior functional materials. Polymerization reactions of C60 precipitated from organic solution were investigated under Free Electron Laser (FEL) irradiation. The two processes: a liquid-liquid interfacial precipitation (LLIP) method and an evaporation technique from supersaturated solution, were studied with a respect of crystal structure and/or Raman spectrum for the precipitates before and after FEL irradiation. It was found that the photopolymerization reaction took place effectively in the LLIP precipitate because of its highly packed molecular crystal structure.

  19. Annual reports in inorganic and general syntheses 1976

    Zimmer, Hans

    2013-01-01

    Annual Reports in Inorganic and General Syntheses-1976 presents an annual review of synthetically useful information that would prove beneficial to nearly all organic chemists, both specialist and nonspecialist in synthesis. It should help relieve some of the information storage burden of the specialist and should aid the nonspecialist who is seeking help with a specific problem to become rapidly aware of recent synthetic advances.This is the fifth volume of ARIGS and is organized along the lines developed for the preceding volumes. The authors were encouraged to use synthetic aspects as their

  20. Erythropoietin is involved in hemoprotein syntheses in developing human decidua.

    Shiota, Mitsuru; Yasuda, Yoshiko; Shimaoka, Masao; Tsuritani, Mitsuhiro; Koike, Eiji; Oiki, Masaaki; Matsubara, Junko; Taketani, Shigeru; Murakami, Hitoshi; Yamasaki, Harufumi; Okumoto, Katsumi; Hoshiai, Hiroshi

    2013-03-01

    Before establishment of feto-placental circulation, decidua can synthesize hemoproteins to maintain oxygen homeostasis in situ. Using the human decidua of induced abortions ranging from 5 to 8 weeks of gestation, we determined the expression levels of erythropoietin, erythropoietin receptor, cytoglobin, myoglobin, embryonic-, fetal- and adult hemoglobin mRNA by quantitative RT-PCR analysis and identified their proteins by Western blot and immunohistochemical analyses. Erythropoietin signaling was demonstrated in phosphatidylinositol-3-kinase/protein kinase B pathway by Western blot, and the transcriptional factors for erythroid and non-erythroid heme synthesis were examined by RT-PCR analysis. In decidua, erythropoietin and its receptor mRNAs, erythropoietin receptor protein and phosphatidylinositol-3-kinase, were expressed with a peak at 6 weeks of gestation. Moreover, the decidua during 5 to 8 weeks of gestation expressed embryonic, fetal and adult hemoglobins additionally cytoglobin and myoglobin at transcriptional and protein levels. The heme portion of these hemoproteins is considered to be synthesized by non-erythroid δ-aminolevulinate synthase. These hemoproteins were discernible especially in decidual cells concomitant with cytotrophoblast cells and macrophage in these developing decidua. Considering the different capacity for oxygen binding and dissociation among hemoglobins with the oxygen storage capacity for cytoglobin and myoglobin, these hemoproteins appear to play a role in oxygen demand in decidua in situ before development of feto-placental circulation under the control of erythropoietin signaling. PMID:23480354

  1. Design of S-Band Frequency Synthesizer for Microwave Applications

    S. Shurender

    2013-08-01

    Full Text Available A phase locked loop based indirect frequency synthesizer is designed for S-band frequency. A Phase locked loop is designed and the phase noise response and transient response of the designed PLL is simulated for 2100MHz frequency. The phase noise response of total PLL and its individual components are obtained. A 3rd order low pass passive loop filter is used and by varying the loop bandwidth and phase margin the trade-off between lock time and phase noise is observed and an optimum value of loop bandwidth and phase margin is chosen such that its phase noise contribution is less. The designed phase locked loop has a low phase noise value of -112.4dBc/Hz at 100 kHz offset frequency and has a fast lock time of 119.5 us. The time taken by the designed frequency synthesizer to lock to 10 Hz frequency error and 1° phase error under transient conditions is found to be 149 us and 116 us respectively. The RMS phase jitter obtained for the designed phase locked loop is 0.3° rms. The phase locked loop is designed and simulated using ADIsimPLL tool. The phase locked loop design aims at achieving low phase noise, reduced lock time and high reliability for S-band applications.

  2. Metal Borohydrides synthesized from metal borides and metal hydrides

    Sommer, Sanna

    2014-01-01

    and Ca(BH4)2, respectively [3,4]. An attempt to synthesize alkali and alkaline earth metal borohydrides from various borides by ball milling under high hydrogen pressure is presented here. MgB2, AlB2 and CaB6 have been milled with MHx (M = Li, Na, Mg, Ca) at p(H2) = 110 bar for 24 hours. All samples......Metal Borohydrides Synthesized from Metal Borides and Metal Hydrides Alexander Fogha, Sanna Sommera, Kasper T. Møllera, T. R. Jensena aCenter for Materials Crystallography (CMC), Interdisciplinary Nanoscience Center (iNANO) and Chemistry Department, Aarhus University, Langelandsgade 140, DK-8000...... Aarhus C, Denmark email: gallafogh@hotmail.com / sanna-sommer@hotmail.com Magnesium boride, MgB2, ball milled with MH (M = Li, Na, Ca) followed by hydrogenation under high hydrogen pressure, readily forms the corresponding metal borohydrides, M(BH4)x (M = Li, Na, Ca) and MgH2 according to reaction scheme...

  3. Dynamic balancing of mechanisms and synthesizing of parallel robots

    Wei, Bin

    2016-01-01

    This book covers the state-of-the-art technologies in dynamic balancing of mechanisms with minimum increase of mass and inertia. The synthesis of parallel robots based on the Decomposition and Integration concept is also covered in detail. The latest advances are described, including different balancing principles, design of reactionless mechanisms with minimum increase of mass and inertia, and synthesizing parallel robots. This is an ideal book for mechanical engineering students and researchers who are interested in the dynamic balancing of mechanisms and synthesizing of parallel robots. This book also: ·       Broadens reader understanding of the synthesis of parallel robots based on the Decomposition and Integration concept ·       Reinforces basic principles with detailed coverage of different balancing principles, including input torque balancing mechanisms ·       Reviews exhaustively the key recent research into the design of reactionless mechanisms with minimum increase of mass a...

  4. Alternative methods of synthesizing 99Tcm-labelled ciprofloxacin

    Full text: 99Tcm-labelled ciprofloxacin (Infecton) is a new class of radiopharmaceutical designed for imaging live bacterial infection. We synthesized Infecton by modifying the procedure described by Keith Britton's group (Lancet 1996; 347: 233-235) and reported our findings at the ANZSNM meeting last year. Since the methodology was cumbersome, we investigated simpler alternative ways of labelling ciprofloxacin with 99Tcm-pertechnetate for routine imaging. There were several limitations in the previously described method: (1) Need to prepare pure ciprofloxacin which was unstable on storage. (2) Synthetic procedure using formimidine sulphinic acid (FSA) was complicated and required boiling step. (3) The radiochemical purity (RCP) of the product was low (45-50%) requiring purification. (4) Biodistribution studies showed a marked uptake by the liver which could interfere with scan interpretation in this region. The results of our present studies showed that Infecton could be prepared by a simple two-step method: (1) Reduce 99Tcm-pertechnetate with stannous salt (SnCl2 or Sn-tartrate). (2) Mix with Ciproxin IV-100. The RCP of the product was up to 98%, which obviates the need for further purification. Infecton synthesized by the above method showed avid localization in abscesses induced with Staphylococcus aureus in rats. The biodistribution studies showed that Infecton was renally excreted with minimal accumulation in the liver or other organs

  5. Multifunctional Martian habitat composite material synthesized from in situ resources

    Sen, S.; Carranza, S.; Pillay, S.

    2010-09-01

    The two primary requirements for a Martian habitat structure include effective radiation shielding against the Galactic Cosmic Ray (GCR) environment and sufficient structural and thermal integrity. To significantly reduce the cost associated with transportation of such materials and structures from earth, it is imperative that such building materials should be synthesized primarily from Martian in situ resources. This paper illustrates the feasibility of such an approach. Experimental results are discussed to demonstrate the synthesis of polyethylene (PE) from a simulated Martian atmosphere and the fabrication of a composite material using simulated Martian regolith with PE as the binding material. The radiation shielding effectiveness of the proposed composites is analyzed using results from radiation transport codes and exposure of the samples to high-energy beams that serve as a terrestrial proxy for the GCR environment. Mechanical and ballistic impact resistance properties of the proposed composite as a function of composition, processing parameters, and thermal variations are also discussed to evaluate the multifunctionality of such in situ synthesized composite materials.

  6. Construction of a cyanobacterium synthesizing cyclopropane fatty acids.

    Machida, Shuntaro; Shiraiwa, Yoshihiro; Suzuki, Iwane

    2016-09-01

    Microalgae have received much attention as a next-generation source of biomass energy. However, most of the fatty acids (FAs) from microalgae are multiply unsaturated; thus, the biofuels derived from them are fluid, but vulnerable to oxidation. In this study, we attempted to synthesize cyclopropane FAs in the cyanobacterium Synechocystis sp. PCC 6803 by expressing the cfa gene for cyclopropane FA synthase from Escherichia coli with the aim of producing FAs that are fluid and stable in response to oxidization. We successfully synthesized cyclopropane FAs in Synechocystis with a yield of ~30% of total FAs. Growth of the transformants was altered, particularly at low temperatures, but photosynthesis and respiration were not significantly affected. C16:1(∆9) synthesis in the desA(-)/desD(-) strain by expression of the desC2 gene for sn-2 specific ∆9 desaturase positively affected growth at low temperatures via promotion of various cellular processes, with the exceptions of photosynthesis and respiration. Estimation of the apparent activities of desaturases suggested that some acyl-lipid desaturases might recognize the lipid side chain. PMID:27263419

  7. Using singlet oxygen to synthesize polyoxygenated natural products from furans.

    Montagnon, Tamsyn; Tofi, Maria; Vassilikogiannakis, Georgios

    2008-08-01

    [Reaction: see text]. Singlet oxygen is a powerful tool in the armament of the synthetic organic chemist and possibly in that of nature itself. In this Account, we illustrate a small selection of the many ways singlet oxygen can be harnessed in the laboratory to aid in the construction of the complex molecular motifs found in natural products. A more philosophical question is also addressed: namely, how much do singlet oxygen oxidations influence the biogenesis of these natural products? All the synthetic examples surveyed in this Account can be characterized as belonging to the same class because they all involve the oxidation of a substituted furan nucleus by singlet oxygen. Readily accessible and relatively simple furans can be transformed into a host of complex motifs present in a diverse range of natural products by the action of singlet-oxygen-mediated reaction sequences. These reactions are highly advantageous because they frequently deliver a rapid and dramatic increase in molecular complexity in high yield. Furthermore, an unusually wide structural diversity is exhibited by the molecular motifs obtained from these reaction sequences. For example, relatively minor modifications to the starting substrate and to the reaction conditions may lead to products as variable as spiroketal lactones, 3-keto-tetrahydrofurans, various types of bis-spiroketals, 4-hydroxy cyclopentenones, or spiroperoxylactones. In addition, two more specialized examples are discussed in this Account. The core of the prunolide molecules and the chinensine family of natural products were rapidly synthesized using effective and short singlet oxygen mediated strategies; this adds weight to the assertion that singlet oxygen is a very effective moderator of complex cascade reaction sequences. We also show how our synthetic investigations have provided evidence that these same strategies might be used in the biogenesis of these molecules. In the cases of the chinensines and the

  8. A green chemistry approach for synthesizing biocompatible gold nanoparticles

    Gurunathan, Sangiliyandi; Han, JaeWoong; Park, Jung Hyun; Kim, Jin-Hoi

    2014-05-01

    Gold nanoparticles (AuNPs) are a fascinating class of nanomaterial that can be used for a wide range of biomedical applications, including bio-imaging, lateral flow assays, environmental detection and purification, data storage, drug delivery, biomarkers, catalysis, chemical sensors, and DNA detection. Biological synthesis of nanoparticles appears to be simple, cost-effective, non-toxic, and easy to use for controlling size, shape, and stability, which is unlike the chemically synthesized nanoparticles. The aim of this study was to synthesize homogeneous AuNPs using pharmaceutically important Ganoderma spp . We developed a simple, non-toxic, and green method for water-soluble AuNP synthesis by treating gold (III) chloride trihydrate (HAuCl4) with a hot aqueous extract of the Ganoderma spp . mycelia. The formation of biologically synthesized AuNPs (bio-AuNPs) was characterized by ultraviolet (UV)-visible absorption spectroscopy, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), energy dispersive X-ray (EDX), dynamic light scattering (DLS), and transmission electron microscopy (TEM). Furthermore, the biocompatibility of as-prepared AuNPs was evaluated using a series of assays, such as cell viability, lactate dehydrogenase leakage, and reactive oxygen species generation (ROS) in human breast cancer cells (MDA-MB-231). The color change of the solution from yellow to reddish pink and strong surface plasmon resonance were observed at 520 nm using UV-visible spectroscopy, and that indicated the formation of AuNPs. DLS analysis revealed the size distribution of AuNPs in liquid solution, and the average size of AuNPs was 20 nm. The size and morphology of AuNPs were investigated using TEM. The biocompatibility effect of as-prepared AuNPs was investigated in MDA-MB-231 breast cancer cells by using various concentrations of AuNPs (10 to 100 μM) for 24 h. Our findings suggest that AuNPs are non-cytotoxic and biocompatible. To the best of our knowledge

  9. Shape dependent heat transport through green synthesized gold nanofluids

    John, Jisha; Thomas, Lincy; Kumar, B. Rajesh; Kurian, Achamma; George, Sajan D.

    2015-08-01

    Nanofluids hold promise as a more efficient coolant for thermoelectric devices. Despite the capability of tailoring the thermo physical properties of nanofluids, by tuning the particle parameters such as shape, size and concentration, the toxicity of chemicals used for the preparation of nanoparticles is a serious concern. Green synthesis of nanoparticles is emerging as an alternative to the conventional chemical and physical methods for the preparation of nanoparticles. In this work, the results of the preparation of gold nanoparticles using plant extracts as reducing agents are presented. The green synthesis route employed for the present study provides particles of similar size, but the shape of the particles is found to vary depending upon the source of the natural reducing agents. The thermal diffusivity values of the gold nanofluid measured using laser based dual beam thermal lens technique elucidate the role of shape and concentration of the green synthesized nanoparticles on the effective thermal diffusivity values of the nanofluids.

  10. Electrochemically synthesized stretchable polypyrrole/fabric electrodes for supercapacitor

    Wearable electronics offer the combined advantages of both electronics and fabrics. Being an indispensable part of these electronics, lightweight, stretchable and wearable power sources are strongly demanded. Here we describe a daily-used cotton fabric coated with polypyrrole as electrode for stretchable supercapacitors. Polypyrrole was synthesized on the Au coated fabric via an electrochemical polymerization process with p-toluenesulfonic acid (p-TS) as dopant from acetonitrile solution. This material was characterized with FESEM, tensile stress, and studied as a supercapacitor electrode in 1.0 M NaCl. This conductive textile electrode can sustain up to 140% strain without electric failure. It delivers a high specific capacitance of 254.9 F g−1 at a scan rate of 10 mV s−1, and keeps almost unchanged at an applied strain (i.e. 30% and 50%) but with an improved cycling stability

  11. Design of a Synthesizing Lecture on Mechanics Concepts

    Strand, Natalie E.; Docktor, Jennifer L.; Gladding, Gary E.; Mestre, José P.; Ross, Brian H.

    2010-10-01

    Within the context of traditional physics problem solving instruction, major concepts are mentioned but often marginalized by the focus on equation manipulation, resulting in students perceiving concepts as unimportant in problem solving. Additionally, since topics are covered as isolated pieces, students also perceive concepts as unrelated. In response to this disconnect, we discuss the development of a short, animated, web-delivered synthesizing presentation modeled after the "common learning resource" from the preparation for future learning construct. In the presentation, major concepts of introductory mechanics are structured hierarchically. More specifically, the presentation is an overview of major theorems and conservation laws in mechanics and the conditions under which they are applied. It is linked to previous problems solved by the students and intended to prepare them for future learning by illustrating how concepts guide problem solving processes.

  12. Method for synthesizing metal bis(borano) hypophosphite complexes

    Cordaro, Joseph G.

    2013-06-18

    The present invention describes the synthesis of a family of metal bis(borano) hypophosphite complexes. One procedure described in detail is the syntheses of complexes beginning from phosphorus trichloride and sodium borohydride. Temperature, solvent, concentration, and atmosphere are all critical to ensure product formation. In the case of sodium bis(borano) hypophosphite, hydrogen gas was evolved upon heating at temperatures above 150.degree. C. Included in this family of materials are the salts of the alkali metals Li, Na and K, and those of the alkaline earth metals Mg and Ca. Hydrogen storage materials are possible. In particular the lithium salt, Li[PH.sub.2(BH.sub.3).sub.2], theoretically would contain nearly 12 wt % hydrogen. Analytical data for product characterization and thermal properties are given.

  13. Oestradiol synthesized by female neurons generates sex differences in neuritogenesis

    Ruiz-Palmero, Isabel; Ortiz-Rodriguez, Ana; Melcangi, Roberto Cosimo; Caruso, Donatella; Garcia-Segura, Luis M.; Rune, Gabriele M.; Arevalo, Maria-Angeles

    2016-01-01

    Testosterone produced by the foetal testis is converted by male neurons to oestradiol, which masculinizes neuronal morphology. Female neurons are known to synthesize oestradiol in absence of exogenous testosterone. However, the role of neuronal oestradiol on the differentiation of foetal female neurons is unknown. Here we show that, due to endogenous neuronal oestradiol synthesis, female hippocampal neurons have higher expression of the neuritogenic protein Neurogenin 3 and enhanced neuritogenesis than males. Exogenous application of testosterone or its metabolite dihydrotestosterone increases Neurogenin 3 expression and promotes neuritogenesis in males, but reduces these parameters in females. Together our data indicate that gonadal-independent oestradiol synthesis by female neurons participates in the generation of sex differences in hippocampal neuronal development. PMID:27553191

  14. Expectations and limits to synthesize nuclei with Z ≥ 120

    In order to explore the possibilities to synthesize the new superheavy elements with Z=120, 122, 124, 126 some hot-fusion (mass asymmetric) reactions and cold-fusion (less mass asymmetric) reactions are studied. The dynamics of reaction with massive nuclei and the formation probability of heavy and superheavy elements with Z=90-126 in the asymmetric and symmetric reactions are discussed. The systematics of fusion probability PCN and evaporation residue cross section σER in these reactions are presented. Moreover, we explore the possibility of synthesis of superheavy nuclei by the use of reaction with the neutron rich radioactive beam 132Sn, and by symmetric reactions like 136Xe+136Xe and 139,149La+ 139,149La. (author)

  15. Enhanced photocatalytic activity of electrochemically synthesized aluminum oxide nanoparticles

    Pathania, Deepak; Katwal, Rishu; Kaur, Harpreet

    2016-03-01

    In this study, aluminum oxide (Al2O3) nanoparticles (NPs) were synthesized via an electrochemical method. The effects of reaction parameters such as supporting electrolytes, solvent, current and electrolysis time on the shape and size of the resulting NPs were investigated. The Al2O3 NPs were characterized by Fourier transform infrared spectroscopy, X-ray diffraction, transmission electron microscopy, thermogravimetric analysis/differential thermal analysis, energy-dispersive X-ray analysis, and ultraviolet-visible spectroscopy. Moreover, the Al2O3 NPs were explored for photocatalytic degradation of malachite green (MG) dye under sunlight irradiation via two processes: adsorption followed by photocatalysis; coupled adsorption and photocatalysis. The coupled process exhibited a higher photodegradation efficiency (45%) compared to adsorption followed by photocatalysis (32%). The obtained kinetic data was well fitted using a pseudo-first-order model for MG degradation.

  16. Shape dependent heat transport through green synthesized gold nanofluids

    Nanofluids hold promise as a more efficient coolant for thermoelectric devices. Despite the capability of tailoring the thermo physical properties of nanofluids, by tuning the particle parameters such as shape, size and concentration, the toxicity of chemicals used for the preparation of nanoparticles is a serious concern. Green synthesis of nanoparticles is emerging as an alternative to the conventional chemical and physical methods for the preparation of nanoparticles. In this work, the results of the preparation of gold nanoparticles using plant extracts as reducing agents are presented. The green synthesis route employed for the present study provides particles of similar size, but the shape of the particles is found to vary depending upon the source of the natural reducing agents. The thermal diffusivity values of the gold nanofluid measured using laser based dual beam thermal lens technique elucidate the role of shape and concentration of the green synthesized nanoparticles on the effective thermal diffusivity values of the nanofluids. (paper)

  17. Thermally stimulated luminescence studies in combustion synthesized polycrystalline aluminum oxide

    K R Nagabhushana; B N Lakshminarasappa; D Revannasiddaiah; Fouran Singh

    2008-08-01

    Synthesis of materials by combustion technique results in homogeneous and fine crystalline product. Further, the technique became more popular since it not only saved time and energy but also was easy to process. Aluminum oxide phosphor was synthesized by using urea as fuel in combustion reaction. Photoluminescence (PL) and thermally stimulated luminescence (TSL) characteristics of -irradiated aluminum oxide samples were studied. A broad PL emission with a peak at ∼ 465 nm and a pair of strong and sharp emissions with peaks at 679 and 695 nm were observed in -rayed samples. The PL intensity was observed to increase with increase in -ray dose. Two prominent and well resolved TSL glows with peaks at 210°C and 365°C were observed in all -irradiated Al2O3 samples. The TSL intensity was also found to increase with increase in -ray dose. The TSL glow curves indicated second order kinetics.

  18. SiC nanowires synthesized from graphene and silicon vapors

    Weichenpei, Luo; Gong-yi, Li; Zengyong, Chu; Tianjiao, Hu; Xiaodong, Li; Xuefei, Zhang

    2016-04-01

    The preparation of silicon carbide (SiC) nanowires is basically important for its potential applications in nanodevices, nanocomposites, etc. In the present work, a simple route was reported to synthesize SiC nanowires by heating commercial graphene with silicon vapors and no catalyst. Characterization by scanning electron microscopy, transmission electron microscopy, high-resolution transmission electron microscopy, electron energy scattering, X-ray diffraction, and Raman dispersive spectrum demonstrates the products are composed of β-SiC crystal. The SiC nanowires have the average diameter of about 50 nm and length of tens of micrometers. The vapor-solid mechanism was employed to interpret the SiC nanowires growth. Gaseous SiO which was produced by the reaction of Si powders with its surface oxidation reacted with the solid graphene to form SiC crystal nuclei. And SiC crystal nuclei would act as active sites for further growing into nanowires.

  19. Silicon carbide nanowires synthesized with phenolic resin and silicon powders

    Zhao, Hongsheng; Shi, Limin; Li, Ziqiang; Tang, Chunhe

    2009-02-01

    Large-scale silicon carbide nanowires with the lengths up to several millimeters were synthesized by a coat-mix, moulding, carbonization, and high-temperature sintering process, using silicon powder and phenolic resin as the starting materials. Ordinary SiC nanowires, bamboo-like SiC nanowires, and spindle SiC nanochains are found in the fabricated samples. The ordinary SiC nanowire is a single-crystal SiC phase with a fringe spacing of 0.252 nm along the [1 1 1] growth direction. Both of the bamboo-like SiC nanowires and spindle SiC nanochains exhibit uniform periodic structures. The bamboo-like SiC nanowires consist of amorphous stem and single-crystal knots, while the spindle SiC nanochains consist of uniform spindles which grow uniformly on the entire nanowires.

  20. Scalable syntheses of the BET bromodomain inhibitor JQ1

    Syeda, Shameem Sultana; Jakkaraj, Sudhakar; Georg, Gunda I.

    2015-01-01

    We have developed methods involving the use of alternate, safer reagents for the scalable syntheses of the potent BET bromodomain inhibitor JQ1. A one-pot three step method, involving the conversion of a benzodiazepine to a thioamde using Lawesson’s reagent, followed by amidrazone formation and installation of the triazole moiety furnished JQ1. This method provides good yields and a facile purification process. For the synthesis of enantiomerically enriched (+)-JQ1, the highly toxic reagent diethyl chlorophosphate, used in a previous synthesis, was replaced with the safer reagent diphenyl chlorophosphate in the three-step one-pot triazole formation without effecting yields and enantiomeric purity of (+)-JQ1. PMID:26034331

  1. Characterization of chemically synthesized CdS nanoparticles

    Rajeev R Prabhu; M Abdul Khadar

    2005-11-01

    II–VI semiconductor nanoparticles are presently of great interest for their practical applications such as zero-dimensional quantum confined materials and for their applications in optoelectronics and photonics. The optical properties get modified dramatically due to the confinement of charge carriers within the nanoparticles. Similar to the effects of charge carriers on optical properties, confinement of optical and acoustic phonons leads to interesting changes in the phonon spectra. In the present work, we have synthesized nanoparticles of CdS using chemical precipitation technique. The crystal structure and grain size of the particles are studied using XRD. The UV–visible absorption, photoluminescence and Raman spectra of the sample are recorded and discussed briefly.

  2. Progress of synthesizing methods and properties of fluorinated carbon nanotubes

    2010-01-01

    In this paper,the recent development of fluorinated carbon nanotubes(F-CNTs) was introduced.The synthesizing methods of F-CNTs,including direct fluorination and plasma treatment,were discussed in detail,and the effects of factors,such as the temperature and pressure in fluorination as well as the kind of fluorine source and carbon nanotubes,on the structures and properties of F-CNTs were also summarized.In the mean time,the special physical and chemical properties of F-CNTs and the relevant applied fields were described briefly,the exisiting problems of F-CNTs were summed up,and the direction of future development was also discussed in the end.

  3. Mesoporous silica magnetite nanocomposite synthesized by using a neutral surfactant

    Souza, K. C.; Salazar-Alvarez, G.; Ardisson, J. D.; Macedo, W. A. A.; Sousa, E. M. B.

    2008-05-01

    Magnetite nanoparticles coated by mesoporous silica were synthesized by an alternative chemical route using a neutral surfactant and without the application of any functionalization method. The magnetite (Fe3O4) nanoparticles were prepared by precipitation from aqueous media, and then coated with mesoporous silica by using nonionic block copolymer surfactants as the structure-directing agents. The mesoporous SiO2-coated Fe3O4 samples were characterized by x-ray diffraction, Fourier-transform infrared spectroscopy, N2 adsorption-desorption isotherms, transmission electron microscopy, 57Fe Mössbauer spectroscopy, and vibrating sample magnetometry. Our results revealed that the magnetite nanoparticles are completely coated by well-ordered mesoporous silica with free pores and stable (~8 nm thick) pore walls, and that the structural and magnetic properties of the Fe3O4 nanoparticles are preserved in the applied synthesis route.

  4. The stabilization and targeting of surfactant-synthesized gold nanorods

    The strong cetyltrimethylammonium bromide (CTAB) surfactant responsible for the synthesis and stability of gold nanorod solutions complicates their biomedical applications. The critical parameter to maintain nanorod stability is the ratio of CTAB to nanorod concentration. The ratio is approximately 740 000 as determined by chloroform extraction of the CTAB from a nanorod solution. A comparison of nanorod stabilization by thiol-terminal PEG and by anionic polymers reveals that PEGylation results in higher yields and less aggregation upon removal of CTAB. A heterobifunctional PEG yields nanorods with exposed carboxyl groups for covalent conjugation to antibodies with the zero-length carbodiimide linker EDC. This conjugation strategy leads to approximately two functional antibodies per nanorod according to fluorimetry and ELISA assays. The nanorods specifically targeted cells in vitro and were visible with both two-photon and confocal reflectance microscopies. This covalent strategy should be generally applicable to other biomedical applications of gold nanorods as well as other gold nanoparticles synthesized with CTAB.

  5. Electrospray deposition of isolated chemically synthesized magnetic nanoparticles

    Agostini, Pierre; Meffre, Anca; Lacroix, Lise-Marie; Ugnati, Damien [Université de Toulouse (France); INSA, UPS, CNRS, Laboratoire de Physique et Chimie des Nano-objets (LPCNO) (France); Ondarçuhu, Thierry [Centre d’Elaboration de Matériaux et d’Etudes Structurales (CEMES-CNRS) (France); Respaud, Marc; Lassagne, Benjamin, E-mail: lassagne@insa-toulouse.fr [Université de Toulouse (France); INSA, UPS, CNRS, Laboratoire de Physique et Chimie des Nano-objets (LPCNO) (France)

    2016-01-15

    The deposition of isolated magnetic nanoparticles onto a substrate was performed using electrohydrodynamic spraying. Two kinds of nanoparticles were sprayed, 11 nm CoFe carbide nanospheres and 10.5 nm Fe nanocubes. By studying carefully the evolution of the sprayed charged droplets and the mechanism of nanoparticle dispersion in them, we could optimize the nanoparticle concentration within the initial nanoparticle solution (i) to reduce the magnetic interaction and therefore prevent agglomeration and (ii) to obtain in a relatively short period (1 h) a deposit of isolated magnetic nanoparticles with a density of up to 400 nanoparticles per µm{sup 2}. These results open great perspectives for magnetic measurements on single objects using advanced magnetometry techniques as long as spintronics applications based on single chemically synthesized magnetic nanoparticles.

  6. SPPS Resins Impact the PNA-Syntheses' Improvement

    Pipkorn, Rüdiger; Rawer, Stephan; Wiessler, Manfred; Waldeck, Waldemar; Koch, Mario; Schrenk, Hans Hermann; Braun, Klaus

    2013-01-01

    The personalized medicine, also documented as “individualized medicine”, is an effective and therapeutic approach. It is designed to treat the disease of the individual patient whose precise differential gene expression profile is well known. The trend in the biomedical and biophysical research shows important consequences for the pharmaceutical drug and diagnostics research. It requires a high variability in the design and safety of target-specific pharmacologically active molecules and diagnostic components for imaging of metabolic processes. A key technology which may fulfill the highest demands during synthesis of these individual drugs and diagnostics is the solid phase synthesis which is congenial to automated manufacturing. Additionally the choice of tools like resins and reagents is pivotal to synthesize drugs and diagnostics in high quality and yields. Here we demonstrate the solid phase synthesis effects dependent on the choice of resin and of the deprotection agent. PMID:23423830

  7. Liquid-phase synthesized mesoporous electrochemical supercapacitors of nickel hydroxide

    Chang, Jinho; Park, Mira; Ham, Dukho; Mane, Rajaram S.; Han, Sung-Hwan [Inorganic Nano-Materials Laboratory, Department of Chemistry, Hanyang University, Sungdong-Ku, Haengdang-dong 17, Seoul 133-791 (Korea); Ogale, S.B. [Physical and Materials Chemsitry Division, National Chemical Laboratory, Dr. Homi Bhabha Road, Pashan, Pune 411008 (India)

    2008-06-01

    Electrochemical supercapacitive (ES) properties of liquid-phase synthesized mesoporous (pore size distribution centered {proportional_to}12 nm) and of 120 m{sup 2}/g surface area nickel hydroxide film electrodes onto tin-doped indium oxide substrate are discussed. The amounts of inner and outer charges are calculated to investigate the contribution of mesoporous structure on charge storage where relatively higher contribution of inner charge infers good ion diffusion into matrix of nickel hydroxide. Effect of different electrolytes, electrolyte concentrations, deposit mass and scan rates on the current-voltage profile in terms of the shape and enclosed area is investigated. Specific capacitance of {proportional_to}85 F/g at a constant current density of 0.03 A/g is obtained from the discharge curve. (author)

  8. Syntheses of CuO nanostructures in ionic liquids

    2007-01-01

    A simple and efficient approach is developed to fabricate single-crystalline CuO nanostructures through an ionic liquid assisted one-step low-temperature solid-state route.Both nanoparticles(5 nm in size)and nanorods(5-10 nm in diameter and 50-100 nm in length)of monoclinic CuO were obtained. These synthesized CuO nanostructures were characterized by X-ray diffraction(XRD),transmission electron microscopy(TEM),selected area electron diffraction(SAED),X-ray photoelectron spectros- copy(XPS),energy dispersive spectroscopy(EDS)and nitrogen adsorption analysis.The morpholo- gies of the nanostructures can be controlled by tuning the amount of NaOH and ionic liquids.The growth mechanism of CuO nanostructures is investigated.

  9. Syntheses of CuO nanostructures in ionic liquids

    WANG Li; ZHAO Bin; YUAN ZhongYong; ZHANG XueJun; Wu QingDuan; CHANG LiXian; ZHENG WenJun

    2007-01-01

    A simple and efficient approach is developed to fabricate single-crystalline CuO nanostructures through an ionic liquid assisted one-step low-temperature solid-state route. Both nanoparticles (5 nm in size) and nanorods (5-10 nm in diameter and 50-100 nm in length) of monoclinic CuO were obtained. These synthesized CuO nanostructures were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), selected area electron diffraction (SAED), X-ray photoelectron spectroscopy (XPS), energy dispersive spectroscopy (EDS) and nitrogen adsorption analysis. The morphologies of the nanostructures can be controlled by tuning the amount of NaOH and ionic liquids. The growth mechanism of CuO nanostructures is investigated.

  10. Dielectric Properties of CDS Nanoparticles Synthesized by Soft Chemical Route

    R Tripathi; A Kumar; T P Sinha

    2009-06-01

    CdS nanoparticles have been synthesized by a chemical reaction route using thiophenol as a capping agent. The frequency-dependent dielectric dispersion of cadmium sulphide (CdS) is investigated in the temperature range of 303–413 K and in a frequency range of 50 Hz–1 MHz by impedance spectroscopy. An analysis of the complex per-mittivity ( and ) and loss tangent (tan ) with frequency is performed by assuming a distribution of relaxation times. The scaling behaviour of dielectric loss spectra sug- gests that the relaxation describes the same mechanism at various temperatures. The frequency-dependent electrical data are analysed in the framework of conductivity and modulus formalisms. The frequency-dependent conductivity spectra obey the power law.

  11. Helical polyacetylene synthesized with a chiral nematic reaction field

    Akagi; Piao; Kaneko; Sakamaki; Shirakawa; Kyotani

    1998-11-27

    Helical polyacetylene was synthesized under an asymmetric reaction field consisting of chiral nematic (N*) liquid crystals (LCs). The chiral nematic LC was prepared by adding a chiroptical binaphthol derivative as a chiral dopant to a mixture of two nematic LCs. Acetylene polymerizations were carried out using the catalyst titanium tetra-n-butoxide-triethylaluminum dissolved in the chiral nematic LC solvent. The polyacetylene film was shown by scanning electron microscopy to consist of clockwise or counterclockwise helical structure of fibrils. A Cotton effect was observed in the region of the pi --> pi* transition of the polyacetylene chain in circular dichroism spectra. The high electrical conductivities of approximately 1500 to 1800 siemens per centimeter after iodine doping and the chiral helicity of these films may be exploited in electromagnetic and optical applications. PMID:9831554

  12. Rheological measurements in titania gels synthesized from reverse micelles

    Romano, S. D.; Kurlat, D. H.

    2000-06-01

    TiO 2 sol and gel systems have been synthesized by hydrolysis of titanium butoxide in microemulsions W/O. Different systems compositions were prepared at constant Wo=[H 2O]/[AOT] and changing R=[H 2O]/[Ti(BuO) 4]. Experimental measurements show a progressive increase of the viscosity with time, characteristic of a sol-gel transition. The rheology of the transition was studied by following the behavior of viscoelastic parameters ( G', G″ and η*) as a function of time at different frequencies. The possibility to apply standard percolation theory was discussed. The application of two alternative growth models — either `fractal growth model' or `nearly linear growth model' — has been analysed.

  13. Electrochemical behavior of chemically synthesized selenium thin film.

    Patil, A M; Kumbhar, V S; Chodankar, N R; Lokhande, A C; Lokhande, C D

    2016-05-01

    The facile and low cost simple chemical bath deposition (CBD) method is employed to synthesize red colored selenium thin films. These selenium films are characterized for structural, morphological, topographical and wettability studies. The X-ray diffraction (XRD) pattern showed the crystalline nature of selenium thin film with hexagonal crystal structure. The scanning electron microscopy (SEM) study displays selenium nanoparticles ranging from 20 to 475nm. A specific surface area of 30.5m(2)g(-1) is observed for selenium nanoparticles. The selenium nanoparticles hold mesopores in the range of 1.39nm, taking benefits of the good physicochemical stability and excellent porosity. Subsequently, the electrochemical properties of selenium thin films are deliberated by cyclic voltammetry (CV), galvanostatic charge-discharge and electrochemical impedance spectroscopy (EIS) techniques. The selenium thin film shows specific capacitance (Cs) of 21.98Fg(-1) with 91% electrochemical stability. PMID:26896773

  14. Polymer Films with Ion-Synthesized Cobalt and Iron Nanoparticles

    Popok, Vladimir

    2014-01-01

    The current paper presents an overview and analysis of data obtained on a few sets of polymer samples implanted by iron and cobalt. The low-energy (40 keV) implantations were carried out into polyimide and polyethyleneterephthalate with fluences between 2.5x10e16-1.5x10e17 cm-2. The samples were...... studied using several different methods to obtain information on structural and compositional changes as well as on the evolution of electrical and magnetic properties. High-fluence implantation led to significant carbonization of the polymers and formation of metal nanoparticles in the shallow layers....... Correlation between the structural changes, nucleation and percolation of the particles in relation to electronic properties of the composites are found, described and analysed. A few models explaining electrical and magnetic properties of the polymer films with synthesized metal nanoparticles are suggested....

  15. Nanostructured superhydrophobic films synthesized by electrodeposition of fluorinated polyindoles

    Gabriela Ramos Chagas

    2015-10-01

    Full Text Available Materials with bioinspired superhydrophobic properties are highly desirable for many potential applications. Here, nine novel monomers derived from indole are synthesized to obtain these properties by electropolymerization. These monomers differ by the length (C4F9, C6F13 and C8F17 and the position (4-, 5- and 6-position of indole of the perfluorinated substituent. Polymeric films were obtained with C4F9 and C6F13 chains and differences in the surface morphology depend especially on the substituent position. The polyindoles exhibited hydrophobic and superhydrophobic properties even with a very low roughness. The best results are obtained with PIndole-6-F6 for which superhydrophobic and highly oleophobic properties are obtained due to the presence of spherical nanoparticles and low surface energy compounds.

  16. Synthesizing and salvaging NAD: lessons learned from Chlamydomonas reinhardtii.

    Huawen Lin

    2010-09-01

    Full Text Available The essential coenzyme nicotinamide adenine dinucleotide (NAD+ plays important roles in metabolic reactions and cell regulation in all organisms. Bacteria, fungi, plants, and animals use different pathways to synthesize NAD+. Our molecular and genetic data demonstrate that in the unicellular green alga Chlamydomonas NAD+ is synthesized from aspartate (de novo synthesis, as in plants, or nicotinamide, as in mammals (salvage synthesis. The de novo pathway requires five different enzymes: L-aspartate oxidase (ASO, quinolinate synthetase (QS, quinolate phosphoribosyltransferase (QPT, nicotinate/nicotinamide mononucleotide adenylyltransferase (NMNAT, and NAD+ synthetase (NS. Sequence similarity searches, gene isolation and sequencing of mutant loci indicate that mutations in each enzyme result in a nicotinamide-requiring mutant phenotype in the previously isolated nic mutants. We rescued the mutant phenotype by the introduction of BAC DNA (nic2-1 and nic13-1 or plasmids with cloned genes (nic1-1 and nic15-1 into the mutants. NMNAT, which is also in the de novo pathway, and nicotinamide phosphoribosyltransferase (NAMPT constitute the nicotinamide-dependent salvage pathway. A mutation in NAMPT (npt1-1 has no obvious growth defect and is not nicotinamide-dependent. However, double mutant strains with the npt1-1 mutation and any of the nic mutations are inviable. When the de novo pathway is inactive, the salvage pathway is essential to Chlamydomonas for the synthesis of NAD+. A homolog of the human SIRT6-like gene, SRT2, is upregulated in the NS mutant, which shows a longer vegetative life span than wild-type cells. Our results suggest that Chlamydomonas is an excellent model system to study NAD+ metabolism and cell longevity.

  17. Phosphorylcholine substituted polyolefins: New syntheses, solution assemblies, and polymer vesicles

    Kratz, Katrina A.

    This thesis describes the synthesis and applications of a new series of amphiphilic homopolymers and copolymers consisting of hydrophobic polyolefin backbone and hydrophilic phosphorylcholine (PC) pendant groups. These polymers are synthesized by ring opening metathesis polymerization (ROMP) of a novel PC- cyclooctene monomer, and copolymerization of various functionalized cyclooctene comonomers. Incorporation of different comonomers into the PC-polyolefin backbone affords copolymers with different functionalities, including crosslinkers, fluorophores, and other reactive groups, that tune the range of applications of these polymers, and their hydrophobic/hydrophilic balance. The amphiphilic nature of PC-polyolefins was exploited in oil-water interfacial assembly, providing robust polymer capsules to encapsulate and deliver nanoparticles to damaged regions of a substrate in a project termed `repair-and-go.' In repair-and-go, a flexible microcapsule filled with a solution of nanoparticles probes an imperfection-riddled substrate as it rolls over the surface. The thin capsule wall allows the nanoparticles to escape the capsules and enter into the cracks, driven in part by favorable interactions between the nanoparticle ligands and the cracked surface (i.e., hydrophobic-hydrophobic interactions). The capsules then continue their transport along the surface, filling more cracks and depositing particles into them. The amphiphilic nature of PC-polyolefins was also exploited in aqueous assembly, forming novel polymer vesicles in water. PC-polyolefin vesicles ranged in size from 50 nm to 30 µm. The mechanical properties of PC-polyolefin vesicles were measured by micropipette aspiration techniques, and found to be more robust than conventional liposomes or polymersomes prepared from block copolymers. PC-polyolefin vesicles have potential use in drug delivery; it was found that the cancer drug doxorubicin could be encapsulated efficiently in PC-polyolefin vesicles. In

  18. Template synthesized chitosan nano test tubes for drug delivery applications

    Perry, Jillian L. Moulton

    There is tremendous current interest in developing nanoscale drug delivery vehicles. Though intensive efforts have focused on developing spherical drug delivery vehicles, cylindrically shaped vehicles such as nanotubes offer many advantages. Typically, nanotubes can carry a larger inner payload than nanoparticles of the same diameter. Also, we can prepare nanotubes in templates whose geometries can be controlled, in turn allowing precise control over the length and diameter of the tubes. In addition, template synthesized nanotubes can be differentially functionalized on the inner and outer surfaces. Furthermore, templates that are closed on one end can be used to fabricate nano test tubes (closed on one end). The geometry of these nano test tubes allows them to be easily filled with a payload, the open end sealed with a nanoparticle to protect the payload from leaking out, and then the exterior of the tube can be functionalized with a targeting moiety. In an effort to develop such a system, we explored the fabrication of chitosan nano test tubes. Defect-free, chitosan nano test tubes of uniform size were synthesized within the pores of a nanoporous alumina template membrane. While the nano test tubes remained within the template membrane, their inner cavities were filled with a model payload. The payload was then trapped inside the nano test tubes by sealing the open ends of the tubes with latex nanoparticle caps. For proof-of-principle studies, imine linkages were used to attach the caps to the nano test tubes. To create a self-disassembling system, disulfide chemistry was used to covalently cap the nano test tubes. Once removed from the template, the exterior of the nano test tubes were modified with a targeting moiety, allowing them to be targeted to pathological sites. We have also shown that the chitosan nano test tubes are biodegradable by two systems: enzymatic cleavage by lysozymes and disulfide cleavage of the crosslinker by reducing environments

  19. Syntheses and Chemosensory of Anthracene and Phenanthrene Bisimide Derivatives

    Bogusz, Zachary A.

    2004-01-01

    As the present technology of biochemical weapons advances, it is essential for science to attempt to prepare our nation for such an occurrence. Various areas of current research are devoted to precautionary measures and potential antidotes for national security. A practical application of these precautions would be the development of a chemical capable of detecting harmful gas. The benefits of being capable to synthesis a chemical compound that would warn and identify potentially deadly gases would ensure a higher level of safety. The chemicals in question can be generalized as bisimide anthracene derivatives. The idea behind these compounds is that in the presence of certain nerve gases, the compound will actually fluoresce, giving an indication that there is a strong likelihood of the presence of a nerve gas and ensure the proper precautionary measures are taken. The fluorescence is due to the quenching of an electric proton transfer within the structure of the molecule. The system proves to be very unique on account of the fact that the fluorescence can be "turned off" by reducing the system. By utilizing the synthesis designed by Dr. Faysal Ilhan, four distinct compounds can be synthesized through photochemical reactions involving para- and ortho- diketones. The photochemistry involved is very modem and much research is being devoted to fully understanding the possibilities and alternative applications of such materials. and meta-nitro anthracene bisimide (ABI-NO2), the amine of each (ABI-NH2), a para- and meta-nitro phenanthrene bisimjde (PBI-NO2), and the amine of each (PBI-NH2). Upon synthesizing these distinct compounds, I must then purify and analyze them in order to obtain any relevant trends, behaviors, and characteristics. The chemical composition analyses that will be conducted are the procedures taken by Dr. Daniel Tyson on previous experiments. The results generated from the data will point further research in the correct direction and hopefully

  20. SO2 removal from flue gases using utility synthesized zeolites

    It is well known that natural and synthetic zeolites (molecular sieves) can adsorb gaseous SO2 from flue gas and do it more efficiently than lime based scrubbing materials. Unfortunately their cost ($500-$800 per ton) has deterred their use in this capacity. It is also known that zeolites are easy to synthesize from a variety of natural and man-made materials. The overall objective of the current work has been to evaluate the feasibility of having a utility synthesize its own zeolites, on-site, from fly ash and other recycled materials and then use these zeolites to adsorb SO2 from their flue gases. Work to date has shown that the efficiency of the capture process is related to the degree of crystallinity and the type of zeolite that forms in the samples. Normally, those samples cured at 150C contained a greater proportion of zeolite and as such were more SO2 adsorptive than their low-temperature counterparts. However, in order for the project to be successful, on site synthesis must remain an option, i.e. 100C synthesis. In light of this, the experimental focus now has two aspects. First, compositions of the starting materials are being altered by blending the current suite of fly ashes with other fly ashes, ground glass cullet and silica fume to promote the formation and growth of well crystallized and highly adsorptive zeolites. Second, greater degrees of reaction at significantly lower temperatures are being promote by ball milling the fly ash prior to use, by the use of more concentrated caustic solutions, and by the addition of zeolite seeds to the reactants. In all cases studies will focus on the effect of structure type and degree of conversion on SO2 adsorption. Future work will concentrate on the study of the effect of weathering on the suitability of converting fly ash into zeolites. This is an especially important study, considering the acres of fly ash now in storage throughout the country

  1. A synthesized windfield model for tornado missile transport

    A tornado windfield model has been developed for use in a probabilistic assessment of the tornado missile hazard to nuclear power plants. Tornado flow characteristics have been identified which are significant in terms of missile transport phenomena. In order to account for both modeling uncertainty and the natural variability observed among tornadoes, several random variables are specified in the model, including: tornado intensity, path width, translational speed, radius to maximum tangential velocity, ratio of radial-to-tangential wind speed, vertical variation of core size, and boundary layer thickness. Considering the lack of agreement regarding detailed tornado dynamics as well as the difficulty in establishing a priori conservative flow characteristics for missile transport, the windfield model was synthesized from theoretical, observational, and probabilistic considerations. A significant aspect of the model is that the parameters can be adjusted to make the intensity size and velocity variables consistent with the tornado path width boundary specification. The modelling considerations are discussed, the windfield model and calculational procedure presented, sample windfield component velocity profiles illustrated, and missile velocity statistics given for a simulation case study involving several thousand missile histories. (Auth.)

  2. Morphology and electrical properties of template-synthesized polypyrrole nanocylinders

    Mativetsky, J. M.; Datars, W. R.

    2002-11-01

    Polypyrrole nanocylinders were fabricated by chemically synthesizing polypyrrole within the pores of nanoporous polycarbonate particle track-etched membranes. The morphology of the nanostructures was characterized by transmission electron microscopy and scanning electron microscopy. The nanocylinders were observed to be cigar-shaped, with the diameter at the center being up to 2.5 times the diameter at the ends. The electrical conductivity of the nanocylinders was measured by leaving the nanocylinders embedded in the insulating template membrane and measuring the trans-membrane resistance. The cigar-like shape of the nanocylinders was taken into account in calculating the conductivity. Contrary to previous reports, the smallest diameter nanocylinders exhibited a slightly lower conductivity relative to the larger diameter nanocylinders. The temperature dependence of the resistance and magnetoresistance was in accordance with Mott variable range hopping at temperatures above 5±1 K and Efros-Shklovskii variable range hopping at temperatures below 5±1 K. Based on the measurements in the Mott regime, the localization length, the density of states at the Fermi energy, and the temperature dependence of the average hopping distance were calculated.

  3. Syntheses of Binuclear Copper(Ⅰ)Complexes Containing Benzimidazole

    LIU Ying-Fan; ZHAO Dong; GUO Li-Bing; ZHENG Xin; SUN Yu-An

    2005-01-01

    A binuclear copper(Ⅰ) complex [Cu2(dppm)2(C7H6N2)2](NO3)2 (C7H6N2 = benzimidazole, dppm = Ph2PCH2PPh2) has been synthesized and characterized by X-ray crystallography.The crystal belongs to monoclinic, space group C2/c with a = 14.167(3), b = 21.209(4), c =20.680(4) A, β = 103.93(3)°, C32H28CuN3O3P2, Mr = 628.05, Z = 8,μ = 0.868 mm-1, V = 6031 (2)(。A)3,F(000) = 2592, Dc= 1.383 g/cm3, R = 0.0593 and wR = 0.1736.A total of 5297 independent reflec tions were collected, of which 3503 were observed with I > 2σ(I).The central copper atom is tri-coordinated by phosphorus atoms from bridging dppm and nitrogen atom from benzimidazole.In the coordination sphere, the bond lengths of Cu-P(1) and Cu-P(2) are 2.2607(17) and 2.2503(16)(。A),respectively and the P-Cu-P bond angle is 127.26(6)°.

  4. Carbon nanofibers synthesized by pyrolysis of chloroform and ethanol mixture

    Platelet graphite nanofibers (PGNFs) and turbostratic carbon nanofibers (TSCNFs) were synthesized by the pyrolysis of 3 and 10 vol% chloroform in ethanol, respectively, in the presence of Ni catalyst at 700 °C. Auger electron spectrometry analysis reveals that the participation of chloroform in the synthesis led to Ni–Cl bonding on the surface of the catalysts, resulting in a relatively poor crystalline layer and a coarse surface. Furthermore, the Ni–Cl compound affected the melting point and mobility of Ni, changing the morphology and geometrical shape of Ni particles. A low amount of chlorine in the catalyst led to the formation of smaller catalyst particles with a flat surface, resulting in graphene nanosheets stacked perpendicular to the fiber axis, which became PGNFs. In contrast, a high amount of chlorine in the catalyst led to the aggregation of the catalyst and thus the formation of large catalyst particles with a rough surface, resulting in the random stacking of graphene nanosheets, which became TSCNFs. The participation of chlorine was found to be important in the synthesis of the PGNFs and TSCNFs. - Graphical abstract: Display Omitted - Highlights: • The morphology of CNFs changed while different amount of CHCl3 presented. • The interaction of Ni and Cl changed the geometry and morphology of catalysts. • The structure of CNFs formed attributed to the surface morphology of catalysts. • PGNFs and TSCNFs were perpendicular and random stacking of graphene

  5. Perfluorocyclobutyl-containing Amphiphilic Block Copolymers Synthesized by RAFT Polymerization

    LI, Yongjun; ZHANG, Sen; FENG, Chun; ZHANG, Yaqin; LI, Qingnuan; LI, Wenxin; HUANG, Xiaoyu

    2009-01-01

    Amphiphilic block copolymers containing hydrophobic perfluorocyclobutyl-based (PFCB) polyacrylate and hydrophilic poly(ethylene glycol) (PEG) segments were prepared via reversible addition-fragmentation chain transfer (RAP-T) polymerization. The PFCB-containing acrylate monomer, p-(2-(p-tolyloxy)perfluorocyclobutoxy)phenyl acrylate, was first synthesized from commercially available compounds in good yields, and this kind of acrylate monomer can be homopolymerized by free radical polymerization or RAFT polymerization. Kinetic study showed the 2,2'-azobis(isobutyronitrile) (AIBN) initiated and cumyl dithiobenzoate (CDB) mediated RAFT polymerization was in a living fashion, as suggested by the fact that the number-average molecular weights (M_n) increased linearly with the conversions of the monomer, while the polydispersity indices kept less than 1.10. The block polymers with narrow molecular weight distributions (M_w/M_n≤1.21) were prepared through RAFT polymerization using PEG monomethyl ether capped with 4-cyanopentanoic acid dithiobenzoate end group as the macro chain transfer agent (mPEG-CTA). The length of the hydrophobic segment can be tuned by the feed ratio of the PFCB-based acrylate monomer and the extending of the polymerization time. The micellization behavior of the block copolymers in aqueous media was investigated by the fluorescence probe technique.

  6. Making the Bread: Insights from Newly Synthesized Allohexaploid Wheat.

    Li, Ai-li; Geng, Shuai-Feng; Zhang, Lian-quan; Liu, Deng-cai; Mao, Long

    2015-06-01

    Bread wheat (or common wheat, Triticum aestivum) is an allohexaploid (AABBDD, 2n = 6x = 42) that arose by hybridization between a cultivated tetraploid wheat T. turgidum (AABB, 2n = 4x = 28) and the wild goatgrass Aegilops tauschii (DD, 2n = 2x = 14). Polyploidization provided niches for rigorous genome modification at cytogenetic, genetic, and epigenetic levels, rendering a broader spread than its progenitors. This review summarizes the latest advances in understanding gene regulation mechanisms in newly synthesized allohexaploid wheat and possible correlation with polyploid growth vigor and adaptation. Cytogenetic studies reveal persistent association of whole-chromosome aneuploidy with nascent allopolyploids, in contrast to the genetic stability in common wheat. Transcriptome analysis of the euploid wheat shows that small RNAs are driving forces for homoeo-allele expression regulation via genetic and epigenetic mechanisms. The ensuing non-additively expressed genes and those with expression level dominance to the respective progenitor may play distinct functions in growth vigor and adaptation in nascent allohexaploid wheat. Further genetic diploidization of allohexaploid wheat is not random. Regional asymmetrical gene distribution, rather than subgenome dominance, is observed in both synthetic and natural allohexaploid wheats. The combinatorial effects of diverged genomes, subsequent selection of specific gene categories, and subgenome-specific traits are essential for the successful establishment of common wheat. PMID:25747845

  7. Characterization of carbon cryogels synthesized by sol-gel polycondensation

    BILJANA BABIC

    2005-02-01

    Full Text Available Resorcinol-formaldehyde (RF cryogels were synthesized by the sol-gel polycondensation of resorcinol (R with formaldehyde (F and freeze-drying was carried out with t-butanol. Carbon cryogels were obtained by pyrolyzing RF cryogels in an inert atmosphere. Characterization by nitrogen adsorption showed that the carbon cryogels were micro and mesoporous materials with high specific surface areas (SBET ~ 550 m2/g. Cyclic voltammetry experiments at various scan rates (2 to 200 mV s-1 were performed to study the electrical double-layer charging of carbon cryogel electrodes in 0.5 mol dm-3 HClO4 solution. It has been demonstrated that it is possible to sub-divide the total specific capacitance into the mesoporous and the microporous specific capacitance by analyzing the linear dependence of the charge (q on the reciprocal of the square root of the potential scan rate (v-1/2, and the linear dependence of the reciprocal charge (1/q on the square root of the potential scan rate (v-1/2. The specific capacitance was found to be constant over a wide range of sample weight (12.5 to 50.0 mg and a very promising specific capacitance value of 150 F/g, was found for this material operating in an acidic 0.5 mol dm-3 HClO4 solution at room temperature.

  8. Antibacterial effect of bismuth subsalicylate nanoparticles synthesized by laser ablation

    Flores-Castañeda, Mariela [Instituto Nacional de Investigaciones Nucleares (Mexico); Vega-Jiménez, Alejandro L., E-mail: argelia.almaguer@mac.com; Almaguer-Flores, Argelia [Universidad Nacional Autónoma de México, Facultad de Odontología, DEPeI, I (Mexico); Camps, Enrique; Pérez, Mario [Instituto Nacional de Investigaciones Nucleares (Mexico); Silva-Bermudez, Phaedra [Instituto Nacional de Rehabilitación, Unidad de Ingeniería de Tejidos, Terapia Celular y Medicina Regenerativa (Mexico); Berea, Edgardo [FarmaQuimia SA de CV. (Mexico); Rodil, Sandra E. [Universidad Nacional Autónoma de México, Instituto de Investigaciones en Materiales (Mexico)

    2015-11-15

    The antimicrobial properties of bismuth subsalicylate (BSS) nanoparticles against four opportunistic pathogens; E. coli, P. aeruginosa, S. aureus, and S. epidermidis were determined. BSS nanoparticles were synthesized by pulse laser ablation of a solid target in distilled water under different conditions. The nanoparticles were characterized using high-resolution transmission electron microscopy and absorption spectra and small angle X-ray scattering. The analysis shows that the colloids maintained the BSS structure and presented average particle size between 20 and 60 nm, while the concentration ranges from 95 to 195 mg/L. The antibacterial effect was reported as the inhibition ratio of the bacterial growth after 24 h and the cell viability was measured using the XTT assay. The results showed that the inhibition ratio of E. coli and S. epidermidis was dependant on the NPs size and/or concentration, meanwhile P. aeruginosa and S. aureus were more sensitive to the BSS nanoparticles independently of both the size and the concentration. In general, the BSS colloids with average particle size of 20 nm were the most effective, attaining inhibition ratios >80 %, similar or larger than those obtained with the antibiotic used as control. The results suggest that the BSS colloids could be used as effective antibacterial agents with potential applications in the medical area.

  9. Evaluation of cytotoxicity of polypyrrole nanoparticles synthesized by oxidative polymerization

    Vaitkuviene, Aida [Department of Physical Chemistry, Faculty of Chemistry, Vilnius University, Naugarduko 24, LT-03225 Vilnius (Lithuania); Department of Stem Cell Biology, State Research Institute Center for Innovative Medicine, Zygimantu 9, LT-01102 Vilnius (Lithuania); Kaseta, Vytautas [Department of Stem Cell Biology, State Research Institute Center for Innovative Medicine, Zygimantu 9, LT-01102 Vilnius (Lithuania); Voronovic, Jaroslav [Department of Physical Chemistry, Faculty of Chemistry, Vilnius University, Naugarduko 24, LT-03225 Vilnius (Lithuania); Ramanauskaite, Giedre; Biziuleviciene, Gene [Department of Stem Cell Biology, State Research Institute Center for Innovative Medicine, Zygimantu 9, LT-01102 Vilnius (Lithuania); Ramanaviciene, Almira [NanoTechnas–Center of Nanotechnology and Material Science at Department of Analytical and Environmental Chemistry, Faculty of Chemistry, Vilnius University, Naugarduko 24, 03225 Vilnius (Lithuania); Ramanavicius, Arunas, E-mail: Arunas.Ramanavicius@chf.vu.lt [Department of Physical Chemistry, Faculty of Chemistry, Vilnius University, Naugarduko 24, LT-03225 Vilnius (Lithuania); Laboratory of BioNanoTechnology, Department of Materials Science and Electronics, Institute of Semiconductor Physics, State Scientific Research Institute Centre for Physical Sciences and Technology, A. Gostauto 11, LT-01108 Vilnius (Lithuania)

    2013-04-15

    Highlights: ► Polypyrrole nanoparticles synthesized by environmentally friendly polymerization at high concentrations are cytotoxic. ► Primary mouse embryonic fibroblast, mouse hepatoma and human T lymphocyte Jurkat cell lines were treated by Ppy nanoparticles. ► Polypyrrole nanoparticles at high concentrations inhibit cell proliferation. -- Abstract: Polypyrrole (Ppy) is known as biocompatible material, which is used in some diverse biomedical applications and seeming to be a very promising for advanced biotechnological applications. In order to increase our understanding about biocompatibility of Ppy, in this study pure Ppy nanoparticles (Ppy-NPs) of fixed size and morphology were prepared by one-step oxidative polymerization and their cyto-compatibility was evaluated. The impact of different concentration of Ppy nanoparticles on primary mouse embryonic fibroblasts (MEF), mouse hepatoma cell line (MH-22A), and human T lymphocyte Jurkat cell line was investigated. Cell morphology, viability/proliferation after the treatment by Ppy nanoparticles was evaluated. Obtained results showed that Ppy nanoparticles at low concentrations are biocompatible, while at high concentrations they became cytotoxic for Jurkat, MEF and MH-22A cells, and it was found that cytotoxic effect is dose-dependent.

  10. Of Syntheses and Surprises:Toward a Critical Integral Theory

    Daniel Gustav Anderson

    2006-12-01

    Full Text Available The central concern of this article is how the search for formal structures with universal values functions ideologically, addressing Zizek’s claim that East-West syntheses may represent the dominant ideology par excellance of global capitalism. To this end, the article offers a Foucaultian genealogy of Integral theory, tracing its origins to the cultural and subjective contingencies of the British Empire, primarily in the work of Integral theory’s foundational thinker, Aurobindo Ghose. The article poses a primary critique of synthesis and evolution as mythological keys to Ultimate Reality which suggests that Zizek’s critique may have some validity, and offers the potential for a “critical integral theory” as an alternative. Situated in Deleuze and Guattari’s concept of becoming, and represented in the ideas and practices of a constellation of thinkers inclusive of Gurdjieff, Benjamin, and Trungpa, the article’s view of integration supports radical democracy as presented in the writings of Laclau and Mouffe as a model outcome for social and personal transformational practices.

  11. Multifunctional Catalysts to Synthesize and Utilize Energy Carriers

    Lercher, Johannes A.; Appel, Aaron M.; Autrey, Thomas; Bullock, R. Morris; Camaioni, Donald M.; Cho, Herman M.; Dixon, David A.; Dohnalek, Zdenek; Gao, Feng; Glezakou, Vassiliki Alexandra; Henderson, Michael A.; Hu, Jian Z.; Iglesia, Enrique; Karkamkar, Abhijeet J.; Kay, Bruce D.; Kimmel, Gregory A.; Linehan, John C.; Liu, Jun; Lyubinetsky, Igor; Mei, Donghai; Peden, Charles HF; Rousseau, Roger J.; Schenter, Gregory K.; Shaw, Wendy J.; Szanyi, Janos; Wang, Huamin; Wang, Yong; Weber, Robert S.

    2014-06-23

    The central role and critical importance of catalysis in a future based on sustainability, together with the insight that developments have to be knowledge-based have motivated significant efforts to better understand catalyzed processes and to develop new catalytic routes from this knowledge. Overall, three main energy carriers are used worldwide, carbon (and hydrocarbons), hydrogen, and electrons. Conventionally, the stored energy is accessed by oxidizing carbon and hydrogen, forming O-H and C-O bonds and performing work with the produced heat or electricity. Conversely, to synthesize energy carriers sustainably, it is consequently required to reverse the direction, i.e., to break C-O and O-H bonds and form C-C, C-H and H-H bonds. To address these challenges, PNNL’s BES-sponsored program comprises three thrust areas with subtasks, focusing on the fundamentals of biomass conversion processes, direct and indirect CO2 reduction, and on elementary studies aimed at generating and using H2. Multi-functionality, i.e., the simultaneous interaction of more than one catalytically active site with the substrate is the key to achieving the atom and energy efficiency in individual steps. The combination of several types of these sites with carefully selected energetics and rate constants is used to generate complex catalysts able to enhance the rates of multistep processes. This short report summarizes recent results obtained in this BES-funded program.

  12. Microreactors—A Powerful Tool to Synthesize Peroxycarboxylic Esters

    Tobias Illg

    2015-12-01

    Full Text Available The synthesis of peroxycarboxylic esters, as one subgroup of organic peroxides, is characterized by a high thermal hazard potential regarding process safety. In case of failure in the production process, e.g., if the heat of reaction cannot be removed sufficiently fast, decomposition reactions can be triggered, and as a result, remarkable amounts of heat and gas can be released and can cause a high extent of damage. Multifarious technical and organizational measures are necessary to ensure the safe industrial production of peroxides. With the introduction of microreaction technology plenty of possibilities have been opened to carry out highly exothermic reactions in smaller volumes and with more efficient heat removal. In this paper we report the application of three different microstructured reactors, representing different mixing strategies, to synthesize two peroxymonocarboxylic esters, namely tert-butyl peroxypivalate and tert-butyl peroxy-2-ethylhexanoate. The following reactor types were considered: an orifice microreactor, a split and recombine microreactor and a capillary tube reactor in combination with ultrasonication. The efficiency of the two phase liquid/liquid reaction is expressed in comparison of conversion and selectivity. With microreaction technology a remarkable increase in space-time-yield, ranging from 12,500 kg·m−3·h−1 to 414,000 kg·m−3·h−1, is achieved.

  13. Design, syntheses, and conformational study of angiogenesis inhibitors

    Since anti-angiogensis could lead to the suppression of tumor growth, angiogenesis inhibitors have received particular attention for their therapeutic potential. In this study, two angiogenic inhibitors using the bioactive sequence from the kringle 5, AK1(KLYDY), AK2(KLWDF) were designed and synthesized. We have investigated their solution structures using NMR spectroscopy and their activities as angiogenesis inhibitors. AK2 has an intramolecular hydrogen bond between the side chain amino proton of Lys1 and the carboxy1 oxygen of Asp4 with a N···O distance of 3.27 A, while AK1 shows more flexible structures than AK2. Indole ring in Trp is much bigger than the phenyl ring in Tyr and may have good face-to-edge interaction enforcing more rigid and constrained conformational features of AK2. Because of this relatively stable structure, Trp3 in AK2 may have better hydrophobic interaction with Phe5 than Tyr3 in AK1 if two adjacent aromatic groups are located in hydrophobic pocket of receptor. Since AK2 shows the similar anti-angiogenic activities to AK1, we are also able to confirm that the activity of AK1 is irrelevant to the Tyr phosphorylation. More rigid drug with higher activities can be provided by the mimetic approaches. For the further development of the angiogenesis inhibitors, these conformational studies on our lead peptides will be helpful in design of peptidomimetics

  14. TOP as ligand and solvent to synthesize silver telluride nanosheets

    Chen, Shutang, E-mail: shutang.chen@uconn.edu [Division of Energy Systems Research, Ajou University, Suwon 443-749 (Korea, Republic of); Department of Chemistry, University of Connecticut, Storrs 06269 (United States); Lee, Soonil, E-mail: soonil@ajou.ac.kr [Division of Energy Systems Research, Ajou University, Suwon 443-749 (Korea, Republic of)

    2015-11-15

    Highlights: • Silver telluride nanosheets were prepared through one-pot synthetic strategy. • TOP as both ligand and solvent favors silver telluride nanosheets growth. • The I–V curve of an Ag{sub 2}Te-nanosheet film indicates that as-prepared Ag{sub 2}Te nanosheets have good electric conductivity. - Abstract: Ag{sub 2}Te nanosheets are synthesized by a simple one-pot route using trioctylphosphine (TOP) as both solvent and stabilizer. Various controlling parameters were examined, such as molar ratios of AgNO{sub 3} to tellurium powder, reaction temperature and time, and precursor concentration. The morphology and composition of the products were characterized by X-ray diffraction, field-emission scanning electron microscopy, energy-dispersive X-ray spectroscopy, and transmission electron microscopy. On the basis of a series of synthesis and characterizations, the formation mechanism of the Ag{sub 2}Te nanosheets are discussed. The I–V curve of an Ag{sub 2}Te-nan osheet film indicates that as-prepared Ag{sub 2}Te nanosheets have good electric conductivity.

  15. Synthesizing complex movement fragment representations from motor cortical ensembles

    Hatsopoulos, Nicholas G.; Amit, Yali

    2011-01-01

    We have previously shown that the responses of primary motor cortical neurons are more accurately predicted if one assumes that individual neurons encode temporally-extensive movement fragments or preferred trajectories instead of static movement parameters (Hatsopoulos et al., 2007). Building on these findings, we examine here how these preferred trajectories can be combined to generate a rich variety of preferred movement trajectories when neurons fire simultaneously. Specifically, we used a generalized linear model to fit each neuron’s spike rate to an exponential function of the inner product between the actual movement trajectory and the preferred trajectory; then, assuming conditional independence, when two neurons fire simultaneously their spiking probabilities multiply implying that their preferred trajectories add. We used a similar exponential model to fit the probability of simultaneous firing and found that the majority of neuron pairs did combine their preferred trajectories using a simple additive rule. Moreover, a minority of neuron pairs that engaged in significant synchronization combined their preferred trajectories through a small scaling adjustment to the additive rule in the exponent, while preserving the predicted trajectory representation from the additive rule. These results suggest that complex movement representations can be synthesized in simultaneously firing neuronal ensembles by adding the trajectory representations of the constituents in the ensemble. PMID:21939762

  16. Characterization of silver nanoparticles synthesized on titanium dioxide fine particles

    Nino-Martinez, N [Facultad de Ciencias, UASLP, Alvaro Obregon 64, CP 78000, San Luis PotosI, SLP (Mexico); Martinez-Castanon, G A [Maestria en Ciencias Odontologicas, Facultad de EstomatologIa, UASLP, Avenida Manuel Nava 2, Zona Universitaria, San Luis PotosI, SLP (Mexico); Aragon-Pina, A [Instituto de Metalurgia, Facultad de IngenierIa, UASLP, Alvaro Obregon 64, CP 78000, San Luis PotosI, SLP (Mexico); Martinez-Gutierrez, F [Facultad de Ciencias Quimicas, UASLP, Alvaro Obregon 64, CP 78000, San Luis PotosI, SLP (Mexico); Martinez-Mendoza, J R [Facultad de Ciencias, UASLP, Alvaro Obregon 64, CP 78000, San Luis PotosI, SLP (Mexico); Ruiz, Facundo [Facultad de Ciencias, UASLP, Alvaro Obregon 64, CP 78000, San Luis PotosI, SLP (Mexico)

    2008-02-13

    Silver nanoparticles with a narrow size distribution were synthesized over the surface of two different commercial TiO{sub 2} particles using a simple aqueous reduction method. The reducing agent used was NaBH{sub 4}; different molar ratios TiO{sub 2}:Ag were also used. The nanocomposites thus prepared were characterized using transmission electron microscopy (TEM), scanning transmission electron microscopy (STEM), scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDS), x-ray photoelectron spectroscopy (XPS), x-ray diffraction (XRD), dynamic light scattering (DLS) and UV-visible (UV-vis) absorption spectroscopy; the antibacterial activity was assessed using the standard microdilution method, determining the minimum inhibitory concentration (MIC) according to the National Committee for Clinical Laboratory Standards. From the microscopy studies (TEM and STEM) we observed that the silver nanoparticles are homogeneously distributed over the surface of TiO{sub 2} particles and that the TiO{sub 2}:Ag molar ratio plays an important role. We used three different TiO{sub 2}Ag molar ratios and the size of the silver nanoparticles is 10, 20 and 80 nm, respectively. It was found that the antibacterial activity of the nanocomposites increases considerably comparing with separated silver nanoparticles and TiO{sub 2} particles.

  17. Characterization of silver nanoparticles synthesized on titanium dioxide fine particles

    Silver nanoparticles with a narrow size distribution were synthesized over the surface of two different commercial TiO2 particles using a simple aqueous reduction method. The reducing agent used was NaBH4; different molar ratios TiO2:Ag were also used. The nanocomposites thus prepared were characterized using transmission electron microscopy (TEM), scanning transmission electron microscopy (STEM), scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDS), x-ray photoelectron spectroscopy (XPS), x-ray diffraction (XRD), dynamic light scattering (DLS) and UV-visible (UV-vis) absorption spectroscopy; the antibacterial activity was assessed using the standard microdilution method, determining the minimum inhibitory concentration (MIC) according to the National Committee for Clinical Laboratory Standards. From the microscopy studies (TEM and STEM) we observed that the silver nanoparticles are homogeneously distributed over the surface of TiO2 particles and that the TiO2:Ag molar ratio plays an important role. We used three different TiO2Ag molar ratios and the size of the silver nanoparticles is 10, 20 and 80 nm, respectively. It was found that the antibacterial activity of the nanocomposites increases considerably comparing with separated silver nanoparticles and TiO2 particles

  18. Three pharmaceuticals cocrystals of adefovir: Syntheses, structures and dissolution study

    Zhang, Xiaoming; Sun, Fuxing; Zhang, Tingting; Jia, Jiangtao; Su, Hongmin; Wang, Chenhui; Zhu, Guangshan

    2015-11-01

    We report here three novel cocrystals, which are composed of adefovir as the API (Active Pharmaceutical Ingredient) with p-aminobenzoic acid (1, 2C8H12N5O4P·C7H6NO2·3H2O), 3,5-dihydroxybenzoic acid (2, C8H12N5O4P·C7H6O4·H2O) and 2,6-pyridinedicarboxlic acid (3, C8H12N5O4P·C7H5NO4) as CCFs (cocrystal formers) respectively by crystal engineering strategy. Their structures were characterized by single crystal X-ray diffraction, powder X-ray diffraction (PXRD) analysis, thermogravimetric analyses (TGA), elemental analysis (EA) and infrared spectral analysis (IR). The analysis of single crystal X-ray diffraction demonstrate that cocrystal 1 and 2 form a strong hydrogen-bonded assembly through the phosphoric acids of API with water in the lattice and carboxylic acids of CCF respectively. Cocrystal 3 is formed in which the phosphoric acid groups of API are also held by the carboxylic acid groups of CCF. The PXRD results indicate their high purity of as-synthesized samples. The TGA, EA, IR and dissolution study of API and the cocrystals were also measured and discussed.

  19. Properties of radiation-synthesized polyvinylpyrrolidone/chitosan hydrogel blends

    Poly(vinylpyrrolidone) (PVP)-crosslinked chitosan hydrogels were prepared by gamma radiation at various doses; 1, 3 5, 7, 10, 15, 20, 25 and 30kGy. Gamma radiation was used as a crosslinking tool which requires no chemical initiator, no heating process and need no purification step on the end products obtained. The hydrogel formulations were composed of 6% chitosan with average molecular weight (Mw) = 48 800 g/mol and 14% PVP with Mw = 10 000 g/mol in 2% lactic acid. Physical properties of hydrogels such as gel fraction and swelling property at pH 5.5 and pH 7.0 as well as syneresis activity were determined. It was found that different radiation dose induces different effect on hydrogels’ network formed. Morphological study of hydrogels has been carried out by scanning electron microscope (SEM). From these preliminary evaluations, it can be concluded that gamma radiation is an effective tool for network development of hydrogels and it also induces enhancement on characteristics of hydrogels synthesized

  20. Properties of radiation-synthesized polyvinylpyrrolidone/chitosan hydrogel blends

    Mahmud, Maznah; Daik, Rusli; Adam, Zainah

    2015-09-01

    Poly(vinylpyrrolidone) (PVP)-crosslinked chitosan hydrogels were prepared by gamma radiation at various doses; 1, 3 5, 7, 10, 15, 20, 25 and 30kGy. Gamma radiation was used as a crosslinking tool which requires no chemical initiator, no heating process and need no purification step on the end products obtained. The hydrogel formulations were composed of 6% chitosan with average molecular weight (Mw) = 48 800 g/mol and 14% PVP with Mw = 10 000 g/mol in 2% lactic acid. Physical properties of hydrogels such as gel fraction and swelling property at pH 5.5 and pH 7.0 as well as syneresis activity were determined. It was found that different radiation dose induces different effect on hydrogels' network formed. Morphological study of hydrogels has been carried out by scanning electron microscope (SEM). From these preliminary evaluations, it can be concluded that gamma radiation is an effective tool for network development of hydrogels and it also induces enhancement on characteristics of hydrogels synthesized.

  1. Microreactors-A Powerful Tool to Synthesize Peroxycarboxylic Esters.

    Illg, Tobias; Knorr, Annett; Fritzsche, Lutz

    2015-01-01

    The synthesis of peroxycarboxylic esters, as one subgroup of organic peroxides, is characterized by a high thermal hazard potential regarding process safety. In case of failure in the production process, e.g., if the heat of reaction cannot be removed sufficiently fast, decomposition reactions can be triggered, and as a result, remarkable amounts of heat and gas can be released and can cause a high extent of damage. Multifarious technical and organizational measures are necessary to ensure the safe industrial production of peroxides. With the introduction of microreaction technology plenty of possibilities have been opened to carry out highly exothermic reactions in smaller volumes and with more efficient heat removal. In this paper we report the application of three different microstructured reactors, representing different mixing strategies, to synthesize two peroxymonocarboxylic esters, namely tert-butyl peroxypivalate and tert-butyl peroxy-2-ethylhexanoate. The following reactor types were considered: an orifice microreactor, a split and recombine microreactor and a capillary tube reactor in combination with ultrasonication. The efficiency of the two phase liquid/liquid reaction is expressed in comparison of conversion and selectivity. With microreaction technology a remarkable increase in space-time-yield, ranging from 12,500 kg·m(-3)·h(-1) to 414,000 kg·m(-3)·h(-1), is achieved. PMID:26703553

  2. Differential Transcriptome Analysis between Paulownia fortunei and Its Synthesized Autopolyploid

    Xiaoshen Zhang

    2014-03-01

    Full Text Available Paulownia fortunei is an ecologically and economically important tree species that is widely used as timber and chemical pulp. Its autotetraploid, which carries a number of valuable traits, was successfully induced with colchicine. To identify differences in gene expression between P. fortunei and its synthesized autotetraploid, we performed transcriptome sequencing using an Illumina Genome Analyzer IIx (GAIIx. About 94.8 million reads were generated and assembled into 383,056 transcripts, including 18,984 transcripts with a complete open reading frame. A conducted Basic Local Alignment Search Tool (BLAST search indicated that 16,004 complete transcripts had significant hits in the National Center for Biotechnology Information (NCBI non-redundant database. The complete transcripts were given functional assignments using three public protein databases. One thousand one hundred fifty eight differentially expressed complete transcripts were screened through a digital abundance analysis, including transcripts involved in energy metabolism and epigenetic regulation. Finally, the expression levels of several transcripts were confirmed by quantitative real-time PCR. Our results suggested that polyploidization caused epigenetic-related changes, which subsequently resulted in gene expression variation between diploid and autotetraploid P. fortunei. This might be the main mechanism affected by the polyploidization. Our results represent an extensive survey of the P. fortunei transcriptome and will facilitate subsequent functional genomics research in P. fortunei. Moreover, the gene expression profiles of P. fortunei and its autopolyploid will provide a valuable resource for the study of polyploidization.

  3. Nanomechanical characterization of bioglass films synthesized by magnetron sputtering

    Popa, A.C. [National Institute of Materials Physics, 077125 Magurele (Romania); Army Centre for Medical Research, 020012 Bucharest (Romania); Department of Cellular and Molecular Medicine, “Carol Davila” University of Medicine and Pharmacy, 050474 Bucharest (Romania); Marques, V.M.F. [Department of Materials, University of Oxford, Parks Road, Oxford OX1 3PH (United Kingdom); Stan, G.E., E-mail: george_stan@infim.ro [National Institute of Materials Physics, 077125 Magurele (Romania); Husanu, M.A.; Galca, A.C.; Ghica, C. [National Institute of Materials Physics, 077125 Magurele (Romania); Tulyaganov, D.U. [Turin Polytechnic University in Tashkent, 100174 Tashkent (Uzbekistan); Lemos, A.F.; Ferreira, J.M.F. [Department of Materials and Ceramics Engineering, CICECO, University of Aveiro, 3810-193 Aveiro (Portugal)

    2014-02-28

    Bioactive glasses are osteoproductive-type inorganic materials possessing the highest indices of bioactivity in both bulk and thin film forms. The prerequisites for reliable implant-type coatings are both their biological and mechanical performances. Whilst the bioglass films' structural, chemical and biological properties have been studied extensively, information about their mechanical performance is scarce. Here, transmission electron microscopy, energy dispersive X-ray spectroscopy, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, nanoindentation and pull-out measurements were employed to assess the morphological, chemical, structural and mechanical properties of the bioglass films deposited onto Ti substrates by radio-frequency magnetron sputtering (RF-MS). The biological safety of the thin bioglass films was evaluated preliminarily in vitro by investigating the adherence, proliferation and cytotoxicity of fibroblast cells cultivated on their surface. Our study emphasize the versatility of RF-MS, showing how bioglass films' features such as composition, structure, bonding strength, hardness, elastic modulus and biological response can be conveniently adapted by tuning the RF-MS working conditions, and therefore demonstrating the unexplored potential of this deposition technique for preparing quality biomimetic glass coatings. - Highlights: • Adherent bioglass films were synthesized by RF-sputtering on titanium plates. • Different bonding configurations were obtained when tuning sputtering conditions. • Films' biological and mechanical responses vary with their structural arrangement. • Nanomechanical properties were enhanced by allowing O{sub 2} in the sputtering atmosphere.

  4. Evaluation of cytotoxicity of polypyrrole nanoparticles synthesized by oxidative polymerization

    Highlights: ► Polypyrrole nanoparticles synthesized by environmentally friendly polymerization at high concentrations are cytotoxic. ► Primary mouse embryonic fibroblast, mouse hepatoma and human T lymphocyte Jurkat cell lines were treated by Ppy nanoparticles. ► Polypyrrole nanoparticles at high concentrations inhibit cell proliferation. -- Abstract: Polypyrrole (Ppy) is known as biocompatible material, which is used in some diverse biomedical applications and seeming to be a very promising for advanced biotechnological applications. In order to increase our understanding about biocompatibility of Ppy, in this study pure Ppy nanoparticles (Ppy-NPs) of fixed size and morphology were prepared by one-step oxidative polymerization and their cyto-compatibility was evaluated. The impact of different concentration of Ppy nanoparticles on primary mouse embryonic fibroblasts (MEF), mouse hepatoma cell line (MH-22A), and human T lymphocyte Jurkat cell line was investigated. Cell morphology, viability/proliferation after the treatment by Ppy nanoparticles was evaluated. Obtained results showed that Ppy nanoparticles at low concentrations are biocompatible, while at high concentrations they became cytotoxic for Jurkat, MEF and MH-22A cells, and it was found that cytotoxic effect is dose-dependent

  5. Properties of radiation-synthesized polyvinylpyrrolidone/chitosan hydrogel blends

    Mahmud, Maznah [School of Chemical Sciences and Food Technology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia 43600 Bangi, Selangor (Malaysia); Radiation Processing Technology Division, Malaysian Nuclear Agency, 43000 Kajang, Selangor (Malaysia); Daik, Rusli [School of Chemical Sciences and Food Technology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia 43600 Bangi, Selangor (Malaysia); Adam, Zainah [Radiation Processing Technology Division, Malaysian Nuclear Agency, 43000 Kajang, Selangor (Malaysia)

    2015-09-25

    Poly(vinylpyrrolidone) (PVP)-crosslinked chitosan hydrogels were prepared by gamma radiation at various doses; 1, 3 5, 7, 10, 15, 20, 25 and 30kGy. Gamma radiation was used as a crosslinking tool which requires no chemical initiator, no heating process and need no purification step on the end products obtained. The hydrogel formulations were composed of 6% chitosan with average molecular weight (Mw) = 48 800 g/mol and 14% PVP with Mw = 10 000 g/mol in 2% lactic acid. Physical properties of hydrogels such as gel fraction and swelling property at pH 5.5 and pH 7.0 as well as syneresis activity were determined. It was found that different radiation dose induces different effect on hydrogels’ network formed. Morphological study of hydrogels has been carried out by scanning electron microscope (SEM). From these preliminary evaluations, it can be concluded that gamma radiation is an effective tool for network development of hydrogels and it also induces enhancement on characteristics of hydrogels synthesized.

  6. Radio-synthesized polyacrylamide hydrogels for proteins release

    The use of hydrogels for biomedical purposes has been extensively investigated. Pharmaceutical proteins correspond to highly active substances which may be applied for distinct purposes. This work concerns the development of radio-synthesized hydrogel for protein release, using papain and bovine serum albumin as model proteins. The polymer was solubilized (1% w/v) in water and lyophilized. The proteins were incorporated into the lyophilized polymer and the hydrogels were produced by simultaneous crosslinking and sterilization using γ-radiation under frozen conditions. The produced systems were characterized in terms of swelling degree, gel fraction, crosslinking density and evaluated according to protein release, bioactivity and cytotoxicity. The hydrogels developed presented different properties as a function of polymer concentration and the optimized results were found for the samples containing 4–5% (w/v) polyacrylamide. Protein release was controlled by the electrostatic affinity of acrylic moieties and proteins. This selection was based on the release of the proteins during the experiment period (up to 50 h), maintenance of enzyme activity and the nanostructure developed. The system was suitable for protein loading and release and according to the cytotoxic assay it was also adequate for biomedical purposes, however this method was not able to generate a matrix with controlled pore sizes. Highlights: • Method for synthesis of polyacrylamide (copolymer) hydrogels using γ-irradiation. • Polyacrylamide hydrogels suitable for protein loading and release. • Controlled release of proteins and bioactivity maintenance. • Noncytotoxic profile observed for these protein containing hydrogels

  7. Silver-based biohybrids "green" synthesized from Chelidonium majus L.

    Barbinta-Patrascu, Marcela Elisabeta; Badea, Nicoleta; Ungureanu, Camelia; Constantin, Marioara; Pirvu, Cristian; Rau, Ileana

    2016-06-01

    This paper describes an original bio-design of organic/inorganic hybrid architectures containing biomimetic membranes and celandine-nanoAg for different bioapplications. A simple, time efficient, low-cost and ecofriendly bottom-up procedure was used to build for the first time, celandine/nanoAg-based hybrids. Dipalmitoyl phosphatidylcholine bio-inspired lipid bilayers were obtained by thin film hydration method. Chlorophyll a inserted into these liposomes was used as a spectral marker to detect the changes occurred in the artificial membranes. For the first time, silver nanoparticles were eco-synthesized using an aqueous extract of celandine (Chelidonium majus L.). The physical stability of the samples was evaluated in terms of zeta potential. Chlorophyll a photonic properties (based on UV-Vis absorption and emission spectra) were used to monitor the synthesis of silver nanoparticles and of bio-based hybrids. The size of samples was monitored by Dynamic Light Scattering measurements and the morphological aspects were provided by Atomic Force Microscopy analysis. The obtained silver-based biohybrids exhibited high antioxidant activity (98.48%) and strong antimicrobial properties against Escherichia coli ATCC 8738 (offering an inhibition zone of 51 mm diameter) and presented good physical stability (zeta potential reached the value of -30.7 mV) as compared to phyto-nanoAg alone.

  8. Conceptualizing and measuring energy security: A synthesized approach

    This article provides a synthesized, workable framework for analyzing national energy security policies and performance. Drawn from research interviews, survey results, a focused workshop, and an extensive literature review, this article proposes that energy security ought to be comprised of five dimensions related to availability, affordability, technology development, sustainability, and regulation. We then break these five dimensions down into 20 components related to security of supply and production, dependency, and diversification for availability; price stability, access and equity, decentralization, and low prices for affordability; innovation and research, safety and reliability, resilience, energy efficiency, and investment for technology development; land use, water, climate change, and air pollution for sustainability; and governance, trade, competition, and knowledge for sound regulation. Further still, our synthesis lists 320 simple indicators and 52 complex indicators that policymakers and scholars can use to analyze, measure, track, and compare national performance on energy security. The article concludes by offering implications for energy policy more broadly. -- Highlights: → Energy security should consist of five dimensions related to availability, affordability, technology development, sustainability, and regulation. → The dimensions of energy security can be broken down into 20 components. → These components can be distilled into 320 simple indicators and 52 complex indicators.

  9. beta-glucosidase catalyzed syntheses of pyridoxine glycosides.

    Charles, Rajachristu Einstein; Divakar, Soundar

    2009-01-01

    Enzymatic syntheses of pyridoxine glycosides were carried out in di-isopropyl ether organic medium using beta-glucosidase isolated from sweet almond. Optimum conditions determined for the reaction with D-glucose were 40% (w/w D-glucose) beta-glucosidase at 0.18 mM (1.8 ml) of pH 5 acetate buffer over a 72 h incubation period. Of 11 carbohydrates employed, beta-glucosidase gave 7-O-(alpha-D-glucopyranosyl)pyridoxine 5a, 7-O-(beta-D-glucopyranosyl)pyridoxine 5b, 6-O-(alpha-D-glucopyranosyl)pyridoxine 5c, 7-O-(alpha-D-galactopyranosyl)pyridoxine 6a, 7-O-(beta-D-galactopyranosyl)pyridoxine 6b, 6-O-(alpha-D-galactopyranosyl)pyridoxine 6c, 7-O-(alpha-D-mannopyranosyl)pyridoxine 7a, 7-O-(beta-D-mannopyranosyl)pyridoxine 7b, and 6-O-(alpha-D-mannopyranosyl)pyridoxine 7c in yields ranging from 23 to 40%. PMID:19129657

  10. Syntheses of alpha-tocopheryl glycosides by glucosidases.

    Ponrasu, Thangavel; Charles, Rajachristu Einstein; Sivakumar, Ramaiah; Divakar, Soundar

    2008-08-01

    Enzymatic syntheses of water-soluble alpha-tocopheryl glycosides were carried out in di-isopropyl ether using amyloglucosidase from Rhizopus mold or beta-glucosidase isolated from sweet almond. Optimum conditions for the amyloglucosidase were: alpha-tocopherol 0.5 mmol, D-glucose 0.5 mmol, 400 activity unit (AU) amyloglucosidase, 0.2 mM pH 7 phosphate buffer and 72 h; and for the beta-glucosidase: alpha-tocopherol 0.5 mmol, D: -glucose 0.5 mmol, 110 AU beta-glucosidase, 0.1 mM pH 6 phosphate buffer and 72 h. Out of 11 carbohydrates employed, amyloglucosidase reacted only with D-glucose to give 50% of 6-O-(alpha-D-glucopyranosyl)alpha-tocopherol. However, the beta-glucosidase gave 6-O-(beta-D-glucopyranosyl)alpha-tocopherol, 6-O-(alpha-D-galactopyranosyl)alpha-tocopherol, 6-O-(beta-D-galactopyranosyl)alpha-tocopherol, 6-O-(alpha-D-mannopyranosyl)alpha-tocopherol and 6-O-(beta-D-mannopyranosyl)alpha-tocopherol in yields ranging from 10-25%. Water solubility of 6-O-(alpha-D-glucopyranosyl)alpha-tocopherol was 26 g/l at 25 degrees C. alpha-Tocopheryl glycosides showed antioxidant activities with IC(50) values from 0.5 to 1 mM and angiotensin-converting enzyme (ACE) inhibitory activity with IC(50) values from 1.3 to 2.6 mM. PMID:18368294